CN104391368B - The pick-up lens of three-chip type - Google Patents

Abstract

The invention discloses a kind of pick-up lens, it is included having the first lens of positive refracting power, have the second lens of negative refracting power and have the 3rd lens of positive refracting power successively by thing side to image side.Described pick-up lens meets relational expression: tan (HFOV) ＞ 0.74；TTL/ImgH ＜ 1.7；0.6 ＜ f1/f ＜ 0.8 and 1.3 ＜ f1/f2 ＜ 0.8.Wherein, HFOV is the half of the angle of visual field of described pick-up lens, TTL is the camera lens overall length of described pick-up lens, ImgH is described pick-up lens half of effective pixel area diameter on imaging surface, f1 is the focal length of described first lens, f2 is the focal length of described second lens, and f is the effective focal length of described pick-up lens.Meeting above-mentioned conditional makes the pick-up lens of better embodiment of the present invention have the characteristics such as larger field angle (Radix Rumicis), miniaturization and high image quality.

Description

The pick-up lens of three-chip type

Technical field

The present invention relates to pick-up lens, especially relate to the pick-up lens of a kind of three-chip type.

Background technology

Along with charge coupled device (charge-coupled device, CCD) and CMOS The performance of (complementary metal-oxide semiconductor, CMOS) imageing sensor improves and size reduces, Corresponding pick-up lens also needs to meet the requirement of high image quality and miniaturization.

Existing three-chip type pick-up lens has developed more ripe, but, the pick-up lens of three-chip type yet suffers from relatively Many restrictions.Such as, miniaturization causes the angle of visual field less, although and can being improved by the diopter of the lens of change camera lens and regard Rink corner, but distortion will be caused to deteriorate, thus cause image quality to decline.

Summary of the invention

It is contemplated that at least solve one of technical problem present in prior art.To this end, the present invention needs to provide one Plant pick-up lens.

Pick-up lens according to better embodiment of the present invention included successively there is positive refracting power by thing side to image side One lens, there are the second lens of negative refracting power and there are the 3rd lens of positive refracting power.Described pick-up lens meets relational expression: Tan (HFOV) ＞ 0.74；TTL/ImgH ＜ 1.7；0.6 ＜ f1/f ＜ 0.8 and-1.3 ＜ f1/f2 ＜-0.8.Wherein, HFOV is institute Stating the half of the angle of visual field of pick-up lens, TTL is the camera lens overall length of described pick-up lens, and ImgH is that described pick-up lens is in imaging The half of effective pixel area diameter on face, f1 is the focal length of described first lens, and f2 is the focal length of described second lens, and f is The effective focal length of described pick-up lens.

Meeting above-mentioned conditional makes the pick-up lens of better embodiment of the present invention have larger field angle (Radix Rumicis), little The characteristic such as type and high image quality.

In some embodiments, described pick-up lens also meets conditional: | (R1+R2)/(R1-R2) | ＜ 0.4 and- 1.5 ＜ R2/f ＜-0.5.Wherein, R1, R2 are respectively thing side and the radius of curvature of image side surface of described first lens.

In some embodiments, described pick-up lens also meets conditional :-8 ＜ (R5+R6)/(R5-R6) ＜-4 and 0.8 ＜ f3/f ＜ 1.6.Wherein, R5, R6 are respectively thing side and the radius of curvature of image side surface of described 3rd lens, and f3 is institute State the focal length of the 3rd lens.

In some embodiments, described pick-up lens also meets conditional: 1.4 ＜ CT1/CT2 ＜ 1.9 and 1.8 ＜ CT3/CT2 ＜ 2.0.Wherein, CT1 is the center thickness of described first lens, and CT2 is the center thickness of described second lens, CT3 Center thickness for described 3rd lens.

In some embodiments, described pick-up lens also meets conditional: 0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6。

In some embodiments, the thing side of described first lens is convex surface, and image side surface is convex surface.Described second lens Thing side be concave surface, image side surface is convex surface.The thing side of described 3rd lens is convex surface, and image side surface is concave surface, and thing side A point of inflexion is all there is with image side surface.

In some embodiments, described pick-up lens also includes the diaphragm being arranged between object and the second lens.

In some embodiments, described first lens, described second lens and described 3rd lens are all made of plastics.

In some embodiments, there is a point of inflexion in the image side surface of described second lens.

