TWI514024B - Image pickup lens, image pickup apparatus and portable terminal - Google Patents

Description

Camera lens, camera device and portable terminal

The present invention relates to an imaging lens suitable for use in combination with an image sensor or the like, an imaging device including the same, and a portable terminal.

In recent years, the imaging device including a solid-state imaging device such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor has high performance and miniaturization. The mobile phone or portable information terminal of the device has become popular. Moreover, the imaging lens mounted on these imaging devices is strongly required to be further reduced in size and performance. As an imaging lens of such a use, since it is more capable of achieving higher performance than a lens composed of three or four lenses, an imaging lens having five lenses has been proposed.

The imaging lens having the five-piece configuration includes a first lens having a positive refractive power from the object side, a second lens having a negative refractive power, a third lens having a positive refractive power, and a negative refractive power. The imaging lens including the fourth lens and the fifth lens having positive refractive power has been Disclosure (for example, Patent Document 1).

However, the imaging lens described in Patent Document 1 is described above. The lens for correcting the image plane is arranged behind the lens having the power of the first lens to the fourth lens, and the aberration correction of the entire system is insufficient. If the lens is shortened again, the lens is shortened. In the entire length, it is difficult to cope with the problem of high pixelation of the imaging element due to deterioration in performance.

Also, the composition similar to the above document is the object side The first lens having positive refractive power, the second lens having negative refractive power, the third lens having positive refractive power, the fourth lens having negative refractive power, and the fifth lens having positive refractive power The imaging lens of the configuration has been disclosed (for example, Patent Document 2).

However, the imaging lens described in Patent Document 2 is described above. The first lens to the third lens are used to absorb the refractive power of almost the entire system, and the fourth lens and the fifth lens are only effective as an image correction lens having a weak refractive power. Further, in the above-mentioned imaging lens, the materials of the fourth lens and the fifth lens are the same, and the correction of various aberrations including the chromatic aberration is insufficient, and if the total length of the lens is shortened, the performance is deteriorated. It is difficult to cope with the problem of high pixelation of the imaging element. In addition, in the above-mentioned imaging lens, the F value is the brightest, and it is only about F2.4. It is difficult to say that it can correspond to high pixelization and high performance in recent years.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-294527

[Patent Document 2] US Patent No. 8000031

The present invention has been made in view of such a problem, and an object thereof is to provide a five-piece imaging lens having a smaller size than the prior type and capable of satisfactorily correcting various aberrations and having a brightness of F2.4 or more.

Moreover, an object of the present invention is to provide an image pickup apparatus and a portable terminal including the above-described image pickup lens.

Here, the scale of the small-sized imaging lens, in the present invention, aims to achieve miniaturization to the extent that the following formula is satisfied. By satisfying this range, the entire imaging device can be made compact and lightweight.

L/2Y<0.90...(12)

Among them, L: the distance from the lens surface of the entire object side of the camera lens to the optical axis from the image side focus

2Y: The image of the solid-state imaging device is facing the diagonal length (the diagonal length of the rectangular effective effect pixel area of the solid-state imaging device)

Here, the image side focus refers to an image point when a parallel light that is parallel to the optical axis is incident on the imaging lens. Further, a parallel plate such as an optical low-pass filter, an infrared cut filter, or a cover glass for a solid-state image sensor package is disposed between the image-side surface of the image pickup lens and the image-side focus position. In the case, the parallel plate portion is regarded as the air conversion distance. Then calculate the value of L above.

Regarding the value L/2Y, the ideal system may also be in the range of the following formula.

L/2Y<0.80...(12)’

In order to achieve the above object, the first imaging lens according to the present invention is an imaging lens required for imaging a subject image on a photoelectric conversion unit or the like of an imaging element, and has a positive sequence from the object side. a first lens having a refractive power and having a convex surface facing the object side in the vicinity of the optical axis, a second lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis, a third lens having a positive refractive power, and a fourth lens having a negative refractive power The lens is formed by a fifth lens having a concave shape facing the image side in the vicinity of the optical axis; the image side surface of the fifth lens is an aspherical shape, and has an inflection point at a position other than the intersection with the optical axis, and satisfies The following conditional expressions (1) and (2).

0.01<f/f3<0.60...(1)

-3.50<f2/f<-1.75...(2)

among them,

F3: focal length of the third lens

F2: focal length of the second lens

f: the focal length of the entire camera lens

In order to obtain an imaging lens that is small and the aberration is well corrected, the first imaging lens according to the present invention has a basic configuration including a positive refractive power and a convex surface facing the object side in the vicinity of the optical axis from the object side. The first lens has a negative refractive power and has a concave surface toward the image side in the vicinity of the optical axis The second lens, the third lens having a positive refractive power, the fourth lens having a negative refractive power, and the fifth lens having a concave surface facing the image side in the vicinity of the optical axis.

By designing the image side of the second lens to be concave, The second lens having a high light ray height has a strong diverging action, so that the field curvature or the distortion aberration can be satisfactorily corrected. Further, by designing the image side surface of the fifth lens disposed on the most image side as an aspherical surface, various aberrations on the peripheral portion of the screen can be satisfactorily corrected. Further, by designing the fifth lens to have an aspherical shape having an inflection point at a position other than the intersection with the optical axis, it is possible to easily ensure the telecentric characteristics of the image side light beam. Here, the "recurve point" is a plane in which the tangent to the curve of the cross-sectional shape of the lens in the effective radius is extended in the vertical direction of the cross-section, and the tangent plane of the aspherical vertex is a plane perpendicular to the optical axis. Such a point on the aspheric surface.

The conditional expression (1) is the reciprocal of the focal length of the third lens, that is, The so-called refractive power is appropriately set so that the shortening of the total length of the imaging lens and the aberration correction can be achieved, and it is a conditional expression required to minimize the performance deterioration at the time of occurrence of a manufacturing error. By setting the value f/f3 of the conditional expression (1) below the upper limit, the positive refractive power of the third lens is not excessively strong, various aberrations occurring on the third lens can be suppressed, and manufacturing errors can be reduced. Performance degradation. In addition, since the combined principal point position of the positive lens group of the first lens to the third lens can be closer to the object side, the entire length of the imaging lens can be shortened. Further, in the present invention, the first lens to the third lens are arranged in the order of positive and negative, that is, a so-called triplet type. Therefore, by making the value of the conditional expression (1) exceed the lower limit, the refractive power of the third lens can be appropriately maintained, and the first lens can be reinforced. The three-in-one effect of the three lenses can well correct spherical aberration or coma aberration.

Further, regarding the value f/f3, it is preferable to be in the range of the following formula.

0.02<f/f3<0.55...(1)’

The conditional expression (2) is a conditional expression for appropriately setting the focal length of the second lens. By setting the value f2/f of the conditional expression (2) below the upper limit, the negative refractive power of the second lens is not excessively strong, and the coma aberration or distortion aberration occurring on the second lens can be suppressed to be more small. Moreover, performance deterioration at the time of occurrence of a manufacturing error can be suppressed. On the other hand, by setting the value of the conditional expression (2) to the lower limit, the negative refractive power of the second lens can be appropriately maintained, and it is effective for the reduction of the Petzval sum or the correction of the field curvature. Moreover, the chromatic aberration can be corrected well.

Further, regarding the value f2/f, it is preferable that the range is the following formula.

-3.40<f2/f<-1.80...(2)’

In the specific aspect of the present invention, in the first imaging lens, the following conditional expression (3) is satisfied: 0.60<f1/f<1.20 (3)

Where f1: the focal length of the first lens

f: The focal length of the entire camera lens.

