CN201298100Y - Image pickup lens and image pickup device - Google Patents

Abstract

The utility model relates to an image pickup lens and an image pickup device; and the image pickup lens is miniature, has low cost and keeps good optical performance. The image pickup lens is subsequently provided with the followings from the object side: a negative first lens (L1), a positive second lens (L2), a diaphragm and a positive third lens (L3), wherein the concave surface of the negative first lens (L1) faces to the image side; the positive second lens (L2) is of a double convex shape when near an optical axis, and the two surfaces are non-spherical; and the convex surface of the positive third lens (L3) faces to the image side when near the optical axis, and both surfaces are non-spherical. The focus of the second lens (L2) is set to be (f[2]), and the synthesis focus of the second lens (L2) and the third lens (L3) is set to be (f[23]); and when the distance from the surface of the object side of the first lens (L1) to the optical axis of the image surface is set to be (L), the following formulas (1), (2) are met: 0.31<f[23]/L<0.45...(1), 0.40<f[2]/f[23]<0.75...(2).

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 requirement is equipped on miniaturization, the lightweight of its imaging lens system.

In addition, be the good visual field of the wide scope of the imaging lens system guaranteeing to use with camera, monitoring camera etc., Yi Bian to require be wide-angle, Yi Bian the high imaging performance that has in whole active area scope at vehicle mounted camera, portable terminal.

Further, in the imaging lens system in above-mentioned field, because of requiring cost degradation, so, require the few optical system of lens number.In the past, as the imaging lens system of the less wide-angle of lens number in the above-mentioned field, had the imaging lens system of the wide-angle of following patent documentation record.Patent documentation 1～4 records has 3 groups of 3 lens that constitute, seek wide-angleization that formed by the 1st negative lens, the 2nd positive lens, the 3rd positive lens that dispose successively from object side.

[patent documentation 1] patent disclosure 2006-201674 communique

[patent documentation 2] patent disclosure 2001-337268 communique

[patent documentation 3] patent disclosure 2006-91046 communique

[patent documentation 4] patent disclosure 2006-220691 communique

The utility model content

Except that above-mentioned requirements, in the imaging lens system in above-mentioned field, be necessary the damage of considering that against weather or dust storm etc. cause.For this reason, preferably do not use resin, preferably use glass as the material at the 1st lens of the most close object side configuration at least.

All faces of the lens of patent documentation 1 record are aspheric surface, and the reason glass lens forms aspheric surface and forms etc., so, and can compare by grinding the spherical lens of making, having becomes expensive unfavorable condition.Especially, the 1st lens that will become the maximum diameter lens are made as aspheric glass lens, then can significantly raise the cost.

The face as side of the 1st lens of patent documentation 2 record, the two sides of the 2nd lens, the two sides of the 3rd lens are aspheric surface, so the lens that have with patent documentation 1 become expensive unfavorable condition equally.

All faces of the lens of patent documentation 3 record are sphere, though help cost, compare with aspheric surface, and because of using the low sphere of design freedom only, so, be difficult to obtain desired high optical property.

The lens of patent documentation 4 record are because of paying attention to the multiplying power chromatic aberation, so, use the big lens of Abbe number difference as the material of the 1st lens and the 2nd lens, but its as a result on the axle chromatic aberation become big, have the unfavorable condition of the image quality reduction of drawing central portion.

The utility model is In view of the foregoing, and its purpose is, provides a kind of small-sized and low-cost, and can keep the imaging lens system of good optical performance and possess the camera head of this imaging lens system.

Imaging lens system of the present utility model is characterized in that, possesses successively from object side: the 1st negative lens, its with concave surface towards the picture side; The 2nd positive lens, when it was the biconvex shape near optical axis, the two sides was an aspheric surface; Diaphragm; The 3rd positive lens, its near the optical axis with convex surface towards the picture side in, the two sides is an aspheric surface.The focal length of above-mentioned the 2nd lens is made as f ₂, the synthetic focal length of above-mentioned the 2nd lens and the 3rd lens is made as f ₂₃, when the distance of face to the optical axis of imaging surface of the object side of above-mentioned the 1st lens is made as L, satisfy following conditions formula (1), (2):

0.31<f ₂₃/L<0.45?…(1)

0.40<f ₂/f ₂₃<0.75?…(2)。

Above-mentioned formation imaging lens system of the present utility model, by the lens number is suppressed at least 3, the 1st lens that dispose at the most close object side needn't necessarily use aspheric formation, seek miniaturization and cost degradation.In addition, imaging lens system of the present utility model comprises non-spherical lens by constituting, and when suitably selecting the formation of each lens, the formation of the formula that satisfies condition (1), (2), seek miniaturization and costization the time, seek all aberrations of revisal well.

