CN201293863Y

CN201293863Y - Photographic lens and photographic device

Info

Publication number: CN201293863Y
Application number: CNU2008201371371U
Authority: CN
Inventors: 浅见太郎
Original assignee: Fujinon Corp
Current assignee: Fujinon Corp
Priority date: 2007-10-05
Filing date: 2008-09-19
Publication date: 2009-08-19
Anticipated expiration: 2018-09-19
Also published as: TWM354745U; JP5042767B2; JP2009092797A

Abstract

The utility model provides a camera lens and a camera device, aiming to realize low F value, wide angles and low cost on one hand, and keep sound optical property and obtain fine images reaching corners of the images on the other hand. The camera lens (1) is equipped with a crescent first lens (L1), a second lens (L2), a third lens (L3), an aperture, a joint lens (LC) and a sixth lens (L6), wherein the crescent first lens (L1) is provided with negative focal power, and a concave surface towards the image side, the second lens (L2) close to an optical axis is in dual-convex shape and is provided with at least one non-spherical surface, the third lens (L3) is provided with positive focal power, the joint lens (LC) is formed by jointing a fourth lens (L4) and a fifth lens (L5) which are provided with positive focal power and negative focal power respectively, and the integral joint lens (LC) is provided with positive focal power, and the sixth lens (L6) with positive focal power is provided with at least one non-spherical surface. Besides, the third lens (L3) is made of glass, and the abbe number (gamma 3) relative to the d line meets a conditional expression (1): gamma 3 < 30...(1).

Description

Imaging lens system and camera head

Technical field

The utility model relates to a kind of imaging lens system and camera head, relates in more detail a kind ofly being suitable at the imaging lens system of uses such as the vehicle mounted camera that uses CCD (Charge Coupled Device) or CMOS imaging apparatuss such as (Complementary Metal OxideSemiconductor), used for mobile terminal camera, monitoring camera and possessing the camera head of this imaging lens system.

Background technology

In recent years, the very miniaturization of imaging apparatus such as CCD or CMOS and high pixelation are developed.Meanwhile, the miniaturization that possesses the picture pick-up device body of these imaging apparatuss is also developed, and the imaging lens system that it carried also requires small-sized, the lightweight except that the good optical performance.

On the other hand, to requirements such as vehicle mounted camera or monitoring cameras, for example, the F value is 2.0 bright optical system, and when having high against weather, the wide-angle lens of the cheapness that can use in the wide temperature range to the automobile in the summer of torrid areas at the extraneous air of cold region.

Patent documentation 1～10 has been put down in writing from object side and has been disposed the 1st negative lens, the 2nd lens, the 3rd lens successively, engages joint lens, the 6th lens of the 4th lens and the 5th lens, and seeks the imaging lens system of wide-angleization.

No. 7023628 instructionss of [patent documentation 1] United States Patent (USP)

The flat 4-68307 communique of [patent documentation 2] patent disclosure

[patent documentation 3] patent disclosure 2006-171597 communique

The clear 62-36622 communique of [patent documentation 4] patent disclosure

No. 3938143 communique of [patent documentation 5] patent gazette

[patent documentation 6] patent disclosure 2004-177435 communique

[patent documentation 7] patent disclosure 2007-108614 communique

[patent documentation 8] patent disclosure 2004-29282 communique

[patent documentation 9] patent disclosure 2003-232998 communique

[patent documentation 10] patent disclosure 2006-119368 communique

The lens that use in above-mentioned field monitor that especially mainly big distortion aberration (distortion aberration) takes place the vehicle mounted lens of wide-angle at the place ahead, side, the rear of automobile easily.The distortion aberration becomes big, then is compressed at the image of imaging apparatus upper periphery portion and dwindles into picture, so even can cause by Flame Image Process revisal distortion aberration, compare with the center, the resolution of periphery is the problem of step-down also.Given this situation except that above-mentioned expectation, in order to obtain good picture till the image corner, just requires good revisal distortion aberration.

Yet

patent documentation

1,2 described imaging lens systems are because of all being made of spherical lens, so, be difficult to the distortion of revisal well aberration.Though patent documentation 3 described imaging lens systems have used non-spherical lens, because of strong the 2nd lens in the distortion optical aberration correcting are not non-spherical lenses, so the revisal of distortion aberration is insufficient.

In addition, patent documentation 4,5 described imaging lens system F values are big, become dark optical system for being applicable to in-vehicle camera or monitoring camera.Patent documentation 6,7 described imaging lens system wide-angleizations are insufficient, not talkative suitable in-vehicle camera or monitoring camera.

Patent documentation 8,9 described imaging lens systems so when being made by glass, cost uprises, during by plastic production, are weaker than temperature variation because of using 3 non-spherical lenses, and it is unstable that performance becomes.

In addition, though patent documentation 10 described imaging lens systems are made as non-spherical lens with the 1st lens, for example, when being applicable to vehicle mounted camera or monitoring camera, owing to require the 1st lens to have against weather, so, be necessary as glass lens.Yet when forming aspheric surface by glass lens, except that cost uprised, the 1st lens L1 was the lens of maximum diameter, so, if as aspheric glass lens, will significantly raise the cost.

The utility model content

The utility model is In view of the foregoing to propose, its purpose is, a kind of F value is little and be wide-angle and can keep the good optical performance also can obtain the imaging lens system of good picture till the corner of image and possess the camera head of this imaging lens system, can provide with inexpensive way.

The 1st imaging lens system of the present utility model is characterized in that possessing successively from object side: the 1st lens of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens, when it was the concave-concave shape near optical axis, at least 1 was aspherical shape; The 3rd lens, it has positive focal power; Diaphragm; Engage lens, it has the 4th lens and the 5th lens that positive focal power the opposing party has a negative focal power and forms by engaging the either party, and wholely has a positive focal power; The 6th lens, when it had positive focal power, at least 1 was aspherical shape, the material of above-mentioned the 3rd lens is a glass, and the Abbe number to the d line of above-mentioned the 3rd lens is made as γ ₃The time, satisfy following conditional (1):

γ ₃＜30…(1)。

The 1st imaging lens system of the present utility model is Yi Bian by suitably selecting the formation of each lens, Yi Bian suitably dispose the non-spherical lens of minority, when seeking cost degradation, seek little F value and wide-angleization and reach all aberrations that good revisal comprises the aberration that distorts.

In addition, the 1st imaging lens system of the present utility model comprises when engaging lens by constituting, and the Abbe number of the 3rd lens formula (1) that satisfies condition is sought the revisal of good multiplying power chromatic aberation.If residual multiplying power chromatic aberation, then resolving power reduces, so in order to obtain at the good picture till the image corner, the chromatic aberation of revisal multiplying power well is effective.

The 2nd imaging lens system of the present utility model is characterized in that possessing successively from object side: the 1st lens of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens, when it was the concave-concave shape near optical axis, at least 1 was aspherical shape; The 3rd lens, it has positive focal power; Diaphragm; Engage lens, it has the 4th lens and the 5th lens that positive focal power the opposing party has a negative focal power and forms by engaging the either party, and wholely has a positive focal power; The 6th lens, when it had positive focal power, at least 1 was aspherical shape, and the effective diameter as the face of side of above-mentioned the 1st lens is made as ED, the radius-of-curvature as the face of side of above-mentioned the 1st lens is made as R ₂The time, satisfy following conditional (2):

1.65＜ED/R ₂＜2.0…(2)。

The 2nd imaging lens system of the present utility model, by suitably selecting the formation of each lens, the formula that satisfies condition (2), and suitably dispose the non-spherical lens of minority, when seeking cost degradation, seek all aberrations that little F value and wide-angleization and revisal well comprise the aberration that distorts.

The 3rd imaging lens system of the present utility model is characterized in that possessing successively from object side: the 1st lens of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens, when it was the concave-concave shape near optical axis, the face as side was an aspherical shape at least, and constituted in the mode that this effective diameter end as the face of side is weaker than its center according to negative focal power; The 3rd lens, it has positive focal power; Diaphragm; Engage lens, its joint either party has positive focal power the opposing party and has negative focal power and the 4th lens and the 5th lens, and integral body has positive focal power; The 6th lens, when it has positive focal power, at least the face as side is an aspherical shape, according to this as face of side near optical axis for convex form and positive focal power are weaker than the mode at center at the effective diameter end, perhaps near optical axis, constitute for convex form and in the mode that the effective diameter end has a negative focal power according to above-mentioned face as side.

The 3rd imaging lens system of the present utility model, by suitably selecting the formation of each lens, suitably dispose the non-spherical lens of minority, and further suitably set its aspherical shape, when seeking cost degradation, seek all aberrations that little F value and wide-angleization and revisal well comprise the aberration that distorts.

Herein, in the of the present utility model the 2nd and the 3rd imaging lens system, the material of the 3rd lens is preferably glass.

In addition, in imaging lens system of the present utility model, the focal length of total system is made as f, face to the distance on the optical axis of image planes of the object side of above-mentioned the 1st lens is made as L, when the distance of face to the optical axis of image planes as side of above-mentioned the 6th lens is made as Bf, satisfies following conditional (3), (4):

14.0＜L/f＜21.0…(3)

1.3＜Bf/f＜2.0…(4)。

In addition, in imaging lens system of the present utility model, the focal power of preferred negative is weaker than the center at the effective diameter end as the face of side of above-mentioned the 2nd lens.