Conditional formula (3) is to make the focal length of the first lens suitable It is a conditional expression required to achieve the shortening of the total length of the imaging lens and the correction of the appropriate aberration. By setting the value f1/f of the conditional expression (3) below the upper limit, the refractive power of the first lens can be appropriately maintained, and the composite main point of the first lens to the third lens can be arranged closer to the object side, and the imaging can be shortened. The full length of the lens. On the other hand, by setting the value of the conditional expression (3) to the lower limit, the refractive power of the first lens is not excessively large, and the high-order spherical aberration or coma aberration occurring on the first lens can be obtained. The suppression is small.

Further, the value f1/f is preferably a range of the following formula.

0.70<f1/f<1.10...(3)’

In another aspect of the invention, the following conditional expression (4) is satisfied: -0.90 < f / f4 < - 0.02 (4)

Where f4: the focal length of the fourth lens

f: The focal length of the entire camera lens.

In the conditional expression (4), in order to appropriately set the refractive power of the fourth lens, it is possible to achieve both the required conditional expression by miniaturization and good aberration correction. By setting the value f/f4 of the conditional expression (4) below the upper limit, the negative refractive power of the fourth lens can be appropriately maintained, and the total length of the imaging lens can be shortened. On the other hand, by setting the value of the conditional expression (4) to the lower limit, it is possible to suppress the negative refractive power of the fourth lens from being excessively strong, and it is possible to suppress performance deterioration at the time of occurrence of manufacturing errors, and it is possible to ensure good performance. Telecentric characteristics.

Further, regarding the value f/f4, it is preferable to be in the range of the following formula.

-0.85<f/f4<-0.03...(4)’

In still another aspect of the present invention, the following conditional expression (5) is satisfied: 0.70 < f123 / f < 1.30 (5)

Where f123: composite focal length from the first lens to the third lens

f: The focal length of the entire camera lens.

The conditional expression (5) is a conditional expression for appropriately setting the composite focal length from the first lens to the third lens having a relatively large refractive power. By setting the value f123/f of the conditional expression (5) below the upper limit, the composite focal length from the first lens to the third lens is not excessively large, which is advantageous in shortening the total length of the imaging lens. On the other hand, when the value of the conditional expression (5) exceeds the lower limit, the composite focal length from the first lens to the third lens having a relatively large refractive power does not become too small, and the first lens to the third lens can be made small. Spherical aberration or field curvature occurring so far can suppress performance degradation at the time of occurrence of manufacturing errors to be small.

Further, regarding the value f123/f, it is preferable to be in the range of the following formula.

0.80<f123/f<1.20...(5)’

In still another aspect of the present invention, the following conditional expression (6) is satisfied: 0.00 < ∣f4 / f5 ∣ < 9.00 (6)

Where f4: the focal length of the fourth lens

F5: focal length of the fifth lens.

By setting the value ∣f4/f5∣ of the conditional expression (6) below the upper limit, the refractive power of the fourth lens can be appropriately maintained for the fifth lens, so that the refractive power of the two lenses can be maintained to a certain degree of balance. Correctly correct image curvature or coma aberration. On the other hand, when the value of the conditional expression (6) exceeds the lower limit, the refractive power of the fourth lens is not excessively strong for the fifth lens, and the total length of the imaging lens can be shortened.

Further, regarding the value ∣f4/f5∣, it is preferable to be in the range of the following formula.

0.00<∣f4/f5∣<8.00...(6)’

In still another aspect of the present invention, the following conditional expression (7) is satisfied: 0.01 < d6 / f < 0.25 (7)

Where d6: the air gap on the optical axis of the third lens and the fourth lens

f: The focal length of the entire camera lens.

The conditional expression (7) is such that the total length of the imaging lens can be shortened, and the conditional expression required for various aberrations outside the axis can be satisfactorily corrected. By setting the value d6/f of the conditional expression (7) to the lower limit, the first lens to the third lens having a strong refractive power and the air gap on the axis of the fourth lens as the aberration correcting lens having a weak refractive power are provided. It can be properly spaced to make the light passing through the 4th lens The line height is separated as the image height. Therefore, by the action of the aspherical shape of the fourth lens, the off-axis aberration of a certain image height can be corrected well. On the other hand, when the value of the conditional expression (7) is lower than the upper limit, the air gap between the third lens and the fourth lens is not excessively exceeded, and as a result, the entire length of the imaging lens can be shortened.

Further, regarding the value d6/f, it is preferable that the range is the following formula.

0.05<d6/f<0.20...(7)’

In still another aspect of the present invention, the following conditional expression (8) is satisfied: 0.02 < THIL2 / f < 0.15 (8)

Where THIL2: the thickness of the second lens on the optical axis

f: The focal length of the entire camera lens.

The conditional expression (8) is a conditional expression for appropriately setting the thickness on the optical axis of the second lens. By setting the value THIL2/f of the conditional expression (8) to a lower limit, the thickness of the second lens is not too thin, and the formability is not impaired. On the other hand, when the value of the conditional expression (8) is lower than the upper limit, the thickness of the second lens is not too thick, and it is easy to ensure the lens interval between the front and the rear of the second lens. As a result, the total length of the imaging lens can be shortened. .

Further, regarding the value THIL2/f, it is preferable that the range is the following formula.

0.03<THIL2/f<0.12...(8)’

In still another aspect of the present invention, the following conditional expression (9) is satisfied: 0.10 < THIL5 / f < 0.30 (9)

Where THIL5: the thickness of the 5th lens on the optical axis

f: The focal length of the entire camera lens.

The conditional expression (9) is a conditional expression for appropriately setting the thickness on the optical axis of the fifth lens. By setting the value THIL5/f of the conditional expression (9) to a lower limit, the thickness of the fifth lens is not too thin, and the formability is not impaired. On the other hand, by setting the value of the conditional expression (9) below the upper limit, the thickness of the fifth lens is not too thick, and it is easy to secure the back focus.

Further, regarding the value THIL5/f, it is preferable that the range is the following formula.

0.15<THIL5/f<0.25...(9)’

In still another aspect of the present invention, the following conditional expression (10) is satisfied: 20 < ν5 - ν4 < 70 (10)

Where ν5: Abbe number of the 5th lens

Ν4: Abbe number of the fourth lens.

The conditional expression (10) is a conditional expression required to satisfactorily correct the chromatic aberration of the entire imaging lens. By exceeding the value of the conditional expression (10) ν5-ν4 The chromatic aberration of the lower limit, axial chromatic aberration or chromatic aberration of magnification can be corrected in a well-balanced manner. On the other hand, by setting the value of the conditional expression (10) to be lower than the upper limit, the lens can be constituted by a glass material which is easily obtained.

Further, regarding the value ν5 - ν4, it is preferable that the range is the following formula.

25<ν5-ν4<65...(10)’

In still another aspect of the present invention, the following conditional expression (11) is satisfied: 20 < ν1 - ν2 < 70 (11)

Where ν1: Abbe number of the first lens

Ν2: Abbe number of the second lens.

The conditional expression (11) is a conditional expression required to satisfactorily correct the chromatic aberration of the entire imaging lens. By making the value ν1 - ν2 of the conditional expression (11) exceed the lower limit, chromatic aberration such as axial chromatic aberration or lateral chromatic aberration can be corrected in a well-balanced manner. On the other hand, by setting the value of the conditional expression (11) below the upper limit, the lens can be constituted by a glass material which is easily obtained.

Further, regarding the value ν1 - ν2, it is preferable that the range is the following formula.