In addition, in imaging lens system of the present utility model, 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 conditions formula (3):

0.10<f ₁₂/L<0.30?…(3)。

In addition, in imaging lens system of the present utility model, the focal length of above-mentioned the 1st lens is made as f ₁, the focal length of above-mentioned the 3rd lens is made as f ₃, near the radius-of-curvature the optical axis of the face of the object side of above-mentioned the 3rd lens is made as R ₅, near the radius-of-curvature as the optical axis of the face of side of above-mentioned the 3rd lens is made as R ₆The time, satisfy in following conditions formula (4)～(7) any one or all:

0.28<f ₃/L<0.75?…(4)

0.20<f ₂/f ₃<1.00?…(5)

-0.40<f ₁/L<-0.20?…(6)

0.50<R ₅/R ₆<1.50?…(7)。

In addition, in imaging lens system of the present utility model, above-mentioned the 1st lens can constitute meniscus shape, also can constitute the concave-concave shape.

Need to prove, when calculating above-mentioned L, divide the distance of using air to convert about rear cut-off distance.For example, when there were opticses such as wave filter in the lens of the most close image planes side between imaging surface, air this optics that converts calculated L.

In addition, above-mentioned conditional (1)～(7) each the value in, with e line (wavelength 546.07nm) as reference wavelength, in this manual, about Abbe number with d line (wavelength 587.6nm) as reference wavelength, but about other short of special requirement, just with the e line as reference wavelength.

Imaging lens system of the present utility model is characterized in that, possesses: claim 1 or 2 described imaging lens systems and will be converted to the imaging apparatus of electric signal by the optical image that this imaging lens system forms.

According to the utility model, by being few lens number of at least 3, and suitably set the shape and the refracting power of each lens, the formation of the formula that satisfies condition (1), (2), a kind of seek miniaturization and cost degradation are provided, and can keep the imaging lens system of good optical performance and possess the camera head of this imaging lens system.

Description of drawings

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

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

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

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

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

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

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

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

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

Figure 10 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 1.

Figure 11 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 2.

Figure 12 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 3.

Figure 13 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 4.

Figure 14 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 5.

Figure 15 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 6.

Figure 16 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 7.

Figure 17 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 8.

Figure 18 is each aberration diagram of the related imaging lens system of expression embodiment of the present utility model 9.

Figure 19 is the figure of the configuration of the related vehicle mounted camera head of explanation embodiment of the present utility model.

Among the figure: 2-axle glazed thread, 3-off-axis ray, 5-imaging apparatus, the 100-automobile, 101,102-side, back sidecar foreign minister machine, camera in the 103-car, face interval on the optical axis of i face of Di-and i+1 face, Pim-image space, L1-the 1st lens, L2-the 2nd lens, L3-the 3rd lens, PP-optics, the radius-of-curvature of i face of Ri-, the St-diaphragm, the Z-optical axis.

Embodiment

Below, describe embodiment of the present utility model in detail with reference to accompanying drawing.Embodiment according to 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 that an embodiment of the present utility model is related.This configuration example shown in Figure 1 constitutes corresponding to the lens of following embodiment 1.In addition, Fig. 2～Fig. 9 represents other the lens profile figure of configuration example of imaging lens system that embodiment of the present utility model is related, and they constitute corresponding to following embodiment 2～9 lens.

The related imaging lens system of embodiment of the present utility model possesses successively from object side: the 1st negative lens L1, its with concave surface towards the picture side; The 2nd positive lens L2, when it was the biconvex shape near optical axis, the two sides was an aspheric surface; Aperture diaphragm St; The 3rd positive lens L3, its near the optical axis with convex surface towards the picture side in, the two sides is an aspheric surface.

Need to prove that Fig. 1～Fig. 9 also represents axle glazed thread 2, off-axis ray 3 in the lump.In addition, consider the situation of Fig. 1～Fig. 9, also illustrate at the image space Pim that comprises imaging lens system at the interior imaging apparatus that imaging surface disposed 5 at the suitable imaging lens system of camera head.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, when being applicable to camera head, according to the formation of the phase pusher side that lens are installed, preferred disposition glass cover or low-pass filter or infrared ray cut off filter etc., Fig. 1～Fig. 9 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 the scotopia camera, also can between lens combination and imaging apparatus, insert by ultraviolet light to the such light filter of azure 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 various wave filter same functions.

Secondly, detailed formation and its action effect of this imaging lens system are described.

By being made as at the 1st lens L1 of the most close object side configuration with the negative lens of concave surface towards the picture side, can be with the optical system wide-angleization.Herein, the 1st lens L1 can be meniscus shape, or also can be the concave-concave shape.

This imaging lens system is for example when harsh environment such as vehicle mounted camera use, with regard to the 1st lens L1 of the most close object side configuration, under having imagined the situation that can be exposed in wind and rain or the carwash solvent, if the 1st lens L1 is formed the meniscus shape of concave surface towards the picture side, then has advantages such as in these situations, being difficult to the residual dust of worrying, dust, water droplet.In addition, compare with the situation of concave-concave shape, because of the mitigation that becomes of light complications, so, can reduce the aberration generating capacity, favourable aspect revisals such as distortion aberration.

When the 1st lens L1 is made as the concave-concave shape, compare, can strengthen the negative focal power (power) that the 1st lens L1 is had with being made as meniscus shape, make from the bending of light of the wide-angle of object side incident by strong negative focal power thus, so, but the reducing glass footpath helps miniaturization.