In addition, in imaging lens system of the present utility model, preferably be constituted as: the face of the object side of above-mentioned the 6th lens is convex form near optical axis, positive focal power is weaker than the center at the effective diameter end.

In addition, in imaging lens system of the present utility model, preferably be constituted as: the face of the picture side of above-mentioned the 6th lens is convex form near optical axis, positive focal power is weaker than the center at the effective diameter end.

In addition, in imaging lens system of the present utility model, the lens that constitute the positive focal power of having of above-mentioned joint lens are preferably two convex forms.

In addition, in imaging lens system of the present utility model, the lens that constitute the negative focal power of having of above-mentioned joint lens are preferably the concave-concave shape.

In addition, in imaging lens system of the present utility model, the focal length of total system is made as f, the synthetic focal length of above-mentioned the 1st lens and above-mentioned the 2nd lens is made as f ₁₂The time, preferably satisfy following conditional (5):

-2.0＜f ₁₂/f＜-1.0…(5)。

In addition, in imaging lens system of the present utility model, the focal length of total system is made as f, above-mentioned the 3rd focal length of lens is made as f ₃The time, preferably satisfy following conditional (6):

4.0＜f ₃/f＜8.0…(6)。

In addition, in imaging lens system of the present utility model, the focal length of total system is made as f, the synthetic focal length of above-mentioned the 4th lens and above-mentioned the 5th lens is made as f ₄₅The time, preferably satisfy following conditional (7):

-6＜f ₄₅/f＜14…(7)。

In addition, in imaging lens system of the present utility model, the focal length of total system is made as f, above-mentioned the 2nd focal length of lens is made as f ₂The time, preferably satisfy following conditional (8):

-3.5＜f ₂/f＜-2.2…(8)。

In addition, in imaging lens system of the present utility model, above-mentioned the 3rd lens are made as D as the face of side to the distance on the optical axis of above-mentioned diaphragm ₆, the distance of above-mentioned diaphragm to the optical axis of above-mentioned the 4th lens is made as D ₇The time, preferably satisfy following conditional (9):

0.0＜D ₇/D ₆＜0.5…(9)。

In addition, in imaging lens system of the present utility model, the refractive index to the d line of above-mentioned the 1st lens is made as N ₁The time, preferably satisfy following conditional (10):

1.70＜N ₁＜1.90…(10)。

In addition, in imaging lens system of the present utility model, the Abbe number to the d line that constitutes the lens with positive focal power of above-mentioned joint lens is made as γ _P, the Abbe number to the d line that will constitute the lens of the negative focal power of having of above-mentioned joint lens is made as γ _nThe time, preferably satisfy following conditional (11), (12):

30＞γ _n…(11)

γ _p＞35…(12)。

In addition, in imaging lens system of the present utility model, the optics face diameter as the face of side of above-mentioned the 1st lens is made as LD, the radius-of-curvature as the face of side of above-mentioned the 1st lens is made as R ₂The time, preferably satisfy following conditional (13):

1.7＜LD/R ₂＜2.0…(13)。

In addition, in imaging lens system of the present utility model, the material of above-mentioned the 2nd lens is preferably plastics.

In addition, in imaging lens system of the present utility model, the material of above-mentioned the 6th lens is preferably plastics.

Need to prove, in the utility model, " effective diameter " regarded as diameter.In addition, " optics face diameter " is the diameter in the zone of working as optical lens face.For example, in by the lens that grind making, the diameter of abrasive surface becomes the optics face diameter.

Need to prove that in the utility model, " effective diameter end " is meant the point that outermost light and each lens face intersect in by the full light of each lens face.

Need to prove that " positive focal power is weaker than " center " at the effective diameter end and is meant to have at the effective diameter end and compares the little positive focal power of absolute value with the center, or has negative focal power at the effective diameter end and also can.Same, " negative focal power is weaker than " center " at the effective diameter end and is meant to have at the effective diameter end and compares the little negative focal power of absolute value with the center, or has positive focal power at the effective diameter end and also can.

Need to prove, the 6th lens in the utility model, " having positive focal power " and being meant not is only by paraxial radius-of-curvature decision, is parallel to when being incident to the 6th lens with effective diameter with the light beam of the optical axis in footpath but make, and the light beam that penetrates from the 6th lens becomes convergent beam.

Need to prove, when calculating above-mentioned L and Bf, the distance of using air to convert about back focal length part.

In addition, in each value of above-mentioned conditional (1)～(12), with d line (wavelength 587.6nm) as reference wavelength, as long as this instructions do not have special requirement, just with the d line as reference wavelength.

Camera head of the present utility model is characterized in that, possesses: the imaging lens system of the present utility model of above-mentioned record and will be converted to the imaging apparatus of electric signal by the optical image that this imaging lens system forms.

According to the 1st imaging lens system of the present utility model, because of at least by 5 groups of 6 lens combinations that form, suitably dispose the non-spherical lens of minority, select the material of the 3rd lens, make its formula that satisfies condition (1), and suitably set the formation of each lens, so, but cost degradation the time, seek little F value and wide-angleization on one side, keep the good optical performance on one side, chromatic aberation of revisal multiplying power especially well and distortion aberration obtain at the good picture till the image corner.

According to the 2nd imaging lens system of the present utility model, because of at least by 5 groups of 6 lens combinations that form, suitably dispose the non-spherical lens of minority, make the formation of its formula that satisfies condition (2), and suitably set the formation of each lens, so, but in the time of cost degradation, Yi Bian seek little F value and wide-angleization, Yi Bian keep the good optical performance, especially well revisal distortion aberration obtains the good picture to the image corner.

According to the 3rd imaging lens system of the present utility model, because of at least by 5 groups of 6 lens combinations that form, suitably dispose the non-spherical lens of minority, suitably set its aspherical shape, and suitably set the formation of each lens, so, but in the time of cost degradation, Yi Bian seek little F value and wide-angleization, Yi Bian keep the good optical performance, especially well revisal distortion aberration obtains the good picture to the image corner.

Description of drawings

Fig. 1 is the index path of the related imaging lens system of an embodiment of the present utility model.

Fig. 2 is the figure of explanation effective diameter end etc.

Fig. 3 is the figure of the face shape of explanation the 2nd lens.

Fig. 4 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 1 constitute.

Fig. 5 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 2 constitute.

Fig. 6 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 3 constitute.

Fig. 7 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 4 constitute.

Fig. 8 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 5 constitute.

Fig. 9 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 6 constitute.

Figure 10 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 7 constitute.

Figure 11 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 8 constitute.

Figure 12 is the sectional view that the lens of the related imaging lens system of expression embodiment of the present utility model 9 constitute.

Figure 13 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 1.

Figure 14 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 2.

Figure 15 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 3.

Figure 16 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 4.

Figure 17 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 5.

Figure 18 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 6.

Figure 19 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 7.

Figure 20 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 8.

Figure 21 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 9.

Figure 22 is the figure of the configuration of the related vehicle mounted camera head of explanation embodiment of the present utility model.

Among the figure: 1-imaging lens system, 2-axle glazed thread, 3,4-downside, upside off-axis ray, the 5-imaging apparatus, 11,12-the 1st, the 2nd light-blocking member, the 100-automobile, 101,102-side, back sidecar foreign minister machine, camera in the 103-car, the face interval on the optical axis of i face of Di-and i+1 face, ED-effective diameter, the Pim-image space, L1-the 1st lens, L2-the 2nd lens, L3-the 3rd lens, L4-the 4th lens, L5-the 5th lens, L6-the 6th lens, LD-optics face diameter, the PP-optics, the radius-of-curvature of i face of Ri-, St-aperture diaphragm, Z-optical axis.

Embodiment

Below, describe embodiment of the present utility model in detail with reference to accompanying drawing.The embodiment of imaging lens system of the present utility model at first is described, the embodiment of camera head is described then.

Fig. 1 represents the lens profile figure of the imaging lens system 1 that an embodiment of the present utility model is related.Fig. 1 also represents axle glazed thread 2, downside off-axis ray 3 in the lump.Need to prove that this configuration example shown in Figure 1 constitutes corresponding to the lens of following embodiment 1 shown in Figure 4.Fig. 5～Figure 12 represents other the sectional view of lens of configuration example of imaging lens system of the present utility model in addition, and they constitute corresponding to the lens of following embodiment 2～9.The basic comprising of embodiment 1～9 is identical, so, below mainly exemplify formation shown in Figure 1 imaging lens system 1 describe.

As shown in Figure 1, the related imaging lens system of embodiment of the present utility model 1 possesses successively from object side: the 1st lens L1 of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens L2, when it was the concave-concave shape near optical axis, at least 1 was aspherical shape; The 3rd lens L3, it has positive focal power; Aperture diaphragm St; Engage lens LC, it has positive focal power the opposing party and has negative focal power and the 4th lens L4 and the 5th lens L5 and form by engaging the either party, and wholely has a positive focal power; The 6th lens L6, when it had positive focal power, at least 1 was aspherical shape.Need to prove that the aperture diaphragm St among Fig. 1 does not represent shape or size, the position on the expression optical axis Z.

