CN101527769B - Illumination unit, image read apparatus and image forming apparatus - Google Patents
Illumination unit, image read apparatus and image forming apparatus Download PDFInfo
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- CN101527769B CN101527769B CN2008100817534A CN200810081753A CN101527769B CN 101527769 B CN101527769 B CN 101527769B CN 2008100817534 A CN2008100817534 A CN 2008100817534A CN 200810081753 A CN200810081753 A CN 200810081753A CN 101527769 B CN101527769 B CN 101527769B
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Abstract
The present invention relates to an illumination unit, an image read apparatus and an image forming apparatus. The illumination unit for use in an image read apparatus is provided which illuminates a surface of an original document with illumination light, reads an image of the original document by a light receiving element, and adjusts an amount of specular light reflection from the surface of the original document on a light receiving plane of the light receiving element by adjusting at least one of an incident angle of the illumination light and a divergence thereof. It includes a plurality of light source units emitting the illumination light and arranged in a direction so that a direction in which intensity of light emitted from at least one of the light source units closest to a center of the arrangement thereof is to be highest makes a non-perpendicular angle with the direction of arrangement.
Description
Technical field
The present invention relates to a kind of the document that will read is carried out light-struck lighting unit, reads the image-reading device of data on the document and information and such as the image forming apparatus of this class of digital copier.
Background technology
Up to now, for example this class fluorescent tube of xenon lamp or Halogen lamp LED uses as the light source of image-reading device usually.But its deficiency is that power consumption is big and caloric value is big, causes entire image fetch equipment temperature to raise.Its temperature of image-reading device raises and causes the conjugate action of optical system to be affected, and with respect to light receiving element its focus is departed from, and hinders the image of high-quality to form.
In this case, because the LED power consumption is low and caloric value is little, so the new light sources that the lighting unit that uses led light source substitutes fluorescent tube as image-reading device receives concern especially.For instance, TOHKEMY 2006-25303 communique has disclosed a kind of lighting unit that uses led light source, and wherein each LED is by linear array, by a smooth guide way original document is thrown light on.TOHKEMY 2005-278132 communique has disclosed another kind of lighting unit, wherein has the long lens combination of a length to be arranged at the good LED of arrangement and is used for making on the vertical direction that LED arranges the illumination improvement to focus on before.
In addition, TOHKEMY 2005-241681 communique has disclosed a kind of lighting unit, and wherein the light of LED emission throws light on to original document through the reflection of a speculum.The flat 8-317133 communique of TOHKEMY 2004-212592 communique and Te Kai has then disclosed the lighting unit that a kind of LED of making row tilt.
Figure 22 be place original document 2 above it, as the end view of the contact glass 1 of the document platen of image-reading device.As shown in the figure, the lighting apparatus that is had does not read original document 2 its reverberation on the minute surface direction that has more light quantity to take place to reflect that contact on the glass 1 by light receiving element with the equipment of LED or fluorescent tube, its arrangement.This is because being not only the reverberation of original document 2 and the reverberation on platen 1 surface on the minute surface direction all has relatively large reverberation, makes it can't accurately read the image information on the document.In general, lighting unit 10 is provided with on diagonal with respect to original document, and is arranged as light receiving element and only reads reverberation on the vertical direction of original document 2.In this manner, can accurately read the image information on the document 2 just, get rid of its catoptrical influence of surface of platen 1.
In addition, TOHKEMY 2005-234109 communique discloses a kind of document lighting unit that uses LED, and the document lighting unit is arranged as to compare with more light quantity with the central part situation of the document that will read its outer part is thrown light on.In addition, Japan's special permission has disclosed a kind of linear light source device No. 3649939, and wherein a plurality of LED are arranged as in order to reduce the illumination unevenness in the LED orientation.
Even if still have problem but on diagonal, original document thrown light on as mentioned above.Shown in Figure 23 A, for instance, under the situation that will read a books b, can not directly contact with platen such as this class bookbinding part of inboard frame, thereby can be in the vertical direction outgoing of platen surface from the specular light reflections of this bookbinding part.This problem of bringing is, the conventional light quantity when reading document is usually compared, and has more specular light reflections amount directly to be captured in the middle of the light receiving element, just produces so-called halation phenomenon in the bookbinding part when reading this book image.
Another problem is, uses this specular light reflections in the lighting unit of LED to comprise the image of LED itself, thereby around the bookbinding partly that has circular light to swoon in reading as Figure 23 image that B is shown in to come across books b.This phenomenon is easy to betide the situation that lighting unit uses the LED with high directivity, uses as diffused light source, such as the situation of this class fluorescent tube of xenon lamp and be not easy to betide.Be easy to when especially reading glossiness document take place.And halation phenomenon often comes across the situation that the optical system of using long burnt depth is used for down scaling image data.Even if but the LED of high directivity also is not easy to betide the situation such as the single amplification imaging element of the short burnt depth of this class of contact-type image sensor.
The lighting unit of prior art can't address the above problem.For instance, have the lighting unit that the LED of inclination arranges in the flat 8-317133 communique of TOHKEMY 2004-212592 communique and Te Kai, not at address the above problem but the peripheral brightness of its reduction of compensate for optical imaging system.In addition, the LED that the lighting unit disclosed in it just will be whole arranges in the same direction, does not disclose the technological means that influences in order to the specular light reflections that reduces from document itself and platen divided portion.
In addition, have the lighting unit of light source cell and reflector element in No. the 3649939th, the Japan special permission, the inhomogeneities of its surface illumination of document placed of being used to reduce contact with platen does not address the above problem; Therefore also can't reduce influence from the specular light reflections of document itself and platen divided portion.
Summary of the invention
Its purpose of the present invention is, even if provide a kind of document some do not contact with platen yet and obtain the lighting unit that this mode of good reverberation is thrown light on to document from this part.Its another purpose of the present invention is, provides a kind of light that efficiently utilizes to cut down the consumption of energy, and therefore helps energy-conservation and lighting unit and image-reading device that comprises this lighting unit and image forming apparatus that protect the global environment.
Lighting unit according to one aspect of the invention, be used for image-reading device, it throws light on to the surface of original document with illumination light, read the image of described original document by light receiving element, and at least one of incidence angle by adjusting illumination light and divergence thereof adjusted on the light-receiving plane of described light receiving element the specular light reflections amount from described original document surface;
Wherein said lighting unit, comprise and be arranged on the direction and launch a plurality of light source cells of light as described illumination light, it will be that the highest direction becomes on-right angle with the orientation of described light source cell that wherein said light source cell is arranged as from the light intensity of at least one emission of described light source cell, and from the light intensity of each light source cell emission will be that the highest direction is different, and at least one of described light source cell be the center of close described arrangement.
Be preferably, light source cell described in the lighting unit respectively comprise radiative light source body and reflection from all or part of light of described light source body emission to change the reflecting part of its direction, described part light comprises the light of maximum intensity.