By the 2nd lens L2 and the 3rd lens L3 are formed the high non-spherical lens of design freedom, favourable aspect optical aberration correcting, can obtain good resolution with few lens number.In addition,, can make the 2nd lens L2 have strong positive focal power, help miniaturization by the 2nd lens L2 is made as the biconvex shape near optical axis.

This imaging lens system is made as f at the focal length with the 2nd lens L2 ₂, the synthetic focal length of the 2nd lens L2 and the 3rd lens L3 is made as f ₂₃, when the distance of face to the optical axis of imaging surface of the object side of the 1st lens L1 is made as L, preferably satisfy following conditions formula (1), (2).

0.31<f ₂₃/L<0.45?…(1)

0.40<f ₂/f ₂₃<0.75?…(2)

The synthetic focal length of 2 positive lenss that conditional (1) this imaging lens system of regulation is possessed and the ratio of optical system length overall.Surpass going up in limited time of conditional (1), the positive focal power of the 2nd lens L2 and the 3rd lens L3 dies down, in order to obtain the balance of the total system of following it, will weaken the negative focal power of the 1st lens L1, so, be difficult to revisal spherical aberration well (also claiming spherical aberration) and astigmatic aberration (also claiming astigmatism).Surpass the lower limit of conditional (1), then be difficult to revisal spherical aberration well, coma aberration (also claiming coma), curvature of the image (also claiming the curvature of field).

The ratio of the synthetic focal length of 2 positive lenss that conditional (2) this imaging lens system of regulation is possessed and the focal length of the 2nd lens L2 that approaches the most close aperture diaphragm St.Surpass the upper limit of conditional (2), then be difficult to revisal coma aberration well, curvature of the image.The lower limit that surpasses conditional (2), the positive focal power grow of the 2nd lens L2 then is so when the 2nd lens L2 sought high form accuracy and positional precision, it is big that multiplying power chromatic aberation (also claiming ratio chromatism) becomes.

In addition, this imaging lens system is made as f at the synthetic focal length with the 1st lens L1 and the 2nd lens L2 ₁₂The time, preferably satisfy following conditions formula (3).

0.10<f ₁₂/L<0.30?…(3)

The focal length of 2 lens of conditional (3) regulation object side and the ratio of optical system length overall.Surpass going up in limited time of conditional (3), the synthetic focal length of the 1st lens L1 and the 2nd lens L2 is elongated, restrain towards imaging surface in order to make light, for the required focal power of integral body, it is big that the burden of the 3rd lens L3 becomes, will seek high form accuracy and positional precision at the 3rd lens L3, have the anxiety of making stability or cost rising.The lower limit that surpasses conditional (3) then is difficult to the astigmatism of revisal well aberration, coma aberration.

In addition, this imaging lens system is made as f at the focal length with the 1st lens L1 ₁, the focal length of the 3rd lens L3 is made as f ₃, near the radius-of-curvature the optical axis of the face of the object side of the 3rd lens L3 is made as R ₅, near the radius-of-curvature as the optical axis of the face of side of the 3rd lens L3 is made as R ₆The time, preferably satisfy in following conditions formula (4)～(7) any one or all.

0.28<f ₃/L<0.75?…(4)

0.20<f ₂/f ₃<1.00?…(5)

-0.40<f ₁/L<-0.20?…(6)

0.50<R ₅/R ₆<1.50?…(7)

Conditional (4) regulation is focal length and the optical system length overall of the 3rd lens L3 of close imaging surface.Surpass the upper limit of conditional (4), the tendency that the aberration that then distorts becomes too big is strong.Surpass the lower limit of conditional (4), then the positive focal power of the 3rd lens L3 becomes too strong, will seek high form accuracy and positional precision at the 3rd lens L3, and has the anxiety of making stability or cost rising.

The ratio of the focal power of conditional (5) regulation the 2nd lens L2 and the 3rd lens L3.Surpass going up in limited time of conditional (5), compare with the 2nd lens L2, the positive focal power of the 3rd lens L3 becomes too strong, will seek high form accuracy and positional precision at the 3rd lens L3.The lower limit that surpasses conditional (5) then is difficult to the astigmatism of revisal well aberration, coma aberration.

Conditional (6) is defined in the 1st lens L1 and the optical system length overall of the most close object configuration.The upper limit that surpasses conditional (6) then is difficult to the astigmatism of revisal well aberration, coma aberration.The lower limit that surpasses conditional (6) obtains the visual angle of wide-angle more than 100 ° in the time of the aberration that then is difficult to keep good.

Conditional (7) regulation is the focal power of the face of the face of the object side of the 3rd lens L3 of close imaging surface and picture side.In the imaging lens system of Fig. 1～configuration example shown in Figure 9, the face of the object side of the 3rd lens L3 is a concave surface, is convex surface as the face of side.In the imaging lens system that so constitutes, surpass the upper limit of conditional (7), then be the focal power grow of the 3rd lens L3 of positive lens, will seek high form accuracy and positional precision at the 3rd lens L3.Surpass the lower limit of conditional (7), then the focal power of the 3rd lens L3 dies down, and it is strong to distort the excessive tendency of aberration.