25<ν1-ν2<65...(11)’

In still another aspect of the invention, the first lens system has a crescent shape. In this way, by designing the first lens to be a crescent-shaped type, the position of the composite main point of the entire imaging lens can be closer to the object side, thereby shortening The full length of the camera lens.

In still another aspect of the present invention, the second lens system has Crescent shape. By designing the second lens to be a crescent-shaped type, the curvature of field occurring on the side surface of the object of the second lens can be satisfactorily corrected, and the refractive power of the second lens can be prevented from becoming too strong. If it is more than necessary, the image surface variation caused by the positional deviation during manufacturing can be reduced, and a lens system having excellent manufacturing stability can be obtained.

In still another aspect of the invention, the fourth lens and the fifth Both sides of the lens system have an aspherical shape, and both sides have an inflection point at a position other than the intersection with the optical axis. In this case, it is possible to achieve both the shortening of the entire length of the imaging lens and the good telecentric characteristics. Moreover, it is possible to satisfactorily correct the peripheral image curvature or the chromatic aberration of magnification.

In still another aspect of the invention, the fourth lens and the fifth The synthetic refractive power of the lens is a negative refractive power. In this case, the negative lens group of the fourth lens and the fifth lens are disposed behind the positive lens group of the first lens to the third lens, and the so-called telephoto type can be designed, so that the total length of the imaging lens can be shortened. Favorable composition.

In still another aspect of the present invention, the fifth lens system has Positive refractive power. As described above, by providing the fifth lens with a positive refractive power, the combined refractive power of the fourth lens and the fifth lens can be made negative, and the optical total length can be shortened, and the back focus can be appropriately lengthened.

In still another aspect of the present invention, the fifth lens system has Negative refractive power. Thus, by causing the fifth lens to have a negative refractive power, the combined refractive power of the fourth lens and the fifth lens can be made negative, and at the same time, The fifth lens of the final lens becomes a negative lens, and it is more suitable for shortening the total length of the imaging lens.

In order to achieve the above objective, the second camera of the present invention The lens is an imaging lens required to image a subject image on a photoelectric conversion portion or the like of an imaging element, and has a positive refractive power and a convex surface toward the object side in the vicinity of the optical axis from the object side. a first lens, a second lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis, a third lens having a positive refractive power, and a fourth lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis The concave surface near the optical axis faces the fifth lens on the image side; the image side surface of the fifth lens has an aspherical shape, and has an inflection point at a position other than the intersection with the optical axis, and satisfies the following conditional expression (1) .

0.01<f/f3<0.60...(1)

Where f3: the focal length of the third lens

f: the focal length of the entire camera lens

In order to obtain an imaging lens that is small and the aberration is well corrected, the second imaging lens according to the present invention has a basic configuration in which a positive refractive power is provided from the object side and a convex surface faces the object side in the vicinity of the optical axis. a first lens, a second lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis; a third lens having a positive refractive power; and a fourth lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis; A concave lens faces the fifth lens on the image side in the vicinity of the optical axis.

By designing the image side of the second lens to be concave, The second lens having a high light ray height has a strong diverging action, so that the field curvature or the distortion aberration can be satisfactorily corrected. Further, by designing the image side surface of the fifth lens disposed on the most image side as an aspherical surface, various aberrations on the peripheral portion of the screen can be satisfactorily corrected. Further, by designing the fifth lens to have an aspherical shape having an inflection point at a position other than the intersection with the optical axis, it is possible to easily ensure the telecentric characteristics of the image side light beam. Here, the "recurve point" is a plane in which the tangent to the curve of the cross-sectional shape of the lens in the effective radius is extended in the vertical direction of the cross-section, and the tangent plane of the aspherical vertex is a plane perpendicular to the optical axis. Such a point on the aspheric surface.

Further, by designing the fourth lens to be concave toward the image side The shape allows the image side of the fourth lens to have a diverging effect, so that the total length of the imaging lens can be shortened while maintaining the back focus. Further, the axial chromatic aberration can be satisfactorily corrected by the above-described divergence.

The conditional expression (1) is the reciprocal of the focal length of the third lens, that is, The so-called refractive power is appropriately set so that the shortening of the total length of the imaging lens and the aberration correction can be achieved, and it is a conditional expression required to minimize the performance deterioration at the time of occurrence of a manufacturing error. By setting the value f/f3 of the conditional expression (1) below the upper limit, the positive refractive power of the third lens is not excessively strong, various aberrations occurring on the third lens can be suppressed, and manufacturing errors can be reduced. Performance degradation. In addition, since the combined principal point position of the positive lens group of the first lens to the third lens can be closer to the object side, the entire length of the imaging lens can be shortened. Further, in the present invention, the first lens to the third lens are arranged in the order of positive and negative, that is, a so-called triplet type. Thus, by making the value of conditional expression (1) exceed the next In addition, the refractive power of the third lens can be appropriately maintained, and the effect of the triplet formed by the first lens to the third lens can be enhanced, and the spherical aberration or the coma aberration can be satisfactorily corrected.

Further, regarding the value f/f3, it is preferable to be in the range of the following formula.

0.02<f/f3<0.55...(1)’

In the specific aspect of the present invention, in the second imaging lens, the following conditional expression (2) is satisfied: -3.50 <f2/f<-1.75 (2)

Where f2: the focal length of the second lens

f: The focal length of the entire camera lens.

The conditional expression (2) is a conditional expression for appropriately setting the focal length of the second lens. By setting the value f2/f of the conditional expression (2) below the upper limit, the negative refractive power of the second lens is not excessively strong, and the coma aberration or distortion aberration occurring on the second lens can be suppressed to be more small. Moreover, performance deterioration at the time of occurrence of a manufacturing error can be suppressed. On the other hand, by setting the value of the conditional expression (2) to the lower limit, the negative refractive power of the second lens can be appropriately maintained, and it is effective for the reduction of the Petzval sum or the correction of the field curvature. Moreover, the chromatic aberration can be corrected well.

Further, regarding the value f2/f, it is preferable that the range is the following formula.

-3.40<f2/f<-1.80...(2)’ In the second aspect of the present invention, in the second imaging lens, the conditional expression (3) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (3)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (4) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (4)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (5) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (5)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (6) is satisfied as in the case of the first imaging lens described above, and it is preferable that the conditional expression (6)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (7) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (7)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (8) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (8)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (9) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (9)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (10) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (10)' is satisfied.

In still another aspect of the present invention, in the second imaging lens, the conditional expression (11) is satisfied as in the case of the first imaging lens, and it is preferable that the conditional expression (11)' is satisfied.

In addition, in the specific side surface of the second imaging lens described above, the first lens has a crescent shape or the second lens has a crescent shape, similarly to the first imaging lens described above. Further, the fourth lens and the fifth lens may have an aspherical shape on both surfaces, and both surfaces have an inflection point at a position other than the intersection with the optical axis. Further, the combined refractive power of the fourth lens and the fifth lens is a negative refractive power. As for the fifth lens, it may have a positive refractive power or a negative refractive power.

In the side surface of the present invention, in the first or second imaging lens described above, a lens having substantially no power is also provided.

In order to achieve the above object, an imaging device according to the present invention includes the above-described imaging lens and imaging element. By using the imaging lens of the present invention, it is possible to obtain an imaging device in which small and bright aberrations are well corrected.

In order to achieve the above object, the portable terminal of the present invention includes an imaging device that is excellent in various small and bright aberrations as described above.

