CN101537737A - Exposure head and an image forming apparatus - Google Patents

Abstract

An exposure head, includes: a substrate that is provided with a first light emitting element, a second light emitting element that is arranged at one side of the first light emitting element in a first direction and a third light emitting element that is arranged at the one side of the second light emitting element in the first direction, the first light emitting element and the second light emitting element being arranged at a first distance from each other in the first direction, the second light emitting element and the third light emitting element being arranged at a second distance, which is different from the first distance, from each other in the first direction; and an imaging optical system that images light from the first, the second and the third light emitting elements.

Description

Photohead and image processing system

Technical field

The present invention relates to a kind ofly will and use the image processing system of this photohead from the photohead of the photoimaging of a plurality of light-emitting components.

Background technology

As this photohead, for example as patent documentation 1 put down in writing the known line head (line head) that a plurality of optical lens systems of alignment arrangements (imaging optical system) are arranged.With respect to each optical lens system, a plurality of luminous points (light-emitting component) are disposed in groups relatively.These a plurality of luminous point alignment arrangements when the light beam that penetrates from each luminous point carries out imaging by optical lens system, go up in prescribed direction (first direction) and to arrange and to form a plurality of luminous points (spot) on prescribed direction (first direction).Then, form sub-image in part by this luminous point exposure.

Patent documentation 1: the spy opens flat 2-4546 communique

But, in above-mentioned line head, on first direction, disposing a plurality of light-emitting components for an imaging optical system, the position relation with imaging optical system between each light-emitting component is different.Therefore, if there is the distortion aberration in imaging optical system, then should arrange a plurality of luminous points of forming by equidistantly (pitch) originally on first direction can not be by equidistant formation, exist the spacing on the first direction can inconsistent situation.

In addition, except that the problems referred to above, also there is the situation that problem as follows takes place.In other words, light-emitting component is by driving luminous the heating.Therefore, near the central authorities of a plurality of light-emitting components (in other words, the center of gravity of a plurality of light-emitting components near), thermal capacitance is easily assembled, the tendency that exists the hot deterioration be configured near central light-emitting component to quicken.Its result, the degree of hot deterioration can produce difference between each light-emitting component, and existence can not be carried out the situation that good sub-image forms (luminous point formation).

Summary of the invention

Carry out the present invention in view of above-mentioned problem, can carry out first purpose that good luminous point forms thereby provide a kind of distortion aberration of realizing suppressing above-mentioned imaging optical system that luminous point is formed the influence that causes, thereby and the generation of degree difference that can suppress the hot deterioration of above-mentioned light-emitting component can carry out the technology of at least one purpose in second purpose of good luminous point formation.

To achieve these goals, the photohead that the present invention is correlated with, it is characterized in that, comprising: substrate, have first light-emitting component, be arranged on first light-emitting component first direction a side second light-emitting component and be arranged on the 3rd light-emitting component of a side of the first direction of second light-emitting component; And imaging optical system, the light of first light-emitting component, second light-emitting component and the 3rd light-emitting component is carried out imaging; On first direction, first light-emitting component and second light-emitting component are set, on first direction, second light-emitting component and the 3rd light-emitting component are set by the second distance different with first distance by first distance.

To achieve these goals, the image processing system that the present invention is correlated with is characterized in that, comprising: sub-image supporting body, carrying sub-image; Photohead, comprise have first light-emitting component, be arranged on first light-emitting component first direction a side second light-emitting component and be arranged on the substrate of the 3rd light-emitting component of a side of the first direction of second light-emitting component, and the imaging optical system that the light of first light-emitting component, second light-emitting component and the 3rd light-emitting component is carried out imaging on the sub-image supporting body; On first direction, first light-emitting component and second light-emitting component are set, on first direction, second light-emitting component and the 3rd light-emitting component are set by the second distance different with first distance by first distance.

The invention of this structure (photohead, image processing system), substrate be provided with first light-emitting component, be arranged on first light-emitting component first direction a side second light-emitting component and be arranged on the 3rd light-emitting component of a side of the first direction of second light-emitting component.And, on first direction, first light-emitting component and second light-emitting component are set by first distance, on first direction, second light-emitting component and the 3rd light-emitting component are set by the second distance different with first distance.In other words, the distance to first direction of first light-emitting component and second light-emitting component is different with the distance to first direction of second light-emitting component and the 3rd light-emitting component.Therefore, as described later, thereby the distortion aberration that can realize suppressing imaging optical system forms the influence that causes to luminous point and can carry out first purpose that good luminous point forms, thereby and the generation of degree difference that suppresses the hot deterioration of above-mentioned light-emitting component can carry out at least one purpose in second purpose that good luminous point forms.

In other words, in order to realize first purpose, can constitute according to distorted image official post first distance of the first direction of imaging optical system different with second distance.Particularly, be provided with in the structure of first light-emitting component, second light-emitting component and the 3rd light-emitting component in a side of the first direction of the optical axis of imaging optical system, if get final product by following formation.

In other words, has more on first direction light at imaging optical system away from optical axis, more under the situation of first aberration as the distortion aberration of first direction of carrying out imaging on the first direction by the optics multiplying power of big absolute value, shorter by constituting second distance than first distance, just can realize first purpose no matter how first aberration all forms luminous point well.

Perhaps, has more on first direction light at imaging optical system away from optical axis, undertaken by the optics multiplying power of little absolute value on the first direction under the distortion aberration situation of second aberration as first direction of imaging more, by constituting second distance than first distance, just can realize first purpose no matter how second aberration all forms luminous point well.

Have again, first light-emitting component, second light-emitting component and the 3rd light-emitting component need not be arranged as linearity on first direction, can in the second direction side with the first direction quadrature second light-emitting component be set with respect to first light-emitting component and the 3rd light-emitting component yet.But imaging optical system is under the situation that has the distortion aberration on the second direction, preferably by following formation.

In other words, can constitute on second direction and first light-emitting component and second light-emitting component are set, on second direction, second light-emitting component and the 3rd light-emitting component are set by the 4th distance different with the 3rd distance by the 3rd distance.Like this, by making the distance to second direction of first light-emitting component and second light-emitting component, different with the distance to second direction of second light-emitting component and the 3rd light-emitting component, the distortion aberration that just can suppress second direction forms the influence that causes to luminous point, forms luminous point well.

In other words, can constitute according to distorted image official post the 3rd distance of the second direction of imaging optical system different with the 4th distance.More specifically, has more on first direction light at imaging optical system away from optical axis, under the situation of the 3rd aberration as the distortion aberration of second direction of carrying out imaging on the second direction by the optics multiplying power of big absolute value, can constitute the 4th distance more than the 3rd distance weak point.Perhaps, has more on first direction light at imaging optical system away from optical axis, under the situation of the 4th aberration as the distortion aberration of second direction of carrying out imaging on the second direction by the optics multiplying power of little absolute value, can constitute the 4th distance more than the 3rd distance.

In addition, be provided with under the situation that contains first light-emitting component, second light-emitting component and the 3rd light-emitting component more than 4 at substrate because of the luminous light-emitting component that generates heat, as mentioned above, the degree of hot deterioration will produce difference between each light-emitting component, might be able to not carry out good luminous point and form.Therefore, can constitute, imaging optical system is the photoimaging of the light-emitting component more than 4, in a side of the first direction of the light-emitting component more than 4 first light-emitting component, second light-emitting component and the 3rd light-emitting component is set, and first distance is longer than second distance.By such formation, just can suppress the generation of degree difference of the hot deterioration of above-mentioned light-emitting component, carry out luminous point formation well, just can realize second order.

In addition, light-emitting component also can be formed in the organic EL on the substrate.Perhaps, also can constitute light-emitting component is the LED element, and substrate is the semiconductor chip that has formed LED, and semiconductor chip is provided on the flat board.

In addition, also can constitute photohead, it is comprised: substrate, it is right to have first light-emitting component that is made of 2 light-emitting components that are provided with by first distance on first direction, with right by constitute, be arranged on second light-emitting component of the 1st right direction side of first light-emitting component by 2 light-emitting components of the second distance setting different with first distance on first direction; And imaging optical system, will carry out imaging from the light that constitutes the right light-emitting component of first light-emitting component and from the light that constitutes the right light-emitting component of second light-emitting component.Like this, by at first light-emitting component to making to the distance of first direction differently with the second light-emitting component centering, just can realize at least one purpose of above-mentioned first purpose and above-mentioned second purpose.

To achieve these goals, the line head that the present invention is correlated with, it is characterized in that, comprise the substrate of 3 above light-emitting components and with respect to the light-emitting component more than 3 configuration, the light of the self-emission device imaging optical system that carries out imaging in the future with the mutually different position that is configured in first direction; In the light-emitting component more than 3, with 2 adjacent light-emitting components of the position in the first direction to being right in abutting connection with light-emitting component, when being the light-emitting component spacing to constitute spacing in this first direction between right 2 light-emitting components of light-emitting component, at least 2 in abutting connection with light-emitting component to constituting this in abutting connection with 2 right light-emitting components of light-emitting component by mutually different light-emitting component spacing configuration respectively.

In addition, to achieve these goals, the image processing system that the present invention is correlated with, it is characterized in that, comprise: line head and sub-image supporting body, wherein line head have the mutually different position that is configured in first direction 3 above light-emitting components substrate and with respect to the imaging optical system of the light-emitting component more than 3 configuration; Line head utilizes the light of imaging optical system light-emitting component in future to carry out imaging, make the face exposure of sub-image supporting body, in the light-emitting component more than 3, with 2 adjacent light-emitting components of the position in the first direction to being right in abutting connection with light-emitting component, when being the light-emitting component spacing to constitute spacing in this first direction between right 2 light-emitting components of light-emitting component, at least 2 in abutting connection with light-emitting component to constituting this in abutting connection with 2 right light-emitting components of light-emitting component by mutually different light-emitting component spacing configuration respectively.

In the invention (line head, image processing system) that constitutes like this, at least 2 in abutting connection with light-emitting component to constituting this in abutting connection with 2 right light-emitting components of light-emitting component by mutually different light-emitting component spacing configuration respectively.Therefore, can alleviate the influence of the problem that the heating of problem that the distortion aberration of above-mentioned imaging optical system causes and light-emitting component causes, can carry out good sub-image and form.

In addition, imaging optical system has the distortion aberration, also can constitute at least 2 in abutting connection with light-emitting component to respectively by configuration constitutes this in abutting connection with 2 right light-emitting components of light-emitting component according to distortion aberration and mutually different light-emitting component spacing, by this structure, can suppress the problem that the distortion aberration of imaging optical system causes effectively, can carry out good sub-image and form.

In other words, imaging optical system also can constitute, this imaging optical system has more on first direction the light away from the light-emitting component of the optical axis of this imaging optical system, more carry out first aberration of imaging as the aberration that distorts by the optics multiplying power of relevant big absolute value with first direction, at at least 2 in abutting connection with light-emitting component in right each, more right in abutting connection with light-emitting component away from optical axis on first direction constitutes this in abutting connection with 2 right light-emitting components of light-emitting component by narrow light-emitting component spacing configuration more.Perhaps, also can constitute, imaging optical system has more on first direction the light away from the light-emitting component of the optical axis of this imaging optical system, more by having the optics multiplying power of the absolute value that turns down to carry out second aberration of imaging as the distortion aberration with first direction, at at least 2 in abutting connection with light-emitting component in right each, more right in abutting connection with light-emitting component away from optical axis on first direction constitutes this in abutting connection with 2 right light-emitting components of light-emitting component by wide light-emitting component spacing configuration more.By this structure, can suppress the problem that the distortion aberration of imaging optical system causes effectively, can carry out good sub-image and form.