In addition, in this imaging lens system, the Abbe number to the d line of the 1st lens is made as γ ₁, the Abbe number to the d line of the 2nd lens is made as γ ₂The time, preferably satisfy following conditions formula (8).

-10<γ ₁-γ ₂<25?…(8)

The upper limit that surpasses conditional (8), then axle is gone up the chromatic aberation change greatly, especially the image degradation of drawing central portion.The lower limit that surpasses conditional (8), then the last chromatic aberation of axle is very changed, but the multiplying power chromatic aberation becomes excessive, the image degradation of picture periphery.

In addition, in this imaging lens system, shown in the embodiment described as follows, the Abbe number of the 1st lens L1 and the 3rd lens L3 is preferably more than 40.At this moment, can suppress a last chromatic aberation, obtain good resolution, simultaneously, can suppress the multiplying power chromatic aberation at the sufficient resolution of the whole acquisition of picture at the picture central part.

Need to prove, when for example in harsh environment such as vehicle mounted camera, using this imaging lens system, preferably use anti-anti-because of the surperficial cracking due to wind and rain or the sandy soil, 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, 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 material hard and that be 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 3rd lens L3, preferably use plastics.Be made as plastics by material, but when precision is made aspherical shape, can seek lightweight and cost degradation goodly the 2nd lens L2 and the 3rd lens L3.

According to plastic material, because of the water absorptivity height then changes refractive index and geomery by the discrepancy of moisture, so, may produce bad influence to optical property.Therefore, by using minimum polycarbonate-based, the polyester of water absorptivity, polyolefins plastics material, the mis-behave that causes because of suction can be suppressed at irreducible minimum as the 2nd lens L2 and the 3rd lens L3.

In addition, in this imaging lens system, 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.

[embodiment]

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

＜embodiment 1 〉

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

[table 1]

Embodiment 1 lens data

Face number	Ri	Di	Nej	γdj
						1	12.0982	1.000	1.77621	49.6
2	2.0932	3.886
					3*	2.2678	1.750	1.53340	55.4
4*	-2.6171	0.100
					5 (aperture diaphragms)	∞	0.938
6*	-1.2827	1.800	1.53340	55.4
					7*	-1.4853

Fno.＝2.8，ω＝56.6，Bf＝2.465，f＝2.050

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.In addition, in the lens data of table 1, aspheric surface at face number with the * seal.

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, Nej 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 e 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.

The various data of the imaging lens system that embodiment 1 is related are represented in the below of table 1.In these various data, Fno. is the F value, and ω is a half angle of view, and Bf is the rear cut-off distance that air converted, and f is the focal length of total system.In these various data, the unit of ω is degree, and the unit beyond Fno. and the ω all is mm.

Table 2 expression is by each aspheric each COEFFICIENT K of following aspheric surface formula definition, the value of B3～B10.Need to prove that the meaning of the various marks in the above-mentioned explanation among the embodiment 1 is also identical with following embodiment.

[mathematical expression 1]

$\mathrm{Zh}=\frac{{\mathrm{<figure-callout\; id="2"\; label="CY"\; filenames="Y200820137138E00272.png,Y200820137138E00281.png"\; state="\{\{state\}\}">CY</figure-callout>}}^2}{1+{(1-K\&CenterDot;C^2{Y}^2)}^{1/2}}+\underset{m=3}{\overset{10}{\mathrm{\&Sigma;}}}\mathrm{Bm}{Y}^m$

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

Y: highly (from the distance of optical axis)

C: the inverse of paraxial radius-of-curvature

K, Bm: asphericity coefficient (m=3～10)

[table 2]

Embodiment 1 asphericity coefficient

Face number	3	4	6	7
					K	-3.8834E+01	3.3344E+00	-1.5540E+03	3.2140E-01
B3	2.2111E-01	5.6232E-02	-3.2633E+00	-9.6709E-02
					B4	-1.5898E-01	-1.7093E-01	1.0706E+01	1.5417E-01
B5	1.7835E-01	1.5991E-01	-1.3798E+01	5.7693E-02
					B6	-6.6522E-02	1.4811E-01	-6.2515E+00	-3.7831E-01
B7	-1.1884E-01	-1.7860E-01	2.5268E+01	2.7955E-01
					B8	3.7318E-02	-1.7746E-01	3.1518E+00	5.8133E-02
B9	9.1555E-02	2.5022E-01	-3.6988E+01	-1.3630E-01
					B10	-5.1071E-02	-6.9704E-02	2.0822E+01	4.0007E-02

＜embodiment 2 〉

Fig. 2 represents the lens pie graph of the imaging lens system that embodiment 2 is related, table 3 expression lens data, each aspheric each coefficient of table 4 expression.Among Fig. 2, symbol Ri, Di are corresponding to Ri, the Di of table 3.