Considered that in Fig. 1 imaging lens system is applicable to the situation of camera head, the imaging apparatus 5 of the image planes configuration of the Pim that also illustrates at the image space that comprises imaging lens system.Imaging apparatus 5 will be converted to electric signal by the optical image that imaging lens system forms, and for example, be formed by ccd image sensor etc.

In addition, at the camera head where applicable, according to the formation of the phase pusher side that lens are installed, preferred disposition cloche or low-pass filter or infrared ray cut off filter etc., Fig. 1 are illustrated in the example that disposes the optics PP of the parallel flat shape of imagining these between lens combination and the imaging apparatus 5.For example, use this imaging lens system at in-vehicle camera, when using with the scotopia camera, also can between lens combination and imaging apparatus, insert by the wave filter of ultraviolet light to azure coloured light as the night vision subsidy.

Need to prove, also can be substituted between lens combination and the imaging apparatus 5 the configuration low-pass filter or by the various wave filters of specific band etc. at these various wave filters of configuration between each lens.Perhaps also can have coating in the lens face enforcement of arbitrary lens with imaging lens system with various wave filter same functions.

By the 1st lens L1 being made as with the negative meniscus lens of concave surface towards the picture side, can catch the big light of incident angle at the convex surface of the object side of the 1st lens L1, in the time of can be with the optical system wide-angleization, can dwindle Petzval and, be easier to the curvature of the image of the whole wide picture area of revisal.

By the 2nd lens L2 is made as the concave-concave shape, compare with the 1st lens L1 of the not too strong meniscus shape of focal power, can make the 2nd lens L2 have strong negative focal power, can guarantee the negative focal power that total system is required.In addition, be made as concave surface by face as side with the 2nd lens L2, on one side can do one's utmost to suppress the aberration generating capacity, Yi Bian can guide to follow-up positive lens with the off-axis ray of wide-angle incident.

Be made as aspheric surface by at least 1 face, each aberration of revisal well, the distortion of revisal especially well aberration with the 2nd lens L2.As shown in Figure 1,, then help optical aberration correcting, also be easier to revisal distortion aberration making the face of a glazed thread 2 and off-axis ray 3 suitable the 2nd lens L2 that separate be made as aspheric surface.

Need to prove that the 1st lens L1 also makes a glazed thread 2 suitably separate with off-axis ray 3, but as following in the configuration of the most close object side the 1st lens L1 preferably with glass as material, form aspheric surface by glass lens, then cost uprises.And the 1st lens L1 is the lens of maximum diameter, so if aspheric glass lens, then cost uprises significantly.Can think that from these situations as present embodiment, select easily to be suitable for aspherical shape among the 2nd lens L2 of plastic material, preferred lens is made and optical aberration correcting.

The face that the 2nd lens L2 is preferably at least as side is an aspherical shape.The light height of off-axis ray because of the face of the object side that is incident in the 2nd lens L2, so, for suppressing the aberration generating capacity, the face of the object side of preferred the 2nd lens L2 that does not make the concave-concave shape is held too strong focal power, its result, be the negative focal power of guaranteeing that total system is required, the just inevitable grow of the focal power of the face of the picture side of the 2nd lens L2.Be made as aspheric surface by the face as side that will have this strong focal power, effectively each aberration of revisal.

The face of the object side of the 2nd lens L2 is preferably aspherical shape, at this moment further each aberration of revisal well.When the face as side of the 2nd lens L2 was made as aspheric surface, the face as side of the 2nd lens L2 was preferably and is concave shape near optical axis, and negative focal power is weaker than the formation at center at the effective diameter end.According to such formation, can make the light that is incident in lens perimeter portion not extreme crooked with regard to optically focused, so, the distortion of revisal well aberration.

Need to prove that the effective diameter end is the point that intersects by outermost light and each lens face in all light of each lens face.For example, example shown in Figure 2 is in the face of the picture side of the 1st lens L1, and the most peripheral light of off-axis ray and the point that lens face intersects become the effective diameter end, and the diameter of a circle that point of crossing is thus formed illustrates as effective diameter ED.Need to prove that Fig. 2 is the part amplification profile of the imaging lens system of following embodiment 5.

The face of the picture side of the 2nd lens L2 is concave shape near optical axis, and negative focal power is weaker than the center at the effective diameter end, on one side and with reference to Fig. 3 the formation (being called the 1st constitutes) that has negative focal power at the effective diameter end is described on one side.In the sectional view of imaging lens system shown in Figure 31, the effective diameter end as the face of side of the 2nd lens L2 is made as an X2, in the time of will being made as a some P2 in the normal H2 of the lens face of its point and the point of crossing on the optical axis Z, the length of the line segment P2-X2 of point of contact X2 and some P2 is made as the radius-of-curvature of an X2.In addition, with the face of the picture side of the 2nd lens L2 and the point of crossing of optical axis Z, that is, the center as the face of side of the 2nd lens L2 is made as a Q2.

The above-mentioned the 1st to constitute be that a P2 more is positioned at the picture side than a some Q2, and also bigger than the absolute value in the radius-of-curvature of a Q2 at the absolute value of the radius-of-curvature of an X2.Fig. 3 understands for helping, and the absolute value (length of line segment P2-X2) of the radius-of-curvature of an X2 is made as radius, by an X2, and the with dashed lines round CX2 at center that the point on the optical axis is made as that draws.In addition, will be made as radius, by an XQ2, with the 2 pecked lines round CQ2 at center that the point on the optical axis is made as that draws at the absolute value of the radius-of-curvature of a Q2.As shown in Figure 3, justifying CX2 becomes greater than the circle of justifying CQ2.

Further, the face as side of the 2nd lens L2 is preferably and is concave shape near optical axis, comprises the formation (being called the 2nd constitutes) of the negative focal power point stronger than the center between center and effective diameter end.This is identical with the 1st formation that illustrates with Fig. 3, can consider as follows.

In lens profile figure (following mark X22, P22, Q22 not shown), a bit being made as X22, when the point of crossing of the normal of its point and optical axis Z is made as P22, the length of the line segment P22-X22 of point of contact X22 and some P22 being made as radius-of-curvature at an X22 the 2nd lens L2 as on the face of side certain.In addition, with the face of the picture side of the 2nd lens L2 and the point of crossing of optical axis Z, that is, the center as the face of side of the 2nd lens L2 is made as a Q22.Above-mentioned the 2nd formation is that a P22 more is positioned at the picture side than a some Q22, and has the absolute value also little some X22 of the absolute value ratio of line segment P22-X22 in the radius-of-curvature at the center of the face of the picture side of the 2nd lens L2 between center and effective diameter end.

Need to prove that when the face of the object side of the 2nd lens L2 is made as aspheric surface, is preferably is concave shape near optical axis, negative focal power is weaker than the formation at center at the effective diameter end.According to this formation, the revisal curvature of the image can make the image planes planarization well, is suitable as the lens in the imaging apparatus imaging.

Herein, the face of the object side of the 2nd lens L2 constitutes negative focal power and is weaker than the center at the effective diameter end, this formation also can have negative focal power at the effective diameter end, also can change the symbol of focal power from the center the way of effective diameter end, has positive focal power at the effective diameter end.

The face that the object side of the 2nd lens L2 has been described is concave shape near optical axis, negative focal power is weaker than the center at the effective diameter end, and has the formation (being called the 3rd constitutes) of negative focal power at the effective diameter end.This is identical with the 1st formation that illustrates with Fig. 3, can consider as follows.

In lens profile figure (following mark X1, P1, Q1 not shown), the effective diameter end of the face of the object side of the 2nd lens L2 is made as an X1, in the time of will being made as a some P1 in the point of crossing of the normal of its point and optical axis Z, the length of the line segment P1-X1 of point of contact X1 and some P1 is made as radius-of-curvature at an X1.In addition, with the face of the picture side of the 2nd lens L2 and the point of crossing of optical axis Z, that is, the center of the face of the object side of the 2nd lens L2 is made as a Q1.The above-mentioned the 3rd to constitute be that a P1 more is positioned at object side than a some Q1, and be that absolute value (length of line segment P1-X1) in the radius-of-curvature on the X1 is greater than the formation of the absolute value of the radius-of-curvature on a Q1.

Secondly, the face of the object side of the 2nd lens L2 is concave shape near optical axis, and change the symbol of focal power the way of effective diameter end from the center, to be the some P1 that defines in the above-mentioned the 3rd explanation that constitutes than the some Q1 of the point of crossing of the face of the object side of the 2nd lens L2 and optical axis Z more be positioned at the formation (be called the 4th constitute) that has a positive focal power at the effective diameter end looks like side.

When adopting the 4th to constitute,, obtain to gather the effect of image planes because of applying flexibly positive focal power effectively at the effective diameter end, and revisal curvature of the image well, the image planes planarization can be made, and the image quality of periphery can be improved, so, be suitable as lens in the imaging apparatus imaging.

The 3rd lens L3 can be with the meniscus shape of convex surface towards object side, also can be two convex forms.

The joint lens LC of example shown in Figure 1 is formed by the 4th lens L4 that holds positive focal power and the 5th lens L5 that holds negative focal power.Constitute the lens of holding positive focal power that engage lens LC and be preferably two convex forms, in addition, the lens of holding negative focal power are preferably the concave-concave shape, so, engage lens LC by constituting by two convex lens and biconcave lens, can strengthen each power of lens, help the chromatic aberation revisal of (also claiming aberration).