The additional aspect of the present invention and advantage will part be given in the following description, and part will become from the following description Obtain substantially, or recognized by the practice of the present invention.

Accompanying drawing explanation

Above-mentioned and/or the additional aspect of the present invention and advantage are from combining the accompanying drawings below description to embodiment and will become Obtain substantially with easy to understand, wherein:

Fig. 1 is the schematic diagram of the pick-up lens embodiment 1 that the present invention provides；

Fig. 2 is chromaticity difference diagram (mm) on the axle of embodiment 1；

Fig. 3 is the astigmatism figure (mm) of embodiment 1；

Fig. 4 is the distortion figure (%) of embodiment 1；

Fig. 5 is the ratio chromatism, figure (μm) of embodiment 1；

Fig. 6 is the schematic diagram of the pick-up lens embodiment 2 that the present invention provides；

Fig. 7 is chromaticity difference diagram (mm) on the axle of embodiment 2；

Fig. 8 is the astigmatism figure (mm) of embodiment 2；

Fig. 9 is the distortion figure (%) of embodiment 2；

Figure 10 is the ratio chromatism, figure (μm) of embodiment 2；

Figure 11 is the schematic diagram of the pick-up lens embodiment 3 that the present invention provides；

Figure 12 is chromaticity difference diagram (mm) on the axle of embodiment 3；

Figure 13 is the astigmatism figure (mm) of embodiment 3；

Figure 14 is the distortion figure (%) of embodiment 3；

Figure 15 is the ratio chromatism, figure (μm) of embodiment 3；

Figure 16 is the schematic diagram of the pick-up lens embodiment 4 that the present invention provides；

Figure 17 is chromaticity difference diagram (mm) on the axle of embodiment 4；

Figure 18 is the astigmatism figure (mm) of embodiment 4；

Figure 19 is the distortion figure (%) of embodiment 4；

Figure 20 is the ratio chromatism, figure (μm) of embodiment 4；

Figure 21 is the schematic diagram of the pick-up lens embodiment 5 that the present invention provides；

Figure 22 is chromaticity difference diagram (mm) on the axle of embodiment 5；

Figure 23 is the astigmatism figure (mm) of embodiment 5；

Figure 24 is the distortion figure (%) of embodiment 5；

Figure 25 is the ratio chromatism, figure (μm) of embodiment 5；

Figure 26 is the schematic diagram of the pick-up lens embodiment 6 that the present invention provides；

Figure 27 is chromaticity difference diagram (mm) on the axle of embodiment 6；

Figure 28 is the astigmatism figure (mm) of embodiment 6；

Figure 29 is the distortion figure (%) of embodiment 6；

Figure 30 is the ratio chromatism, figure (μm) of embodiment 6；

Figure 31 is the schematic diagram of the pick-up lens embodiment 7 that the present invention provides；

Figure 32 is chromaticity difference diagram (mm) on the axle of embodiment 7；

Figure 33 is the astigmatism figure (mm) of embodiment 7；

Figure 34 is the distortion figure (%) of embodiment 7；And

Figure 35 is the ratio chromatism, figure (μm) of embodiment 7.

Detailed description of the invention

Embodiments of the present invention are described below in detail, and the example of described embodiment is shown in the drawings, the most ad initio Represent same or similar element to same or similar label eventually or there is the element of same or like function.Below by ginseng The embodiment examining accompanying drawing description is exemplary, is only used for explaining the present invention, and is not considered as limiting the invention.

In describing the invention, it is to be understood that term " first ", " second " are only used for describing purpose, and can not It is interpreted as that instruction or hint relative importance or hidden conjunction indicate the quantity of indicated technical characteristic.Thus, define " the The feature of one ", " second " can express or hidden conjunction include one or more described features.In description of the invention In, " multiple " are meant that two or more, unless otherwise expressly limited specifically.

In describing the invention, it should be noted that unless otherwise clearly defined and limited, term " install ", " phase Even ", " connection " should be interpreted broadly, for example, it may be fixing connection, it is also possible to it is to removably connect, or is integrally connected；Can To be mechanical connection, it is also possible to be to electrically connect maybe can be in communication with each other；Can be to be joined directly together, it is also possible to by between intermediary Connect connected, can be connection or the interaction relationship of two elements of two element internals.Ordinary skill for this area For personnel, above-mentioned term concrete meaning in the present invention can be understood as the case may be.