Be preferably, a plurality of light source cells are arranged as and satisfy following formula in the lighting unit:
θb＜90°-0.5*θa
Here, θ a is the half-value angle from the light intensity of described light source cell emission, and θ b is that the light intensity from least one emission of described light source cell will be the highest direction and the angle between the orientation.
In addition, be preferably, lighting unit comprises that further reflection is from the mirror of the light of described light source cell emission and of light guide way.
Be preferably, the number of light source cell is an even number in the lighting unit, and each light source cell is symmetric arrays with respect to the center of arranging.
Lighting unit according to a further aspect of the invention, be used for image-reading device, it throws light on to the surface of original document with illumination light, read the image of described original document by light receiving element, and at least one of incidence angle by adjusting illumination light and divergence thereof adjusted on the light-receiving plane of described light receiving element the specular light reflections amount from described original document surface;
Wherein said lighting unit comprises and is arranged on the direction and launches a plurality of light source cells of light as described illumination light that wherein said light source cell is arranged as and satisfies following expression formula:
θa≤D/30
Here, θ a is that D is the length of exit facet in the orientation of described light source cell of described light from the half-value angle of the light intensity of described light source cell emission.In this lighting unit, better be that described light source cell respectively comprises the light source body of launching described light and reflects the light reflecting portion of launching from described light source body.In addition, better be described reflecting part with the direction of described light source cell orientation approximate vertical on reflection from the light of described light source body emission.In addition, better be that described reflecting part comprises the reflecting surface as diffusing surface.Be preferably, the number of light source cell is an even number, and light source cell is symmetric arrays with respect to the center of arranging.
Image-reading device according to a further aspect of the invention comprises: above-mentioned lighting unit; Light signal is converted to the light receiving element of the signal of telecommunication; And make from the optical imaging system of photoimaging on described light receiving element of the surface reflection of the original document that thrown light on by described lighting unit.
Image forming apparatus according to a further aspect of the invention comprises: above-mentioned image-reading device, and the image formation unit that forms image according to the image of the original document that is read by described image-reading device.
Description of drawings
Fig. 1 is the schematic side elevation of the image-reading device of first embodiment of the invention.
Fig. 2 is the schematic side elevation of the image forming apparatus of first embodiment of the invention.
Fig. 3 is the schematic side elevation of another image-reading device of first embodiment of the invention.
Fig. 4 is the schematic side elevation of the lighting unit of first embodiment of the invention.
Fig. 5 schematically shows an example of the lighting unit of first embodiment of the invention and arranges.
Fig. 6 schematically shows another example of the lighting unit of first embodiment of the invention and arranges.
Fig. 7 schematically shows another example of the lighting unit of first embodiment of the invention and arranges.
Fig. 8 schematically shows another example of the lighting unit of first embodiment of the invention and arranges.
Fig. 9 A, Fig. 9 B illustrate half-value angle.
Figure 10 schematically shows another example of the lighting unit of first embodiment of the invention and arranges.
Figure 11 is the schematic side elevation of the image-reading device of second embodiment of the invention.
Figure 12 is the schematic side elevation of another image-reading device of second embodiment of the invention.
The orientation of the light source cell of Figure 13 A, Figure 13 B explanation second embodiment of the invention.
The schematic arrangement and the light exit direction thereof of the light source cell of Figure 14 A, Figure 14 B, Figure 14 C explanation second embodiment of the invention.
Figure 15 is the key diagram of its light exit direction of light source cell of second embodiment of the invention.
Figure 16 schematically shows an example of the lighting unit of second embodiment of the invention and arranges.
Figure 17 schematically shows another example of the lighting unit of second embodiment of the invention and arranges.
Figure 18 schematically shows another example of the lighting unit of second embodiment of the invention and arranges.
Figure 19 schematically shows another example of the lighting unit of second embodiment of the invention and arranges.
Figure 20 A, Figure 20 B are the side sectional views of the lighting unit of third embodiment of the invention.
Figure 21 illustrates the light receiving element and the specular light reflections flux relation between the two of third embodiment of the invention.
Figure 22 schematically shows an example of the lighting unit of prior art and arranges.
Figure 23 A, Figure 23 B schematically show another example of the lighting unit of prior art and arrange.
Figure 24 is the key diagram of problem of the lighting unit of prior art.
Figure 25 is the key diagram of another problem of the lighting unit of prior art.
Embodiment
Various embodiments of the present invention are described with reference to the accompanying drawings.
[first embodiment]
Fig. 1 schematically shows the end view of the image-reading device 100 of first embodiment.Among the figure, the original document 2 that comprises the image that will be read is flat on the contact glass 1 as the document platen.The lighting unit 10 that is provided with after a while explanation below the contact glass 1 carries out sunset illumination in order to the bottom surface to original document 2 thus.In the lighting unit 10, the normal direction of accompanying drawing is provided with a plurality of light source cells 21 (not shown), wherein have small area such as the radiative point-source of light of this class of LED, on this normal direction, carry out the illumination of original document 2 in slot-shaped mode.
Be illuminated the first reflective mirror 3C reflection that reverberation partly is provided with from original document 2 in first sweep volume 3, then second reflective mirror 4A and the three reflective mirror 4B reflection of order in second sweep volume 4, therefore conduction forms the downscaled images of original document image on the imaging plane of light receiving element 6 by condenser lens 5.First reflective mirror 3, the second reflective mirror 4A and the 3rd reflective mirror 4B constitute reflective optical system.
The lighting unit 10 and first sweep volume 3 are combined into one to move, and whole original document 2 on the butt joint contact glass 1 throws light on and scan.Here, the ratio of the translational speed of first and second sweep volumes 3,4 is V: V/2, is scanned document to the optical path length of condenser lens 5 and is set at a constant.
The image-reading device 100 color separation reading images of present embodiment, and comprise to the light path of light receiving element 6 as the color separation parts of RGB filter etc. in the part that is illuminated of original document 2.
In addition, the image-reading device 100 of present embodiment can have difference as shown in Figure 3 to arrange.Specifically, the original document 2 that comprises the image that will be read is flat on the contact glass 1 as the document platen.Be provided with lighting unit 10 in order on its normal direction, thrown light in the bottom surface of original document 2 below the contact glass 1 by slot-shaped mode.Be illuminated the reflection of the reverberation of part through 5 reflective mirror M1 to M5 from original document 2, then conduction forms the downscaled images of original document image on the imaging plane of light receiving element 6 by condenser lens 5.10,5 reflective mirrors of lighting unit, condenser lens 5, and light receiving element 6 is contained in the housing 50 that is driven on the direction of arrow by not shown driver element in conjunction with forming as one.The equipment among Fig. 3 of it should be noted that uses 5 reflective mirrors, but the number of reflective mirror is not limited thereto.
In addition, with regard to color separation, can be selectively colour splitting prism or filter be inserted the color separation that condenser lens 5 and light receiving element 6 are used for red, green, blue between the two.Select as another kind, the light source of red-emitting, green glow, blue light can be opened the illumination of carrying out original document in proper order, perhaps can read the information of document under the situation that the color separation parts are not provided by the black and white mode.