In addition, also can constitute, at least 2 in abutting connection with light-emitting component in right each, right in abutting connection with light-emitting component near the center of gravity of the light-emitting component more than 3 in first direction constitutes this in abutting connection with 2 right light-emitting components of light-emitting component by wide light-emitting component spacing configuration more more.By this structure, can suppress the problem that the heating of light-emitting component causes effectively, can carry out good sub-image and form.

In addition, light-emitting component also can be an organic EL.In other words, so constitute under the situation of light-emitting component, be necessary to apply organic EL Material being provided with on the substrate of light-emitting component with organic EL.At this moment, for the characteristics of luminescence that makes each light-emitting component is even, wish that smearing of organic EL Material is more even.With respect to this, in the present invention, at least 2 in abutting connection with light-emitting component to constituting this in abutting connection with 2 right light-emitting components of light-emitting component by the configuration of mutually different light-emitting component spacing respectively.Therefore, the present invention has the structure that helps smearing coating organic EL Material under the uniform state.

Description of drawings

Fig. 1 is that the figure that can use the image processing system of line head of the present invention has been equipped in expression.

Fig. 2 is the figure of electrical structure of the image processing system of presentation graphs 1.

Fig. 3 is the oblique view that expression can be used the overview of line head of the present invention.

Fig. 4 is the A-A line part sectioned view of line head shown in Figure 3.

Fig. 5 is the figure of the structure of expression light-emitting component.

Fig. 6 is the plane of structure at the back side of expression head substrate.

Fig. 7 is the plane of the structure of expression lens arra.

Fig. 8 is the profile of the long side direction of lens arra and head substrate etc.

Fig. 9 is the structure of expression light emitting device group and the plane of operation.

Figure 10 is expression forms operation according to the luminous point sub-image of line head figure.

Figure 11 is the profile of the main scanning direction section of the imaging optical system in expression first embodiment.

Figure 12 is the profile of the sub scanning direction section of the imaging optical system in expression first embodiment.

Figure 13 is the figure that the lens data of the imaging optical system in first embodiment is shown with the form of table.

Figure 14 is the figure that the optical system various factors of the imaging optical system in first embodiment is shown with the form of table.

Figure 15 is the figure of the distortion aberration that imaging optical system had in expression first embodiment.

Figure 16 is illustrated in the figure that imaging optical system has the problem that can produce under the first aberration situation.

Figure 17 is the plane of the structure of the light emitting device group in expression first embodiment.

Figure 18 is the figure of the structure of the light emitting device group of expression in first embodiment etc.

Figure 19 is the profile of the main scanning direction section of the imaging optical system in expression second embodiment.

Figure 20 is the profile of the sub scanning direction section of the imaging optical system in expression second embodiment.

Figure 21 is the figure that the lens data of the imaging optical system in second embodiment is shown with the form of table.

Figure 22 is the figure that the optical system various factors of the imaging optical system in second embodiment is shown with the form of table.

Figure 23 is the figure of the distortion aberration that imaging optical system had in expression second embodiment.

Figure 24 is illustrated in the figure that imaging optical system has the problem that can produce under the second aberration situation.

Figure 25 is the plane of the structure of the light emitting device group in expression second embodiment.

Figure 26 is the figure of the structure of the light emitting device group of expression in second embodiment etc.

Figure 27 is the figure that is illustrated in the problem that can produce in the structure that disposes with the light-emitting component spacing that equates.

Figure 28 is the structure chart of the light emitting device group in expression the 3rd embodiment.

Figure 29 is the structure chart of the light emitting device group in expression the 4th embodiment.

Figure 30 be expression in the 4th embodiment imaging optical system had to the figure of the distortion aberration of sub scanning direction.

Figure 31 is illustrated in the figure that imaging optical system has the problem that can produce under the 4th aberration situation.

Figure 32 is the structure and the design sketch of expression the 4th embodiment.

Figure 33 is to use the plane of LED element as the structure of light-emitting component.

Figure 34 is to use the part sectioned view of LED element as the long side direction of the structure of light-emitting component.

Symbol description:

21Y, 21K ... photoconductor drum (sub-image supporting body), 29 ... line head, 293 ... head substrate (substrate), 295 ... light emitting device group (3 above light-emitting components), 2951 ... light-emitting component, 2951R ... light-emitting component is capable, and 299,299A, 299B ... lens arra, LS1, LS2 ... lens (imaging optical system), SP ... luminous point, SPR ... luminous point is capable, SG ... the luminous point group, MD ... main scanning direction (first direction), SD ... sub scanning direction (second direction), LGD long side direction (first direction), LTD ... width (second direction), OA ... optical axis, Doa ... the direct of travel of light beam, ELP ... right in abutting connection with light-emitting component, Pel ... the light-emitting component spacing, Psp ... the luminous point spacing.

The specific embodiment

Below, at first, the basic structure that explanation can be used line head of the present invention and equipped the image processing system of this line head.Then, after basic structure has been described, embodiments of the present invention are described.

Basic structure

Fig. 1 is the figure that an example of the image processing system that can use line head of the present invention has been equipped in expression.In addition, Fig. 2 is the electrical structure diagram of the image processing system of presentation graphs 1.This device is selectively to carry out stack black (K), blue-green (C), magenta (M), yellow (Y) 4 colour toners (toner) to form the color mode of coloured image and only use the toner of black (K) to form the image processing system of the monochromatic mode of monochrome (monochrome) image.Have, Fig. 1 is the corresponding color mode accompanying drawing when carrying out again.In this image processing system, have CPU when paying from external device (ED)s such as host computers, when the master controller MC image of memory etc. forms instruction, this master controller MC just pays control signal etc. to engine controller EC, also head controller HC is paid the video data VD that correspondence image forms instruction simultaneously.In addition, this head controller HC controls line head 29 of all kinds according to the video data VD that comes autonomous controller MC with from vertical synchronizing signal Vsync and the parameter value of engine controller EC.Thus, image that the EG of engine portion puts rules into practice forms operation, forms correspondence image and form the image that instructs on copy paper, transfer paper, the thin slice that waits with transparent sheet (sheet) with paper and OHP.

In case (housing) main body 3 that image processing system had, be provided with Denso product box 5, these Denso product box 5 built-in power circuit substrates, master controller MC, engine controller EC and head controller HC.In addition, image formation unit 7, transfer belt unit 8, paper supply unit 11 also are set in case main body 3.Among this external Fig. 1, the right side is provided with 2 transfer printing units 12, fixation unit 13, thin slice guiding elements 15 in case main body 3.Have again, freely constitute paper supply unit 11 with respect to apparatus main body 1 loading and unloading.And, about this paper supply unit 11 and transfer belt unit 8, for dismantling the structure of place under repair or exchange respectively.

Image formation unit 7 comprises that 4 images of the image that forms a plurality of different colors form station (station) Y (yellow with), M (blue-green with), C (magenta with), K (black with).In addition, each image formation station Y, M, C, K are provided with the columnar photoconductor drum 21 on the surface that has specific length on main scanning direction MD.And each image forms station Y, M, C, K form corresponding color respectively on the surface of photoconductor drum 21 toner picture.The configuration photoconductor drum is so that direction of principal axis can be almost parallel with main scanning direction MD.In addition, each photoconductor drum 21 is connected respectively to special-purpose CD-ROM drive motor, is driven in rotation with fixing speed by the direction of arrow mark D21 among the figure.Thus, just by with the main scanning direction MD quadrature or the surface of the sub scanning direction SD carrying photoconductor drum 21 of quadrature almost.In addition, around photoconductor drum 21, electro-mechanical part 23, line head 29, development section 25 and photoreceptor cleaner 27 are set along direction of rotation.And, carry out hot line job, sub-image formation operation and toner development operation by these function portions.Therefore, when color mode is carried out, to form the toner that form among station Y, M, C, the K at all image looks like to be superimposed upon on the transfer belt 81 that transfer belt unit 8 had, forms coloured image, and, when monochromatic mode is carried out, only use at image and form the toner picture formation monochrome image that forms among the K of station.Have again, in Fig. 1, because each image formation station structure of image formation unit 7 is mutually the same, thus only give symbol in order to illustrate conveniently to the image formation station of a part, to other image formation station ellipsis.

Electro-mechanical part 23 comprises the charged roller that its surface is made of elastic caoutchouc.This charged roller structure is followed the spinning movement of photoconductor drum 21 for carrying out driven rotation at the surperficial butt of charged position and photoconductor drum 21, with respect to photoconductor drum 21 on driven direction this charged roller with the driven rotation of peripheral speed.In addition, this charged roller is connected to charged biasing (bias) generating unit (omitting diagram), accepts the power supply from the charged biasing of charged biasing generating unit, makes the surface charging of photoconductor drum 21 in the photoconductor drum 21 and the charged position of electro-mechanical part 23 butts.

With respect to photoconductor drum 21 configuration line heads 29, so that make the corresponding main scanning direction MD of its long side direction, the corresponding sub scanning direction SD of its width stipulates that the long side direction of line head 29 is almost parallel with main scanning direction MD simultaneously.Line head 29 is included in a plurality of light-emitting components of alignment arrangements on the long side direction, and away from photoconductor drum 21 configuration line heads 29.And, from the surface irradiation light of these light-emitting components charged photoconductor drum 21, form electrostatic latent image on this surface to passing through electro-mechanical part 23.

Development section 25 has the developer roll 251 at its surface bears toner.And, the developing bias that utilization applies developer roll 251 from the developing bias generating unit (omitting diagram) that is electrically connected with developer roll 251, developing location at developer roll 251 and photoconductor drum 21 butts, charged toner is moved on the photoconductor drum 21 from developer roll 251, make the manifesting of electrostatic latent image that forms by line head 29.

Direction of rotation D21 carrying by photoconductor drum 21 is like this behind the toner picture of above-mentioned manifesting of developing location, and the transfer belt 81 that describes in detail in the back and 1 transfer position TR1 of each photoconductor drum 21 butt are carried out 1 transfer printing to it on transfer belt 81.

In addition, in this embodiment,, photoreceptor cleaner 27 is set with the surperficial butt of photoconductor drum 21 at the downstream of 1 transfer position TR1 of the direction of rotation D21 of photoconductor drum 21 and the upstream side of electro-mechanical part 23.This photoreceptor cleaner 27, by with the surperficial butt of photoconductor drum, clean and remove the lip-deep toner that remains in photoconductor drum 21 after 1 transfer printing.

Transfer belt unit 8 comprises the driven voller 83 (scraper plate (blade) opposed roll) and the transfer belt 81 in the left side that is configured in driven roller 82 among driven roller 82, Fig. 1,81 framves of this transfer belt are on these rollers, to direction (carrying direction) the circulation driving of diagram arrow mark D81.In addition, transfer belt unit 8 comprises 41 transfer roll 85Y, 85M, 85C, 85K, they form the station photoconductor drum 21 that Y, M, C, K had with respect to each image in the inboard of transfer belt 81 respectively when photoreceptor (cartridge) is installed, one to one configuration relatively.These 1 transfer roll 85 is electrically connected with 1 transfer printing biasing generating unit (diagram is omitted) respectively.And, such as the back detailed description, when color mode is carried out, form station Y, M, C, K side by all 1 transfer roll 85Y, 85M, 85C, 85K being positioned at image as shown in Figure 1, with transfer belt 81 push to each image form photoconductor drum 21 that station Y, M, C, K had separately and with its butt, between each photoconductor drum 21 and transfer belt 81, form 1 transfer position TR1.Then, by by above-mentioned 1 transfer printing biasing generating unit 1 transfer roll 85 being applied 1 transfer printing biasing with suitable timing (timing), the lip-deep toner picture that just will be formed on each photoconductor drum 21 is transferred to transfer belt 81 surfaces at each self-corresponding 1 transfer position TR1 place, forms coloured image.