Following disclosure provides many different embodiments or example for realizing the different structure of the present invention.In order to Simplifying disclosure of the invention, hereinafter parts and setting to specific examples are described.Certainly, they are the most merely illustrative, and And be not intended to limit the present invention.Additionally, the present invention can in different examples repeat reference numerals and/or reference letter, This repetition is for purposes of simplicity and clarity, between itself not indicating discussed various embodiment and/or arranging Relation.Additionally, the various specific technique that the invention provides and the example of material, but those of ordinary skill in the art are permissible Recognize the application of other techniques and/or the use of other materials.

Referring to Fig. 1, the pick-up lens of better embodiment of the present invention is included having positive flexion successively by thing side to image side First lens E1 of power, there is the second lens E2 of negative refracting power and there is the 3rd lens E3 of positive refracting power.Pick-up lens is full Foot relational expression:

Tan (HFOV) ＞ 0.74；

TTL/ImgH ＜ 1.7；

0.6 ＜ f1/f ＜ 0.8；And

-1.3 ＜ f1/f2 ＜-0.8.Wherein, HFOV is the half of the angle of visual field of pick-up lens, and TTL is the mirror of pick-up lens Head overall length, ImgH is pick-up lens half of effective pixel area diameter on imaging surface, and f1 is the focal length of the first lens E1, f2 Being the focal length of the second lens E2, f is the effective focal length of pick-up lens.

Meeting above-mentioned conditional makes the pick-up lens of better embodiment of the present invention have larger field angle (Radix Rumicis), little The characteristic such as type and high image quality.Concrete, it is bigger that relational expression tan (HFOV) ＞ 0.74 can ensure that pick-up lens has The angle of visual field, and relational expression TTL/ImgH ＜ 1.7 is conducive to the miniaturization of pick-up lens.First lens E1 provides foot for pick-up lens Enough refracting powers, it is ensured that contribute to shortening the camera lens overall length of pick-up lens while image quality.Second lens E2 and first saturating Mirror E1 carries out the distribution of suitable refracting power, is conducive to improving the resolution of pick-up lens.

In some embodiments, pick-up lens also meets conditional:

| (R1+R2)/(R1-R2) | ＜ 0.4；And

-1.5 ＜ R2/f ＜-0.5.

Wherein, R1, R2 are respectively thing side and the radius of curvature of image side surface of the first lens E1.

The shape so limiting the first lens E1 is conducive to increasing the angle of visual field of pick-up lens.

In some embodiments, pick-up lens also meets conditional:

-8 ＜ (R5+R6)/(R5-R6) ＜-4；And

0.8 ＜ f3/f ＜ 1.6.

Wherein, R5, R6 are respectively thing side and the radius of curvature of image side surface of the 3rd lens E3, and f3 is the 3rd lens E3's Focal length.

So limit shape facility and the refracting power of the 3rd lens E3, the distortion of pick-up lens can be effectively eliminated, promote Image quality.

In some embodiments, pick-up lens also meets conditional:

1.4 ＜ CT1/CT2 ＜ 1.9；And

1.8 ＜ CT3/CT2 ＜ 2.0.

Wherein, CT1 is the center thickness of the first lens E1, and CT2 is the center thickness of the second lens E2, and CT3 is the 3rd saturating The center thickness of mirror E3.

Be arranged such the first lens E1, the center of the second lens E2 and the 3rd lens E3 is conducive to the miniaturization of pick-up lens With produce, being smoothed out of packaging technology.

In some embodiments, pick-up lens also meets conditional: 0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6.

Being arranged such, beneficially requirements above is conducive to reducing the camera lens overall length of pick-up lens, promotes miniaturization.

In some embodiments, the thing side of the first lens E1 is convex surface, and image side surface is convex surface.The thing of the second lens E2 Side is concave surface, and image side surface is convex surface.The thing side of the 3rd lens E3 is convex surface, and image side surface is concave surface, and thing side and image side All there is a point of inflexion in face.

In some embodiments, pick-up lens also includes the diaphragm being arranged between object and the second lens E2.

In some embodiments, the first lens E1, the second lens E2 and the 3rd lens E3 are all made of plastics.

In some embodiments, there is a point of inflexion in the image side surface of the second lens E2.

Aspheric shape is determined by below equation:

$x=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(k+1)c^2{h}^2}}+\Σ{\mathrm{Aih}}^i,$

Wherein, h is that in aspheric surface, arbitrary point is vertex curvature to the height of optical axis, c, and k is conic constants, and Ai is aspheric surface The correction factor on the i-th-th rank.