Fig. 2 is the end view that present embodiment comprises the image forming apparatus (photocopier) of the image-reading device 100 among Fig. 1.This image forming apparatus comprises the image-reading device 100 on top and the image formation unit 200 of bottom.Arrangement and Fig. 1 of this image-reading device are similar.For convenience of explanation, the electric wiring between the each several part is connected this and is omitted.
Signal of telecommunication output from the light receiving element 6 of image-reading device 100 is sent to graphics processing unit 1200, by its signal of telecommunication that is converted to each light beam, be used for and be formed into photoreceptor 1100 with corresponding each electrostatic latent image of yellow, aubergine, blue-green and black.
Among the figure, label 1160 expression fusion fuser, 1180 expression cartons, a pair of register roller of 1190 expressions, 1210 expression pallets, 1220 expression intake rollers, S represents the paper as recording medium.
Form for image, photoreceptor 1100 rotates in a clockwise direction by constant speed, and is charged uniformly by charged roller 1100.The face exposure of photoreceptor 1100 forms electrostatic latent image thereon thus in the light beam of light scanning unit 1170.Formed electrostatic latent image is negative sub-image, and manifests image section.
Along with the rotation of photoreceptor 1100, the order by yellow, aubergine, blue-green and black on photoreceptor 1100 surfaces forms each electrostatic latent image.Formed electrostatic latent image is oppositely developed by the Y of Yellow ink powder portion, the aubergine ink powder M of portion, the blue-green ink powder C of portion and the B of powdered black ink portion of rotary developing unit 1130 successively, and manifests as ink powder image (erect image).Ink powder image separately applies roller 114A by transfer voltage successively and is transferred on the transfer belt 1140, and stack forms coloured image thereon.
The carton 1180 of depositing paper S is arranged in the image forming apparatus can shirk mode.When loading onto, paper S topmost one extract by intake roller 1220, and capture at its terminal part by a pair of register roller 1190, register roller 110 was sent to transfer printing unit with paper S when the coloured image on transfer belt 1140 moved to transfer position.In the transfer printing unit paper S be set to transfer belt 1140 on coloured image overlapping, and the action by transfer roll 114B presses on paper S on the coloured image on the transfer belt 1140, thereby coloured image is transferred on the paper S with electrostatic means.Subsequently, paper S is sent to the fusion fuser and makes the coloured image photographic fixing, by the carrying path of not shown guidance set, and is discharged on the pallet 1210 by a pair of exit roller (not shown).
Ink powder image is transferred to photoreceptor 1100, its surface is used for removing from it remaining toner particles, paper scrap etc. by cleaning unit 1150 cleanings at every turn.
It should be noted that image formation unit 200 can be arranged is used for known monochrome colors such as (just) black image and forms.
The following describes lighting unit used in the image-reading device 100 10.Below with reference to accompanying drawing in, the arrow of solid line is represented the highest direction of light of intensity that light source cell 21 is launched.
The lighting unit that the image-reading device of prior art at first is described is used for contrast.Figure 24 is the schematic diagram of optical system of the image-reading device of prior art, wherein can shown in Figure 23 A specular light reflections be incided on the light receiving element.Among Figure 24, document surfaces 2001 is in conjugate action with light receiving element 2002.Each LED2003 that is in document surfaces 2001 belows is in conjugate action at light receiving element 2002 with as the optical imaging system 2004 position PF between the two of condenser lens.Under this state, there is halation to produce in the light receiving element 2002.Direction that light emitted intensity is the highest and the light-emitting face of each LED 2003 are perpendicular.Form image in the PF position because be in LED 2003 one of them light of launching at lighting unit center, thereby have bigger halation in light receiving element 2002, to produce.
Figure 25 illustrates another arrangement of lighting unit 10.As shown in the figure, tilt in the same direction by making each LED 2003, the LED that is in peripheral position has bigger halation to produce.For fear of the generation of this halation phenomenon, each LED 2003 direction is further tilted, but therefore destroy illumination efficiency.
Can reach a conclusion from foregoing, at least be that the direction that will arrange of the LED 2003 near the center of lighting unit 10 is not perpendicular with document surfaces 2001 (all orientations of LED 2003), and comprise that whole LED 2003 of one of them LED at close lighting unit 10 centers needn't be towards identical direction.Can prevent that so the high light of intensity from forming image on light receiving element 2002, thereby reduce halation.That is to say,, can reduce on the light receiving element surface, reduce the halation in the light receiving element 2002 thus from the specular light reflections amount of document to the adjustment of illumination light with respect to the incidence angle of document surfaces.It should be noted that the LED 2003 near lighting unit 10 centers refers to the LED that the most close this center is provided with.
The following describes the lighting unit 10 of present embodiment.
Fig. 4 illustrates wherein a plurality of light source cells 13 and comprises LED respectively and be arranged as and be used for radiative lighting unit 10.Lighting unit 10 is arranged as the orientation and the out of plumb of light source cell 13 its light emission directions with the whole light source cells 13 that are close light source cell 13 its centers of being arranged at least, and the light emission direction of a plurality of light source cells 13 is inequality.Light emission direction that it should be noted that light source cell 13 refers to and the perpendicular direction of light-emitting face of light source cell 13 separately.The orientation of light source cell 13 then refers to the direction that each light source cell 13 is arranged, as shown in Figure 4.
Use the lighting unit 10 of above-mentioned arrangement, can reduce wherein not enter the specular light reflections of light receiving element 6 and the halation that produces with the contacted part of document platen from document.
Fig. 5 illustrates each light source cell 13 another routine lighting unit 10 towards the center of lighting unit 10 wherein is set.Fig. 6 illustrates its another example, and the outside of each light source cell 13 towards lighting unit 10 wherein is set.In the lighting unit 10 of Fig. 5 and Fig. 6, from its center, 13 one-tenth opposite inclinations of the light source cell in right side and left side.This arrangement can reduce the halation in the light receiving element.
In addition, it is different each other that Fig. 7 and Fig. 8 illustrate light source cell 13 its inclinations in wherein lighting unit 10 left sides and right side.This arrangement has not only reduced halation, also the peripheral brightness of compensating focusing lens 5.
θb＜90°-0.5*θa
Wherein, θ a be half-value angle (°) (wherein light source cell 13 light emitted intensity are half this direction of peak, as shown in Figure 9), θ b be as shown in Figure 4 near the light emission direction of the light source cell 13 at lighting unit 10 centers and all between the two the angle of orientation of light source cells 13 (°).
When light source cell 13 is one when having the light source that Lambert distributes, θ a is 60 °, obtains θ b=60 ° by formula (1).In this case, near for the light source cell 13 at lighting unit 10 centers, on its direction and whole orientations of light source cells 13 were vertical direction, its emergent light direction that influences halation was spent with respect to this vertical off setting 30 or is more.Suppose that the highest luminous intensity of intensity is 1, its intensity of the incident light on the light receiving element 2002 is cos30 ° of ≈ 0.87 or littler, therefore reduces about 13% halation.