On the other hand, when monochromatic mode is carried out, by making colored 1 transfer roll 85Y, 85M in 41 transfer rolls 85,85C form station Y, M, C away from the image of facing separately, only make simultaneously monochromatic 1 transfer roll 85K and image form station K butt, only make monochrome image form station K and transfer belt 81 butts.Its result only forms 1 transfer position TR1 of formation between the K of station at monochromatic 1 transfer roll 85K and image.Then, by from above-mentioned 1 transfer printing biasing generating unit monochromatic 1 transfer roll 85K being applied 1 transfer printing biasing with suitable timing, the lip-deep toner picture that just will be formed on each photoconductor drum 21 is transferred to transfer belt 81 surfaces at 1 transfer position TR1 place, forms monochrome image.

And transfer belt unit 8 comprises the downstream deflector roll 86 of the upstream side of the downstream that is arranged on monochromatic 1 transfer roll 85K and driven roller 82.In addition, constitute this downstream deflector roll 86, form on the common internal wiring of 1 transfer roll 85K among 1 the transfer position TR1 that forms on the photoconductor drum 21 of station K and photoconductor drum 21, with transfer belt 81 butts so that it is connected to image at monochromatic 1 transfer roll 85K.

Driven roller 82 drives transfer belt 81 by the direction circulation of diagram arrow mark D81, and double simultaneously is the reserve roller of 2 transfer rolls 121.At the rubber layer that forms on the surrounded surface of driven roller 82 about thick 3mm, below the specific insulation 1000k Ω cm, by the metal ground that is coupling, thus as from omitting the conductive path of 2 transfer printings biasing that illustrated 2 transfer printings biasing generating unit provides by 2 transfer rolls 121.So, by the high rubber layer that rubs and have impact absorbency is set on driven roller 82, thin slice is difficult to be delivered to transfer belt 81 to the impact of abutment portion (2 transfer position TR2) when entering of driven roller 82 and 2 transfer rolls 121, can prevent the deterioration of image quality.

Paper supply unit 11 comprises: have paper feeding cassette 77 that can stacked maintenance thin slice and carry the sheet feed section of the pick-up roller 79 of thin slice from paper feeding cassette 77 one by one.By the thin slice of pick-up roller 79 from the sheet feed section paper supply, stop adjust during roller (resist roller) is to 80 paper supply regularly after, along thin slice guide member 15 to 2 transfer position TR2 paper supplies.

From connecing transfer roll 121 is set freely 2 times with respect to transfer belt 81, is undertaken from connecing driving by 2 transfer roll driving mechanisms (omitting diagram).Fixation unit 13 has that heaters such as built-in halogen heater rotate freely warm-up mill 131 and this warm-up mill 131 is pushed the pressurization part 132 of energizing.And, in its 2 transfer printings in surface the thin slice of image, be directed to the folder portion of pinching (nip) that pressure zone 1323 forms that adds by thin slice guide member 15 by warm-up mill 131 and pressurization part 132, pinch the hot photographic fixing image of folder portion temperature in accordance with regulations at this.Pressurization part 132 is made of 2 rollers 1321,1322 and the pressure zone 1323 that adds of frame on them.And the band stretching, extension face that constitutes by being stretched by 2 rollers 1321,1322 in the surface that will add pressure zone 1323 presses against on the surrounded surface of warm-up mill 131, expands by backer roll 131 and adds the folder portion of pinching that pressure zone 1323 forms.In addition, the thin slice of having accepted this photographic fixing processing is transported to the facial row's paper carrier 4 that is provided with on case main body 3.

In addition, in this device, towards scraper plate opposed roll 83 configuration cleaner portions 71.Cleaner portion 71 has cleaning balde 711 and used toner box 713.Cleaning balde 711 is connected to its leading section on the scraper plate opposed roll 83 via transfer belt 81, removes foreign matters such as the toner that remains in after 2 transfer printings on the transfer belt and paper powder.Then, the foreign matter of so removing is recovered in the used toner box 713.

Fig. 3 is the oblique view that expression can be used the overview of line head of the present invention.In addition, Fig. 4 is the A-A line part sectioned view of line head shown in Figure 3, is the section parallel with the optical axis of lens.Have, the A-A line is parallel with lens arrays LSC or almost parallel with light emitting device group row 295C described later again.According to above-mentioned, with respect to photoconductor drum 21 configuration line heads 29, so that the corresponding main scanning direction MD of its long side direction LGD makes the corresponding sub scanning direction SD of its width LTD simultaneously.In other words, long side direction LGD is parallel with main scanning direction MD or almost parallel, and width LTD is parallel with sub scanning direction SD or almost parallel.Mutually orthogonal or the quadrature almost of long side direction LGD and width LTD is arranged again.As described later, in this line head 29, form a plurality of light-emitting components on head substrate 293, each light-emitting component is to the surperficial outgoing beam of photoconductor drum 21.Therefore, in this manual, establishing the direction with long side direction LGD and width LTD quadrature, is the direct of travel Doa of light beam from the direction of light-emitting component towards the photoconductor drum surface promptly.The direct of travel Doa of this light beam is parallel or almost parallel with optical axis OA described later.

Line head 29 possesses box (case) 291, and the while is provided with alignment pin 2911 and screw insertion hole 2912 at the two ends of the long side direction LGD of this box 291.And, by this alignment pin 2911 being embedded in the locating hole (omitting diagram) that wears on the photoreceptor lid (omit and illustrate) that covers photoconductor drum 21 and position with respect to photoconductor drum 21 simultaneously, just can be with respect to photoconductor drum 21 location line heads 29.Further the screw hole (omitting diagram) that hold-down screw is screwed into photoreceptor lid is fixed then, thus with respect to photoconductor drum 21 location and fixing line head 29 by screw insertion hole 2912.

At the internal configurations head substrate 293 of box 291, light-blocking member 297, and 2 chip-lens arrays 299 (299A, 299B).The inside of butt box 291 on the surperficial 293-h of head substrate 293, on the other hand, butt bonnet 2913 on the 293-t of the back side of head substrate 293.This bonnet 2913 utilize fixer 2914 across head substrate 293 by being pressed in box 291 inside.In other words, fixer 2914 has bonnet 2913 by the elastic force that is pressed in box 291 private sides (upside among Fig. 4), push bonnet by utilizing this elastic force, light thickly (in other words, make light not from box 291 internal leakages, and light invaded from the outside of box 291) inside of airtight box 291.Have again, on the long side direction LGD of box 291, fixer 2914 is set at a plurality of positions.

The light emitting device group 295 that a plurality of light-emitting components have been divided into groups is set on the 293-t of the back side of head substrate 293.Head substrate 293 is formed by transparent members such as glass, and the light beam that each light-emitting component of light emitting device group 295 penetrates can be from the back side 293-t of head substrate 293 to surperficial 293-h transmission.This light-emitting component is the organic EL of bottom emission (bottom emission) type (Electro-Luminescence, an electroluminescent) element, and sealed parts 294 cover.

Fig. 5 is the figure of structure of expression light-emitting component, illustrate simultaneously the expression light-emitting component vertical structure part sectioned view (epimere of Fig. 5 " profile ") and represent the plane (hypomere of Fig. 5 " plane ") of the planar structure of light-emitting component.Shown in same accompanying drawing, form wiring layer 261 at the back side of head substrate 293.Though the diagram of omission, wiring layer 261 has the structure of stacked conductive layer and insulating barrier.Conductive layer be have control light-emitting component 2951 light quantity active component (transistor) and transmit the layer of various wiring lines etc.Stacked insulating barrier is so that make each conductive layer electric insulation.Form first electrode 262 on the surface of wiring layer.This first electrode 262 is formed by the conductive material of ITO light transmissions such as (Indium Tin Oxide, tin indium oxides), works as the anode of light-emitting component 2951.

Carry out stackedly with respect to wiring layer 261 and first electrode 262, form insulating barrier 263.Insulating barrier 263 is film bodies of insulating properties.In this insulating barrier 263, see that at direct of travel Doa the zone that overlaps with first electrode 262 is provided with peristome 264 from light.Form this peristome 264 as the hole that on thickness direction, connects insulating barrier 263 by first electrode 262.The luminescent layer 265 that first electrode 262 and insulating barrier 263 are formed by organic EL Material covers.Utilize spin-coating method film techniques such as (spin coat method) to form luminescent layer 265 continuously by way of a plurality of light-emitting components 2951.Have again,, on each light-emitting component 2951, form first electrode 262 independently though on a plurality of light-emitting components 2951, form luminescent layer 265 continuously.Therefore, according to the electric current that provides by first electrode 262, each light-emitting component 2951 is individually controlled the light quantity of light-emitting component 2951.But, also can utilize for example drop ejection method printing technologies such as (ink-jet methods), on each light-emitting component 2951, form luminescent layer 265.

Be layered in and form second electrode 267 on the luminescent layer 265.Second electrode 267 is conducting films of reflective, forms second electrode 267 continuously by way of a plurality of light-emitting components 2951.So, by first electrode 262 and 267 clampings of second electrode, the intensity of drive current that flows to second electrode 267 with correspondence from first electrode 262 is luminous on longitudinal direction for luminescent layer 265.,, shown in the blank arrow mark of Fig. 5, see through first electrode 263 and head substrate 293 and penetrate to the ejaculation light of first electrode, 262 sides ejaculation with by the reverberation of the surface of second electrode 267 reflection from luminescent layer 265 to imaging optical system described later.Because electric current does not flow through the zone that promptly clips insulating barrier 263 between first electrode 262 and second electrode 267, so not luminous in the luminescent layer 265 with the part of insulating barrier 263 stacks.That is, as shown in Figure 5, in the laminated construction of being made up of first electrode 262, luminescent layer 265 and second electrode 267, the part that is positioned at the inboard of peristome 264 works as light-emitting component 2951.Therefore, according to the position of the position of peristome 264 and the form decision light-emitting component 2951 when the direct of travel Doa of light overlooks and form (size, shape) (with reference to the hurdle of " plane " of same accompanying drawing).Therefore, in the figure of this specification, by the light-emitting component 2951 of peristome 264 representative expression when the direct of travel Doa of light overlooks.In addition, in this manual, though use the such performance in the position of light-emitting component 2951 as required, the position Te that establishes light-emitting component 2951 is the center of gravity of the light-emitting component 2951 (peristome 264) when overlooking.

In addition, in this manual,, establish distance between light-emitting component and be the distance between the center of gravity of light-emitting component though use between light-emitting component the such performance of distance as required.And " center of gravity " is meant " geometric center of gravity " in this manual.

So like this, be formed on each light-emitting component 2951 on the head substrate 293, penetrate the light beam of the wavelength that is equal to each other.This light-emitting component 2951 is so-called complete diffusingsurface light sources, follows Lambert's cosine law from the light beam that light-emitting area penetrates.

Fig. 6 is the plane of structure at the back side of expression head substrate, is equivalent to see from the face side of head substrate the situation at the back side.Have again, in the same accompanying drawing, though lens LS represents that with two chain-dotted lines this is for the corresponding relation of light emitting device group 295 and lens LS is shown, and is not to be illustrated in head substrate back side 293-t to form lens LS.Shown in same accompanying drawing, 15 light-emitting components 2951 are divided into groups to constitute 1 light emitting device group 295, a plurality of light emitting device group 295 of configuration on the 293-t of the back side of head substrate 293.Shown in same accompanying drawing, in head substrate 293, dispose a plurality of light emitting device group 295 two-dimensionally.Details as Follows.

3 light emitting device group of mutually different position configuration 295 constitute light emitting device group row 295C in width LTD.In each light emitting device group row 295C, displacement light emitting device group spacing Peg disposes 3 light emitting device group 295 mutually on long side direction LGD.And a plurality of light emitting device group row 295C are arranged on the long side direction LGD by light emitting device group column pitch (=Peg * 3).Like this, by light emitting device group spacing Peg each light emitting device group 295 is set on long side direction LGD, the position Teg among the long side direction LGD of each light emitting device group 295 is different.