In addition, in engaging lens LC, preferably hold the lens of positive focal power in the object side configuration.In the formation of present embodiment, disposed joint lens LC in the dead astern of aperture diaphragm St.For example, when in-vehicle camera or monitoring camera etc. used, the F value was preferably the bright lens combination about 2.0.In this bright lens combination, to engage the configuration of positive negative lens of lens in contrast to the configuration of present embodiment, the lens configuration that to hold negative focal power is when object side, the light height as the face of side that might produce the lens of holding positive focal power uprises, and can't fully obtain to hold the rims of the lens of positive focal power.

The 6th lens L6 is by being made as aspheric surface with at least 1 face, each aberration of revisal well.In the 6th lens L6, preferred is aspherical shape as the face of side at least.Identical with the 2nd lens L2, in the 6th lens L6 also because of suitably having separated axle glazed thread 2 and off-axis ray 3, so, the face of the lens of the 6th lens L6 is made as aspheric surface, then help optical aberration correcting.

When the face of the object side of the 6th lens L6 was made as aspheric surface, the face of the object side of preferred the 6th lens L6 was convex form near optical axis, and positive focal power is weaker than the formation at center at the effective diameter end.According to such formation, the revisal curvature of the image can make the image planes planarization well, is suitable as the lens in the imaging apparatus imaging.

The face that the object side of the 6th lens L6 is described is convex form near optical axis, positive focal power is weaker than the center at the effective diameter end, and has the formation (being called the 5th constitutes) of positive focal power at the effective diameter end.This is identical with the 1st formation that illustrates with Fig. 3, can consider as follows.

In lens profile figure (following mark X3, P3, Q3 not shown), the effective diameter end of the face of the object side of the 6th lens L6 is made as an X3, in the time of will being made as a some P3 in the point of crossing of the normal H3 of its point and optical axis Z, the length of the line segment P3-X3 of point of contact X3 and some P3 is made as radius-of-curvature at an X3.In addition, with the face of the object side of the 6th lens L6 and the point of crossing of optical axis Z, that is, the center of the face of the object side of the 6th lens L6 is made as a Q3.Above-mentioned the 5th formation is that a P3 more is positioned at the picture side than a some Q3, and the absolute value of line segment P3-X3 ratio is also big at the absolute value of the radius-of-curvature at the center of the face of the object side of the 6th lens L6.

When the face as side of the 6th lens L6 was made as aspheric surface, the face of the picture side of preferred the 6th lens L6 was convex form near optical axis, and positive focal power is weaker than the formation at center at the effective diameter end.According to such formation, the revisal curvature of the image can make the image planes planarization well, is suitable as the lens in the imaging apparatus imaging.

Herein, the face as side of the 6th lens L6 constitutes negative focal power and is weaker than the center at the effective diameter end, this formation also can have positive focal power at the effective diameter end, also can change the symbol of focal power from the center the way of effective diameter end, has negative focal power at the effective diameter end.

The face that the picture side of the 6th lens L6 is described is convex form near optical axis, positive focal power is weaker than the center at the effective diameter end, and has the formation (being called the 6th constitutes) of positive focal power at the effective diameter end.This is identical with the 1st formation that illustrates with Fig. 3, can consider as follows.

In lens profile figure (following mark X4, P4, Q4 not shown), the effective diameter end as the face of side of the 6th lens L6 is made as an X4, in the time of will being made as a some P4 in the point of crossing of the normal of its point and optical axis Z, the length of the line segment P4-X4 of point of contact X4 and some P4 is made as radius-of-curvature at an X4.In addition, with the face of the picture side of the 6th lens L6 and the point of crossing of optical axis Z, that is, the center as the face of side of the 6th lens L6 is made as a Q4.Above-mentioned the 6th formation is that a P4 more is positioned at object side than a some Q4, and the absolute value of line segment P4-X4 ratio is also big at the absolute value of the radius-of-curvature at the center of the face of the picture side of the 6th lens L6.

Secondly, the face that the picture side of the 6th lens L6 is described is convex form near optical axis, and change the symbol of focal power the way of effective diameter end from the center, to be the some P4 that defines in the above-mentioned the 6th explanation that constitutes than the some Q4 as the intersection point of the face of side and optical axis Z of the 6th lens L6 more be positioned at the formation (be called the 7th constitute) that has a negative focal power at the effective diameter end looks like side.

When adopting the 7th to constitute,, obtain to gather the effect of image planes because of applying flexibly negative focal power effectively at the effective diameter end, and revisal curvature of the image well, the image planes planarization can be made, and the image quality of periphery can be improved, so, be suitable as lens in the imaging apparatus imaging.

Need to prove, with the two sides of the 6th lens L6 be made as aspheric surface, in each face, be convex form near the optical axis of face, when positive focal power is weaker than the formation at center at the effective diameter end, the revisal curvature of the image can make the image planes planarization well, is suitable as the lens in the imaging apparatus imaging.

Herein, the related imaging lens system of embodiment of the present utility model is being made as γ with the 3rd lens L3 to the Abbe number of d line ₃The time, the formula that preferably satisfies condition (1).

γ ₃＜30…(1)

The 3rd lens L3 is configured near the intensive aperture diaphragm St of light, meanwhile, is to act on the lens that make the direction that the diverging light that penetrates from the 1st lens L1 that holds negative focal power and the 2nd lens L2 assembles.Make its formula that satisfies condition (1), the chromatic aberation of revisal multiplying power well by the glass material of selecting the 3rd lens L3.

In addition, the related imaging lens system of embodiment of the present utility model is made as ED, the radius-of-curvature as the face of side of the above-mentioned the 1st saturating L1 is made as R at the effective diameter as the face of side with the 1st lens L1 ₂The time, preferably satisfy following conditional (2).

1.65＜ED/R ₂＜2.0…(2)

Surpass going up in limited time of conditional (2), the face as side of the 1st lens almost becomes hemisphere or surpasses the shape of hemisphere, so, be difficult to processing, become the reason that cost rises.Surpass the following of conditional (2) and prescribe a time limit, the distortion of revisal well aberration.

Further, the related imaging lens system of embodiment of the present utility model preferably satisfies following conditional (2-1), at this moment can suppress the further rising and the distortion of the revisal well aberration of cost.

1.70＜ED/R ₂＜1.95…(2-1)

In addition, the related imaging lens system of embodiment of the present utility model is made as f, face to the distance on the optical axis of image planes of the object side of the 1st lens L1 is made as L, when the distance of face to the optical axis of image planes as side of the 6th lens L6 is made as Bf, preferably satisfies following conditional (3), (4) at the focal length with total system.

14.0＜L/f＜21.0…(3)

1.3＜Bf/f＜2.0…(4)

Surpass going up in limited time of conditional (3), the elongated system of total length maximizes.Surpass conditional (3) following the focal length of total system is oversize and wide-angleization is insufficient in limited time, in order to seek wide-angleization, just need guarantee the picture angle, and greatly by distorted image official post periphery anamorphosis change.Or total length is too short, and the thickness attenuation of each lens worsens processability.

In addition, for miniaturization, the face of the object side of preferred the 1st lens L1 to the distance L on the optical axis of image planes is below the 25mm, more preferably below the 21mm.

In addition, for wide-angleization, when the full visual angle on the diagonal angle of imaging apparatus 5 was made as 2 ω, 2 ω were preferably more than 140 degree.Herein, as shown in Figure 2,2 ω are the angle that chief ray became that is incident in downside off-axis ray 3 with the upside off-axis ray 4 of the 1st lens L1.

Surpass going up in limited time of conditional (4), it is oversize that back focal length becomes, and system maximizes as a result.Surpass the following of conditional (4) and prescribe a time limit, it is too short that back focal length becomes, and is difficult to insert between lens combination and imaging apparatus glass cover or various wave filter.

In addition, the related imaging lens system of embodiment of the present utility model is made as f, the synthetic focal length of the 1st lens L1 and the 2nd lens L2 is made as f at the focal length with total system ₁₂The time, preferably satisfy following conditional (5).

-2.0＜f ₁₂/f＜-1.0…(5)

Surpass going up in limited time of conditional (5), can reach wide-angleization easily, but curvature of the image becomes big, is difficult to obtain good picture.What surpass conditional (5) is disposed at that the focal power of 2 negative lenses of close object side dies down in limited time down, so light can not be crooked doughtily and be difficult to reach wide-angleization, perhaps, in order to reach wide-angleization, then lens maximize.

In addition, the imaging lens system that embodiment of the present utility model is related is made as f, the focal length of the 3rd lens L3 is made as f at the focal length with total system ₃The time, preferably satisfy following conditional (6).

4.0＜f ₃/f＜8.0…(6)

Surpass going up in limited time of conditional (6), the focal power of the 3rd lens L3 dies down, and is difficult to revisal multiplying power chromatic aberation.It is too strong that the focal power of the 3rd lens L3 becomes in limited time to surpass conditional (6) following, and the sensitivity of off-centre is uprised, and productivity reduces.

In addition, the imaging lens system that embodiment of the present utility model is related is made as f, the synthetic focal length of the 4th lens L4 and the 5th lens L5 is made as f at the focal length with total system ₄₅The time, preferably satisfy following conditional (7).