In addition, in order further to reduce halation, light source cell 13 better is to be arranged as to satisfy following formula (2):
θb＜90°*θa
The light source of the Lambert distribution of above-mentioned expression formula is satisfied in use, can reduce about 50% halation.
It should be noted that light source cell 13 can use the light source with directivity.This result further reduces halation, and increases the degree of freedom that light source cell 13 is arranged.
In addition, lighting unit 10 can be arranged as light that light source cell 13 as shown in figure 10 launched through reflective mirror or the reflection of light guide way, utilizes the high light of intensity as illumination light, improves illumination efficiency.In addition, use reflective mirror or light guide way to allow light direction that bigger inclination is arranged, thereby further reduce halation.Here, the light guide way refers to by utilizing total reflection with the optical element of light from the end guiding other end.
In addition, better be that light source cell 13 is not the center that is arranged at lighting unit 10, but be arranged at its excentral position.This is because the light source cell 13 at lighting unit 10 centers need be set to have bigger inclination, causes the high this problem of luminous intensity on the incline direction.Therefore, the number of light source cell 13 better is an even number, so that each light source cell is with respect to the center symmetric arrays of lighting unit 10.
And light source cell 13 better is to use such as this class of white light LEDs LED.LED has than such as the higher light service efficiency of this class fluorescent tube of xenon lamp, and realizes lower power consumption.Because its high directivity can suitably tilt by the adjacent light that it is configured such that high-strength light, further reduces halation.
In addition, light source cell 13 can be read as the required colour information of image information of obtaining color separation by using white light LEDs.Generally, when reading colour information, colored blur or halation take place probably in the middle of the image that is duplicated, this can cause bigger reduction to picture quality.But use this lighting unit 10, can reduce the halation of any wavelength light.
In addition, light source cell 13 can be the light source of the different colouramas of emission (, red (R), green (G), blue (B) corresponding with the filter color of light receiving element).Use this light source cell can improve the light service efficiency, and read color image information.Its wavelength bandwidth of LED is very narrow in this example, thereby the color of light does not need to be limited to three kinds of colors.Also can be by the light source cell in order to emission different colours light is provided in addition, improve the color rendition degree in the color information of original document.
[second embodiment]
The following describes the second embodiment of the present invention.Present embodiment is identical with first embodiment, is used to reduce on the light receiving element surface to suppress halation by the incidence angle of adjusting illumination light thus from the specular light reflections amount of document surfaces.
Figure 11 is the schematic side elevation of the image-reading device 101 of present embodiment.In the image-reading device 101, the original document 2 with the image that will be read is flat on the contact glass 1 as the document platen.The lighting unit 20 that is provided with an explanation after a while below the contact glass 1 carries out sunset illumination in order to the bottom surface to original document 2 thus.In the lighting unit 20, the normal direction of accompanying drawing is provided with a plurality of light source cells 21 (Figure 13), wherein have small area such as the radiative point-source of light of this class of LED, on this normal direction, carry out the illumination of original document 2 in slot-shaped mode.
Be illuminated the first reflective mirror 3C reflection that reverberation partly is provided with from original document 2 in first sweep volume 3, then second reflective mirror 4A and the three reflective mirror 4B reflection of order in second sweep volume 4, therefore conduction forms the downscaled images of original document image on the imaging plane of light receiving element 6 by condenser lens 5.First reflective mirror 3, the second reflective mirror 4A and the 3rd reflective mirror 4B constitute reflective optical system.
The lighting unit 20 and first sweep volume 3 are combined into one to move, and whole original document 2 on the butt joint contact glass 1 throws light on and scan.Here, the ratio of the translational speed of first and second sweep volumes 3,4 is V: V/2, is scanned document surfaces to the optical path length of condenser lens 5 and is set at constant.
Light receiving element 6 is 3 row ccd sensors of single-chip, be arranged with by 3 row it on have redness (R) respectively, photo- electric conversion element 6A, 6B, the 6C of the dichroic filter of green (G) and blueness (B).Light receiving element 6 is the signal of telecommunication according to the scanning to original document 2 with the image transitions that forms on the imaging plane.Thereby original document 2 is to carry out the color separation of Red Green Blue and read through light receiving element 6.
The image-reading device 101 color separation reading images of present embodiment, and comprise to the light path of light receiving element 6 as the color separation parts of RGB filter etc. in the part that is illuminated of original document 2.
In addition, the image-reading device 101 of present embodiment can have difference as shown in figure 12 to arrange.Specifically, the original document 2 that comprises the image that will be read is flat on the contact glass 1 as the document platen.Be provided with lighting unit 20 in order on its normal direction, thrown light in the bottom surface of original document 2 below the contact glass 1 by slot-shaped mode.Be illuminated the reflection of the reverberation of part through 5 reflective mirror M1 to M5 from original document 2, then conduction forms the image of original document on the imaging plane of light receiving element 6 by condenser lens 5.20,5 reflective mirrors of lighting unit, condenser lens 5 and light receiving element 6 are contained in the housing 50 that is driven on the direction of arrow by not shown driver element in conjunction with forming as one.The equipment among Figure 12 of it should be noted that uses 5 reflective mirrors, but the number of reflective mirror is not limited thereto.
In addition, with regard to color separation, can be selectively colour splitting prism or filter be inserted the color separation that condenser lens 5 and light receiving element 6 are used for red, green, blue between the two.Select as another kind, red, green, blue light source can be opened the illumination of carrying out original document in order, perhaps can read the information of document under the situation that the color separation parts are not provided by the black and white mode.
The following describes the lighting unit 20 of second embodiment.
In the lighting unit 20, it is not perpendicular with the orientation of whole light source cells 21 that each light source cell 21 is arranged as the highest direction of the luminous intensity of each light source cell 21.Better be in the middle of whole light source cells 21 of lighting unit 20, have at least a light source cell 21 to arrange in the above described manner near lighting unit 20 centers.
As mentioned above, original document and platen can produce halation thereon when the specular light reflections of contacted part does not incide on the light receiving element 6.Generally, the light emitted intensity of light source cell 21 with the perpendicular direction of the exit plane of light source cell 21 on the highest.That is to say that its each light source cell on every side of the center of condenser lens 5 residing lighting units is easy to generate halation.Present embodiment its be intended that by will be at least light source cell near lighting unit 20 centers be arranged as original document and platen not the specular light reflections of contacted part can not be directly incident on the light receiving element 6 by condenser lens 5, suppress halation.
Specifically, be an on-right angle in order to make direction of light that wherein intensity is the highest and whole orientations of light source cells 21, each light source cell 21 was arranged as before radiative light source body 21A and comprises reflecting part 22.Reflecting part 22 reflection is from the part light that comprises the light LA that wherein intensity is the highest of light source body 21a, make it with respect to the perpendicular direction of the exit plane of light source body 21A by predetermined angle tilt.
Figure 14 A to Figure 14 C illustrates the arrangement example of the light source cell 21 of present embodiment.Reflecting part 22 is arranged at before the light source body 21a, is used to reflect from the part light that comprises the light LA that wherein intensity is the highest of light source body 21a and makes it.Reflecting part 22 is set to adjacent, allows the size of reflecting part 22 to reduce with the exit plane of light source body 21a.