During according to another view, we can say that also light emitting device group 295 is performed as follows configuration.In other words, in the 293-t of the back side of head substrate 293, on long side direction LGD, arrange a plurality of light emitting device group 295 and constitute light emitting device group row 295R, 3 light emitting device group row 295R are set in the mutually different position of width LTD simultaneously.These 3 light emitting device group row 295R arrange by light emitting device group line space Pegr on width LTD.And each light emitting device group row 295R is mutual displacement light emitting device group spacing Peg on long side direction LGD.Therefore, just become on long side direction LGD and by light emitting device group spacing Peg a plurality of light emitting device group 295 are set, the position Teg among the long side direction LGD of each light emitting device group 295 is different.

At this, the position of light emitting device group 295 can be used as the center of gravity of the light emitting device group 295 when the direct of travel Doa of light sees and obtain.The center of gravity of light emitting device group 295 can be used as the center of gravity of these a plurality of light-emitting components 2951 when the direct of travel Doa of light sees a plurality of light-emitting component 2951 that constitutes light emitting device group 295 and obtain.In addition, can obtain light emitting device group spacing Peg, as the interval of each the position Teg among the long side direction LGD of 2 adjacent light emitting device group 295 of the position Teg among the long side direction LGD (for example light emitting device group 295_1,295_2).Have, in Fig. 6, the position Teg among the long side direction LGD of light emitting device group 295 uses from the position of light emitting device group 295 and represents to the intersection point of the sagging vertical line of long side direction axle LGD again.

Return Fig. 3, Fig. 4, go on to say.Butt configuration light-blocking member 297 on the surperficial 293-h of head substrate 293.On light-blocking member 297, light-conductive hole 2971 (in other words with respect to a plurality of light emitting device group 295 a plurality of light-conductive holes 2971 being set one to one) is set by each of a plurality of light emitting device group 295.Each light-conductive hole 2971 is formed in the light-blocking member 297 for the hole on the direct of travel Doa that connects light beam.In addition, alignment arrangements 2 chip-lens arrays 299 on the direct of travel Doa of upside (opposition side of head substrate 293) at light beam of light-blocking member 297.

So, in the direct of travel Doa of light beam, between light emitting device group 295 and lens arra 299, be configured in the light-blocking member 297 that is provided with light-conductive hole 2971 by light emitting device group 295.Therefore, the light beam that penetrates from light emitting device group 295 is by the light-conductive hole 2971 directive lens arras 299 corresponding with this light emitting device group 295.Say that on the contrary from the light beam that light emitting device group 295 penetrates, the light beam beyond the light-conductive hole 2971 corresponding with this light emitting device group 295 will be covered by light-blocking member 297.Like this, the light that penetrates from 1 light emitting device group 295 all passes through identical light-conductive hole 2971 directive lens arras 299, utilizes light-blocking member 297 to prevent to interfere mutually from the light beam that different light emitting device group 295 penetrates simultaneously.

Fig. 7 is the plane of the structure of expression lens arra, is equivalent to see from image planes side (the direct of travel Doa side of light beam) situation of lens arra.Have, each the lens LS in the same accompanying drawing is formed on the back side 2991-t of array substrate 2991 again, and same accompanying drawing illustrates the structure of this array substrate back side 2991-t.As shown in also waiting, in lens arra 299, lens LS is set by light emitting device group 295 as Fig. 6.In other words, in each lens arra 299, dispose a plurality of lens LS two-dimensionally.Details as Follows.

In width LTD, constitute lens arrays LSC at 3 lens LS of mutually different position configuration.In each lens arrays LSC, displacement lenticular spacing Pls disposes 3 lens LS mutually on long side direction LGD.And a plurality of lens arrays LSC are arranged on the long side direction LGD by lens arrays spacing (=Pls * 3).Like this, by lenticular spacing Pls each lens LS is set on long side direction LGD, the position Tls among the long side direction LGD of each lens LS is different.

During according to another view, we can say that also lens LS is performed as follows configuration.In other words, on long side direction LGD, arrange a plurality of lens LS and constitute the capable LSR of lens, 3 capable LSR of lens are set in the mutually different position of width LTD simultaneously.These 3 capable LSR of lens press lens line space Plsr and arrange on width LTD.And the capable LSR of each lens is mutual displacement lenticular spacing Pls on long side direction LGD.Therefore, just become on long side direction LGD and by lenticular spacing Pls a plurality of lens LS are set, the position Tls among the long side direction LGD of each lens LS is different.

Have again, in same accompanying drawing, the position of lens LS is represented with the summit (being that sag (サ グ) becomes maximum point) of lens LS, and the position Tls among the long side direction LGD of lens LS uses from the summit of lens LS and represents to the intersection point of the sagging vertical line of long side direction axle LGD.

Fig. 8 is the profile of the long side direction of lens arra and head substrate etc., and the long side direction section of the optical axis that comprises formed lens LS in the lens arra is shown.Lens arra 299 has on long side direction LGD the array substrate 2991 of the light transmission that is long chi shape.This array substrate 2991 is formed by the smaller glass of linear expansion coefficient.Among the surperficial 2991-h and back side 2991-t of array substrate 2991, on the 2991-t of the back side of array substrate 2991, form lens LS.Lens LS for example can form with ray hardening resin.

In this line head 29, for the free degree that realizes optical design improves, the lens arra 299 that alignment arrangements 2 (299A, 299B) has this structure on the direct of travel Doa of light beam.These 2 chip- lens arrays 299A, 299B are across pedestal 296 mutually opposed (Fig. 3, Fig. 4), and the function at the interval of lens arra 299A, 299B is stipulated in these pedestal 296 performances.Like this, just become in each light emitting device group 295 and be configured in 2 lens LS1, the LS2 (Fig. 3, Fig. 4, Fig. 8) that arrange on the direct of travel Doa of light beam on each.At this, the lens LS of the lens arra 299A of the upstream side of the direct of travel Doa of light beam is the first lens LS1, and the lens LS of the lens arra 299B in the downstream of the direct of travel Doa of light beam is the second lens LS2.

The light beam LB that penetrates from light emitting device group 295 utilizes 2 lens LS1, LS2 of these light emitting device group 295 arranged opposite and imaging, and (sub-image formation face) forms luminous point SP on the photoconductor drum surface.In other words, constitute imaging optical systems, at each light emitting device group 295 this imaging optical system of arranged opposite in each with 2 lens LS1, LS2.The optical axis OA of imaging optical system is parallel with the direct of travel Doa of light, by the position of centre of gravity of light emitting device group 295.This imaging optical system has the optical characteristics that so-called counter-rotating is amplified.That is, imaging optical system carries out the inverted image imaging, and the absolute value of the optics multiplying power of imaging optical system is bigger than 1.

Fig. 9 is the structure of expression light emitting device group and the plane that forms operation by the luminous point of this light emitting device group.At first, one side is with reference to " light emitting device group " hurdle of same accompanying drawing, and one side illustrates the structure of light emitting device group.Have, in the hurdle, the first straight line AL_md is by the optical axis OA straight line parallel with main scanning direction MD again, and the second straight line AL_sd is by the optical axis OA straight line parallel with sub scanning direction SD.If these the first straight line AL_md and the second straight line AL_sd are on the head substrate back side 293-t that has formed light-emitting component 2951.

In light emitting device group 295, in long side direction LGD, press light-emitting component spacing Pel and dispose 15 light-emitting components 2951 in mutually different position.Light-emitting component spacing Pel is the spacing (for example the distance between principal direction position Tel_1, the Tel_2 is equivalent to this spacing) among the long side direction LGD (main scanning direction MD) between 2 adjacent light-emitting components 2951 of principal direction position Tel (for example light-emitting element E L_1, EL_2).In addition, in same accompanying drawing, principal direction position Tel uses from the position Te of the light-emitting component of gazing at 2951 and represents to the intersection point of the sagging vertical line of long side direction axle LGD (main scanning direction axle MD).Have again, 2 light-emitting components 2951 in this manual,, will meet the adjacent relation of principal direction position Tel, on long side direction LGD, arranging by light-emitting component spacing Pel as light-emitting element E L_1, EL_2 to being called " in abutting connection with light-emitting component to ELP ".In same accompanying drawing, each constitutes this in abutting connection with light-emitting component 2 light-emitting components 2951 to ELP to ELP by the light-emitting component spacing Pel configuration that is equal to each other in abutting connection with light-emitting component.

Dispose this light emitting device group 295 so that constitute the capable 2951R of light-emitting component.2 above light-emitting components 2951 of mutually different position configuration at long side direction LGD constitute the capable 2951R of this light-emitting component.During detailed description, on long side direction LGD, press 2 times the spacing of light-emitting component spacing Pel and arrange the capable 2951R_1 of 8 light-emitting components, 2951 formation light-emitting components, on long side direction LGD, press 2 times the spacing of light-emitting component spacing Pel simultaneously and arrange the capable 2951R_2 of 7 light-emitting components, 2951 formation light-emitting components.

In the capable 2951R of each light-emitting component, a plurality of light-emitting components 2951 are arranged point-blank.In with the hurdle,, be marked with arranging line LN (dummy line) together in order to represent the spread pattern of this light-emitting component 2951.In other words, in the capable 2951R of each light-emitting component, a plurality of light-emitting components 2951 are configured in mutually the same position in width LTD.Therefore, as using the capable 2951R_1 of light-emitting component illustrated, light-emitting component 2951 among the width LTD and the distance, delta EL of the first straight line AL_md (distance, delta EL between auxiliary direction element optical axis) equate between each light-emitting component 2951.Have again,, can obtain distance, delta EL between auxiliary direction element optical axis as the distance among the width LTD of the position Te of light-emitting component 2951 and the first straight line AL_md.

The capable 2951R_1 of these light-emitting components, 2951R_2 press light-emitting component line space Pelr configuration on width LTD, we can say the different position of alignment arrangements at width LTD.And displacement light-emitting component spacing Pel disposes the capable 2951R_1 of each light-emitting component, 2951R_2 mutually on long side direction LGD.Like this, in light emitting device group 295, dispose 15 light-emitting components 2951 two-dimensionally.In addition, in long side direction LGD, dispose each light-emitting component 2951 by light-emitting component spacing Pel in mutually different position.And, at 2 light-emitting components 2951 pressing light-emitting component spacing Pel configuration on the long side direction LGD mutual displacement light-emitting component line space Pelr on width LTD.

The light emitting device group 295 of Gou Chenging just has the wide Weg=of light emitting device group (15-1) * Pel like this.At this, the wide Weg of light emitting device group is the distance that is in long side direction LGD between each position Te of light-emitting component 2951 at two ends of light emitting device group 295.And configuration light emitting device group 295 makes it with respect to the second straight line AL_sd symmetry.

Then, one side illustrates simultaneously that with reference to " luminous point group " hurdle of Fig. 9 the luminous point by light emitting device group forms operation.In with the hurdle, the first projection straight line PJ (AL_md) is from the straight line of light direct of travel Doa to the first straight line AL_md of photoconductor drum surface projection, and the second projection straight line PJ (AL_sd) is from the straight line of light direct of travel Doa to the second straight line AL_sd of photoconductor drum surface projection.

The light that each light-emitting component 2951 of the capable 2951R_1 of light-emitting component sends is inverted to picture by imaging optical system, forms the capable SPR_1 of luminous point.The capable SPR_1 of this luminous point presses 2 times the spacing of luminous point spacing Psp and arranges 8 luminous point SP on main scanning direction MD.In addition, the light that each light-emitting component 2951 of the capable 2951R_2 of light-emitting component sends is inverted to picture by imaging optical system, forms the capable SPR_2 of luminous point.The capable SPR_2 of this luminous point presses 2 times the spacing of luminous point spacing Psp and arranges 7 luminous point SP on main scanning direction MD.So, the capable 2951R of each light-emitting component makes a plurality of 2951 whiles of light-emitting component luminous, can form the capable SPR of luminous point that arranges a plurality of luminous point SP on main scanning direction MD.