6＜f ₄₅/f＜14…(7)

Surpass going up in limited time of conditional (7), a little less than the focal power of joint lens LC becomes too, be difficult to revisal chromatic aberation well.Surpass the following of conditional (7) and prescribe a time limit, the focal power that engages the positive lens among the lens LC becomes too strong, so the radius-of-curvature of lens diminishes, is difficult to processing.

In addition, the imaging lens system that embodiment of the present utility model is related is made as f, the focal length of the 2nd lens L2 is made as f at the focal length with total system ₂The time, preferably satisfy following conditional (8).

-3.5＜f ₂/f＜-2.2…(8)

Surpass going up in limited time of conditional (8), be difficult to revisal spherical aberration well, be difficult to the bright optical system that realizes that the F value is little.Surpass the following of conditional (8) and prescribe a time limit, the negative focal power of the 2nd lens L2 dies down, and is difficult to wide-angleization.

In addition, the related imaging lens system of embodiment of the present utility model is made as D in face to the distance on the optical axis of aperture diaphragm St as side with the 3rd lens L3 ₆, the distance of aperture diaphragm St to the 4 lens L4 is made as D ₇The time, preferably satisfy following conditional (9).

0.0＜D ₇/D ₆＜0.5…(9)

By the formula of satisfying condition (9), aperture diaphragm St more approaches the 4th lens L4 than the 3rd lens L3, and in the 1st lens L1 to the 3 lens L3, separable axle is gone up light beam 2 and axle outer light beam 3, revisal distortion aberration easily.

In addition, the imaging lens system that embodiment of the present utility model is related is made as N in the refractive index to the d line with the 1st lens L1 ₁The time, preferably satisfy following conditional (10).

1.70＜N ₁＜1.90…(10)

The upper limit that surpasses conditional (10) is then used material at high price, becomes the essential factor that cost rises.In addition, in present spendable optics material, if surpass the upper limit of conditional (10) more, it is high more that refractive index becomes, and then Abbe number is more little, and the result will use the little material of Abbe number, be difficult to the chromatic aberation of revisal multiplying power.The lower limit that surpasses conditional (10) then is difficult to reach wide-angleization because of the refractive index of material is too low, perhaps becomes the shape of the little processing difficulties of the radius-of-curvature of face of picture side in order to obtain necessary focal power, becomes the reason that cost rises.

In addition, the imaging lens system that embodiment of the present utility model is related is made as γ at the Abbe number to the d line that will constitute the lens with positive focal power that engage lens LC _P, the Abbe number to the d line that will constitute the lens with negative focal power that engage lens LC is made as γ _nThe time, preferably satisfy following conditional (11), (12).

30＞γ _n…(11)

γ _p＞35…(12)

Make its formula that satisfies condition (11), (12) by the material of selecting to engage lens, well chromatic aberation and multiplying power chromatic aberation on the revisal axle.

In addition, the imaging lens system that embodiment of the present utility model is related is made as LD, the radius-of-curvature as the face of side of above-mentioned the 1st lens is made as R at the optics face diameter as the face of side with above-mentioned the 1st lens ₂The time, preferably satisfy following conditional (13).

1.7＜LD/R ₂＜2.0…(13)

Need to prove, the optics face diameter is the diameter in the zone of working as optical lens face, in the present embodiment, as shown in Figure 2, prolong by the face as the object side of the face of side and the 2nd lens L2 with the 1st lens L1, the diameter of a circle that is formed by both cross spider is made as optics face diameter LD.

The upper limit that surpasses conditional (13), then because of the face as side of the 1st lens becomes shape above hemisphere, so, be difficult to processing, become the reason of cost rising.The lower limit that surpasses conditional (13), the then distortion of revisal well aberration.

In addition, the imaging lens system that embodiment of the present utility model is related is made as f, the center thickness of the 1st lens L1 is made as D at the focal length with total system ₁The time, preferably satisfy following conditional (14).

0.55＜D ₁/f…(14)

For example, as purposes such as vehicle-mounted lens the time, require the intensity of the 1st lens L1 to various impacts.Surpass the lower limit of conditional (14), then the 1st lens attenuation is isolated easily.The center thickness D of further preferred the 1st lens L1 ₁More than 0.8mm.

In addition, the related imaging lens system of embodiment of the present utility model is made as f at the focal length with the 1st lens L1 ₁, the focal length of the 2nd lens L2 is made as f ₂The time, preferably satisfy following conditional (15).

2.5＜f ₁/f ₂＜4.0…(15)

Surpass the upper limit of conditional (15), a little less than then the focal power of the 1st lens L1 becomes too, be difficult to reach wide-angleization, or the 1st lens L1 maximizes.Surpass the lower limit of conditional (15), then be difficult to revisal coma aberration and curvature of the image.

In addition, the related imaging lens system of embodiment of the present utility model is made as f, the radius-of-curvature of the face of the object side of the 1st lens L1 is made as R at the focal length with total system ₁The time, preferably satisfy following conditional (16).

10.0＜R ₁/f＜20.0…(16)

Surpass the upper limit of conditional (16), then the radius-of-curvature of the face of the object side of the 1st lens L1 becomes too big, and light is sharply crooked at the periphery quilt, so the distortion aberration becomes greatly.Surpass the lower limit of conditional (16), then the radius-of-curvature of the face of the object side of the 1st lens L1 becomes too little, is difficult to reach wide-angleization.

Need to prove, for example, when in harsh environment such as vehicle mounted camera, using this imaging lens system, preferably use anti-anti-because of the surperficial cracking due to the wind and rain, the temperature variation due to the direct sunlight at the 1st lens L1 of the most close object side configuration, and, the material of chemicalss such as anti-anti-grease washing agent, that is, and water tolerance, against weather, acid resistance, the contour material of resistance to chemical reagents.In addition, as the material of the 1st lens L1 that disposes at the most close object side, preferably use the hard material that is difficult for isolating.By more than, as the material of the 1st lens L1, particularly, preferably use glass, or also can use transparent pottery.Pottery has intensity height, character that thermotolerance is high than common glass.

As the material of the 2nd lens L2 and the 6th lens L6, preferably use plastics.Be made as plastics by material, but precision is made aspherical shape goodly with the 2nd lens L2 and the 6th lens L6.In addition, by using plastics, can seek cost degradation.

As the material of the 3rd lens L3, preferably use glass, at this moment, the mis-behave due to variation of temperature can be suppressed to irreducible minimum.

Need to prove that the material of the 6th lens L6 also can be used glass, at this moment, the mis-behave due to variation of temperature can be suppressed to irreducible minimum.

In addition, for example, when the vehicle mounted camera was suitable for this imaging lens system, requirement can be used this imaging lens system in extraneous air to the temperature range of the automobile inner width in the summer of torrid areas of cold region.When wide temperature range is used, preferably use the little material of linear expansion coefficient as the material of lens.

Need to prove, probably can become parasitic light arrival image planes by the outer light beam of the effective diameter between each lens and become ghost image, so, the preferred as required light-blocking member that blocks this parasitic light that is provided with.As this light-blocking member, for example, can lens as the effective diameter of side outside part coat opaque coating, or also opaque sheet material can be set.In addition, also opaque sheet material can be set in the light path of the light beam that becomes parasitic light as light-blocking member.As 1 example, Fig. 1 has represented that the face as side at the 1st lens L1 and the 2nd lens L2 is provided with the example of light-blocking

member

11,12 respectively.Need to prove that the place that light-blocking member is set is not limited to example shown in Figure 1, also can be configured between the other lenses as required.

[embodiment]

Next, the concrete numerical value embodiment of the imaging lens system that the utility model is related is described.

＜embodiment 1 〉

Fig. 4 represents the lens pie graph of the imaging lens system that embodiment 1 is related, table 1 expression lens data.Among Fig. 4, symbol Ri, Di (i=1,2,3 ...) corresponding to Ri, the Di of table 1.

[table 1]

Embodiment 1

In the lens data of table 1, the face number expression face of the inscape of close object side is made as the 1st, to the i that increases successively as side (i=1,2,3 ...) individual face number.Need to prove, in the lens data of table 1, also comprise and enclosed aperture diaphragm St and optics PP.

The Ri of table 1 represents i (i=1,2,3 ...) radius-of-curvature of individual face, Di represents i (i=1,2,3 ...) on the optical axis Z of individual face and i+1 face face at interval.In addition, Ndj represents the optical parameter of close object side is made as the 1st to the j that increases successively as side (j=1,2,3 ...) refractive index to the d line of individual optical parameter, γ dj represents the Abbe number to the d line of j optical parameter.In table 1, radius-of-curvature and face unit at interval is mm, and radius-of-curvature will just be made as when being protruding at object side, be made as negative when being protruding as side.In the lens data of table 1, aspheric surface at face number with the * seal.

Table 2 expression is by each aspheric each COEFFICIENT K of the definition of the aspheric surface formula shown in the following mathematical expression 1, the value of B3～B20.