Figure 14 A illustrates 21 orientation right sides, the routine reflecting part 22 reflection source unit situation of whole light basically.The light of reflecting part 22 reflections comprises the central the highest light LA of intensity of light that light source body 21a is launched.
Figure 14 B illustrates the wherein situation of half side almost half light of another routine reflecting part 22 reflection source unit, 21 orientations.The light of reflecting part 22 reflections comprises the central the highest light LA of intensity of light that light source body 21a is launched.
Similar with Figure 14 A, Figure 14 C illustrates the wherein situation of half side whole light of routine reflecting part 22 reflection source unit, 21 orientations.The light of reflecting part 22 reflections comprises the central the highest light LA of intensity of light that light source body 21a is launched.Among Figure 14 C, reflecting part 22 is arranged as and has curvature (convex surface), thereby light is reflected in the same direction.And the curvature of reflecting part 22 can opposite with the situation among Figure 14 C (concave surface) be used for convergence reflex light, and perhaps the surface of reflecting part 22 can form aspheric shape or be used to obtain the surface of the free form of required reflectivity.
Here, the light source cell 21 near lighting unit 20 centers better is to be arranged as to satisfy following formula (3):
θb＜90°-0.5*θa
Wherein, θ a be above-mentioned half-value angle (°), θ b be intensity is the highest in the middle of the light launched of light source body 21a light through the direction of reflecting part 22 reflections and all between the two the angle of orientation of light source cells 13 (°) (Figure 15).
For instance, half-value angle θ a is 50 °, and θ b is under 65 ° or the littler situation, be directly incident on light intensity on the light receiving element 6 can be reduced to peaked half or lower, reduce the halation on it thus.
When each light source cell 21 is that θ a is 60 °, thereby obtains θ b=60 ° by formula (3) when having the light source of Lambert distribution.In this case, near the direction of light that influences halation of its emission for the light source cell 21 at lighting unit 20 centers with respect to perpendicular direction skew 30 degree or more of the orientation of whole light source cells 21.Suppose that its intensity of light that wherein intensity is the highest is 1, its intensity of light that is incident on the light receiving element 6 is cos30 ° of ≈ 0.87 or littler, therefore makes the halation amount reduce about 13%.
In addition, better be that the number of light source cell 21 in the lighting unit 20 is an even number.This is because lighting unit 20 need evenly throw light on to original document, thereby each light source cell 21 must be with respect to lighting unit 20 center symmetric arrays.When the number of light source cell is odd number, for the whole light source cell 21 of symmetric arrays, a single source unit 21 need be arranged at the center of condenser lens 5 residing lighting units 20, therefore be easy to generate halation.Thereby, can avoid light source cell 21 being set by the light source cell 21 that the even number number is provided, thereby avoid taking place halation at the center of lighting unit 20 annex.
In addition, light source cell better is to use such as this class of white light LEDs LED.It is low that LED has ratio such as this class fluorescent tube of xenon lamp higher light service efficiency and power consumption.Because its higher directivity can suitably tilt further to reduce halation by the adjacent light of the light that LED is set to wherein intensity is the highest.
In addition, light source cell 21 can be read as and obtain the required colouring information of color image information by using white light LEDs.Generally, when reading colouring information, color is blured or halation takes place in the image that reduction reappears probably, can cause picture quality to have substantial degradation.But can reduce the halation of any wavelength light by using this lighting unit 20.
In addition, light source cell 21 can be the monochromatic source of emission different colours (corresponding with the color promptly red (R) of the filter of light receiving element, green (G), blue (B)) light.Can be by arranging this light source cell, the illumination light of synthetic multiple color is used for white-light illuminating on original document.In this case, and the light source cell that can be arranged as by multiple color read document successively.
In addition, light source cell 21 can be the light source cell of emission different colours (corresponding with the color promptly red (R) of the filter of light receiving element, green (G), blue (B)) light.Use this light source cell can improve the light service efficiency, and read color image information.In this case, its wavelength bandwidth of LED is narrower, so the color of light is not necessarily limited to 3 kinds of colors.Can improve the color rendition degree of the colouring information of original document by using the light source cell of other emission different colours light.
The concrete arrangement of the lighting unit 20 of present embodiment is described below with reference to Figure 16 to Figure 19.
In the lighting unit 20 of Figure 16, the reflecting part 22 of each light source cell 21 is arranged as the center in the face of lighting unit 20, then is arranged as the outside in the face of lighting unit 20 among Figure 17.Both all are arranged as the center reversed dip of the reflecting part 22 in right side and left side with respect to lighting unit 20 lighting unit 20.This arrangement can reduce halation.
As another selection, as shown in Figure 18, lighting unit 20 can be arranged as the left side and each reflecting part 22 its inclinations on right side different each other.This arrangement not only reduces halation, the also peripheral brightness of compensate for optical imaging system, thus obtain uniform illumination light.
Among Figure 19, lighting unit is arranged as the light by reflective mirror or 21 emissions of light guide way reflection source unit.This allows the light that wherein intensity is high is used as illumination light, improves illumination efficiency thus.In addition, use reflective mirror or light guide way can make direction of light that bigger inclination is arranged, thereby further reduce halation.Here, the light guide way is meant by using total reflection to make light be directed to the optical element of the other end from an end wherein.
In sum, have good reading quality and reduce the image-reading device 101 that halation produces by using the lighting unit 20 of present embodiment, can providing.In addition, optical imaging system halation, that be used to form the image that dwindles often occurs, also halation can be suppressed to be insignificant level in actual the use even if image-reading device 101 has.
[the 3rd embodiment]
The following describes the third embodiment of the present invention.Other are all identical with first embodiment except lighting unit 10 is substituted by lighting unit 30 for present embodiment.Therefore only lighting unit 30 is described below.Present embodiment be used for by adjust illumination light with respect to the divergence of the document surfaces that will be read to reduce its specular light reflections on light receiving element 2002, reduce the halation on the light receiving element.
Figure 20 A illustrates comprising the lighting unit 30 that is arranged in a plurality of light source cells 31 of delegation on single substrate 34.As shown in the figure, light source cell 31 is light source cells of reflection type, by light source body 31a emission light, and by reflecting part 32 reverberation, thus optical illumination is carried out on the surface of document.Present embodiment light source body 31a uses LED.Reflecting part 32 has the surface that is parabolic shape in the lighting unit 30, and light source body 31a places the focal position of this reflecting part 32, thus allow from the light of this paraboloidal focus emission towards on the substantially parallel direction of document, promptly with the direction of document surfaces perpendicular on outgoing.Therefore, even if the Lambert diffused light that very undersized light source cell 31a launches on the direction of perpendicular also can be thrown light on to document surfaces, and the light that light source cell 31a is launched is efficiently as illumination light.
When image-reading device belongs to this situation of optical system with the view data that is used to dwindle document, as shown in figure 22,, need on light receiving element, not assemble specular light reflections for fear of the generation of halation.