In addition, in the capable SPR of each luminous point, a plurality of luminous point SP are configured in mutually the same position in secondary scan direction SD.Therefore, as using the capable SPR_1 of luminous point illustrated, the distance, delta SP of the luminous point SP among the sub scanning direction SD and the first projection straight line PJ (AL_md) (distance, delta SP between auxiliary direction luminous point optical axis) equates between each light-emitting component 2951.Have again,, can obtain distance, delta SP between auxiliary direction luminous point optical axis as the distance among the sub scanning direction SD of the center of gravity of luminous point SP and the first projection straight line PJ (AL_md).

And the capable SPR_1 of these luminous points, SPR_2 arrange the mutually different position that is formed on secondary scan direction SD.And displacement luminous point spacing Psp forms the capable SPR_1 of each luminous point, SPR_2 mutually on long side direction LGD.Like this, form the luminous point group SG that has disposed 15 luminous point SP two-dimensionally, in luminous point group SG, form each luminous point SP by luminous point spacing Psp simultaneously in the mutually different position of main scanning direction MD.In other words, utilize formation to be formed on luminous point SP_1, the SP_2 that arranges by luminous point spacing Psp among the main scanning direction MD in abutting connection with the right light-emitting element E L1 of light-emitting component, EL2.In addition, be equivalent to the situation of the undistorted aberration of imaging optical system, in main scanning direction MD, form each luminous point SP by the luminous point spacing Psp that is equal to each other with the hurdle.Have, luminous point spacing Psp is the spacing (for example, the distance between principal direction position Tsl_1, the Tsl_2 is equivalent to this spacing) among the main scanning direction MD between 2 adjacent luminous points of principal direction position Tsl (for example luminous point SP_1, SP_2) again.In addition, in same accompanying drawing, principal direction position Tsl uses from the center of gravity of the luminous point of gazing at and represents to the intersection point of the sagging vertical line of main scanning direction axle MD.

But, in line head 29, dispose a plurality of light emitting device group 295 two-dimensionally according to above-mentioned.Therefore, operate by following control, carry out the luminous of each light emitting device group 295 by the sub-image formation of line head 29.Figure 10 is expression forms operation by the luminous point sub-image of line head figure.Below, one side illustrates simultaneously that with reference to Fig. 6, Fig. 9, Figure 10 the luminous point sub-image by line head forms operation.As summary, each light emitting device group 295 forms luminous point and carries out sub-image formation in mutually different exposure area ER.Form in the operation at this sub-image, a surface towards width of cloth scan direction SD carrying photoconductor drum 21, one side makes each light-emitting component 2951 luminous by a control module 54 timing in accordance with regulations, arranges on main scanning direction MD thus and forms a plurality of luminous point SP.Below explain.

At first, at first when the capable 2951R_2 of light-emitting component of the light emitting device group 295 (295_1,295_4 etc.) of the light emitting device group row 295R_A that belongs to upstream on width LTD is luminous, just form the capable SPR of luminous point.Like this, exposed in the zone that has formed each luminous point SP, form figured 7 the luminous point sub-images of hacures with " for the first time " of Figure 10.Have again, in Figure 10, the predetermined luminous point sub-image that blank circle seal expression does not also form, form from now on.In addition, in same accompanying drawing,, represent respectively to be endowed the luminous point sub-image that the light emitting device group 295 of symbol forms by correspondence with the luminous point of symbol 295_1,295_2,295_3 mark.

Follow the capable 2951R_2 of light-emitting component, capable 2951R_1 is luminous for light-emitting component, forms figured 8 the luminous point sub-images of hacures with " for the second time " of Figure 10.So, can form 2 the luminous point sub-images (for example luminous point sub-image Lsp1, Lsp2) that are arranged in adjacency on the main scanning direction MD at 2 light-emitting components 2951 by light-emitting component spacing Pel configuration on the long side direction LGD.At this, luminous successively from the capable 2951R of light-emitting component in the downstream of width LTD is for to have the handstand characteristic corresponding with imaging optical system.

Then, the light emitting device group 295 (295_2 etc.) of light emitting device group row 295R_B that belongs to the downstream of light emitting device group row 295R_A in width LTD is carried out the identical light emission operation with above-mentioned light emitting device group row 295R_A, forms the figured luminous point sub-image of hacures with " for the third time "～" the 4th time " of Figure 10.In addition, the light emitting device group 295 (295_3 etc.) of light emitting device group row 295R_C that belongs to the downstream of light emitting device group row 295R_B in width LTD is carried out the identical light emission operation with above-mentioned light emitting device group row 295R_A, forms the figured luminous point sub-image of hacures with " the 5th time "～" the 6th time " of Figure 10.So, by carrying out the first～six time light emission operation, just on main scanning direction MD, arrange and form a plurality of luminous point sub-images.

First embodiment

But above-mentioned basic structure is prerequisite with undistorted aberration in imaging optical system.But, in the reality, be difficult to make the imaging optical system of undistorted aberration, in imaging optical system, all can there be certain distortion aberration.

Figure 11 is the profile of the main scanning direction section of the imaging optical system in expression first embodiment.Figure 12 is the profile of the sub scanning direction section of the imaging optical system in expression first embodiment.Figure 13 is the figure that the lens data of the imaging optical system in first embodiment is shown with the form of table.Figure 14 is the figure that the optical system various factors of the imaging optical system in first embodiment is shown with the form of table.As Figure 11～Figure 13 as can be known, the first lens LS1 and the second lens LS2 any one all be non-spherical lens.In addition, configuration aperture 2982 between object plane S1 and aspheric surface S2 (the first lens LS1).

In Figure 11, object point OJm0 is positioned on the optical axis OA, and the light that penetrates from object point OJm0 is imaged as picture IMm0 at optical axis OA.Never the light of the ejaculation of object point OJm1, the OJm2 on optical axis OA reverses respectively and is imaged as picture IMm1, IMm2.In addition, as shown in figure 12, the light that the object point OJs0 from optical axis OA penetrates is imaged as IMs0 at optical axis OA.Have, when asking Figure 11, light path shown in Figure 12 by simulation, establishing light wavelength is 685.5[nm again] (Figure 14).

Figure 15 is the figure of the distortion aberration that imaging optical system had in expression first embodiment.The transverse axis of same accompanying drawing is represented light-emitting component principal direction position [mm], and the longitudinal axis of same accompanying drawing is represented the local multiplying power [doubly] of principal direction.At this, light-emitting component principal direction position is the distance among the main scanning direction MD (long side direction LGD) of light-emitting component 2951 and optical axis OA.The local multiplying power of principal direction is the imaging multiplying power relevant with sub scanning direction SD during with the light beam imaging of penetrating from the position shown in the transverse axis.Have, the initial point that the transverse axis and the longitudinal axis intersect is by optical axis OA again.

Shown in same accompanying drawing, that light-emitting component principal direction position becomes more is big (promptly along with the position of light-emitting component 2951 away from optical axis OA), and it is big that the absolute value of the local multiplying power of principal direction becomes more.In other words, the imaging optical system of first embodiment, have more at main scanning direction MD (long side direction LGD) and go up light away from above-mentioned optical axis, " first aberration " that carries out imaging by the optics multiplying power of relevant big absolute value with main scanning direction MD is as the aberration that distorts more.Therefore, shown in basic structure, in light emitting device group 295, disposing under the situation of each light-emitting component 2951 by the light-emitting component spacing Pel that is equal to each other on the long side direction LGD, there is the situation that problem as follows takes place.

Figure 16 is illustrated in the figure that imaging optical system has the problem that can produce under the first aberration situation.The transverse axis of same accompanying drawing is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of same accompanying drawing is represented light-emitting component spacing Pel (same accompanying drawing+mark) and luminous point spacing Psp (same accompanying drawing zero mark).As shown in figure 16, about each light-emitting component 2951, any one is about 0.028[mm for light-emitting component spacing Pel], be equal to each other.With respect to this, imaging optical system has first aberration shown in Figure 15.Therefore, as shown in figure 16, just form along with the luminous point spacing Psp this luminous point group SG that broadens away from optical axis OA.Therefore, in the first embodiment,, be constructed as follows this light emitting device group 295 for this problem of correspondence.

Figure 17 is the plane of the structure of the light emitting device group in expression first embodiment.In addition, Figure 18 is the structure of the light emitting device group in expression first embodiment and the figure of the effect that this light emitting device group is brought into play.The transverse axis of Figure 18 is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of Figure 18 is represented light-emitting component spacing Pel (same accompanying drawing+mark) and luminous point spacing Psp (same accompanying drawing zero mark).

As shown in figure 17, in light emitting device group 295,17 light-emitting components 2951 of alignment arrangements on long side direction LGD.In addition, in the first embodiment, adjust the light-emitting component spacing Pel (Figure 17, Figure 18) of each light-emitting component 2951 in advance.In other words, more on long side direction LGD away from optical axis OA in abutting connection with light-emitting component to ELP, constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component by narrow light-emitting component spacing configuration more to ELP.For example, in Figure 17, in long side direction, by from the near arranged in order of optical axis OA in abutting connection with light-emitting component to ELP_1, ELP_2, ELP_3, in abutting connection with light-emitting component ELP_1, ELP_2, ELP_3 light-emitting component spacing Pel_1, Pel_2, Pel_3 separately satisfied following magnitude relationship: Pel_1＞Pel_2＞Pel_3.In other words, in the first embodiment,, adjust light-emitting component spacing Pel in order to eliminate first aberration that imaging optical system has.Therefore, as shown in figure 18, no matter the principal direction position how, forms each luminous point SP by the luminous point spacing Psp that is equal to each other (=about 0.042[mm]).

So, in the light emitting device group 295 of first embodiment, at least 2 in abutting connection with light-emitting component to EPL respectively by configuration constitutes this in abutting connection with 2 light-emitting components 2951 of light-emitting component to EPL according to distortion aberration mutually different light-emitting component spacing Pel.Therefore, can suppress the problem that the distortion aberration of imaging optical system causes effectively, can carry out good sub-image and form.

In other words, in light emitting device group 295, at least 2 in abutting connection with light-emitting component in each of EPL, more on long side direction LGD away from optical axis OA in abutting connection with light-emitting component to EPL, constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component by narrow light-emitting component spacing Pel configuration more to EPL.Therefore, eliminate first aberration that imaging optical system had, light emitting device group 295 can be on main scanning direction MD forms a plurality of luminous point SP by about equally luminous point spacing Psp each other, can carry out good sub-image and form.

Second embodiment

Figure 19 is the profile of the main scanning direction section of the imaging optical system in expression second embodiment.Figure 20 is the profile of the sub scanning direction section of the imaging optical system in expression second embodiment.Figure 21 is the figure that the lens data of the imaging optical system in second embodiment is shown with the form of table.Figure 22 is the figure that the optical system various factors of the imaging optical system in second embodiment is shown with the form of table.Below, the difference part of the structure that main explanation is above-mentioned and the structure of second embodiment is given respective symbol for common part and is suitably omitted explanation.

As Figure 19～shown in Figure 21, any one is non-spherical lens for the first lens LS1 and the second lens LS2.In addition, configuration aperture 2982 between face S3 and aspheric surface S5 (the second lens LS2).In Figure 19, object point OJm0 is positioned on the optical axis OA, and the light that penetrates from object point OJm0 is imaged as picture IMm0 at optical axis OA.Never the light of the ejaculation of object point OJm1, the OJm2 on optical axis OA reverses respectively and is imaged as picture IMm1, IMm2.In addition, as shown in figure 20, never the light of the ejaculation of object point OJs1, the OJs2 on optical axis OA reverses respectively and is imaged as IMs1, IMs2.Have, when asking Figure 19, light path shown in Figure 20 by simulation, establishing light wavelength is 685.5[nm again] (Figure 22).