Embodiment 1

Referring to Fig. 1, in the pick-up lens of embodiment 1, diaphragm is arranged between object and the first lens E1.Camera lens Head is included the thing side S2 and image side surface S3 of diaphragm face S1, the first lens E1, the thing side of the second lens E2 by thing side to image side The thing side S6 and image side surface S7 of S4 and image side surface S5, the 3rd lens E3.Through the light of pick-up lens by optical filter E4 imaging In imaging surface S10.Optical filter E4 includes thing side S8 and image side surface S9.

Pick-up lens meets following parameter:

TTL=2.83；F1=1.39；F2=-1.6；F3=2.79；F=1.98；

Tan (HFOV)=0.97；TTL/ImgH=1.45；

(R1+R2)/(R1-R2)=0.24；R2/f=-0.58；

F1/f=0.7；F1/f2=-0.87；

(R5+R6)/(R5-R6)=-7.11；F3/f=1.41；

CT1/CT2=1.74；CT3/CT2=1.83；

(CT1+CT2+CT3)/TTL=0.54；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 1-2:

Table 1

Table 2

Fig. 2 is chromaticity difference diagram (mm) on the axle of embodiment 1, and Fig. 3 is the astigmatism figure (mm) of embodiment 1, and Fig. 4 is embodiment 1 Distortion figure (%) and Fig. 5 are the ratio chromatism, figures (μm) of embodiment 1.It can be seen that the aberration of pick-up lens is meeting big Radix Rumicis And in the range of being still controlled in the case of miniaturization reasonably, thus ensure image quality.

Embodiment 2

Referring to Fig. 6, the pick-up lens of embodiment 2 is essentially identical with the pick-up lens of embodiment 1, but meets following ginseng Number:

TTL=2.66；F1=1.37；F2=-1.67；F3=2.65；F=1.83；

Tan (HFOV)=1.04；TTL/ImgH=1.37；

(R1+R2)/(R1-R2)=0.11；R2/f=-0.69；

F1/f=0.74；F1/f2=-0.82；

(R5+R6)/(R5-R6)=-6.68；F3/f=1.45；

CT1/CT2=1.44；CT3/CT2=1.82；

(CT1+CT2+CT3)/TTL=0.54；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 3-4:

Table 3

Table 4

Fig. 7 is chromaticity difference diagram (mm) on the axle of embodiment 2, and Fig. 8 is the astigmatism figure (mm) of embodiment 2, and Fig. 9 is embodiment 2 Distortion figure (%) and Figure 10 are the ratio chromatism, figures (μm) of embodiment 2.It can be seen that the aberration of pick-up lens is meeting big Radix Rumicis And in the range of being still controlled in the case of miniaturization reasonably, thus ensure image quality.

Embodiment 3

Referring to Figure 11, the pick-up lens of embodiment 3 is essentially identical with the pick-up lens of embodiment 1, but meets following ginseng Number:

The pick-up lens relevant parameter of the present embodiment is as follows:

TTL=2.94；F1=1.47；F2=-1.52；F3=2.47；F=2.10；

Tan (HFOV)=0.89；TTL/ImgH=1.52；

(R1+R2)/(R1-R2)=0.17；R2/f=-0.62；

F1/f=0.7；F1/f2=-0.96；

(R5+R6)/(R5-R6)=-5.04；F3/f=1.17；

CT1/CT2=1.51；CT3/CT2=1.87；

(CT1+CT2+CT3)/TTL=0.47；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 5-6:

Table 5

Table 6

Figure 12 is chromaticity difference diagram (mm) on the axle of embodiment 3, and Figure 13 is the astigmatism figure (mm) of embodiment 3, and Figure 14 is embodiment 3 Distortion figure (%) and Figure 15 be the ratio chromatism, figure (μm) of embodiment 3.It can be seen that the aberration of pick-up lens is meeting the most extensively In the range of being still controlled in the case of angle and miniaturization reasonably, thus ensure image quality.