[mathematical expression 1]

Zh = \frac{C Y^{2}}{1 + {(1 - K \cdot C^{2} Y^{2})}^{1 / 2}} + Σ_{m = 3}^{20} Bm Y^{m}

Zh: the aspheric surface degree of depth (hanging down to the length of the perpendicular line on the vertical plane of the optical axis that contacts with the aspheric surface summit) from the point on the aspheric surface of height Y

Y: highly (from the distance of optical axis)

C: the inverse of paraxial radius-of-curvature

K, Bm: asphericity coefficient (m=3～20)

[table 2]

Embodiment 1

The various data of the imaging lens system that table 3 expression embodiment 1 is related.In table 3, FNo. be the F value, ω is a half angle of view, L is the distance (back focal length part air conversion) of face to the optical axis Z of image planes of object side of the 1st lens L1 of total system, and Bf is the back focal length that air converted, and IH is maximum image height, LD is the optics face diameter, ED is an effective diameter, and f is the focal length of total system, f ₁Be the focal length of the 1st lens L1, f ₂Be the focal length of the 2nd lens L2, f ₃Be the focal length of the 3rd lens L3, f ₄₅Be the synthetic focal length of the joint lens LC that constitutes by the 4th lens L4 and the 5th lens L5, f ₆It is the focal length of the 6th lens L6.In the various data of table 3, the unit of ω is degree, and the unit beyond FNo. and the ω all is mm.

[table 3]

Embodiment 1

FNo.	2.0	ω	79.7
FNo.	2.0	ω	79.7	L	20.27	IH	2.40
Bf	2.3	LD	8.94	L	20.27	IH	2.40
Bf	2.3	LD	8.94	f	1.3	ED	8.72
f ₁	-8.9	f ₁₂	-1.9	f	1.3	ED	8.72
f ₁	-8.9	f ₁₂	-1.9	f ₂	-3.3	f ₄₅	8.8
f ₃	7.3	f ₆	3.6	f ₂	-3.3	f ₄₅	8.8

Table 4 is illustrated in about the radius-of-curvature P1-X1 on the effective diameter end, the P2-X2 that uses in the explanation of above-mentioned aspherical shape, P3-X3, P4-X4 with at supercentral radius of curvature R 3, R4, R11, the R12 of the face of correspondence.

[table 4]

Embodiment 1

P1-X1	-61.12	R3	-10.21
P1-X1	-61.12	R3	-10.21	P2-X2	3.25	R4	2.22
P3-X3	4.75	R11	3.67	P2-X2	3.25	R4	2.22
P3-X3	4.75	R11	3.67	P4-X4	-14.78	R12	-3.16

Need to prove that the meaning of the mark in the table 1 of above-mentioned explanation～table 4 is also identical to following embodiment.

＜embodiment 2 〉

Fig. 5 represents the lens pie graph of the imaging lens system that embodiment 2 is related, table 5 expression lens data, each aspheric each coefficient of table 6 expression, the various data of table 7 expression, table 8 expression effective diameter end and in the radius-of-curvature at center.Among Fig. 5, symbol Ri, Di are corresponding to Ri, the Di of table 5.

[table 5]

Embodiment 2

Face number	Ri	Di	Ndj	vdj
Face number	Ri	Di	Ndj	vdj		1	18.22	1.00	1.8348	42.7
2	4.68	2.82				1	18.22	1.00	1.8348	42.7
2	4.68	2.82			3*	-7.23	1.25	1.5316	55.4
4*	2.52	1.64			3*	-7.23	1.25	1.5316	55.4
4*	2.52	1.64			5	7.56	2.00	1.9229	18.9
6	-17.49	2.59			5	7.56	2.00	1.9229	18.9
6	-17.49	2.59			7 (aperture diaphragms)	∞	0.00
8	5.34	3.00	1.8348	42.7	7 (aperture diaphragms)	∞	0.00
8	5.34	3.00	1.8348	42.7	9	-3.50	1.04	1.9229	18.9
10	13.34	0.10			9	-3.50	1.04	1.9229	18.9
10	13.34	0.10			11*	3.75	2.21	1.5316	55.4
12*	-2.88	1.27			11*	3.75	2.21	1.5316	55.4
12*	-2.88	1.27			13	∞	0.50	1.5168	64.2
14	∞	0.50			13	∞	0.50	1.5168	64.2
14	∞	0.50			15 (image planes)	∞

[table 6]

Embodiment 2

[table 7]

Embodiment 2

FNo.	2.0	ω	79.7
FNo.	2.0	ω	79.7	L	19.75	IH	2.40
Bf	2.1	LD	8.28	L	19.75	IH	2.40
Bf	2.1	LD	8.28	f	1.3	ED	8.11
f ₁	-7.8	f ₁₂	-1.8	f	1.3	ED	8.11
f ₁	-7.8	f ₁₂	-1.8	f ₂	-3.4	f ₄₅	11.0
f ₃	5.9	f ₆	3.5	f ₂	-3.4	f ₄₅	11.0

[table 8]

Embodiment 2

P1-X1	-20.67	R3	-7.23
P1-X1	-20.67	R3	-7.23	P2-X2	3.62	R4	2.52
P3-X3	5.22	R11	3.75	P2-X2	3.62	R4	2.52
P3-X3	5.22	R11	3.75	P4-X4	-9.51	R12	-2.88

＜embodiment 3 〉

Fig. 6 represents the lens pie graph of the imaging lens system that embodiment 3 is related, table 9 expression lens data, each aspheric each coefficient of table 10 expression, the various data of table 11 expression, table 12 expression effective diameter end and in the radius-of-curvature at center.Among Fig. 6, symbol Ri, Di are corresponding to Ri, the Di of table 9.

[table 9]

Embodiment 3

Face number	Ri	Di	Ndj	vdj
Face number	Ri	Di	Ndj	vdj		1	27.22	1.00	1.7725	49.6
2	5.44	3.25				1	27.22	1.00	1.7725	49.6
2	5.44	3.25			3*	-7.83	1.25	1.5316	55.4
4*	2.59	2.06			3*	-7.83	1.25	1.5316	55.4
4*	2.59	2.06			5	5.72	2.00	1.8467	23.8
6	325.09	3.15			5	5.72	2.00	1.8467	23.8
6	325.09	3.15			7 (aperture diaphragms)	∞	0.00
8	4.54	3.00	1.7130	53.9	7 (aperture diaphragms)	∞	0.00
8	4.54	3.00	1.7130	53.9	9	-3.50	1.04	1.9229	18.9
10	30.19	0.10			9	-3.50	1.04	1.9229	18.9
10	30.19	0.10			11*	4.02	2.50	1.5316	55.4
12*	-2.81	1.37			11*	4.02	2.50	1.5316	55.4
12*	-2.81	1.37			13	∞	0.50	1.5168	64.2
14	∞	0.50			13	∞	0.50	1.5168	64.2
14	∞	0.50			15 (image planes)	∞

[table 10]

Embodiment 3

[table 11]

Embodiment 3

FNo.	2.0	ω	79.2
FNo.	2.0	ω	79.2	L	21.54	IH	2.40
Bf	2.2	LD	10.00	L	21.54	IH	2.40
Bf	2.2	LD	10.00	f	1.3	ED	9.42
f ₁	-9.0	f ₁₂	-2.0	f	1.3	ED	9.42
f ₁	-9.0	f ₁₂	-2.0	f ₂	-3.5	f ₄₅	10.7
f ₃	6.9	f ₆	3.6	f ₂	-3.5	f ₄₅	10.7

[table 12]

Embodiment 3

P1-X1	380.83	R3	-7.83
P1-X1	380.83	R3	-7.83	P2-X2	3.56	R4	2.59
P3-X3	4.26	R11	4.02	P2-X2	3.56	R4	2.59
P3-X3	4.26	R11	4.02	P4-X4	-185.25	R12	-2.81

＜embodiment 4 〉

Fig. 7 represents the lens pie graph of the imaging lens system that embodiment 4 is related, table 13 expression lens data, each aspheric each coefficient of table 14 expression, the various data of table 15 expression, table 16 expression effective diameter end and in the radius-of-curvature at center.Among Fig. 7, symbol Ri, Di are corresponding to Ri, the Di of table 13.

[table 13]

Embodiment 4

Face number	Ri	Di	Ndj	vdj
Face number	Ri	Di	Ndj	vdj		1	23.71	1.20	1.7725	49.6
2	6.34	4.18				1	23.71	1.20	1.7725	49.6
2	6.34	4.18			3*	-3.80	1.25	1.5316	55.4
4*	3.78	1.87			3*	-3.80	1.25	1.5316	55.4
4*	3.78	1.87			5	7.24	2.00	1.8467	23.8
6	-44.66	4.88			5	7.24	2.00	1.8467	23.8
6	-44.66	4.88			7 (aperture diaphragms)	∞	0.00
8	4.57	3.00	1.7130	53.9	7 (aperture diaphragms)	∞	0.00
8	4.57	3.00	1.7130	53.9	9	-3.50	1.03	1.8467	23.8
10	9.21	0.10			9	-3.50	1.03	1.8467	23.8
10	9.21	0.10			11*	3.65	2.69	1.5316	55.4
12*	-2.60	1.51			11*	3.65	2.69	1.5316	55.4
12*	-2.60	1.51			13	∞	0.50	1.5168	64.2
14	∞	0.50			13	∞	0.50	1.5168	64.2
14	∞	0.50			15 (image planes)	∞

[table 14]

Embodiment 4

[table 15]

Embodiment 4

FNo.	2.0	ω	78.9
FNo.	2.0	ω	78.9	L	24.54	IH	2.40
Bf	2.3	LD	11.16	L	24.54	IH	2.40
Bf	2.3	LD	11.16	f	1.2	ED	10.93
f ₁	-11.5	f ₁₂	-2.0	f	1.2	ED	10.93
f ₁	-11.5	f ₁₂	-2.0	f ₂	-3.4	f ₄₅	14.7
f ₃	7.5	f ₆	3.4	f ₂	-3.4	f ₄₅	14.7

[table 16]

Embodiment 5

P1-X1	-21.39	R3	-3.80
P1-X1	-21.39	R3	-3.80	P2-X2	4.53	R4	3.78
P3-X3	4.19	R11	3.65	P2-X2	4.53	R4	3.78
P3-X3	4.19	R11	3.65	P4-X4	5070.69	R12	-2.60

＜embodiment 5 〉

Fig. 8 represents the lens pie graph of the imaging lens system that embodiment 5 is related, table 17 expression lens data, each aspheric each coefficient of table 18 expression, the various data of table 19 expression, table 20 expression effective diameter end and in the radius-of-curvature at center.Among Fig. 8, symbol Ri, Di are corresponding to Ri, the Di of table 17.