Figure 23 is the figure of the distortion aberration that imaging optical system had in expression second embodiment, and the transverse axis of same accompanying drawing is represented light-emitting component principal direction position [mm], and the longitudinal axis of same accompanying drawing is represented the local multiplying power [doubly] of principal direction.Shown in same accompanying drawing, light-emitting component principal direction position becomes big (position that is light-emitting component 2951 is far away more from optical axis OA) more, and the absolute value of the local multiplying power of principal direction just diminishes more.In other words, the imaging optical system of second embodiment, have more at the last light of main scanning direction MD (long side direction LGD), more by having the optics multiplying power of the absolute value that turns down to carry out " second aberration " conduct distortion aberration of imaging with main scanning direction MD away from optical axis OA.Therefore, shown in basic structure, in light emitting device group 295, disposing under the situation of each light-emitting component 2951 by the light-emitting component spacing Pel that is equal to each other on the long side direction LGD, there is the situation that problem as follows takes place.

Figure 24 is illustrated in the figure that imaging optical system has the problem that can produce under the second aberration situation.The transverse axis of same accompanying drawing is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of same accompanying drawing is represented light-emitting component spacing Pel (same accompanying drawing+mark) and luminous point spacing Psp (same accompanying drawing zero mark).As shown in figure 24, about each light-emitting component 2951, any one is about 0.028[mm for light-emitting component spacing Pel], be equal to each other.With respect to this, imaging optical system has second aberration shown in Figure 23.Therefore, as shown in figure 24, just form along with this luminous point group SG that narrows down away from optical axis OA, luminous point spacing Psp.Therefore, in second embodiment,, be constructed as follows such light emitting device group 295 for the such problem of correspondence.

Figure 25 is the plane of the structure of the light emitting device group in expression second embodiment.In addition, Figure 26 is the structure of the light emitting device group in expression second embodiment and the figure of the effect that this light emitting device group is brought into play.The transverse axis of Figure 26 is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of Figure 26 is represented light-emitting component spacing Pel (same accompanying drawing+mark) and luminous point spacing Psp (same accompanying drawing zero mark).

As shown in figure 25, in light emitting device group 295, on long side direction LGD with 17 light-emitting components 2951 of zigzag alignment arrangements.In addition, in second embodiment, adjust the light-emitting component spacing Pel (Figure 25, Figure 26) of each light-emitting component 2951 in advance.In other words, more on long side direction LGD away from optical axis OA in abutting connection with light-emitting component to ELP, constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component by wide light-emitting component spacing configuration more to ELP.For example, in Figure 25, in long side direction LGD, by from the near arranged in order of optical axis OA in abutting connection with light-emitting component to ELP_1, ELP_2, ELP_3, in abutting connection with light-emitting component ELP_1, ELP_2, ELP_3 light-emitting component spacing Pel_1, Pel_2, Pel_3 separately satisfied following magnitude relationship: Pel_1＜Pel_2＜Pel_3.In other words, in second embodiment,, adjust light-emitting component spacing Pel in order to eliminate second aberration that imaging optical system has.Therefore, as shown in figure 26, no matter the principal direction position how, forms each luminous point SP by the luminous point spacing Psp that is equal to each other (=about 0.042[mm]).

So, in the light emitting device group 295 of second embodiment, at least 2 in abutting connection with light-emitting component to EPL respectively by configuration constitutes this in abutting connection with 2 light-emitting components 2951 of light-emitting component to EPL according to distortion aberration mutually different light-emitting component spacing Pel.Therefore, can suppress the problem that the distortion aberration of imaging optical system causes effectively, can carry out good sub-image and form.

In other words, in light emitting device group 295, at least 2 in abutting connection with light-emitting component to EPL in each, more on long side direction LGD away from optical axis OA in abutting connection with light-emitting component to EPL, constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component by wide light-emitting component spacing Pel configuration more to EPL.Therefore, eliminate second aberration that imaging optical system had, light emitting device group 295 can be on main scanning direction MD forms a plurality of luminous point SP by about equally luminous point spacing Psp each other, can carry out good sub-image and form.

The 3rd embodiment

Then, the 3rd embodiment of the present invention is described.This 3rd embodiment is a purpose to solve the problem different with the first/the second embodiment.In other words, in above-mentioned basic structure, on long side direction LGD, arrange and use a plurality of light-emitting components.But light-emitting component 2951 generates heat because drive luminous.Therefore, near (in other words, the center of gravity of light emitting device group 295) thermal capacitance is easily assembled near the central authorities of light emitting device group 295, these central authorities are neighbouring dispose the hot deterioration of light-emitting component 2951 will have the tendency of acceleration.Its result will make the degree of 2951 hot deteriorations of each light-emitting component produce difference, and existence can not be carried out the situation that good sub-image forms.

Figure 27 is illustrated in the figure that disposes the problem that can produce in the structure of a plurality of light-emitting components with the spacing of the light-emitting component that is equal to each other." Temperature Distribution in the light emitting device group " hurdle of same accompanying drawing illustrates the temperature on the first straight line AL_md, and transverse axis is represented the principal direction position, longitudinal axis representation temperature.Having, is position among the main scanning direction MD (long side direction LGD) on the first straight line AL_md with the principal direction position in the hurdle again, is initial point with optical axis OA.In addition, " light emitting device group " hurdle of same accompanying drawing illustrates the structure of the light emitting device group 295 under overlooking.

Shown in " light emitting device group " hurdle, configuration light emitting device group 295 makes its position of centre of gravity overlap with optical axis OA.Constitute a plurality of light-emitting components 2951 of this light emitting device group 295, on long side direction LGD, dispose with zigzag by the light-emitting component spacing Pel that is equal to each other.And, so dispose the result of each light-emitting component 2951, the shown this Temperature Distribution in " Temperature Distribution in the light emitting device group " hurdle will take place in light emitting device group 295.Shown in the hurdle, in main scanning direction MD (long side direction LGD), uprise near near (be optical axis OA) temperature center of gravity of light emitting device group 295,, producing temperature difference Δ T1 near the center of gravity of light emitting device group 295 and between the end at position temperature step-down away from center of gravity.Its result near the propelling of the hot deterioration of the light-emitting component 2951 center of gravity, exists the degree of hot deterioration to produce the situation of difference 2951 of each light-emitting components.Therefore, the 3rd embodiment is by following formation light emitting device group 295.

Figure 28 is the figure of the structure of the light emitting device group in expression the 3rd embodiment." Temperature Distribution in the light emitting device group " hurdle of same accompanying drawing illustrates the temperature on the first straight line AL_md, and transverse axis is represented the principal direction position, longitudinal axis representation temperature.In addition, " light emitting device group " hurdle of same accompanying drawing illustrates the structure of the light emitting device group 295 under overlooking.Make on this aspect that its position of centre of gravity overlaps with optical axis OA in what is called configuration light emitting device group 295, the light emitting device group of Figure 27 and the light emitting device group of Figure 28 are common.But they are different in following point.In other words, shown in " light emitting device group " hurdle of Figure 28, in long side direction LGD, more near the center of gravity (with optical axis OA in the hurdle) of light emitting device group 295 in abutting connection with light-emitting component to ELP, constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component by wide light-emitting component spacing Pel configuration more to ELP.For example, in Figure 28, in long side direction LGD, by apart from the near arranged in order of optical axis OA in abutting connection with light-emitting component to ELP_1, ELP_2, ELP_3, in abutting connection with light-emitting component ELP_1, ELP_2, ELP_3 light-emitting component spacing Pel_1, Pel_2, Pel_3 separately satisfied following magnitude relationship: Pel_1＞Pel_2＞Pel_3.

Therefore, near the center of gravity of light emitting device group 295, the density of light-emitting component 2951 is thinning dredges, and promotes near the heat radiation of optical axis OA in the light emitting device group 295 effectively.Its result, shown as the hurdle of " light emitting device group in Temperature Distribution ", make the Temperature Distribution levelized of light emitting device group 295.Particularly, temperature difference Δ T2 shown in Figure 28 diminishes than temperature difference Δ T1 shown in Figure 27.Therefore, will be roughly the same in the degree of 2951 hot deteriorations of each light-emitting component, can carry out good sub-image and form operation.

The 4th embodiment

Figure 29 is the plane that the structure (same accompanying drawing epimere) of the light emitting device group in expression the 4th embodiment reaches the luminous point group (same accompanying drawing hypomere) that is formed by this light emitting device group.In the 4th embodiment, each light-emitting component of light emitting device group 295 is formed in the organic EL of head substrate back side 293-t, and " light emitting device group " hurdle of same accompanying drawing epimere illustrates head substrate back side 293-t.In addition, " luminous point group " hurdle of same accompanying drawing hypomere illustrates photoconductor drum 21 surfaces.Have, in each hurdle, though lens LS is shown, this is in order to represent the corresponding relation of light emitting device group 295 or luminous point group SG and lens LS, is not to be provided with lens LS at head substrate back side 293-t or photoconductor drum 21 surfaces again.In addition, the imaging optical system of the 4th embodiment has the structure identical with the imaging optical system of second embodiment.Therefore, the imaging optical system of the 4th embodiment has more at main scanning direction MD (long side direction LGD) goes up light away from the light-emitting component 2951 of optical axis OA, more by " second aberration " that the optics multiplying power of the absolute value that turns down carries out imaging being arranged as the distortion aberration with main scanning direction MD.

Shown in " light emitting device group " hurdle of the epimere of same accompanying drawing, on long side direction LGD with 2 row 17 light-emitting components 2951 of saw-tooth arrangement (EL_1 etc.).Its result arranges 2 row light-emitting component 2951R_1,2951R_2 on width LTD.Have again, in the hurdle, give symbol EL_1 the light-emitting component that is configured on the second straight line AL_sd.In addition, give symbol EL_2 to right side (side) with the light-emitting component of light-emitting element E L_1 principal direction position disposed adjacent on the same hurdle of the long side direction LGD of light-emitting element E L_1.And, to giving symbol EL_3 on the right side, same hurdle of the long side direction LGD of light-emitting element E L_2 and the light-emitting component of light-emitting element E L_2 principal direction position disposed adjacent, and, to giving symbol EL_4 on the right side, same hurdle of the long side direction LGD of light-emitting element E L_3 and the light-emitting component of light-emitting element E L_3 principal direction position disposed adjacent.

In addition, give symbol Pel_1 (between the principal direction light-emitting component apart from Pel_1) to the distance between the center of gravity among the main scanning direction MD (long side direction LGD) of light-emitting element E L_1 and light-emitting element E L_2.And, give symbol Pel_2 (between the principal direction light-emitting component apart from Pel_2) to the distance between the center of gravity among the main scanning direction MD (long side direction LGD) of light-emitting element E L_2 and light-emitting element E L_3, give symbol Pel_3 (between the principal direction light-emitting component apart from Pel_3) the distance between the center of gravity among the main scanning direction MD (long side direction LGD) of light-emitting element E L_3 and light-emitting element E L_4.So, distance is defined as between the principal direction light-emitting component apart from Pel between the center of gravity among the main scanning direction MD of 2 light-emitting components that the principal direction position is adjacent one another are.Have, distance is equivalent to the light-emitting component spacing Pel in first～the 3rd embodiment between the principal direction light-emitting component again.