Embodiment 4

Referring to Figure 16, the pick-up lens of embodiment 4 is essentially identical with the pick-up lens of embodiment 1, but meets following ginseng Number:

The pick-up lens relevant parameter of the present embodiment is as follows:

TTL=3.02；F1=1.54；F2=-1.6；F3=2.71；F=2.23；

Tan (HFOV)=0.84；TTL/ImgH=1.56；

(R1+R2)/(R1-R2)=-0.03；R2/f=-0.73；

F1/f=0.69；F1/f2=-0.96；

(R5+R6)/(R5-R6)=-5.82；F3/f=1.22；

CT1/CT2=1.85；CT3/CT2=1.898；

(CT1+CT2+CT3)/TTL=0.48；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 7-8:

Table 7

Table 8

Figure 17 is chromaticity difference diagram (mm) on the axle of embodiment 4, and Figure 18 is the astigmatism figure (mm) of embodiment 4, and Figure 19 is embodiment 4 Distortion figure (%) and Figure 20 be the ratio chromatism, figure (μm) of embodiment 4.It can be seen that the aberration of pick-up lens is meeting the most extensively In the range of being still controlled in the case of angle and miniaturization reasonably, thus ensure image quality.

Embodiment 5

Referring to Figure 21, the pick-up lens of embodiment 5 is essentially identical with the pick-up lens of embodiment 1, but meets following ginseng Number:

The pick-up lens relevant parameter of the present embodiment is as follows:

TTL=3.14；F1=1.73；F2=-1.59；F3=2.35；F=2.38；

Tan (HFOV)=0.8；TTL/ImgH=1.62；

(R1+R2)/(R1-R2)=-0.25；R2/f=-1.02；

F1/f=0.73；F1/f2=-1.09；

(R5+R6)/(R5-R6)=-4.56；F3/f=0.99；

CT1/CT2=1.5；CT3/CT2=1.805；

(CT1+CT2+CT3)/TTL=0.45；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 9-10:

Table 9

Table 10

Figure 22 is chromaticity difference diagram (mm) on the axle of embodiment 5, and Figure 23 is the astigmatism figure (mm) of embodiment 5, and Figure 24 is embodiment 5 Distortion figure (%) and Figure 25 be the ratio chromatism, figure (μm) of embodiment 5.It can be seen that the aberration of pick-up lens is meeting the most extensively In the range of being still controlled in the case of angle and miniaturization reasonably, thus ensure image quality.

Embodiment 6

Referring to Figure 26, the pick-up lens of embodiment 6 is essentially identical with the pick-up lens of embodiment 1, but meets following ginseng Number:

The pick-up lens relevant parameter of the present embodiment is as follows:

TTL=3.26；F1=1.92；F2=-1.61；F3=2.20；F=2.55；

Tan (HFOV)=0.75；TTL/ImgH=1.68；

(R1+R2)/(R1-R2)=-0.39；R2/f=-1.29；

F1/f=0.75；F1/f2=-1.2；

(R5+R6)/(R5-R6)=-4.02；F3/f=0.86；

CT1/CT2=1.73；CT3/CT2=1.82；

(CT1+CT2+CT3)/TTL=0.41；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 11-12:

Table 11

Table 12

Figure 27 is chromaticity difference diagram (mm) on the axle of embodiment 6, and Figure 28 is the astigmatism figure (mm) of embodiment 6, and Figure 29 is embodiment 6 Distortion figure (%) and Figure 30 be the ratio chromatism, figure (μm) of embodiment 6.It can be seen that the aberration of pick-up lens is meeting the most extensively In the range of being still controlled in the case of angle and miniaturization reasonably, thus ensure image quality.

Embodiment 7

Referring to Figure 31, the pick-up lens of embodiment 7 is essentially identical with the pick-up lens of embodiment 1, but diaphragm is arranged on Between first lens E1 and the second lens E2, therefore pick-up lens include successively from thing side the first lens E1 thing side S1 and Image side surface S2 and diaphragm face are S3.Pick-up lens meets following parameter:

The pick-up lens relevant parameter of the present embodiment is as follows:

TTL=2.89；F1=1.53；F2=-1.66；F3=2.55；F=2.07；

Tan (HFOV)=0.742；TTL/ImgH=1.49；

(R1+R2)/(R1-R2)=0.06；R2/f=-0.71；

F1/f=0.74；F1/f2=-0.92；

(R5+R6)/(R5-R6)=-5.42；F3/f=1.23；

CT1/CT2=1.74；CT3/CT2=1.89；

(CT1+CT2+CT3)/TTL=0.50；

Stop value: 2.4 and ImgH:1.94.