[table 3]

Embodiment 2 lens datas

Face number	Ri	Di	Nej	γdj
						1	17.9362	1.000	1.77621	49.6
2	2.4688	4.150
					3*	2.3050	1.750	1.53340	55.4
4*	-2.4997	0.100
					5 (aperture diaphragms)	∞	0.992
6*	-1.1102	1.800	1.53340	55.4
					7*	-1.2715

Fno.＝2.8，ω＝55.7，Bf＝2.172，f＝1.956

[table 4]

Embodiment 2 asphericity coefficients

Face number	3	4	6	7
					K	-1.1701E+01	2.9960E+00	-4.6065E+02	5.7561E-01
B3	4.3968E-02	5.7115E-02	-2.5623E+00	-7.1209E-02
					B4	-2.7154E-02	-1.9070E-01	6.6131E+00	2.2171E-01
B5	1.8266E-01	1.5051E-01	-6.6422E+00	-9.4123E-02
					B6	-1.0939E-01	2.1803E-01	-6.9029E+00	-2.8715E-01
B7	-1.3613E-01	-2.3827E-01	2.0295E+01	3.2271E-01
					B8	5.7913E-02	-2.4483E-01	-1.0071E+01	4.5935E-02
B9	1.0077E-01	3.7688E-01	-7.3856E+00	-1.7764E-01
					B10	-5.9459E-02	-1.1937E-02	6.1393E+00	6.0336E-02

＜embodiment 3 〉

Fig. 3 represents the lens pie graph of the imaging lens system that embodiment 3 is related, table 5 expression lens data, each aspheric each coefficient of table 6 expression.Among Fig. 3, symbol Ri, Di are corresponding to Ri, the Di of table 5.

[table 5]

Embodiment 3 lens datas

Face number	Ri	Di	Nej	γdj
						1	29.2927	1.000	1.77621	49.6
2	2.7000	4.146

3*	2.2074	1.750	1.53340	55.4
					4*	-2.8778	0.100
5 (aperture diaphragms)	∞	0.992
					6*	-1.1757	1.800	1.53340	55.4
7*	-1.2664

Fno.＝2.8，ω＝55.8，Bf＝2.174，f＝1.964

[table 6]

Embodiment 3 asphericity coefficients

Face number	3	4	6	7
					K	-1.2171E+01	-1.1470E+01	-5.0930E+02	5.5187E-01
B3	4.6128E-02	1.0056E-01	-2.2910E+00	-6.0166E-02
					B4	-1.2654E-02	-3.9254E-01	5.7488E+00	1.6356E-01
B5	1.8751E-01	2.2205E-01	-5.9540E+00	5.1332E-04
					B6	-1.1330E-01	3.3357E-01	-5.8167E+00	-3.2843E-01
B7	-1.4254E-01	-2.3907E-01	1.9687E+01	2.9470E-01
					B8	5.9119E-02	-3.9870E-01	-1.4350E+01	5.4177E-02
B9	1.0409E-01	3.9801E-01	-1.0678E+00	-1.5866E-01
					B10	-5.8639E-02	-8.0021E-02	3.5444E+00	5.1960E-02

＜embodiment 4 〉

Fig. 4 represents the lens pie graph of the imaging lens system that embodiment 4 is related, table 7 expression lens data, each aspheric each coefficient of table 7 expression.Among Fig. 4, symbol Ri, Di are corresponding to Ri, the Di of table 7.

[table 7]

Embodiment 4 lens datas

Face number	Ri	Di	Nej	γdj
						1	12.6215	1.000	1.77621	49.6
2	1.6840	2.507
					3*	1.4273	1.750	1.53340	55.4
4*	-2.7525	0.100
					5 (aperture diaphragms)	∞	0.510

6*	-0.9129	1.800	1.53340	55.4
					7*	-1.2168

Fno.＝2.8，ω＝56.5，Bf＝2.466，f＝2.052

[table 8]

Embodiment 4 asphericity coefficients

Face number	3	4	6	7
					K	-6.2822E-01	-9.1370E+00	-4.5560E+02	-2.6820E+00
B3	4.9939E-02	-5.1775E-03	-3.3945E+00	1.1181E-03
					B4	-3.1603E-02	2.6507E-02	1.0902E+01	-6.8988E-02
B5	1.3953E-01	-2.8015E-02	-1.6810E+01	-1.1004E-01
					B6	-5.8409E-02	1.0301E-02	-7.2808E-01	-1.4547E-01
B7	-9.7332E-02	-1.4166E-01	2.7622E+01	3.2187E-01
					B8	4.6188E-02	-4.8878E-02	-3.8862E+00	-1.0265E-02
B9	8.8407E-02	3.3435E-01	-4.5843E+01	-1.7692E-01
					B10	-6.0050E-02	-1.7974E-01	3.3220E+01	6.7206E-02

＜embodiment 5 〉

Fig. 5 represents the lens pie graph of the imaging lens system that embodiment 5 is related, table 9 expression lens data, each aspheric each coefficient of table 10 expression.Among Fig. 5, symbol Ri, Di are corresponding to Ri, the Di of table 9.