[table 17]

Embodiment 5

[table 18]

Embodiment 5

[table 19]

Embodiment 5

FNo.	2.0	ω	79.4
FNo.	2.0	ω	79.4	L	24.75	IH	2.40
Bf	2.3	LD	11.23	L	24.75	IH	2.40
Bf	2.3	LD	11.23	f	1.2	ED	10.81
f ₁	-10.8	f ₁₂	-1.9	f	1.2	ED	10.81
f ₁	-10.8	f ₁₂	-1.9	f ₂	-3.4	f ₄₅	16.1
f ₃	7	f ₆	3.3	f ₂	-3.4	f ₄₅	16.1

[table 20]

Embodiment 5

P1-X1	-18.51	R3	-3.64
P1-X1	-18.51	R3	-3.64	P2-X2	4.68	R4	3.69
P3-X3	3.45	R11	3.42	P2-X2	4.68	R4	3.69
P3-X3	3.45	R11	3.42	P4-X4	19.46	R12	-2.36

＜embodiment 6 〉

Fig. 9 represents the lens pie graph of the imaging lens system that embodiment 6 is related, table 21 expression lens data, each aspheric each coefficient of table 22 expression, the various data of table 23 expression, table 24 expression effective diameter end and in the radius-of-curvature at center.Among Fig. 9, symbol Ri, Di are corresponding to Ri, the Di of table 21.

[table 21]

Embodiment 6

[table 22]

Embodiment 6

[table 23]

Embodiment 6

FNo.	2.0	ω	79.2
FNo.	2.0	ω	79.2	L	22.71	IH	2.40
Bf	2.2	LD	10.56	L	22.71	IH	2.40
Bf	2.2	LD	10.56	f	1.3	ED	9.94
f ₁	-10.7	f ₁₂	-2.1	f	1.3	ED	9.94
f ₁	-10.7	f ₁₂	-2.1	f ₂	-3.5	f ₄₅	8.3
f ₃	7.9	f ₆	3.9	f ₂	-3.5	f ₄₅	8.3

[table 24]

Embodiment 6

P1-X1	182.71	R3	-6.42
P1-X1	182.71	R3	-6.42	P2-X2	3.77	R4	2.80
P3-X3	4.56	R11	4.10	P2-X2	3.77	R4	2.80
P3-X3	4.56	R11	4.10	P4-X4	8.44	R12	-3.34

＜embodiment 7 〉

Figure 10 represents the lens pie graph of the imaging lens system that embodiment 7 is related, table 25 expression lens data, each aspheric each coefficient of table 26 expression, the various data of table 27 expression, table 28 expression effective diameter end and in the radius-of-curvature at center.Among Figure 10, symbol Ri, Di are corresponding to Ri, the Di of table 25.Need to prove, glass is used as the material of the 6th lens L6 at embodiment 7.

[table 25]

Embodiment 7

[table 26]

Embodiment 7

[table 27]

Embodiment 7

[table 28]

Embodiment 7

P1-X1	-63.01	R3	-9.09
P1-X1	-63.01	R3	-9.09	P2-X2	4.11	R4	2.75
P3-X3	4.4	R11	4.72	P2-X2	4.11	R4	2.75
P3-X3	4.4	R11	4.72	P4-X4	8.11	R12	-4.17

＜embodiment 8 〉

Figure 11 represents the lens pie graph of the imaging lens system that embodiment 8 is related, table 29 expression lens data, each aspheric each coefficient of table 30 expression, the various data of table 31 expression, table 32 expression effective diameter end and in the radius-of-curvature at center.Among Figure 11, symbol Ri, Di are corresponding to Ri, the Di of table 29.

[table 29]

Embodiment 8

[table 30]

Embodiment 8

[table 31]

Embodiment 8

FNo.	2.0	ω	79.2
FNo.	2.0	ω	79.2	L	25.35	IH	2.40
Bf	2.3	LD	11.50	L	25.35	IH	2.40
Bf	2.3	LD	11.50	f	1.3	ED	11.36
f ₁	-12.6	f ₁₂	-2.5	f	1.3	ED	11.36
f ₁	-12.6	f ₁₂	-2.5	f ₂	-4.3	f ₄₅	9.0
f ₃	10.4	f ₆	4.7	f ₂	-4.3	f ₄₅	9.0

[table 32]

Embodiment 8

P1-X1	-49.35	R3	-7.28
P1-X1	-49.35	R3	-7.28	P2-X2	4.53	R4	3.54
P3-X3	5.25	R11	4.30	P2-X2	4.53	R4	3.54
P3-X3	5.25	R11	4.30	P4-X4	25.39	R12	-4.89

＜embodiment 9 〉

Figure 12 represents the lens pie graph of the imaging lens system that embodiment 9 is related, table 33 expression lens data, each aspheric each coefficient of table 34 expression, the various data of table 35 expression, table 36 expression effective diameter end and in the radius-of-curvature at center.Among Figure 12, symbol Ri, Di are corresponding to Ri, the Di of table 33.

[table 33]

Embodiment 9

Face number	Ri	Di	Ndj	vdj
Face number	Ri	Di	Ndj	vdj		1	15.19	1.50	1.8348	42.7
2	4.24	3.26				1	15.19	1.50	1.8348	42.7
2	4.24	3.26			3*	-14.29	1.25	1.5316	55.4
4*	2.41	2.01			3*	-14.29	1.25	1.5316	55.4
4*	2.41	2.01			5	6.04	2.00	1.9229	18.9
6	44.66	2.88			5	6.04	2.00	1.9229	18.9
6	44.66	2.88			7 (aperture diaphragms)	∞	0.00
8	5.11	3.00	1.8348	42.7	7 (aperture diaphragms)	∞	0.00
8	5.11	3.00	1.8348	42.7	9	-3.50	1.04	1.9229	18.9
10	18.33	0.10			9	-3.50	1.04	1.9229	18.9
10	18.33	0.10			11*	3.69	2.41	1.5316	55.4
12*	-3.78	1.43			11*	3.69	2.41	1.5316	55.4
12*	-3.78	1.43			13	∞	0.50	1.5168	64.2
14	∞	0.50			13	∞	0.50	1.5168	64.2
14	∞	0.50			15 (image planes)	∞

[table 34]

Embodiment 9

Face number	K	B3	B4	B5	B6
Face number	K	B3	B4	B5	B6	3	-2.40E+02	2.41E-02	-3.22E-03	-1.66E-03	5.89E-04
4	-1.76E+01	1.76E-01	-4.71E-02	1.53E-03	8.26E-04	3	-2.40E+02	2.41E-02	-3.22E-03	-1.66E-03	5.89E-04
4	-1.76E+01	1.76E-01	-4.71E-02	1.53E-03	8.26E-04	11	-4.19E+00	8.20E-03	1.94E-03	3.97E-04	3.19E-05
12	-1.57E+01	-3.55E-02	1.42E-02	2.04E-03	2.23E-05	11	-4.19E+00	8.20E-03	1.94E-03	3.97E-04	3.19E-05
12	-1.57E+01	-3.55E-02	1.42E-02	2.04E-03	2.23E-05	Face number	B7	B8	B9	B10
3	-6.81E-05	2.00E-06	4.81E-08	-1.84E-10		Face number	B7	B8	B9	B10
3	-6.81E-05	2.00E-06	4.81E-08	-1.84E-10		4	1.01E-04	-6.85E-05	1.78E-06	8.64E-07
11	-1.66E-05	-1.15E-05	-4.85E-06	-1.90E-06		4	1.01E-04	-6.85E-05	1.78E-06	8.64E-07
11	-1.66E-05	-1.15E-05	-4.85E-06	-1.90E-06		12	-5.09E-05	-1.83E-05	-7.92E-06	-5.22E-06

[table 35]

Embodiment 9

FNo.	2.0	ω	78.8
FNo.	2.0	ω	78.8	L	21.70	IH	2.40
Bf	2.3	LD	8.36	L	21.70	IH	2.40
Bf	2.3	LD	8.36	f	1.3	ED	8.30
f ₁	-7.5	f ₁₂	-1.9	f	1.3	ED	8.30
f ₁	-7.5	f ₁₂	-1.9	f ₂	-3.8	f ₄₅	8.9
f ₃	7.4	f ₆	4.0	f ₂	-3.8	f ₄₅	8.9

[table 36]

P1-X1	42.45	R3	-14.29
P1-X1	42.45	R3	-14.29	P2-X2	3.52	R4	2.41
P3-X3	4.47	R11	3.69	P2-X2	3.52	R4	2.41
P3-X3	4.47	R11	3.69	P4-X4	-32.83	R12	-3.78

Embodiment 9

Conditional (1)～(16) pairing value of the imaging lens system of table 37 expression and embodiment 1～9.Known to from table 37, embodiment 1～9 formula (1)～(16) that all satisfy condition.