Pick-up lens also meets table 13-14:

Table 13

Table 14

Figure 31 is chromaticity difference diagram (mm) on the axle of embodiment 7, and Figure 32 is the astigmatism figure (mm) of embodiment 7, and Figure 33 is embodiment 7 Distortion figure (%) and Figure 35 be the ratio chromatism, figure (μm) of embodiment 7.It can be seen that the aberration of pick-up lens is meeting the most extensively In the range of being still controlled in the case of angle and miniaturization reasonably, thus ensure image quality.

In the description of this specification, reference term " embodiment ", " some embodiments ", " schematically implement The concrete example of mode ", " example ", " " or " some examples " description waited means to combine described embodiment or example description Specific features, structure, material or feature are contained at least one embodiment or the example of the present invention.In this specification In, the schematic representation of above-mentioned term is not necessarily referring to identical embodiment or example.And, the concrete spy of description Levy, structure, material or feature can combine in any one or more embodiments or example in an appropriate manner.

While embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that: Without departing from these embodiments being carried out multiple change in the case of the principle of the present invention and objective, revise, replace and become Type, the scope of the present invention is limited by claim and equivalent thereof.

Claims (11)

1. a pick-up lens, it is characterised in that included successively to image side by thing side:

There are the first lens of positive refracting power；

There are the second lens of negative refracting power；And

There are the 3rd lens of positive refracting power；

Described first lens, described second lens and described 3rd lens are all made of plastics

Described pick-up lens meets relational expression:

Tan (HFOV) ＞ 0.74；

TTL/ImgH ＜ 1.7；

| (R1+R2)/(R1-R2) | ＜ 0.4；And

-1.5 ＜ R2/f ＜-0.5；

0.6 ＜ f1/f ＜ 0.8；And

-1.3 ＜ f1/f2 ＜-0.8；

Wherein, HFOV is the half of the angle of visual field of described pick-up lens, and TTL is the camera lens overall length of described pick-up lens, and ImgH is Described pick-up lens is the half of effective pixel area diameter on imaging surface, and R1, R2 are respectively the thing side of described first lens With the radius of curvature of image side surface, f1 is the focal length of described first lens, and f2 is the focal length of described second lens, and f is described shooting The effective focal length of camera lens.

2. pick-up lens as claimed in claim 1, it is characterised in that described pick-up lens also meets conditional:

-8 ＜ (R5+R6)/(R5-R6) ＜-4；And

0.8 ＜ f3/f ＜ 1.6；

Wherein, R5, R6 are respectively thing side and the radius of curvature of image side surface of described 3rd lens, and f3 is described 3rd lens Focal length.

3. pick-up lens as claimed in claim 1, it is characterised in that described pick-up lens also meets conditional:

1.4 ＜ CT1/CT2 ＜ 1.9；

And 1.8 ＜ CT3/CT2 ＜ 2.0；

Wherein, CT1 is the center thickness of described first lens, and CT2 is the center thickness of described second lens, and CT3 is described The center thickness of three lens.

4. pick-up lens as claimed in claim 2, it is characterised in that described pick-up lens also meets conditional:

1.4 ＜ CT1/CT2 ＜ 1.9；

And 1.8 ＜ CT3/CT2 ＜ 2.0；

Wherein, CT1 is the center thickness of described first lens, and CT2 is the center thickness of described second lens, and CT3 is described The center thickness of three lens.

5. pick-up lens as claimed in claim 1, it is characterised in that described pick-up lens also meets conditional:

0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6.

6. pick-up lens as claimed in claim 2, it is characterised in that described pick-up lens also meets conditional:

0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6.

7. pick-up lens as claimed in claim 3, it is characterised in that described pick-up lens also meets conditional:

0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6.

8. pick-up lens as claimed in claim 4, it is characterised in that described pick-up lens also meets conditional:

0.4 ＜ (CT1+CT2+CT3)/TTL ＜ 0.6.

9. pick-up lens as claimed in claim 1, it is characterised in that the thing side of described first lens is convex surface, image side surface For convex surface；The thing side of described second lens is concave surface, and image side surface is convex surface；The thing side of described 3rd lens is convex surface, as Side is concave surface, and thing side and image side surface all exist a point of inflexion.

10. pick-up lens as claimed in claim 1, it is characterised in that described pick-up lens also include being arranged at object and Diaphragm between second lens.

11. pick-up lenss as claimed in claim 1, it is characterised in that the image side surface of described second lens exists a contrary flexure Point.