[table 9]

Embodiment 5 lens datas

Face number	Ri	Di	Nej	γdj
					1	-17.9737	1.000	1.77621	49.6
2	2.5000	1.589
					3*	1.9024	1.700	1.58820	30.3
4*	-2.3239	0.200
					5 (aperture diaphragms)	∞	0.594
6*	-1.0472	1.800	1.51081	56.0
					7*	-1.0413

Fno.＝2.8，＝58.4，Bf＝2.096，f＝1.950

[table 10]

Embodiment 5 asphericity coefficients

Face number	3	4	6	7
					K	9.7669E-01	2.1649E+00	-2.5195E+02	-3.6310E+00
B3	-5.1481E-02	-5.4321E-02	-1.9830E+00	3.3638E-02
					B4	1.4034E-01	1.3158E-01	3.6197E+00	-4.3607E-01
B5	-1.2922E-01	-1.3150E-01	-2.3059E+00	2.6749E-01
					B6	-3.6644E-02	-1.8378E-02	-3.1776E+00	-2.7885E-02
B7	6.8169E-03	1.8110E-02	2.2126E+00	5.2462E-03
					B8	4.2919E-02	2.3655E-02	4.6582E+00	-1.8792E-02
B9	2.3791E-02	2.1598E-02	-2.3233E+00	-1.0816E-02
					B10	-4.3067E-02	-2.2442E-02	-2.1123E+00	9.1046E-03

＜embodiment 6 〉

Fig. 6 represents the lens pie graph of the imaging lens system that embodiment 5 is related, table 11 expression lens data, each aspheric each coefficient of table 12 expression.Among Fig. 6, symbol Ri, Di are corresponding to Ri, the Di of table 11.

[table 11]

Embodiment 6 lens datas

Face number	Ri	Di	Nej	γdj
					1	-29.2847	1.000	1.77621	49.6
2	2.5000	1.499
					3*	1.9282	1.700	1.53340	55.4
4*	-2.0696	0.201
					5 (aperture diaphragms)	∞	0.568
6*	-1.1777	1.800	1.51081	56.0
					7*	-1.0404

Fno.＝2.8，ω＝56.6，Bf＝2.120，f＝1.900

[table 12]

Embodiment 6 asphericity coefficients

Face number	? 3	? 4	? 6	? 7
					K	6.1688E-01	2.1393E+00	-2.7687E+02	-1.0654+01
B3	-2.8404E-02	-1.9076E-02	-1.9749E+00	-2.7164E-01
					B4	1.2770E-01	1.0436E-01	4.0090E+00	-2.3958E-01
B5	-1.1805E-01	-1.0518E-01	-3.3107E+00	3.3620E-01
					B6	-2.9444E-02	-4.0963E-03	-3.4980E+00	-9.0807E-02
B7	3.9623E-03	2.0892E-02	4.8704E+00	-2.7756E-02
					B8	3.9178E-02	1.8288E-02	6.1705E+00	-1.0791E-02
B9	2.4819E-02	1.7311E-02	-9.9353E+00	3.3357E-03
					B10	-4.1938E-02	-1.7746E-02	2.6359E+00	6.3802E-03

＜embodiment 7 〉

Fig. 7 represents the lens pie graph of the imaging lens system that embodiment 7 is related, table 13 expression lens data, each aspheric each coefficient of table 14 expression.Among Fig. 7, symbol Ri, Di are corresponding to Ri, the Di of table 13.

[table 13]

Embodiment 7 lens datas

Face number	Ri	Di	Nej	γdj
						1	50.0000	1.000	1.77621	49.6
2	2.5000	1.913
					3*	2.2664	1.700	1.53340	55.4
4*	-1.8881	0.200
					5 (aperture diaphragms)	∞	0.600
6*	-1.1298	1.800	1.53340	55.4
					7*	-1.0346

Fno.＝2.8，ω＝54.5，Bf＝2.017，f＝1.825

[table 14]

Embodiment 7 asphericity coefficients

Face number	3	4	6	7
					K	7.9380E-01	1.6885E+00	-2.5259E+02	-5.0556E+00

B3	-3.8848E-02	-8.4625E-03	-1.9482E+00	-1.0610E-01
					B4	1.2875E-01	1.0876E-01	3.4765E+00	-3.4349E-01
B5	-1.2866E-01	-1.5470E-01	-1.5814E+00	2.3628E-01
					B6	-2.7954E-02	3.4711E-02	-4.8507E+00	1.0420E-02
B7	-3.7808E-03	5.9919E-02	2.3807E+00	3.1802E-03
					B8	4.5844E-02	-6.7222E-04	7.4041E+00	-3.9492E-02
B9	3.8122E-02	-3.2474E-02	-3.2261E+00	-2.2346E-02
					B10	-5.2955E-02	1.3116E-02	-3.0973E+00	2.1636E-02

＜embodiment 8 〉

Fig. 8 represents the lens pie graph of the imaging lens system that embodiment 8 is related, table 15 expression lens data, each aspheric each coefficient of table 16 expression.Among Fig. 8, symbol Ri, Di are corresponding to Ri, the Di of table 15.