[table 37]

Figure 13～Figure 21 represents (A) spherical aberration, (B) astigmatic aberration, (C) distortion aberration (distortion aberration) of the imaging lens system that the foregoing description 1～9 is related, the aberration diagram of (D) multiplying power chromatic aberation respectively.Each aberration diagram represents the d line is made as the aberration of reference wavelength, but also represents aberration about F line (wavelength 486.1nm), C line (wavelength 656.3nm) at spherical aberration diagram and multiplying power chromatic aberation figure.(parameter is handled, and 0≤θ≤ω), desirable image height is made as f * tan θ represents the departure from them for the focal distance f of distortion aberration diagram usefulness total system, half angle of view θ.The FNo. of spherical aberration diagram is the F value, and the ω of other aberration diagram represents half angle of view.Known to Figure 13～Figure 21, the foregoing description 1～9 revisal well each aberration.

The imaging lens system of embodiment 1～9 has suitably disposed 2 non-spherical lenses, when realizing cost degradation, has realized the good optical performance.Aspheric number many optical aberration correctings ability more is high more, but it is many that the sheet number of non-spherical lens becomes, and when then material all being made as plastics, can produce the unfavorable conditions such as unstable properties that are weaker than temperature variation, when material all is made as glass, can produce unfavorable conditions such as cost rising.

The imaging lens system of embodiment 1～9 has the good optical performance, have the F value concurrently and be 2.0 bright optical system and wide-angleization, can obtain good picture to the drawing corner, so, can be suitable for taking the vehicle mounted camera of image such as the place ahead, side, rear of automobile or monitoring camera etc.

Figure 22 carries the imaging lens system of present embodiment and the state of camera head as making use-case be illustrated in automobile 100.In Figure 22, automobile 100 possesses the outer camera 101 of side car of the dead range that is used to take its codriver's seat side side and is used to take the back sidecar foreign minister machine 102 of the dead range of automobile 100 rear sides, be installed in the back side of rearview mirror, take and the interior camera 103 of the car of driver's same field of view scope.The outer camera 101 of side car and back sidecar foreign minister's machine 102 and Che Nei camera 103 are camera head, possess the imaging lens system 1 of with good grounds embodiment of the present utility model and will be converted to the imaging apparatus 5 of electric signal by the optical image that imaging lens system 1 forms.

As above-mentioned, the related imaging lens system 1 of embodiment of the present utility model is sought miniaturization and lightweight, has the good optical performance, so also can small-sized, light weight constitute the interior camera 103 of side, back sidecar foreign minister's machine 101,102 and car, can be at the good picture of the shooting surface imaging of its imaging apparatus 5.

More than, exemplify embodiment and embodiment has illustrated the utility model, but the utility model is not limited to above-mentioned embodiment and embodiment, can be all distortion.For example, the value of the radius-of-curvature of each lens composition, face interval and refractive index can be not limited to the value shown in above-mentioned each numerical value embodiment, desirable other values.

In addition, in the embodiment of camera head, be suitable for example of the present utility model to illustrate, but the utility model is not limited to this purposes at the vehicle mounted camera, for example, also applicable to portable terminal with camera or monitoring camera etc.

Claims

1. an imaging lens system is characterized in that,

Possess successively from object side: the 1st lens of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens, when it was the concave-concave shape near optical axis, at least 1 was aspherical shape; The 3rd lens, it has positive focal power; Diaphragm; Engage lens, it has the 4th lens and the 5th lens that positive focal power the opposing party has a negative focal power and forms by engaging the either party, and wholely has a positive focal power; The 6th lens, when it had positive focal power, at least 1 was aspherical shape,

The material of above-mentioned the 3rd lens is a glass, and the Abbe number to the d line of above-mentioned the 3rd lens is made as γ ₃The time, satisfy following conditional (1):

γ ₃＜30 …(1)。

2. an imaging lens system is characterized in that,

The effective diameter as the face of side of above-mentioned the 1st lens is made as ED, the radius-of-curvature as the face of side of above-mentioned the 1st lens is made as R ₂The time, satisfy following conditional (2):

1.65＜ED/R ₂＜2.0…(2)。

3. an imaging lens system is characterized in that,

Possess successively from object side: the 1st lens of meniscus shape, its have negative focal power and with concave surface towards the picture side; The 2nd lens, when it was the concave-concave shape near optical axis, the face as side was an aspherical shape at least, and constituted in the mode that this effective diameter end as the face of side is weaker than its center according to negative focal power; The 3rd lens, it has positive focal power; Diaphragm; Engage lens, it has the 4th lens and the 5th lens that positive focal power the opposing party has a negative focal power and forms by engaging the either party, and wholely has a positive focal power; The 6th lens, when it has positive focal power, at least 1 is aspherical shape, according to this as the face of side near optical axis for convex form and positive focal power constitute in the mode that the effective diameter end is weaker than the center, perhaps near optical axis, constitute for convex form and in the mode that the effective diameter end has a negative focal power according to above-mentioned face as side.

4. according to claim 2 or 3 described imaging lens systems, it is characterized in that the material of above-mentioned the 3rd lens is a glass.

5. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The focal length of total system is made as f, face to the distance on the optical axis of image planes of the object side of above-mentioned the 1st lens is made as L, when the distance of face to the optical axis of image planes as side of above-mentioned the 6th lens is made as Bf, satisfies following conditional (3), (4):

14.0＜L/f＜21.0…(3)

1.3＜Bf/f＜2.0 …(4)。

6. imaging lens system according to claim 1 and 2 is characterized in that,

The face as side of above-mentioned the 2nd lens constitutes in the mode that the effective diameter end is weaker than the center according to negative focal power.

7. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The face of the object side of above-mentioned the 6th lens is according to constituting in the mode that the effective diameter end is weaker than the center for convex form and positive focal power near optical axis.

8. imaging lens system according to claim 1 and 2 is characterized in that,

Above-mentioned the 6th lens as the face of side according near optical axis, constituting in the mode that the effective diameter end is weaker than the center for convex form and positive focal power.

9. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The lens that constitute the positive focal power of having of above-mentioned joint lens are two convex forms.

10. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The lens that constitute the negative focal power of having of above-mentioned joint lens are the concave-concave shape.

11. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The focal length of total system is made as f, the synthetic focal length of above-mentioned the 1st lens and above-mentioned the 2nd lens is made as f ₁₂The time, satisfy following conditional (5):

-2.0＜f ₁₂/f＜-1.0…(5)。

12. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The focal length of total system is made as f, the focal length of above-mentioned the 3rd lens is made as f ₃The time, satisfy following conditional (6):

4.0＜f ₃/f＜8.0 …(6)。

13. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The focal length of total system is made as f, the synthetic focal length of above-mentioned the 4th lens and above-mentioned the 5th lens is made as f ₄₅The time, satisfy following conditional (7):

-6＜f ₄₅/f＜14 …(7)。

14. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The focal length of total system is made as f, above-mentioned the 2nd focal length of lens is made as f ₂The time, satisfy following conditional (8):

-3.5＜f ₂/f＜-2.2…(8)。

15. according to each described imaging lens system in the claim 1～3, it is characterized in that,

Face to the distance on the optical axis of above-mentioned diaphragm as side of above-mentioned the 3rd lens is made as D ₆, the distance of above-mentioned diaphragm to the optical axis of above-mentioned the 4th lens is made as D ₇The time, satisfy following conditional (9):

0.0＜D ₇/D ₆＜0.5 …(9)。

16. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The refractive index to the d line of above-mentioned the 1st lens is made as N ₁The time, satisfy following conditional (10):

1.70＜N ₁＜1.90 …(10)。

17. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The Abbe number to the d line that constitutes the lens with positive focal power of above-mentioned joint lens is made as γ _P, the Abbe number to the d line that will constitute the lens of the negative focal power of having of above-mentioned joint lens is made as γ _nThe time, satisfy following conditional (11), (12):

30＞γ _n …(11)

γ _p＞35 …(12)。

18. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The optics face diameter as the face of side of above-mentioned the 1st lens is made as LD, the radius-of-curvature as the face of side of above-mentioned the 1st lens is made as R ₂The time, satisfy following conditional (13):

1.7＜LD/R ₂＜2.0 …(13)。

19. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The material of above-mentioned the 2nd lens is plastics.

20. according to each described imaging lens system in the claim 1～3, it is characterized in that,

The material of above-mentioned the 6th lens is plastics.

21. a camera head is characterized in that possessing:

In the claim 1～3 each described imaging lens system and

To be converted to the imaging apparatus of electric signal by the optical image that this imaging lens system forms.