10,11-19‧‧‧ camera lens

50‧‧‧ camera module

51‧‧‧Photographic components

51a‧‧‧Photoelectric Conversion Department

52‧‧‧Wiring substrate

54‧‧‧Mirror tube

55a‧‧‧Drive mechanism

100‧‧‧ camera

103‧‧‧Control Department

105‧‧‧Optics Department

107‧‧‧Photographic component drive unit

108‧‧‧Image memory

300‧‧‧Portable communication terminal

310‧‧‧Control Department

320‧‧‧Display Operation Department

330‧‧‧Operation Department

340‧‧‧Wireless Communications Department

341‧‧‧Antenna

360‧‧‧Memory Department

370‧‧‧ Temporary Memory

AX‧‧‧ optical axis

F‧‧‧parallel plate

I‧‧‧ imaging surface

L1-L5‧‧ lens

OP‧‧‧ openings

P‧‧‧reflexion point

S‧‧‧ aperture

S11, S41, S51‧‧‧ side of the object

S22, S42, S52‧‧‧ side

Fig. 1 is an explanatory view of an image pickup apparatus including an image pickup lens according to an embodiment of the present invention.

FIG. 2 is a block diagram for explaining a portable terminal including the imaging device of FIG. 1. FIG.

3A and 3B are perspective views of a front side and a back side of a portable terminal, respectively.

Fig. 4 is a cross-sectional view of the imaging lens of the first embodiment.

5A to 5E are aberration diagrams of the imaging lens of Example 1.

Fig. 6 is a cross-sectional view showing an image pickup lens of a second embodiment.

7] FIGS. 7A to 7E are aberration diagrams of the imaging lens of Example 2. FIG.

8 is a cross-sectional view of an imaging lens of Embodiment 3.

9] FIG. 9A to FIG. 9E are aberration diagrams of the imaging lens of Example 3. FIG.

Fig. 10 is a cross-sectional view showing an image pickup lens of a fourth embodiment.

11A to 11E are aberration diagrams of the imaging lens of Example 4.

Fig. 12 is a cross-sectional view showing an image pickup lens of a fifth embodiment.

13] FIGS. 13A to 13E are aberration diagrams of the imaging lens of Example 5. FIG.

Fig. 14 is a cross-sectional view showing an image pickup lens of a sixth embodiment.

15A to 15E are aberration diagrams of the imaging lens of Example 6.

Fig. 16 is a cross-sectional view showing an image pickup lens of a seventh embodiment.

17] FIGS. 17A to 17E are aberration diagrams of the imaging lens of Example 7. FIG.

Fig. 18 is a cross-sectional view showing an imaging lens of Example 8.

19A to 19E are aberration diagrams of the imaging lens of Example 8.

Fig. 20 is a cross-sectional view showing an image pickup lens of a ninth embodiment.

21A to 21E are aberration diagrams of the imaging lens of Example 9.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 and the like. State camera lens. In addition, the imaging lens 10 illustrated in FIG. 1 has the same configuration as the imaging lens 11 of the first embodiment to be described later.

1 is an image pickup lens including an embodiment of the present invention; A description of the camera module is made using a cross-sectional view.

The camera module 50 includes an image forming mirror that forms a subject image The head 10, the imaging element 51 for detecting the subject image formed by the imaging lens 10, the wiring substrate 52 holding the imaging element 51 from the back and having wiring, etc., holding the imaging lens 10 and the like and having the object from the object The lens portion 54 of the opening portion OP on which the light beam is incident on the side. The imaging lens 10 has a function of imaging a subject image on the image plane or imaging surface (projected surface) I of the imaging element 51. The camera module 50 is used by being incorporated in an imaging device to be described later, but may be referred to as an imaging device alone.

The camera lens 10 is sequentially arranged from the object side and has an opening The aperture S, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5. The imaging lens 10 is small in size, and as a measure thereof, it is intended to achieve a miniaturization that satisfies the following formula (12).

L/2Y<0.90...(12)

Here, L is the distance from the most object-side lens surface (object side surface S11) of the entire imaging lens 10 to the optical axis AX from the image side focus, and 2Y is the imaging facing angle of the imaging element 51. The length (the diagonal length of the rectangular effective pixel area of the imaging element 51), the image side focus refers to the image when the imaging lens 10 is incident on parallel rays parallel to the optical axis AX. point. By satisfying this range, the entire camera module 50 can be made compact and lightweight.

Further, if it is on the image side of the image pickup lens 10 (image) When the parallel plate F such as an optical low-pass filter, an infrared cut filter, or a cover glass of an image sensor package is disposed between the side surface S52) and the image side focus position, the parallel flat plate F portion is viewed. Calculate the distance for the air and then calculate the value of L above.

Moreover, regarding the above-mentioned value L/2Y, the ideal system may be of the following formula The scope.

L/2Y<0.80...(12)’

The imaging element 51 is a sensor wafer formed of a solid-state imaging element. The photoelectric conversion portion 51a of the imaging element 51 is formed of a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and photoelectrically converts incident light to RGB, and outputs an analog signal. The photoelectric conversion surface of the photoelectric conversion portion 51a as the light receiving portion is an image surface or an imaging surface (projected surface) I.

The wiring board 52 has a function of positioning and fixing the image pickup element 51 to another member (for example, the barrel portion 54). The wiring substrate 52 receives a supply of a voltage or a signal required for driving the image pickup element 51 or the drive mechanism 55a from an external circuit, and outputs a detection signal to an external circuit or the like.

On the side of the imaging lens 10 of the imaging element 51, the parallel flat plate F covers the imaging element 51 or the like by a holding member (not shown). The way to configure and fix.

The lens barrel portion 54 houses and holds the image pickup lens 10. mirror The tubular portion 54 has, for example, a drive mechanism 55a in order to move one or more of the lenses L1 to L5 constituting the imaging lens 10 along the optical axis AX to cause the imaging lens 10 to perform a focusing operation. The drive mechanism 55a reciprocates a specific lens along the optical axis AX. The drive mechanism 55a is provided with, for example, a voice coil motor and a guide rail. Further, the drive mechanism 55a may be configured by using a stepping motor or the like instead of a voice coil motor or the like.

Next, referring to FIG. 2 and FIG. 3A, FIG. An example of a mobile phone or other portable communication terminal 300 of the camera module 50 exemplified.

Portable communication terminal 300 is a smart phone type The tape type communication terminal (portable type terminal) includes: an image pickup apparatus 100 having a camera module 50, a control unit (CPU) 310 that performs control of each unit and executes each process, display communication related information, a camera image, and the like and accept The display operation unit 320 of the touch panel operated by the user, the operation unit 330 including the power switch, the wireless communication unit 340 required to realize various information communication between the external antenna and the like via the antenna 341, and the portable communication type The system program of the terminal 300, the memory unit (ROM) 360 of various processing programs and the necessary information such as the terminal ID, the various processing programs or data executed by the control unit 310, the processing data, or the imaging data of the imaging device 100 are temporarily stored. A temporary memory unit (RAM) 370 used as a work area.

The camera device 100 is in addition to the camera module 50 already described. In addition to the control unit 103, the optical system drive unit 105, the imaging device drive unit 107, the video memory 108, and the like.

The control unit 103 controls each unit of the imaging apparatus 100. control The system 103 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and performs various processes by cooperation with the CPU by various programs developed in the RAM and being developed from the ROM. . Further, the control unit 310 is connected to the control unit 103 of the imaging device 100 to be communicable, and can receive control signals or video data.