Avoid on light receiving element, assembling the situation of specular light reflections below with reference to Figure 21 explanation.
Figure 21 illustrates a plurality of CCD pixels 35 and is arranged in light receiving element 6 on the substrate 36.Among the figure, converging light L1, L2 from the specular light reflections of books b among expression Figure 22 assemble on not shown condenser lens.When converging light L1, L2 assembled on CCD pixel 35, its intensity of light that incides above it was too high, can produce above-mentioned halation.
When the converging light L1, the L2 that assemble on the CCD pixel 35 meaned when the very close document 2 of light source cell 31 surperficial, CCD pixel 35 and light source cell 31 were in the conjugate relation state by the effect of condenser lens.Gather on the CCD pixel 35 for fear of converging light L1, L2, light source cell 31 has to place the position away from document surfaces, thereby converging light L1, L2 are in position, the front imaging of light receiving element 6.
Here, for the position that makes light source cell 31 away from document surfaces, the illumination light of document 2 is set at parallel broadening light.When illumination light was set at directional light, light source cell 31 can be taken as apart from document 2 infinities.Therefore, converging light L1, L2 assemble in the focal position of condenser lens, and disperse fuzzy on light receiving element 6 (CCD pixel 35).Thereby, can reduce the intensity of incident light on each CCD pixel 35, avoid the halation on it thus.
Among Figure 21, Δ LB represents that light receiving element 6 is to the distance of the focal position PS of converging light L1, L2 when any distance with document when light source cell 31 places, and δ represents converging light L1, the divergence of L2 on light receiving element 6 when the PS=Δ LB of focal position.
Δ LB and δ relation is between the two represented by following formula (4):
δ＝2ΔL
B·NA
img
ΔL
B＝δF(1+|m|)
Wherein f is the focal length of condenser lens, and F is the f number, and m is the multiplication factor of optical imaging system.
In addition, the multiplication factor m ' of optical system and δ relation is between the two represented by following formula (5):
Wherein m ' is the multiplication factor of optical imaging system, allows converging light L1, L2 departing from the position gathering that light receiving element 6 reaches Δ LB.
With the m ' in the formula (4), document surfaces and light source cell 31 distance, delta LA are between the two represented by following formula (6):
Thereby when the 31 pairs of documents of light source cell by the Δ LA that obtains at a distance of formula (6) with document surfaces threw light on, the broadening of its specular light reflections on light receiving element 6 was δ.For instance, suppose that divergence δ reaches CCD pixel 35 at more than 6 times of the Pixel Dimensions P in the orientation, the ratio of its area is 36 to 1, thereby the ratio of light quantity is 1/36.Specular light reflections can be reduced to about 3% or littler.Thereby, can suppress the generation of halation, thus the reading quality image of document 2 preferably.
δ and Pixel Dimensions P relation are between the two represented by following formula (7):
δ＝6P
By the relation of formula (7), Δ LA is represented by following formula (8):
Make light source cell 31 be positioned to satisfy the position of formula (8), make specular light reflections on light receiving element 6, quite to disperse, thereby the image that can not influence document reads.
Below table 1 the Δ LA that focal distance f, f are counted the multiplication factor m of F, condenser lens and Δ LB, m ' and obtained with Pixel Dimensions P computing is shown.
[table 1]
| F | 4.2 | 5.6 | 5.0 | 6.0 |
| f[mm] | 45 | 45 | 18 | 18 |
| P[mm] | 0.0047 | 0.0047 | 0.00525 | 0.00525 |
| δ[mm] | 0.0282 | 0.0282 | 0.0315 | 0.0315 |
| m | 0.11102 | 0.11102 | 0.12400 | 0.12400 |
| ΔLB[mm] | 0.132 | 0.175 | 0.177 | 0.212 |
| m’ | 0.10810 | 0.10712 | 0.11417 | 0.11220 |
| ΔLA[mm] | 10.965 | 14.753 | 12.505 | 15.269 |
F=5.0 in the table 1 is compared with F=5.6, and obviously the f number of condenser lens is more little, and the depth of focus of optical imaging system is more little, thereby required distance, delta LA reduces.In the contrast, by F=5.0 and F=5.6 more as can be known, when each f number near the time, the focal length of condenser lens is long more, the depth of focus of optical imaging system is long more, thereby required Δ LA increases.In addition, by F=5.6 and F=6.0 more as can be known, distance, delta LA also is directly proportional with the multiplication factor m of optical imaging system.Therefore, multiplication factor m is more little, and the depth of focus is more little, thereby required distance, delta LA reduces.
According to table 1, Δ LA is set at 15mm or more for a long time, can disperse on light receiving element 6 from converging light L1, the L2 of the specular light reflections of document surfaces.
Increase that it should be noted that distance, delta LA can be equal to reducing of the light emitted diffusion angle of the light source cell 31 of lighting unit 30.
Figure 20 B illustrates the enlarged drawing of light source cell 31.The exit plane of light source body 31a is equal to the light of a pseudo-luminous position O emission by the light of unspecified angle emission.The exit plane of light source cell 31 is represented by following formula (9) to the distance, delta LA of pseudo-luminous position O:
Wherein D is the length of exit plane in light source cell 31 orientations.
As shown in the formula (10) distance, delta LA is 15mm or more for a long time, then has following formula (11) to set up:
ΔLA≥15(10)
θa≤D/30(11)
Wherein θ a (rad) is the half-value angle of the light emitted intensity of light source cell 31, and D is the length (millimeter) of exit plane in the orientation of light source cell 31.
Thereby, satisfying the lighting unit 30 of formula (11) by use, can on light receiving element 6, disperse from converging light L1, the L2 of the specular light reflections of document surfaces.
It should be noted that half-value angle θ a refers to half the direction that light source cell 31 light emitted intensity wherein are peaks, and refer to and the exit plane of light source cell 31 angle with respect to vertical direction.For instance, when the length D of exit plane was 7mm, according to formula (11), reflecting part 32 forms and makes half-value angle θ a was 0.23rad (13 °) or littler.Therefore, converging light L1, the L2 from the specular light reflections of document surfaces can disperse on light receiving element 6.
Provide diffusion plane to reflecting part 32, can reduce the intensity of specular light reflections more effectively, irregular luminous because exit plane of light source cell 31 takes place for it.
And light source cell 31a and reflecting part 32 in light source cell 31 provide fluorophor between the two, and can obtain white light easily, thereby read color document.
In addition, light source cell 31 can be the monochromatic source of emission different colours (corresponding with the color promptly red (R) of the filter of light receiving element, green (G), blue (B)) light.Can be by arranging this light source cell, the illumination light to the synthetic multiple color of original document is used for white-light illuminating.In this case, and the light source cell that can be arranged as by multiple color read document successively.
It should be noted that, when lighting unit 30 must satisfy when reducing the requirements at the higher level of halation, can through type (7) to formula (11) Δ LA be set at bigger value, thereby the incidence angle of light on document surfaces is more near vertical direction, and, further reduce halation by increasing the divergence δ of converging light on light receiving element 6.