In addition, give symbol Pels_1 (between the auxiliary direction light-emitting component apart from Pels_1) to the distance between the center of gravity among the sub scanning direction SD (width LTD) of light-emitting element E L_1 and light-emitting element E L_2.And, give symbol Pels_2 (between the auxiliary direction light-emitting component apart from Pels_2) to the distance between the center of gravity among the sub scanning direction SD (width LTD) of light-emitting element E L_2 and light-emitting element E L_3, give symbol Pels_3 (between the auxiliary direction light-emitting component apart from Pels_3) the distance between the center of gravity among the sub scanning direction SD (width LTD) of light-emitting element E L_3 and light-emitting element E L_4.So, distance is defined as between the auxiliary direction light-emitting component apart from Pels between the center of gravity among the sub scanning direction SD of 2 light-emitting components that the principal direction position is adjacent one another are.

Then, luminous by each light-emitting component of this light emitting device group 295, form the luminous point group SG shown in " luminous point group " hurdle.In " luminous point group " hurdle, give symbol SP_1～SP_4 to the luminous point that forms by light-emitting element E L_1～EL_4.In addition, give symbol Psp_1 (between the principal direction luminous point apart from Psp_1), and similarly, give symbol Psp_2, Psp_3 distance between the principal direction luminous point to the distance between the center of gravity among the main scanning direction MD of luminous point SP_1 and luminous point SP_2.So, distance is defined as between the principal direction luminous point apart from Psp between the center of gravity among the main scanning direction MD of 2 luminous point SP that the principal direction position is adjacent one another are.And, give symbol Psps_1 (between the auxiliary direction luminous point apart from Psps_1) to the distance between the center of gravity among the sub scanning direction SD of luminous point SP_1 and luminous point SP_2, and similarly, give symbol Psps_2, Psps_3 distance between the auxiliary direction luminous point.So, distance is defined as between the auxiliary direction luminous point apart from Psps between the center of gravity among the sub scanning direction SD of 2 luminous point SP that the principal direction position is adjacent one another are.

And the imaging optical system of the 4th embodiment has aforesaid second aberration (Figure 23).Therefore, no matter second aberration is how, in order to make principal direction luminous point spacing Psp certain, so more away from the light-emitting component of optical axis OA, more by between bigger principal direction light-emitting component apart from the Pel alignment arrangements.For example, arrange light-emitting element E L_1～EL_4, so that satisfy following formula apart from Pel between the principal direction light-emitting component:

Pel_1＜Pel_2＜Pel_3。Therefore, by between the principal direction luminous point that equates on the main scanning direction MD, arranging formation luminous point SP_1～SP_4 apart from Psp.

But the imaging optical system of the 4th embodiment is main scanning direction MD not only, and among the sub scanning direction SD distortion aberration is arranged also.Figure 30 be expression in the 4th embodiment imaging optical system had to the figure of the distortion aberration of sub scanning direction, the transverse axis of same accompanying drawing represent light-emitting component principal direction position [mm], the longitudinal axis of same accompanying drawing is represented auxiliary direction part multiplying power [doubly].Here, the local multiplying power of auxiliary direction is an imaging multiplying power during with the light beam imaging penetrated from the position shown in the transverse axis, relevant with sub scanning direction SD.Have, the initial point that the transverse axis and the longitudinal axis intersect is by optical axis OA again.Shown in same accompanying drawing, light-emitting component principal direction position becomes more big (position that is light-emitting component 2951 is more away from optical axis OA), and the absolute value of the local multiplying power of auxiliary direction just diminishes more.In other words, the imaging optical system of the 4th embodiment, have more at main scanning direction MD (long side direction LGD) and go up light, more by " the 4th aberration " that the optics multiplying power of the absolute value that turns down carries out imaging being arranged as the distortion aberration with sub scanning direction MD away from the light-emitting component 2951 of optical axis OA.Therefore, in light emitting device group 295, dispose under the situation of each light-emitting component 2951, have the situation that problem as follows takes place by the auxiliary direction light-emitting component spacing Pels that is equal to each other.

Figure 31 is illustrated in the figure that imaging optical system has the problem that can produce under the 4th aberration situation.The transverse axis of same accompanying drawing is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of same accompanying drawing is represented auxiliary direction light-emitting component spacing Pels (same accompanying drawing+mark) and auxiliary direction luminous point spacing Psps (same accompanying drawing zero mark).As shown in figure 31, about each light-emitting component 2951, any one is about 0.042[mm for auxiliary direction light-emitting component spacing Pels], be equal to each other.With respect to this, imaging optical system has the 4th aberration shown in Figure 30.Therefore, as shown in figure 31, just form along with this luminous point group SG that narrows down away from optical axis OA auxiliary direction luminous point spacing Psps.In other words, expand with near the central portion the second straight line AL_sd and narrow this cup type shape at two ends and form luminous point group SG.Its result promptly enables to form this capable sub-image shown in Figure 10, and the sub-image of also might going can rock.

Therefore, in the 4th embodiment,, constitute as Figure 29, light emitting device group 295 shown in Figure 32 for the such problem of correspondence.At this, Figure 32 is the structure of expression the 4th embodiment and the figure of effect, and the transverse axis of same accompanying drawing is represented the principal direction position [mm] of light-emitting component or luminous point.The longitudinal axis of Figure 32 is represented auxiliary direction light-emitting component spacing Pels (same accompanying drawing+mark) and auxiliary direction luminous point spacing Psps (same accompanying drawing zero mark).As Figure 29, shown in Figure 32, no matter the 4th aberration is how, in order to make auxiliary direction luminous point spacing Psps certain, so more away from the light-emitting component of optical axis OA, more by between bigger auxiliary direction light-emitting component apart from Pels alignment arrangements (Figure 29, Figure 30).For example, arrange light-emitting element E L_1～EL_4 shown in Figure 29 so that satisfy following formula apart from Pels between the auxiliary direction light-emitting component:

Pels_1＜Pels_2＜Pels_3。Therefore, by between the auxiliary direction luminous point that equates on the sub scanning direction SD, arranging formation luminous point SP_1～SP_4 apart from Psps.That is, in the 4th embodiment,, adjust auxiliary direction light-emitting component spacing Pels in order to eliminate the 4th aberration that imaging optical system has.Therefore, shown in figure 32, no matter the principal direction position how, forms each luminous point SP by the auxiliary direction luminous point spacing Psps that is equal to each other (=about 0.063[mm]).

So, this line head 29 of the 4th embodiment (photohead) is according to adjusting between the principal direction light-emitting component of each light-emitting component 2951 of light emitting device group 295 apart from Pel to the distortion aberration of main scanning direction MD of imaging optical system.Therefore, the distortion aberration that can suppress imaging optical system forms the influence that causes to luminous point, can be by forming each luminous point apart from Psp between the principal direction luminous point that equates, and existing good luminous point forms.

If illustrate, then in the 4th embodiment, by the distance to main scanning direction MD (first direction) between center of gravity is that distance P el_1 (first distance) is provided with light-emitting element E L_1 (first light-emitting component) and light-emitting element E L_2 (second light-emitting component), is that distance P el_2 (second distance) is provided with second light-emitting element E L_2 (second light-emitting component) and light-emitting element E L_3 (the 3rd light-emitting component) by the distance to main scanning direction MD between center of gravity.And, make distance P el_1 and Pel_2 difference (Pel_1＜Pel_2) according to second aberration to the main scanning direction MD of imaging optical system.Therefore, just become, realize good luminous point formation arranging each the luminous point SP that forms by light-emitting element E L_1～EL_3 apart from Psp between by the principal direction luminous point that equates on the main scanning direction MD.

And, in the above-described embodiment, according between the auxiliary direction light-emitting component of each light-emitting component 2951 from light emitting device group 295 to the distortion aberration of the sub scanning direction SD of imaging optical system that adjust apart from Pels.Therefore, can realize that good luminous point forms by forming each luminous point apart from Psps between the auxiliary direction luminous point that equates.

If illustrate, then in the 4th embodiment, light-emitting element E L_2 (second light-emitting component) is set in the sub scanning direction SD (width LTD) of light-emitting element E L_1 (first light-emitting component) and light-emitting element E L_3 (the 3rd light-emitting component) side.And, by the distance to sub scanning direction SD (second direction) between center of gravity is that distance P els_1 (the 3rd distance) is provided with light-emitting element E L_1 (first light-emitting component) and light-emitting element E L_2 (second light-emitting component), is that Pels_2 (the 4th distance) is provided with light-emitting element E L_2 (second light-emitting component) and light-emitting element E L_3 (the 3rd light-emitting component) by the distance to sub scanning direction SD between center of gravity.And, make the different (Pels_1＜Pels_2) of distance P els_1 according to the 4th aberration of imaging optical system with Pels_2.Therefore,, form by forming each luminous point SP apart from Psps between the sub scanning direction luminous point that equates by light-emitting element E L_1～EL_3 so can realize the luminous point that rock, good that can suppress above-mentioned this capable sub-image.

Other

So, in the above-described embodiment, long side direction LGD and main scanning direction MD are equivalent to " first direction " of the present invention, and width LTD and sub scanning direction SD are equivalent to " second direction " of the present invention.In addition, lens LS1, LS2 work as " imaging optical system " of the present invention.In addition, light emitting device group 295 is equivalent to " four above light-emitting components " of the present invention.In addition, head substrate 293 is equivalent to " substrate (substrate) " of the present invention.In addition, photoconductor drum 21 is equivalent to " sub-image supporting body " of the present invention.In addition, line head 29 is equivalent to " photohead " of the present invention.In addition, in first～the 3rd embodiment, for example press 2 light-emitting components that light-emitting component spacing Pel_1 arranges and constitute " first light-emitting component to " of the present invention, press 2 light-emitting components formations that light-emitting component spacing Pel_2 arranges " second light-emitting component to " of the present invention.

Have again, the invention is not restricted to above-mentioned embodiment, only otherwise break away from its purport, beyond aforesaid way, can carry out various changes.In other words, in first, second embodiment, for the problem that the distortion aberration that improves imaging optical system causes, in abutting connection with light-emitting component ELP is pressed mutually different light-emitting component spacing Pel configuration respectively at least 2 and constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component to ELP.In addition, in the 3rd embodiment, the influence of the problem that causes for the heating that reduces light-emitting component 2951, at least 2 constitute this in abutting connection with 2 light-emitting components 2951 of light-emitting component to ELP by mutually different light-emitting component spacing Pel configuration in abutting connection with light-emitting component respectively to ELP.But, in order to improve problem beyond these (for example the shade of imaging optical system (shading) etc.), also can constitute at least 2 and ELP be constituted this in abutting connection with 2 light-emitting components 2951 of light-emitting component to ELP by mutually different light-emitting component spacing Pel configuration respectively in abutting connection with light-emitting component.

In addition, in above-mentioned the first/the second embodiment, eliminate the first/the second aberration that imaging optical system 295 is had, on main scanning direction MD, arrange a plurality of luminous point SP, we can say discrete (the in other words error) that almost completely suppress luminous point spacing Psp by the luminous point spacing Psp that is equal to each other.But, judge that based on the image quality that requires etc. luminous point spacing Psp discrete is under the situation of admissible a certain degree, also can constitute till this permission rank, relaxes the discrete structure of luminous point spacing Psp.

In other words, with with the imaging optical system with distorted image difference to coming comfortable long side direction LGD and going up that the light beam that has disposed the light emitting device group 295 of a plurality of light-emitting components 2951 by the light-emitting component spacing Pel that is equal to each other carries out imaging and the discrete comparison of the luminous point spacing Psp among the luminous point group SG that produces, if the light beam that comes self-application light emitting device group 295 of the present invention is carried out imaging and the discrete quilt of luminous point spacing Psp among the luminous point group SG that produces relaxes with this imaging optical system, then can be judged as and bring into play effect of the present invention.