The optical system driving unit 105 is controlled by the control unit 103 When focusing, exposure, or the like is performed, the drive mechanism 55a of the imaging lens 10 is operated to control the state of the imaging lens 10. The optical system driving unit 105 can move the specific lens of the imaging lens 10 along the optical axis AX by operating the driving mechanism 55a, so that the imaging lens 10 can perform the focusing operation.

The imaging element driving unit 107 is controlled by the control unit 103 The operation of the image sensor 51 is controlled while performing exposure or the like. Specifically, the imaging device driving unit 107 controls the imaging element 51 to perform scanning driving based on the timing signal. Further, the imaging device driving unit 107 converts the analog signal of the detection signal or the photoelectric conversion signal output from the imaging device 51 into digital image data. Then, the image sensor driving unit 107 performs various kinds of image processing such as distortion correction, color correction, and compression on the image signal detected by the image sensor 51.

Image memory 108, which is a digital signal that has been digitized The image pickup device drive unit 107 collects and stores the image data that can be read and written.

Here, the imaging operation of the portable communication terminal 300 including the above-described imaging device 100 will be described. When the portable communication terminal 300 is set to a camera mode that operates with a camera, subject monitoring (perspective image display) and image capturing are performed. During the monitoring, the image of the subject obtained through the imaging lens 10 is imaged on the imaging surface I of the imaging element 51 (see FIG. 1). The image sensor 51 is scanned and driven by the image sensor driving unit 107, and outputs an analog signal as a photoelectric conversion output corresponding to the imaged light image every predetermined period.

The analog signal is converted into digital data by appropriately adjusting the gain in accordance with each of the RGB color components in the circuit attached to the image sensor 51. The digital data is subjected to color processing including pixel interpolation processing and Y correction processing, and a luminance signal Y and a color difference signal Cb and Cr (image data) of a digital value are generated and stored in the image memory 108. The stored digital data is periodically read from the image memory 108 to generate a video signal, and is output to the display operation unit 320 via the control unit 103 and the control unit 310.

The display operation unit 320 is a function of an electronic viewfinder during monitoring, and displays a captured image immediately. In this state, the focus, exposure, and the like of the imaging lens 10 are set by the driving of the optical system driving unit 105 at any time based on the operation input by the user through the display operation unit 320 or the like.

In this monitoring state, the user is exposed by appropriate operation. The still image data can be captured by the operation unit 320 and the like. In response to the operation content of the display operation unit 320, the image data of one frame stored in the image memory 108 is read and compressed by the image sensor driving unit 107. The compressed video data is recorded, for example, by the control unit 103 and the control unit 310, for example, in the RAM 370 or the like.

In addition, the above-described image pickup apparatus 100 is suitable for the present invention. An example of the imaging device of the present invention is not limited thereto.

That is, the camera module 50 or the camera lens 10 is mounted. The imaging device is not limited to being embedded in the smart phone type portable communication terminal 300, and may be built in a mobile phone, a PHS (Personal Handyphone System), or the like, or may be built in a PDA (Personal Digital Assistant). , tablet PCs, mobile PCs, digital still cameras, video cameras, etc.

Hereinafter, back to FIG. 1, an embodiment of the present invention will be described in detail. State of the camera lens 10. The imaging lens 10 shown in FIG. 1 images an object image on an imaging surface (projected surface) I of the imaging element 51, and sequentially passes from the object side: an aperture stop S, a positive refractive power, and an optical axis. The first lens L1 having a convex surface facing the object side in the vicinity of AX, the second lens L2 having a negative refractive power and having a concave surface toward the image side in the vicinity of the optical axis AX, the third lens L3 having positive refractive power, and the fourth lens having negative refractive power L4 is formed by a fifth lens L5 having a crescent shape whose concave surface faces the image side in the vicinity of the optical axis AX. The imaging lens 10 is arranged in a positive and negative order from the first lens L1 to the third lens L3, that is, a so-called triplet type. Here, the first lens L1 has a crescent shape. Similarly, the second lens L2 is designed to Crescent shape. Further, the image side surface S52 of the fifth lens L5 has an aspherical shape and has an inflection point at a position P other than the intersection with the optical axis AX. The object side surface S51 of the fifth lens L5 is also an aspherical shape. Further, the fourth lens L4 has a concave surface facing the image side in the vicinity of the optical axis AX. Here, the image side surface S42 of the fourth lens L4 has an aspherical shape and has an inflection point at a position other than the intersection with the optical axis AX. The object side surface S41 of the fourth lens L4 is also aspherical.

In the above, the synthetic folding of the fourth lens L4 and the fifth lens L5 The radiation force is a negative value, and the fifth lens L5 has a positive or negative refractive power.

In the imaging lens 10 of the present embodiment, by the second Since the image side surface S22 of the lens L2 is designed to have a concave surface, the second lens L2 having a high light ray height can have a strong diverging action, so that the field curvature or the distortion aberration can be satisfactorily corrected. Further, by designing the image side surface S52 of the fifth lens L5 disposed on the most image side as an aspherical surface, various aberrations on the peripheral portion of the screen can be satisfactorily corrected. Further, by designing the fifth lens L5 to have an aspherical shape having an inflection point at a position P other than the intersection with the optical axis AX, it is possible to easily ensure the telecentric characteristics of the image side light beam.

Further, by designing the fourth lens L4 to be concave toward the image side Since the shape of the image side surface S42 of the fourth lens L4 is divergent, the entire length of the imaging lens 10 can be shortened while maintaining the back focus. Further, the axial chromatic aberration can be satisfactorily corrected by the above-described divergence.

The imaging lens 10 of the present embodiment is such that f3 is the third The focal length of the lens L3 is f2, which is the focal length of the second lens L2, and f is the focal length of the entire imaging lens 10, and satisfies the following conditional expressions (1) and (2).

0.01<f/f3<0.60...(1)

-3.50<f2/f<-1.75...(2)

By setting the value f/f3 of the conditional expression (1) above the upper limit, the positive refractive power of the third lens L3 is not excessively strong, and various aberrations occurring on the third lens L3 can be suppressed and can be reduced. Performance degradation at the time of manufacturing error. In addition, since the combined principal point position of the positive lens group of the first lens L1 to the third lens L3 can be closer to the object side, the entire length of the imaging lens 10 can be shortened. On the other hand, when the value f/f3 of the conditional expression (1) exceeds the lower limit, the refractive power of the third lens L3 can be appropriately maintained, and the effect of the triple type formed by the first lens L1 to the third lens L3 can be enhanced. Can correct spherical aberration or coma aberration well.

Further, the value f/f3 of the conditional expression (1) is preferably set within the range of the following formula.

0.02<f/f3<0.55...(1)’

By lowering the value f2/f of the conditional expression (2) above the upper limit, the negative refractive power of the second lens L2 is not excessively strong, and the coma aberration or distortion aberration occurring on the second lens L2 can be obtained. The inhibition is smaller. Moreover, performance deterioration at the time of occurrence of a manufacturing error can be suppressed. On the other hand, by setting the value f2/f of the conditional expression (2) to the lower limit, the negative refractive power of the second lens L2 can be appropriately maintained, and it is effective for the reduction of the Petzval sum or the correction of the field curvature. Moreover, the chromatic aberration can be corrected well.

Further, the value f2/f of the conditional expression (2) is preferably set within the range of the following formula.

-3.40<f2/f<-1.80...(2)’

The imaging lens 10 of the embodiment satisfies the conditional expression (3) already described in addition to the conditional expressions (1) and (2) above.

0.60<f1/f<1.20...(3)

Here, f1 is the focal length of the first lens L1.

The imaging lens 10 of the embodiment is more preferably configured to satisfy the conditional expression (3)' below.