Should be understood that image-reading device of the present invention is not limited to wherein contacts the equipment of glass 1 as the document platen.The present invention is applied to that first and second sweep volumes 3,4 wherein are fixed in arbitrary position so that also can obtain same effect when reading the image-reading device of file and picture in the feeding document.
The lighting unit that provides according to the preferred embodiment of the present invention, be used for image-reading device, it throws light on to the surface of original document with illumination light, read the image of original document by light receiving element, and the incidence angle by adjusting illumination light and divergence are wherein adjusted one of at least on the sensitization plane of light receiving element the specular light reflections amount from the original document surface.
Another preferred embodiment according to the present invention, lighting unit be arranged as be included on the direction arrange and emission light as a plurality of light source cells of illumination light.Each light source cell is arranged as from each light source cell direction that wherein its intensity of light of at least one light source cell emission is the highest and the orientation of each light source cell and is on-right angle, and described each light source cell is at least one light source cell center of close this arrangement wherein.
In the above-mentioned lighting unit, can reduce to incide specular light reflections amount on the light receiving element by adjusting from the angle of the illumination light of light source cell emission from the original document surface.Can reduce image like this and read the middle halation that produces, thereby realize that preferable image reads.
According to the present invention in the lighting unit of another preferred embodiment, each light source cell is arranged as respectively and comprises all or part of light that radiative light source body and reflection source body launched to change the reflecting part of its direction, and described part light comprises maximum intensity light.This arrangement can be by adjusting reflecting part, suitably sets the angle of the light (illumination light) that light source cell launches.
In the lighting unit of another preferred embodiment, a plurality of light source cells are arranged as and satisfy following formula according to the present invention:
θb＜90°-0.5*θa
Wherein, θ a is the half-value angle of light emitted its intensity of light source cell, and θ b is light source cell direction and an orientation angle between the two that wherein at least one its intensity of light of launching is the highest.
This arrangement can reduce to incide from the original document surface specular light reflections amount on the light receiving element by the angle of adjusting the illumination light that light source cell launches.Can reduce image like this and read the middle halation that produces, thereby realize that preferable image reads.
Another preferred embodiment according to the present invention, lighting unit be arranged as comprise reflective mirror that the reflection source unit is light emitted and light guide way one of them.In this lighting unit, can freely set the light emitted direction of light source cell, so illumination efficiency and energy efficiency raising.And the increase that is used for the degree of freedom of direction initialization makes the flexibility of each arrangement of parts of lighting unit increase, thereby the size of entire lighting unit is reduced.
Another preferred embodiment according to the present invention, lighting unit are arranged as and comprise the light source cell that is the even number number of symmetric arrays with respect to the center of arranging.This arrangement can make lighting unit evenly the throw light on original document and the peripheral brightness of compensate for optical imaging system.
The image-reading device that another preferred embodiment provides according to the present invention comprises: above-mentioned lighting unit; Light signal is converted to the light receiving element of the signal of telecommunication; And the optical imaging system that on light receiving element, makes its surperficial reverberation imaging of original document of throwing light on by lighting unit.The image-reading device of Pai Lieing as mentioned above can be realized higher light service efficiency, lower power consumption and lower caloric value with respect to having such as the image-reading device of the prior art of this class fluorescent tube of xenon lamp.
The image forming apparatus that another preferred embodiment provides according to the present invention comprises above-mentioned image-reading device, and the image of the original document that reads according to image-reading device forms the image formation unit of an image.This image forming apparatus can be exported the image than good quality, reduces the halation that specular light reflections produced owing to document surfaces significantly, and can reduce power consumption.
Another preferred embodiment according to the present invention, lighting unit be arranged as be included on the direction arrange and emission light as a plurality of light source cells of illumination light, wherein each light source cell is arranged as from each light source cell direction that wherein its intensity of light of at least one light source cell emission is the highest and the orientation of each light source cell and is an on-right angle, and different each other from the direction that its intensity of light of the emission of light source cell separately is the highest, described each light source cell is at least one light source cell center of close this arrangement wherein.
This arrangement can reduce to incide from the original document surface specular light reflections amount on the light receiving element by adjusting from the angle of the illumination light of light source cell emission.Can reduce image like this and read the middle halation that produces, thereby realize that preferable image reads.
According to the present invention in the lighting unit of another preferred embodiment, each light source cell is arranged as respectively and comprises all or part of light that radiative light source body and reflection source body launched to change the reflecting part of its direction, and described part light comprises maximum intensity light.This arrangement can be by adjusting reflecting part, suitably sets the angle of the light (illumination light) that light source cell launches.
In the lighting unit of another preferred embodiment, a plurality of light source cells are arranged as and satisfy following formula according to the present invention:
θb＜90°-0.5*θa
Wherein, θ a is the half-value angle of light emitted its intensity of light source cell, θ b is light source cell direction and an orientation angle between the two that wherein at least one its intensity of light of launching is the highest, and described each light source cell is at least one light source cell center of close this arrangement wherein.
This arrangement can reduce to incide from the original document surface specular light reflections amount on the light receiving element by the angle of adjusting the illumination light that light source cell launches.Can reduce image like this and read the middle halation that produces, thereby realize that preferable image reads and higher illumination efficiency.
Another preferred embodiment according to the present invention, lighting unit be arranged as further comprise reflective mirror that the reflection source unit is light emitted and light guide way one of them.This value of joining can freely be set the light emitted direction of light source cell, so illumination efficiency and energy efficiency raising.And the increase that is used for the degree of freedom of direction initialization makes the flexibility of each arrangement of parts of lighting unit increase, thereby the size of entire lighting unit is reduced.
Another preferred embodiment according to the present invention, lighting unit are arranged as and comprise the light source cell that is the even number number of symmetric arrays with respect to the center of arranging.This arrangement can make lighting unit evenly the throw light on original document and the peripheral brightness of compensate for optical imaging system.
In addition, the another kind of image-reading device that another preferred embodiment provides according to the present invention comprises: above-mentioned lighting unit; Light signal is converted to the light receiving element of the signal of telecommunication; And the optical imaging system that on light receiving element, makes its surperficial reverberation imaging of original document of throwing light on by lighting unit.
This image-reading device is compared with for example using the image-reading device of the prior art of this class fluorescent tube of xenon lamp, can have higher light service efficiency, lower power consumption and lower caloric value.
The another kind of lighting unit that another preferred embodiment provides according to the present invention, be included on the direction arrange and emission light as a plurality of light source cells of illumination light, wherein each light source cell is arranged as and satisfies following formula:
θa≤D/30
Wherein, θ a is the half-value angle of light emitted its intensity of light source cell, and D is the length of light-emitting face in the orientation of light source cell.
This arrangement can reduce to incide from the original document surface specular light reflections amount on the light receiving element by the divergence of adjusting the illumination light that light source cell launches.Can reduce image like this and read the middle halation that produces, thereby realize that preferable image reads.
In the lighting unit of another preferred embodiment, each light source cell is arranged as respectively and comprises radiative light source body and the light emitted reflecting part of reflection source body according to the present invention.