And, so, in abutting connection with light-emitting component ELP is pressed mutually different light-emitting component spacing Pel configuration respectively at least 2 and constitute this in abutting connection with the structure of light-emitting component to 2 light-emitting components 2951 of ELP, except that above-mentioned action effect, performance action effect as follows.In other words, as above-mentioned embodiment, constituting under the situation of light-emitting component 2951, be necessary on the head substrate 293 that is provided with light-emitting component 2951, to apply organic EL Material by organic EL.At this moment, for the characteristics of luminescence that makes each light-emitting component 2951 is even, wish that smearing of organic EL Material is more even.With respect to this, the structure that disposes light-emitting component 2951 as mentioned above helps smearing than applying organic EL Material under the state uniformly.

In addition, in Figure 28 of above-mentioned the 3rd embodiment, the light-emitting component on the same accompanying drawing right side of 2 the light-emitting component that not special record is provided with by light-emitting component spacing Pel_1 and light-emitting component spacing Pel between 2 the light-emitting component in same accompanying drawing left side of light-emitting component is set by light-emitting component spacing Pel_2.But, by making this light-emitting component spacing Pel (second distance) littler and bigger than light-emitting component Pel_2 than light-emitting component spacing Pel_1 (first distance), near near the heat radiation of the heat of the center of gravity that just can promote to accumulate in light emitting device group 295 (in the same accompanying drawing optical axis OA), the degradation between the inhibition light-emitting component poor.Its result can carry out good luminous point and form.In the case, for example, be equivalent to " the 3rd light-emitting component " of the present invention by the light-emitting component on same accompanying drawing right side in 2 the light-emitting component of light-emitting component spacing Pel configuration.In addition, the light-emitting component in same accompanying drawing left side is equivalent to " first light-emitting component " of the present invention in 2 the light-emitting component by light-emitting component spacing Pel_1 configuration, and the light-emitting component on same accompanying drawing right side is equivalent to " second light-emitting component " of the present invention.

In addition, in the above-described 4th embodiment, illustrated to have more and gone up light, more by having the optics multiplying power of the absolute value that turns down to carry out " second aberration " of imaging situation as the distortion aberration with main scanning direction MD away from the light-emitting component 2951 of optical axis OA at main scanning direction MD (long side direction LGD).Even but go up light for having more away from the light-emitting component 2951 of optical axis OA at main scanning direction MD (long side direction LGD), " first aberration " that carries out imaging by the big optics multiplying power of relevant absolute value with main scanning direction MD also can be used the present invention as the situation of distortion aberration more.In the case, can adjust between the principal direction light-emitting component apart from Pel according to first aberration.If for example, then by make the different (Pel_1＞Pel_2), just can form each luminous point SP well by the principal direction spot distance Psp that equates of distance P el_1 according to first aberration by light-emitting element E L_1～EL_3 with distance P el_2.

In addition, in the above-described 4th embodiment, having illustrated that imaging optical system has more at main scanning direction MD (long side direction LGD) goes up light away from the light-emitting component 2951 of optical axis OA, more by having the optics multiplying power of the absolute value that turns down to carry out the situation of " the 4th aberration " of imaging with sub scanning direction SD.Even go up light away from the light-emitting component 2951 of optical axis OA but have more at main scanning direction MD (long side direction LGD) for imaging optical system, the situation of carrying out " the 3rd aberration " of imaging by the big optics multiplying power of relevant absolute value with sub scanning direction SD also can be used the present invention more.In the case, can adjust between the auxiliary direction light-emitting component apart from Pels according to the 3rd aberration.If for example, then by make the different (Pels_1＞Pels_2) of distance P els_1 according to the 3rd aberration with distance P els_2, form each luminous point SP by light-emitting element E L_1～EL_3 by the auxiliary direction spot distance Psps that equates, form so can realize the luminous point that rock, good that can suppress above-mentioned this capable sub-image.

In addition, in the above-described embodiment, though light-emitting component 2951 is circular, the shape of light-emitting component is not limited thereto, and both can be that rectangle also can be oval.In addition, even in shape arbitrarily, also can obtain the position of light-emitting component 2951 as the center of gravity of the light-emitting component in overlooking 2951.

In addition, can suitably change the number of the light-emitting component 2951 in the light emitting device group 295 or the number of the capable 2951R of light-emitting component etc.In addition, can also suitably change the number of the light-emitting component 2951 that constitutes the capable 2951R of light-emitting component.

In addition, can also suitably change the number of light emitting device group row 295R or the capable LSR of lens.

In addition, in the above-described embodiment, though use 2 chip-lens arrays 299, the sheet number of lens arra 299 is not limited thereto.

In addition, in the above-described embodiment, used the organic EL of bottom emissive type as light-emitting component 2951.But the organic EL that also can use top-emission (top emission) type maybe can also use LED (Light Emitting Diode, light emitting diode) as light-emitting component 2951 as light-emitting component 2951.

Figure 33 is to use the plane of LED element as the structure of light-emitting component, is equivalent to overlook the situation of structure of the surperficial 292-h of installing plate 292.Have, in same accompanying drawing, though lens LS is shown, this is in order to represent the relation of lens LS and light emitting device group 295, is not to form lens LS on the 292-h of installing plate surface again.In addition, Figure 34 is to use the part sectioned view of LED element as the long side direction of the structure of light-emitting component.In Figure 34, represent with two chain-dotted lines or dotted line from the central portion of the long side direction LGD of light emitting device group 295 and the track of the light beam that both ends are penetrated respectively.As shown in these figures, on semiconductor chip CP, form LED element as light-emitting component 2951.On the long axis direction at this semiconductor chip on this semiconductor chip CP, arrange the light emitting device group 295 that forms 3 groupings a plurality of (8) light-emitting component 2951.And a plurality of semiconductor chip CP are installed on the surperficial 292-h of flat installing plate 292.At this moment, stipulate that the long axis direction of each semiconductor chip CP is parallel with long side direction LGD.And, even with respect to the line head 29 that uses this LED element as light-emitting component, adjust between the principal direction light-emitting component apart from Pel by the same with above-mentioned embodiment, also can bring into play effect of the present invention.So, in Figure 33, structure shown in Figure 34, semiconductor chip CP is equivalent to " substrate (substrate) " of the present invention, and installing plate 292 is equivalent to " dull and stereotyped (board) " of the present invention.Have, in this structure, though relative 1 semiconductor chip CP forms 3 light emitting device group 295, the number of the light emitting device group 295 that forms with respect to 1 semiconductor chip CP is not limited thereto again.

In addition, in the above-described embodiment, though use the imaging optical system of optical characteristics as imaging optical system with counter-rotating amplification, but imaging optical system is not limited thereto, the imaging optical system that can use the imaging optical system with the optical characteristics of just changeing and have the optical characteristics of dwindling.

Claims (15)

1, a kind of photohead comprises:

Substrate, have first light-emitting component, be arranged on above-mentioned first light-emitting component first direction a side second light-emitting component and be arranged on the 3rd light-emitting component of an above-mentioned side of the above-mentioned first direction of above-mentioned second light-emitting component; And

Imaging optical system carries out imaging with the light of above-mentioned first light-emitting component, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component;

On above-mentioned first direction, above-mentioned first light-emitting component and above-mentioned second light-emitting component are set, on above-mentioned first direction, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component are set by the second distance different with above-mentioned first distance by first distance.

2, photohead according to claim 1 is characterized in that,

Above-mentioned first distance of distorted image official post according to the above-mentioned first direction of above-mentioned imaging optical system is different with above-mentioned second distance.

3, photohead according to claim 2 is characterized in that,

Above-mentioned side at the above-mentioned first direction of the optical axis of above-mentioned imaging optical system is provided with above-mentioned first light-emitting component, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component.

4, photohead according to claim 3 is characterized in that,

Above-mentioned imaging optical system has more on above-mentioned first direction the light away from above-mentioned optical axis, carries out first aberration of imaging by the optics multiplying power of big absolute value more on above-mentioned first direction and with the distortion aberration of this first aberration as above-mentioned first direction; Above-mentioned second distance is shorter than above-mentioned first distance.

5, photohead according to claim 3 is characterized in that,

Above-mentioned imaging optical system has more on above-mentioned first direction the light away from above-mentioned optical axis, carries out second aberration of imaging by the optics multiplying power of little absolute value more on above-mentioned first direction and with the distortion aberration of this second aberration as above-mentioned first direction; Above-mentioned second distance is than above-mentioned first distance.

6, according to any described photohead in the claim 3～5, it is characterized in that,

In second direction side above-mentioned second light-emitting component is set with respect to above-mentioned first light-emitting component and above-mentioned the 3rd light-emitting component with above-mentioned first direction quadrature.

7, photohead according to claim 6 is characterized in that,

On above-mentioned second direction, above-mentioned first light-emitting component and above-mentioned second light-emitting component are set, on above-mentioned second direction, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component are set by the 4th distance different with above-mentioned the 3rd distance by the 3rd distance.

8, photohead according to claim 7 is characterized in that,

Above-mentioned the 3rd distance of distorted image official post according to the above-mentioned second direction of above-mentioned imaging optical system is different with above-mentioned the 4th distance.

9, photohead according to claim 8 is characterized in that,

Above-mentioned imaging optical system has more on above-mentioned first direction the light away from above-mentioned optical axis, carries out the 3rd aberration of imaging by the optics multiplying power of big absolute value more on above-mentioned second direction and with the distortion aberration of the 3rd aberration as above-mentioned second direction; Above-mentioned the 4th distance is shorter than above-mentioned the 3rd distance.

10, photohead according to claim 8 is characterized in that,

Above-mentioned imaging optical system has more on above-mentioned first direction the light away from above-mentioned optical axis, carries out the 4th aberration of imaging by the optics multiplying power of little absolute value more on above-mentioned second direction and with the distortion aberration of the 4th aberration as above-mentioned second direction; Above-mentioned the 4th distance is than above-mentioned the 3rd distance.

11, photohead according to claim 1 is characterized in that,

The light-emitting component more than four that generates heat because of luminous is being set on the aforesaid substrate, is comprising above-mentioned first light-emitting component, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component in this light-emitting component more than four; Above-mentioned imaging optical system is with the photoimaging of above-mentioned light-emitting component more than four; Side at the above-mentioned first direction of above-mentioned light-emitting component more than four is provided with above-mentioned first light-emitting component, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component; Above-mentioned first distance is longer than above-mentioned second distance.

12, according to any described photohead in the claim 1～11, it is characterized in that,

Above-mentioned light-emitting component is formed in the organic EL on the aforesaid substrate.

13, according to any described photohead in the claim 1～11, it is characterized in that,

Above-mentioned light-emitting component is the LED element, and aforesaid substrate is the semiconductor chip that has formed above-mentioned LED, and above-mentioned semiconductor chip is provided on the flat board.

14, a kind of photohead comprises:

Substrate, it is right to have first light-emitting component that is made of 2 light-emitting components that are provided with by first distance on first direction; With right by second light-emitting component that on first direction, constitutes by 2 light-emitting components with the different second distance setting of above-mentioned first distance; Above-mentioned second light-emitting component is to being arranged on the right above-mentioned first direction side of above-mentioned first light-emitting component; And

Imaging optical system will carry out imaging from the light that constitutes the right light-emitting component of above-mentioned first light-emitting component and from the light that constitutes the right light-emitting component of above-mentioned second light-emitting component.

15, a kind of image processing system comprises:

The sub-image supporting body, the carrying sub-image;

Photohead comprises: have first light-emitting component, be arranged on above-mentioned first light-emitting component the 1st direction a side second light-emitting component and be arranged on the substrate of the 3rd light-emitting component of an above-mentioned side of the above-mentioned first direction of above-mentioned second light-emitting component; And the light of above-mentioned first light-emitting component, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component is carried out imaging on above-mentioned sub-image supporting body imaging optical system;

On above-mentioned first direction, above-mentioned first light-emitting component and above-mentioned second light-emitting component are set, on above-mentioned first direction, above-mentioned second light-emitting component and above-mentioned the 3rd light-emitting component are set by the second distance different with above-mentioned first distance by first distance.

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