0.70<f1/f<1.10...(3)’

The imaging lens 10 of the embodiment satisfies the conditional expression (4) already described in addition to the conditional expressions (1) and (2) above.

-0.90<f/f4<-0.02...(4)

Here, f4 is the focal length of the fourth lens L4.

The imaging lens 10 of the embodiment is more preferably configured to satisfy the conditional expression (4)' below.

-0.85<f/f4<-0.03...(4)’

The imaging lens 10 of the embodiment satisfies the conditional expression (5) already described in addition to the conditional expressions (1) and (2) above.

0.70<f123/f<1.30...(5)

Here, f123 is a composite focal length of the first lens L1 to the third lens L3.

The imaging lens 10 of the embodiment is more preferably configured to satisfy the conditional expression (5)' below.

0.80<f123/f<1.20...(5)’

The imaging lens 10 of the embodiment satisfies the conditional expression (6) already described in addition to the conditional expressions (1) and (2) above.

0.00<∣f4/f5∣<9.00...(6)

Here, f5 is the focal length of the fifth lens L5.

The imaging lens 10 of the embodiment is more preferably configured to satisfy the conditional expression (6)' below.

0.00<∣f4/f5∣<8.00...(6)’

The imaging lens 10 of the embodiment satisfies the conditional expression (7) already described in addition to the conditional expressions (1) and (2) above.

0.01<d6/f<0.25...(7)

Here, d6 is an air gap between the third lens L3 and the optical axis AX of the fourth lens L4.

More preferably, the imaging lens 10 of the embodiment satisfies the following conditional expression (7)'.

0.05<d6/f<0.20...(7)’

The imaging lens 10 of the embodiment satisfies the conditional expressions (8) and (9) already described in addition to the conditional expressions (1) and (2) above.

0.02<THIL2/f<0.15...(8)

0.10<THIL5/f<0.30...(9)

Here, THIL2 is the thickness of the second lens L2 on the optical axis AX, and THIL5 is the thickness of the fifth lens L5 on the optical axis AX.

More preferably, the imaging lens 10 of the embodiment satisfies the following conditional expressions (8)' and (9)'.

0.03<THIL2/f<0.12...(8)’

0.15<THIL5/f<0.25...(9)’

The imaging lens 10 of the embodiment satisfies the conditional expressions (10) and (11) already described in addition to the conditional expressions (1) and (2) above.

20<ν5-ν4<70...(10)

20<ν1-ν2<70...(11)

Here, ν5 is the Abbe number of the fifth lens L5, ν4 is the Abbe number of the fourth lens L4, ν1 is the Abbe number of the first lens L1, and ν2 is the Abbe number of the second lens L2.

More preferably, the imaging lens 10 of the embodiment satisfies the following conditional expressions (10)' and (11)'.

25<ν5-ν4<65...(10)’

25<ν1-ν2<65...(11)’

The imaging lens 10 of the embodiment may have a lens having substantially no power, although not specifically shown.

[Examples]

Embodiments of the image pickup lens of the present invention are disclosed below. The meanings of the symbols used in the respective embodiments are as follows.

f: the focal length of the entire camera lens

fB: back focus

F: F value

2Y: The camera's camera face length is long

ENTP: Incident pupil position (distance from the first face to the entrance pupil position)

EXTP: The position of the exit pupil (the distance from the imaging surface to the position where the pupil exits)

H1: Front side main point position (distance from the first side to the front side main point position)

H2: Rear main point position (distance from the final surface to the rear main point position)

R: radius of curvature

D: spacing above the shaft

Nd: refractive index of the d-line of the lens material

Νd: Abbe number of lens material

In each of the examples, the surface in which "*" is described after each surface number is a surface having an aspherical shape. The shape of the aspheric surface is the vertex of the face At the origin, the X-axis is taken in the direction of the optical axis AX, and the height in the direction perpendicular to the optical axis AX is designated as h, and is represented by the following "number 1".

Where Ai: i times the aspheric coefficient

R: radius of curvature

K: conic constant

(Example 1)

The overall performance of the imaging lens of the first embodiment is as follows.

f=2.95mm

fB=0.2mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.82mm

H1=-1.36mm

H2=-2.75mm

The data of the lens surface of Example 1 is shown in Table 1 below.

The aspherical coefficients of the lens surface of Example 1 are shown in Table 2 below. Further, in the following (including the lens data of the table), a power of 10 (for example, 2.5 × 10 ^-02 ) is expressed by using E (for example, 2.5E-02).

The single lens data of Example 1 is shown in Table 3 below.

4 is a cross-sectional view of the imaging lens 11 and the like of the first embodiment. The imaging lens 11 includes a crescent-shaped first lens L1 having a positive refractive power around or in the vicinity of the optical axis AX and convex on the object side, and an optical axis AX. a second lens L2 having a negative refractive power and having a convex shape on the object side and a concave crescent shape on the image side, and a third lens L3 having a positive weak refractive power around the optical axis AX and being biconvex, in the light The fourth lens L4 having a negative weak refractive power around the axis AX and having a biconcave shape, and a fifth lens L5 having a refractive index on the periphery of the optical axis AX and convex on the object side and concave on the image side. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

5A to 5C are aberration diagrams (spherical aberration, astigmatism, and distortion aberration) of the imaging lens 11 of the first embodiment, and FIGS. 5D and 5E are diagrams showing the meridional coma aberration of the imaging lens 11 of the first embodiment. .

(Example 2)

The overall performance of the imaging lens of the second embodiment is as follows.

f=2.91mm

fB=0.29mm

F=2.07

2Y=4.59mm

ENTP=0mm

EXTP=-1.88mm

H1=-1mm

H2=-2.62mm

The data of the lens surface of Example 2 is shown in Table 4 below.

The aspherical coefficient of the lens surface of Example 2 is shown below. Table 5.

The single lens data of Example 2 is shown in Table 6 below.

Fig. 6 is a cross-sectional view showing the imaging lens 12 and the like of the second embodiment. The imaging lens 12 includes a crescent-shaped first lens L1 having a positive refractive power around the optical axis AX and convex on the object side, and having an optical axis AX periphery. a second lens L2 having a negative refractive power and convex on the object side and a crescent shape on the image side, a third lens L3 having a positive refractive power on the periphery of the optical axis AX and a convex shape on the image side, A fourth lens L4 having a negative refractive power around the optical axis AX and having a convex shape on the object side, a positive weak refractive power around the optical axis AX, and a convex on the object side and a concave on the image side The fifth lens L5 of the moon shape. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

7A to 7C are aberration diagrams (spherical aberration, astigmatism, and distortion aberration) of the imaging lens 12 of the second embodiment, and FIGS. 7D and 7E are diagrams showing the meridional coma aberration of the imaging lens 12 of the second embodiment. .

(Example 3)

The overall performance of the imaging lens of the third embodiment is as follows.

f=2.9mm

fB=0.23mm

F=2.25

2Y=4.59mm

ENTP=0mm

EXTP=-1.93mm

H1=-0.99mm

H2=-2.67mm

The data of the lens surface of Example 3 is shown in Table 7 below.

The aspherical coefficient of the lens surface of Example 3 is shown below. Table 8.

The single lens data of Example 3 is shown in Table 9 below.