[table 15]

Embodiment 8 lens datas

Face number	Ri	Di	Nej	γdj
						1	50.0000	1.000	1.77621	49.6
2	2.5000	2.647
					3*	1.4130	1.750	1.53340	55.4
4*	-5.1431	0.200
					5 (aperture diaphragms)	∞	0.313
6*	-1.0818	1.800	1.53340	55.4
					7*	-1.0928

Fno.＝2.8，ω＝55.3，Bf＝2.118，f＝1.933

[table 16]

Embodiment 8 asphericity coefficients

Face number	3	4	6	7
					K	3.6254E-01	-2.0546E+00	-6.8375E+02	-3.0769E+00
B3	-8.0497E-03	1.6974E-03	-3.2673E+00	-6.5583E-02
					B4	-8.0405E-03	1.9503E-02	1.1132E+01	-9.5702E-02

B5	1.3261E-01	-3.5808E-02	-1.7965E+01	-6.1054E-02
					B6	-6.9851E-02	8.1837E-03	-1.3118E+00	-1.2123E-01
B7	-1.0007E-01	-1.3561E-01	2.9521E+01	2.9885E-01
					B8	4.8654E-02	-4.3548E-02	3.7707E-01	-3.4998E-02
B9	9.1244E-02	3.3401E-01	-4.5153E+01	-1.7865E-01
					B10	-5.9203E-02	-1.8133E-01	2.3399E+01	7.9149E-02

＜embodiment 9 〉

Fig. 9 represents the lens pie graph of the imaging lens system that embodiment 9 is related, table 17 expression lens data, each aspheric each coefficient of table 18 expression.Among Fig. 9, symbol Ri, Di are corresponding to Ri, the Di of table 17.

[table 17]

Embodiment 9 lens datas

Face number	Ri	Di	Nej	γdj
						1	50.0000	1.000	1.77621	49.6
2	2.5000	2.507
					3*	1.6804	1.750	1.53340	55.4
4*	-2.4092	0.100
					5 (aperture diaphragms)	∞	0.509
6*	-0.9619	1.800	1.53340	55.4
					7*	-1.0680

Fno.＝2.8，ω＝55.5，Bf＝2.112，f＝1.888

[table 18]

Embodiment 9 asphericity coefficients

Face number	3	4	6	7
					K	-1.0081E+00	-1.7994E+00	-4.1271E+02	-1.9326E+00
B3	2.5730E-02	-2.1679E-02	-3.4682E+00	-8.0811E-02
					B4	-3.8289E-02	-8.7819E-06	1.0974E+01	-2.8169E-03
B5	1.3452E-01	-4.4351E-02	-1.6851E+01	-1.0223E-01
					B6	-6.1225E-02	1.5557E-02	-8.6507E-01	-1.5853E-01

B7	-9.9078E-02	-1.1477E-01	2.7487E+01	3.0988E-01
					B8	4.3956E-02	-1.4496E-02	-3.8978E+00	-1.5341E-02
B9	8.4767E-02	3.4910E-01	-4.5618E+01	-1.7586E-01
					B10	-6.5317E-02	-2.2736E-01	3.3726E+01	7.2036E-02

In the foregoing description 1～4,6～9, as the material of lens, used optical glass at the 1st lens L1, used the polyolefins plastics at the 2nd lens L2 and the 3rd lens L3.In embodiment 5,, used optical glass in addition, used polycarbonate-based plastics, used the polyolefins plastics at the 3rd lens L3 at the 2nd lens L2 at the 1st lens L1 as the material of lens.

Above-mentioned conditional (1)～(7) corresponding value in the imaging lens system of table 19 expression and the foregoing description 1～9.As known from Table 19, all imaging lens systems of embodiment 1～9 all satisfy above-mentioned conditional (1)～(7).

[table 19]

	Formula (1) f 23/L	Formula (2) f 2/f 23	Formula (3) f 12/L	Formula (4) f 3/L?	Formula (5) f 2/f 3	Formula (6) f 1/L?	Formula (7) R 5/R 6
								Embodiment 1	0.320	0.681	0.144	0.706	0.309	-0.286	0.864
Embodiment 2	0.332	0.649	0.138	0.476	0.452	-0.317	0.873
								Embodiment 3	0.334	0.666	0.147	0.436	0.510	-0.326	0.928
Embodiment 4	0.355	0.574	0.155	0.638	0.319	-0.257	0.750
								Embodiment 5	0.395	0.589	0.222	0.387	0.602	-0.308	1.006
Embodiment 6	0.381	0.649	0.249	0.362	0.683	-0.329	1.132
								Embodiment 7	0.359	0.679	0.222	0.329	0.741	-0.371	1.092
Embodiment 8	0.361	0.647	0.198	0.367	0.636	-0.348	0.990
								Embodiment 9	0.357	0.625	0.179	0.379	0.589	-0.350	0.901

Figure 10～Figure 18 represents (A) spherical aberration (also claiming spherical aberration), (B) astigmatic aberration (also claiming astigmatism), (C) distortion aberration (distorton aberration) (also claiming distortion), (D) multiplying power chromatic aberation (also claiming ratio chromatism) of the imaging lens system that the foregoing description 1～9 is related, the aberration diagram of (E) coma aberration (also claiming coma) respectively.Need to prove each aberration that Figure 10～Figure 18 is illustrated in and is configured to parallel flat shape, thickness between the 3rd lens L3 and the imaging surface when be 0.5mm to the refractive index of e line being 1.52 optics PP.Each aberration diagram represents that with the aberration of e line as reference wavelength spherical aberration diagram and multiplying power chromatic aberation figure also represent the aberration about C line (wavelength 656.3nm), g line (wavelength 436nm), and have enclosed e, C, g symbol respectively.The longitudinal axis Fno. of spherical aberration diagram is the F value, and the ω of the longitudinal axis of other aberration diagram represents half angle of view.