In the lighting unit of another preferred embodiment, reflecting part is arranged as the light that the reflection source body is launched on the direction of the perpendicular of light source cell orientation according to the present invention.This arrangement can suitably be provided with the divergence that reflecting part is adjusted the illumination light that light source cell launches.
In the lighting unit of another preferred embodiment, reflecting part is arranged as the reflecting surface that is included as diffusing surface according to the present invention.In this arrangement, its direction of the illumination light that each light source cell is launched is irregular.Thereby like this can be with the level that halation is suppressed to and for example this class fluorescent tube situation of xenon lamp is equal to basically owing to specular light reflections produced.
Another preferred embodiment according to the present invention, lighting unit are arranged as and comprise the light source cell that is the even number number of symmetric arrays with respect to the center of arranging.Evenly the to throw light on original document and the peripheral brightness of compensate for optical imaging system of the lighting unit of Pai Lieing as mentioned above.
The another kind of image-reading device that another preferred embodiment provides according to the present invention comprises: above-mentioned lighting unit; Light signal is converted to the light receiving element of the signal of telecommunication; And the optical imaging system that on light receiving element, makes its surperficial reverberation imaging of original document of throwing light on by lighting unit.
This image-reading device is compared with for example using the image-reading device of the prior art of this class fluorescent tube of xenon lamp, can have higher light service efficiency, lower power consumption and lower caloric value.
The present invention has obtained explanation according to one exemplary embodiment, but is not limited to this.Should be understood that those skilled in the art can carry out various modifications to illustrated embodiment under the situation that does not deviate from the scope of the invention that limits as following claim.
Claims (11)
1. lighting unit, be used for image-reading device, it throws light on to the surface of original document with illumination light, read the image of described original document by light receiving element, it is characterized in that the incidence angle by adjusting illumination light and at least one of divergence thereof are adjusted on the light-receiving plane of described light receiving element the specular light reflections amount from described original document surface;
Wherein, described lighting unit comprises and is arranged on the direction and launches a plurality of light source cells of light as illumination light, wherein
It will be that the highest direction becomes on-right angle with the orientation of described light source cell that described light source cell is arranged as from the light intensity of at least one emission of described light source cell, and from the light intensity of each light source cell emission will be that the highest direction is different, and at least one of described light source cell be the center of close described arrangement.
2. lighting unit as claimed in claim 1 is characterized in that,
Described light source cell respectively comprise radiative light source body and reflection from all or part of light of described light source body emission to change the reflecting part of its direction, described part light comprises the light of maximum intensity.
3. lighting unit as claimed in claim 1 is characterized in that,
Described a plurality of light source cell is arranged as and satisfies following expression formula:
θb＜90°-0.5*θa
Here, θ a is the half-value angle from the light intensity of described light source cell emission, and θ b is that the light intensity from least one emission of described light source cell will be the highest direction and the angle between the orientation.
4. lighting unit as claimed in claim 1 is characterized in that, further comprises
Reflection from the mirror of the light of described light source cell emission and light guide way.
5. lighting unit, be used for image-reading device, it throws light on to the surface of original document with illumination light, read the image of described original document by light receiving element, it is characterized in that, incidence angle by adjusting illumination light and at least one of divergence thereof are adjusted on the light-receiving plane of described light receiving element the specular light reflections amount from described original document surface
Wherein, described lighting unit comprises and is arranged on the direction and launches a plurality of light source cells of light as described illumination light that described light source cell is arranged as and satisfies following expression formula:
θa≤D/30
Here, θ a is that D is the length of exit facet in the orientation of described light source cell of described light from the half-value angle of the light intensity of described light source cell emission.
6. lighting unit as claimed in claim 5 is characterized in that,
Described light source cell respectively comprises the light source body of launching described light and reflects from the light reflecting portion of described light source body emission.
7. lighting unit as claimed in claim 6 is characterized in that,
Described reflecting part with the direction of described light source cell orientation approximate vertical on reflection from the light of described light source body emission.
8. lighting unit as claimed in claim 6 is characterized in that,
Described reflecting part comprises the reflecting surface as diffusing surface.
9. as each the described lighting unit in claim 1 and 5, it is characterized in that,
The number of described light source cell is an even number; And
Described light source cell is symmetric arrays with respect to the center of described arrangement.
10. an image-reading device is characterized in that, comprising:
As each the described lighting unit in claim 1 and 5;
Light signal is converted to the light receiving element of the signal of telecommunication; And
Make from the optical imaging system of photoimaging on described light receiving element of the surface reflection of the original document that thrown light on by described lighting unit.
11. an image forming apparatus is characterized in that, comprising:
Image-reading device as claimed in claim 10; And
Form the image formation unit of image according to the image of the original document that reads by described image-reading device.
Applications Claiming Priority (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007-054740 | 2007-03-05 | ||
| JP2007054740A JP5032864B2 (en) | 2007-03-05 | 2007-03-05 | Illumination unit, image reading apparatus, and image forming apparatus |
| JP2007054740 | 2007-03-05 | ||
| JP2007058195 | 2007-03-08 | ||
| JP2007058195A JP4972432B2 (en) | 2007-03-08 | 2007-03-08 | Illumination unit, image reading apparatus, and image forming apparatus |
| JP2007-058195 | 2007-03-08 | ||
| JP2007-063932 | 2007-03-13 | ||
| JP2007063932A JP2008227961A (en) | 2007-03-13 | 2007-03-13 | Illumination unit and image reader using the same, and image forming apparatus |
| JP2007063932 | 2007-03-13 |
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| CN101527769A CN101527769A (en) | 2009-09-09 |
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| JP5267239B2 (en) * | 2008-12-26 | 2013-08-21 | 株式会社リコー | Image reading apparatus, image reading method, image reading program, and recording medium |
| JP2011004288A (en) | 2009-06-19 | 2011-01-06 | Konica Minolta Business Technologies Inc | Image reader |
| CN102894951B (en) * | 2012-10-26 | 2015-07-08 | 成都海瑞康科技有限公司 | Optical laryngoscope |
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| CN1645894A (en) * | 2004-01-21 | 2005-07-27 | 佳能株式会社 | Image reading apparatus and image printing apparatus using the same |
| EP1615418A1 (en) * | 2004-07-09 | 2006-01-11 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
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| JP2005027082A (en) * | 2003-07-03 | 2005-01-27 | Ricoh Co Ltd | Original image reader and image forming device provided with the original image reader |
| JP2006245955A (en) * | 2005-03-02 | 2006-09-14 | Ricoh Co Ltd | Image reader illumination distribution |
| JP2008067276A (en) * | 2006-09-11 | 2008-03-21 | Canon Inc | Image reading apparatus, and printed circuit board used therefor |
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| CN1645894A (en) * | 2004-01-21 | 2005-07-27 | 佳能株式会社 | Image reading apparatus and image printing apparatus using the same |
| EP1615418A1 (en) * | 2004-07-09 | 2006-01-11 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
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| JP特开2004-212592A 2004.07.29 |
| JP特开2005-234109A 2005.09.02 |
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