Fig. 8 is a cross-sectional view showing the imaging lens 13 and the like of the third embodiment. The imaging lens 13 includes a first lens L1 having a positive refractive power around the optical axis AX and convex on the object side and a concave shape on the image side. A second lens L2 having a negative refractive power around the axis AX and having a convex crescent shape on the object side, a third lens L3 having a positive weak refractive power around the optical axis AX and being biconvex, and having a periphery around the optical axis AX The fourth lens L4 having a negative weak refractive power and having a convex crescent shape on the object side, a fifth lens having a refractive index on the periphery of the optical axis AX and convex on the object side and a concave crescent on the image side L5. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

9A to 9C are views showing the image pickup lens 13 of the third embodiment. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), FIGS. 9D and 9E show the meridional coma aberration of the imaging lens 13 of the third embodiment.

(Example 4)

The overall performance of the imaging lens of the fourth embodiment is as follows.

f=3.28mm

fB=0.15mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.94mm

H1=-1.86mm

H2=-3.13mm

The data of the lens surface of Example 4 is shown in Table 10 below.

The aspherical coefficients of the lens surface of Example 4 are shown in Table 11 below.

The single lens data of Example 4 is shown in Table 12 below.

Figure 10 is a cross-sectional view showing the image pickup lens 14 and the like of the fourth embodiment. . The imaging lens 14 includes a crescent-shaped first lens L1 having a positive refractive power around the optical axis AX and convex on the object side, and having a periphery around the optical axis AX. a second lens L2 having a negative refractive power and convex on the object side and a crescent shape on the image side, a third lens L3 having a positive weak refractive power around the optical axis AX and being biconvex, and an optical axis The fourth lens L4 having a negative weak refractive power and having a negative weak refractive power and having a biconcave shape, a negative weak refractive power around the optical axis AX, and a convex shape on the object side and a concave crescent on the image side . All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

11A to 11C show the image pickup lens 14 of the embodiment 4. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), and FIGS. 11D and 11E show the meridional coma aberration of the imaging lens 14 of the fourth embodiment.

(Example 5)

The overall performance of the imaging lens of the fifth embodiment is as follows.

f=3.21mm

fB=0.15mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.97mm

H1=-1.65mm

H2=-3.06mm

The data of the lens surface of Example 5 is shown in Table 13 below.

The aspherical coefficient of the lens surface of Example 5 is shown below. Table 14.

The single lens data of Example 5 is shown in Table 15 below.

Fig. 12 is a cross-sectional view showing an image pickup lens 15 and the like of the fifth embodiment. The imaging lens 15 includes a crescent-shaped first lens L1 having a positive refractive power around the optical axis AX and convex on the object side, and having a periphery around the optical axis AX. a second lens L2 having a negative refractive power and convex on the object side and a crescent shape on the image side, a positive weak refractive force around the optical axis AX, and a third crescent shape on the image side The lens L3 has a negative refractive power and a biconcave fourth lens L4 around the optical axis AX, a positive weak refractive power around the optical axis AX, and a convex shape on the object side and a concave crescent shape on the image side. The fifth lens L5. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

13A to 13C show the image pickup lens 15 of the embodiment 5. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), FIGS. 13D and 13E show the meridional coma aberration of the imaging lens 15 of the fifth embodiment.

(Example 6)

The overall performance of the imaging lens of the sixth embodiment is as follows.

f=3.01mm

fB=0.24mm

F=2.20

2Y=4.59mm

ENTP=0mm

EXTP=-1.89mm

H1=-1.25mm

H2=-2.77mm

The data of the lens surface of Example 6 is shown in Table 16 below.

The aspherical coefficient of the lens surface of Example 6 is shown below. Table 17.

The single lens data of Example 6 is shown in Table 18 below.

Figure 14 is a cross-sectional view showing the image pickup lens 16 and the like of the sixth embodiment. . The imaging lens 16 includes a crescent-shaped first lens L1 having a positive refractive power around the optical axis AX and convex on the object side, and having a periphery around the optical axis AX. a second lens L2 having a negative refractive power and convex on the object side and a crescent shape on the image side, and a biconvex third lens L3 having a positive refractive power around the optical axis AX, and having a periphery around the optical axis AX The fourth lens L4 having a negative weak refractive power and having a convex crescent shape on the object side, a negative weak refractive power around the optical axis AX, and a convex shape on the object side and a concave crescent shape on the image side 5 lens L5. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

15A to 15C show the image pickup lens 16 of the embodiment 6. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), FIGS. 15D and 15E show the meridional coma aberration of the imaging lens 16 of the sixth embodiment.

(Example 7)

The overall performance of the imaging lens of the seventh embodiment is as follows.

f=2.81mm

fB=0.21mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.81mm

H1=-1.09mm

H2=-2.6mm

The data of the lens surface of Example 7 is shown in Table 19 below.

The aspherical coefficient of the lens surface of Example 7 is shown below. Table 20.

The single lens data of Example 7 is shown in Table 21 below.

Figure 16 is a cross-sectional view showing the image pickup lens 17 and the like of the seventh embodiment. . The imaging lens 17 includes a crescent-shaped first lens L1 having a positive refractive power around the optical axis AX and convex on the object side, and having a periphery around the optical axis AX. The second lens L2 having a negative refractive power and convex on the object side and a crescent shape on the image side, the third weak lens having a positive weak refractive power around the optical axis AX and convex on the object side The lens L3 has a negative weak refractive power around the optical axis AX and is a biconcave fourth lens L4, has almost no refractive power around the optical axis AX, and is convex on the object side and concave on the image side. The fifth lens L5. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

17A to 17C show the image pickup lens 17 of the embodiment 7. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), and FIGS. 17D and 17E show the meridional coma aberration of the imaging lens 17 of the seventh embodiment.

(Example 8)

The overall performance of the imaging lens of Example 8 is as follows.

f=2.95mm

fB=0.23mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.82mm

H1=-1.3mm

H2=-2.72mm

The data of the lens surface of Example 8 is shown in Table 22 below.

The aspherical coefficient of the lens surface of Example 8 is shown below. Table 23.

The single lens data of Example 8 is shown in Table 24 below.

Fig. 18 is a cross-sectional view showing an image pickup lens 18 and the like of the eighth embodiment. The imaging lens 18 is provided with a positive refractive power around the optical axis and is in the object The first lens L1 having a convex crescent shape and the second lens L2 having a negative refractive power around the optical axis and convex on the object side have a positive weak refractive power around the optical axis and The third lens L3 having a crescent shape like a convex side, the fourth lens L4 having a negative but almost no refractive power around the optical axis and convex on the image side, and a negative weak refraction around the optical axis The force is also a convex crescent-shaped fifth lens L5 on the object side. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

19A to 19C show the image pickup lens 18 of the embodiment 8. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), FIGS. 19D and 19E show the meridional coma aberration of the imaging lens 18 of the eighth embodiment.

(Example 9)

The overall performance of the imaging lens of Example 9 is as follows.

f=2.95mm

fB=0.29mm

F=2.47

2Y=4.59mm

ENTP=0mm

EXTP=-1.89mm

H1=-1.04mm

H2=-2.66mm

The data of the lens surface of Example 9 is shown in Table 25 below.

The aspherical coefficient of the lens surface of Example 9 is shown below. Table 26.

The single lens data of Example 9 is shown in Table 27 below.

Fig. 20 is a cross-sectional view showing an image pickup lens 19 and the like of the ninth embodiment. The imaging lens 19 has a positive refractive power around the optical axis AX and The first lens L1 having a convex crescent shape on the object side, the second lens L2 having a negative refractive power around the optical axis AX, and being convex on the object side and concave on the image side, on the optical axis AX a third lens L3 having a crescent shape which is hardly convex at the image side and convex on the image side, a fourth lens L4 having a negative refractive power around the optical axis AX and a convex crescent on the image side, and an optical axis AX The fifth lens L5 having a positive weak refracting force on the periphery and convex on the object side and a crescent shape on the image side. All lenses L1~L5 are formed of plastic materials. An aperture stop S is disposed on the object side of the first lens L1. Further, between the light exit surface of the fifth lens L5 and the image pickup surface (image surface) I, a parallel flat plate F having an appropriate thickness can be disposed.