Need to prove, with regard to the distortion aberration diagram, use total system focal distance f, half angle of view θ (parameter is handled, 0≤θ≤ω), and desirable image height is made as f * tan θ, expression is from their departure.This is that the imaging lens system of present embodiment will be the lens of benchmark based on the image height of stereoprojection, and has considered to compare with the general lens that will be benchmark based on the image height of equidistant projection, and the image of periphery amplifies appears before one's eyes.As can be known from Figure 10～Figure 18, the foregoing description 1～9 revisal well each aberration.

In addition, in the foregoing description 1～9, because of the 1st lens L1 is made as its material optical glass, the two sides is made as spherical shape, so, when can obtain not easy damaged that good against weather and sand and dust etc. cause, can make more at an easy rate.In addition,, and its material is made as plastics because of the 2nd lens L2 and the 3rd lens L3 are made as the high non-spherical lens of optical aberration correcting power, so, can realize aspherical shape accurately, and, light weight and imaging lens system cheaply can be provided.

That is, the imaging lens system of embodiment 1～9 is made of few lens number of 3, can seek miniaturization and lightweight, and makes at an easy rate, and, keep the good optical performance.Imaging lens system with embodiment 1～9 of these advantages can be adapted at being used to take the uses such as vehicle mounted camera of images such as vehicle front, side, rear.

Figure 19 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 19, automobile 100 install at the back side of rearview mirror be used to possess the outer camera 101 of side car of the dead range of taking its codriver's seat side side and be used to take automobile 100 rear sides dead range back sidecar foreign minister machine 102 and be installed on the back side of rearview mirror, and the interior camera 103 of the car of shooting and driver's same field of view scope.Outer camera 101 of car and the outer camera 102 of car and Che Nei camera 103 are camera head, possess the imaging lens system 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 forms.

The related imaging lens system of embodiment of the present utility model is because of having above-mentioned advantage, so, camera 103 in side, back sidecar foreign minister's machine 101,102 and the car also can be constituted small-sized, light weight, and cheap the manufacturing, but at the good picture of the shooting face 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 (10)

1. imaging lens system is characterized in that possessing successively from object side: the 1st negative lens, its with concave surface towards the picture side; The 2nd positive lens, when it was the biconvex shape near optical axis, the two sides was an aspheric surface; Diaphragm; The 3rd positive lens, its near the optical axis with convex surface in the picture side, the two sides is an aspheric surface, and the focal length of above-mentioned the 2nd lens is made as f ₂, the synthetic focal length of above-mentioned the 2nd lens and the 3rd lens is made as f ₂₃, when the distance of face to the optical axis of imaging surface of the object side of above-mentioned the 1st lens is made as L, satisfy following conditions formula (1), (2):

0.31<f ₂₃/L<0.45…(1)

0.40<f ₂/f ₂₃<0.75…(2)。

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

The synthetic focal length of above-mentioned the 1st lens and above-mentioned the 2nd lens is made as f ₁₂The time, satisfy following conditions formula (3):

0.10<f ₁₂/L<0.30…(3)。

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

The focal length of above-mentioned the 3rd lens is made as f ₃The time, satisfy following conditions formula (4):

0.28<f ₃/L<0.75…(4)。

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

The focal length of above-mentioned the 3rd lens is made as f ₃The time, satisfy following conditions formula (5):

0.20<f ₂/f ₃<1.00…(5)。

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

The focal length of above-mentioned the 1st lens is made as f ₁The time, satisfy following conditions formula (6):

-0.40<f ₁/L<-0.20…(6)。

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

Near the optical axis of the face of the object side of above-mentioned the 3rd lens radius-of-curvature is made as R ₅, near the radius-of-curvature as the optical axis of the face of side of above-mentioned the 3rd lens is made as R ₆The time, satisfy following conditions formula (7):

0.50<R ₅/R ₆<1.50…(7)。

7. imaging lens system according to claim 1 and 2 is characterized in that, above-mentioned the 1st lens are meniscus shape.

8. imaging lens system according to claim 1 and 2 is characterized in that, above-mentioned the 1st lens are the concave-concave shape.

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

The focal length of above-mentioned the 1st lens is made as f ₁, the focal length of above-mentioned the 3rd lens is made as f ₃, near the radius-of-curvature the optical axis of the face of the object side of above-mentioned the 3rd lens is made as R ₅, near the radius-of-curvature as the optical axis of the face of side of above-mentioned the 3rd lens is made as R ₆The time, satisfy following conditions formula (4)～(7):

0.28<f ₃/L<0.75…(4)

0.20<f ₂/f ₃<1.00…(5)

-0.40<f ₁/L<-0.20…(6)

0.50<R ₅/R ₆<1.50…(7)。

10. imaging lens system is characterized in that possessing:

Claim 1 or 2 described imaging lens systems and

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

Images