21A to 21C show the image pickup lens 19 of the ninth embodiment. The aberration diagrams (spherical aberration, astigmatism, and distortion aberration), FIGS. 21D and 21E show the meridional coma aberration of the imaging lens 19 of the ninth embodiment.

Table 28 below is a reference for arranging the values of the respective Examples 1 to 9 corresponding to the conditional expressions (1) to (12).

The present invention has been described above by way of embodiments or examples, but the invention is not limited to the above embodiments.

In recent years, as a low-cost and large-scale assembly of imaging devices The method consists of placing a chip on a solder wire in advance, mounting an IC chip or other electronic component and an optical component, and then directly performing a reflow process (heat treatment) to melt the solder to simultaneously mount the electronic component and the optical component to The technology of the substrate has been proposed. In order to perform such a reflow process, it is necessary to heat the electronic component together with the optical component to about 200 to 260 ° C, but at such a high temperature, the lens using the thermoplastic resin may be thermally deformed or discolored. The problem that causes its optical performance to decrease. As one of the methods for solving such a problem, although a glass-molded lens having excellent heat resistance is used, a technique that can balance both optical performance in a high-temperature environment and a high-temperature environment has been proposed, but the cost is generally higher than that of heat. The lens of the plastic resin is also high. Therefore, by using the energy curable resin on the materials of the image pickup lenses 11 to 19 of Examples 1 to 9, the lens can be exposed to a high temperature as compared with a lens using a thermoplastic resin such as polycarbonate or polyolefin. The reduction in optical performance at the time is small, is effective for the reflow process, and is cheaper than the manufacturing cost of the glass mold lens, and can achieve both the low cost and the mass productivity of the image pickup apparatus in which the image pickup lens is assembled. In addition, the energy curable resin means any of a thermosetting resin and an ultraviolet curable resin.

In addition, the above examples 1 to 9 are for incident to the camera element. The principal ray incident angle of the light beam of the imaging surface I of the member 51 does not have to be designed to be extremely small on the peripheral portion of the imaging surface I. However, in recent technology, shading can be gradually alleviated by the redesign of the arrangement of the color filter of the image pickup element 51 or the arrangement of the microlens array on the wafer. Specifically, if the pixel pitch of the imaging surface I of the imaging element 51 is a color filter or a crystal When the pitch of the arrangement of the on-chip microlens arrays is set to be slightly smaller, the color filter or the on-wafer microlens array will go to the imaging lens 10 with respect to each pixel as it goes to the peripheral portion of the imaging surface I (11~ 19) The optical axis AX side is translated, and the obliquely incident light beam can be efficiently guided to the light receiving portion of each pixel. Thereby, the shading occurring on the image pickup element 51 can be suppressed to be small. The above-described first to ninth embodiments are design examples for further miniaturization in response to the relaxation of the above requirements.

10‧‧‧ camera lens

50‧‧‧ camera module

51‧‧‧Photographic components

51a‧‧‧Photoelectric Conversion Department

52‧‧‧Wiring substrate

54‧‧‧Mirror tube

AX‧‧‧ optical axis

F‧‧‧parallel plate

I‧‧‧ imaging surface

L1-L5‧‧ lens

OP‧‧‧ openings

S41, S51‧‧‧ object side

S42, S52‧‧‧ like side

P‧‧‧reflexion point

S‧‧‧ aperture

Claims (21)

An imaging lens is a first lens having a positive refractive power and having a convex surface facing the object side in the vicinity of the optical axis, a second lens having a negative refractive power and a concave surface facing the image side in the vicinity of the optical axis, and having an image pickup lens a third lens having a positive refractive power, a fourth lens having a negative refractive power, and a fifth lens having a crescent shape in which the concave surface faces the image side in the vicinity of the optical axis; and the image side surface of the fifth lens is an aspherical shape. The position other than the intersection of the optical axes has an inflection point, and satisfies the following conditional expression: 0.01 < f / f3 < 0.60 (1) - 3.50 < f2 / f < - 1.75 (2) where F3: Note the focal length f2 of the third lens: the focal length f of the second lens: the focal length of the entire imaging lens. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 0.60<f1/f<1.20 (3), wherein f1: the focal length of the first lens f: The focal length of the entire camera lens. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: −0.90<f/f4<−0.02 (4), wherein f4: the focal length of the fourth lens is f: the focal length of the entire imaging lens . The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 0.70 < f123 / f < 1.30 (5) wherein f123: a composite focal length f from the first lens to the front third lens: The focal length of the entire camera lens. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 0.00<∣f4/f5∣<9.00 (6) wherein f4: the focal length f5 of the fourth lens is preceded by the fifth lens focal length. The imaging lens described in claim 1, wherein the following conditional expression is satisfied: 0.01<d6/f<0.25 (7) where d6: the air gap f on the optical axis of the third lens and the fourth lens of the preceding note: the focal length of the entire imaging lens. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 0.02<THIL2/f<0.15 (8) wherein THIL2: the thickness of the second lens on the optical axis is f: the entire imaging lens The focal length. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 0.10<THIL5/f<0.30 (9) wherein THIL5: the thickness of the fifth lens on the optical axis is f: the entire imaging lens The focal length. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 20<ν5-ν4<70...(10) Here, ν5: the Abbe number ν4 of the fifth lens: the Abbe number of the fourth lens. The imaging lens according to claim 1, wherein the following conditional expression is satisfied: 20 < ν1 - ν2 < 70 (11), wherein ν1: the Abbe number of the first lens ν2: the second lens of the second lens Abbe number. The imaging lens according to claim 1, wherein the first lens system has a crescent shape. The imaging lens according to claim 1, wherein the second lens system has a crescent shape. The imaging lens according to claim 1, wherein the fourth lens and the fifth lens have an aspherical shape on both sides, and both surfaces have an inflection point at a position other than the intersection with the optical axis. The imaging lens according to claim 1, wherein the synthetic refractive power of the fourth lens and the fifth lens is a negative refractive power. The imaging lens according to claim 14, wherein the fifth lens system has a positive refractive power. The imaging lens according to claim 14, wherein the fifth lens system has a negative refractive power. An imaging lens From the object side, the first lens having a positive refractive power and having a convex surface facing the object side in the vicinity of the optical axis, a second lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis, and a positive refractive power 3 lenses, a fourth lens having a negative refractive power and having a concave surface facing the image side in the vicinity of the optical axis; and a fifth lens having a concave surface facing the image side in the vicinity of the optical axis; and the image side surface of the fifth lens is an aspherical shape, and The position other than the intersection of the optical axes has an inflection point, and satisfies the following conditional expression: 0.01 < f / f3 < 0.60 (1) where f3: the focal length of the third lens f: the focal length of the entire imaging lens . The imaging lens according to claim 17, wherein the following conditional expression is satisfied: -3.50 < f2 / f < - 1.75 (2) wherein f2: the focal length of the second lens f: the focal length of the entire imaging lens . The imaging lens according to any one of claims 1 to 17, further comprising: a lens having substantially no power. An image pickup apparatus having any one of claims 1 and 17 The imaging lens and the pre-recording element described in the item. A portable terminal is provided with the imaging device described in claim 20.