Optical lens assembly for imaging pickup

An optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side, comprising: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power has bi-aspheric surfaces. The fourth lens element with positive refractive power has a concave object-side surface and a convex image-side surface and both being aspheric. The fifth lens element with negative refractive power has a concave image-side surface, bi-aspheric surfaces and at least one inflection point. Therefore, the optical lens assembly for imaging pickup satisfies conditions related to shorten the total length and to reduce the sensitivity for use in compact cameras and mobile phones with camera functionalities.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical lens assembly for imaging pickup, and more particularly to the optical lens assembly for imaging pickup comprised of five lens elements to provide a good image quality and reduce the total length to satisfy the specifications for electronic products.

2. Description of the Related Art

Currently, a personal computer is generally equipped with a web camera, and a mobile phone camera has become a necessary item. To meet user requirements, compact electronic products such as web cameras, mobile phone cameras, and digital still cameras tend to be developed with a thin design, and an optical lens assembly for imaging pickup is generally installed for capturing images of an object, and the optical lens assembly for imaging pickup must be installed in the thin computer, mobile phone or camera, and thus the compact and thin optical lens assembly for imaging pickup has a high demand. As the pixel of the camera keeps increasing, the optical lens assembly for imaging pickup tends to be developed with smaller volume and thickness, while meeting the user requirements by improving the resolution, the telecentricity, and the optical performance of the aberration correction.

In general, a conventional optical lens assembly for imaging pickup of a compact electronic product comes with different designs, including the two-lens, three-lens, four-lens, and five-or-more lens designs. If the imaging quality is taken into consideration, the optical lens assembly for imaging pickup with the four-lens or five-lens designs has advantages on image aberration and modulation transfer function (MTF) performance, wherein the five-lens design having a higher resolution than the four-lens designs thus being applicable for electronic products requiring the high quality and high pixels.

In various compact designs of the five-lens optical lens assembly for imaging pickup having a fixed focal length, prior arts adopt different combinations of positive and negative refractive powers and a group of stacked lens elements as disclosed in publications and U.S. Pat. Nos. 7,663,813, in which the two cemented glass lenses incur a higher manufacturing cost, and such conventional optical lens assembly for imaging pickup is unfavorable for the cost control of mass production. Another conventional technique is the combination of a first lens element with negative refractive power and a second lens element with positive refractive power as disclosed in U.S. Pat. No. 7,480,105, but such conventional optical lens assembly for image pickup cannot reduce the total length of the optical system easily to meet the requirement of the compact design.

In products such as compact digital cameras, web cameras, and mobile phone cameras, the optical lens assembly for imaging pickup requires a compact design, a short focal length, and a good aberration correction. As disclosed in U.S. Pat. No. 7,502,181, a first lens element with positive refractive power, a second lens element with negative refractive power, and a fourth lens element with negative refractive power are installed to shorten the total length of the optically system. Since the fourth lens element has a convex object-side surface and a concave image-side surface, the aberration correction can be compensated, and the surface shapes of the fourth lens element and the fifth lens element have a large change and must be matched with each other, and such requirements are unfavorable for mass production. In the description above, the conventional designs will increase the back focal length and the total length of the optical lens assembly for imaging pickup. In various different designs of the five-lens focal length optical lens assembly for imaging pickup with a fixed focal length, a first lens element having a convex object-side surface is used for decreasing the refractive angle of the incident light to avoid an excessive aberration, so as to facilitate obtaining a good balance between the effects of increasing the view angle of the system and correcting the aberration. If the complementary combination of the fourth lens element with positive refractive power and the fifth lens element with negative refractive power is adopted, the telecentric effect can be improved to facilitate reducing the total length of the optical lens assembly for imaging pickup effectively. Therefore, the present invention provides a more practical design to shorten the optical lens assembly for imaging pickup, while using a combination of refractive powers and a combination of convex and concave surfaces of five lens elements to lower the cost for mass production easily and apply the optical lens assembly for imaging pickup to compact electronic products.

SUMMARY OF THE INVENTION

Therefore, it is a primary objective of the present invention to provide an optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along the optical axis, comprising: the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element; wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element has negative refractive power; the third lens element with refractive power is made of plastic and has both aspheric object-side surface and image-side surface; the fourth lens element with positive refractive power is made of plastic and has a concave object-side surface and a convex image-side surface, and both object-side surface and image-side surface are aspheric; the fifth lens element with negative refractive power is made of plastic and has a concave image-side surface, and both object-side surface and image-side surface are aspheric, and at least one of the object-side surface and image-side surface has at least one inflection point, and the following relation is satisfied:
1.35 mm<TD<1.85 mm;  (1)

wherein, TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element (as shown inFIG. 9).

On the other hand, the present invention provides an optical lens assembly for imaging pickup, as described above, and further comprises a stop; wherein the second lens element has a concave image-side surface, and the optical lens assembly for imaging pickup satisfies one or more of the following relations in addition to the relation (1):
0.85<SD/TD<1.15;  (2)
30<v1−v2<42;  (3)
|f/f3|<0.3;  (4)
0.2<f4/f<0.65;  (5)
−0.65<f5/f<−0.2;  (6)
0.15 mm<ET3<0.25 mm;  (7)

wherein, SDis the axial distance between the stop and the image-side surface of the fifth lens element, TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element, v1is the Abbe number of the first lens element, v2is the Abbe number of the second lens element, f is the focal length of the optical lens assembly for imaging pickup, f3is the focal length of the third lens element, f4is the focal length of the fourth lens element, f5is the focal length of the fifth lens element, and ET3is the edge thickness of the third lens element at the maximum effective diameter (as shown inFIG. 9).

Another objective of the present invention is to provide an optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along the optical axis, comprising: the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element; wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element has negative refractive power; the third lens element with refractive power is made of plastic and has both aspheric object-side surface and image-side surface; the fourth lens element with positive refractive power is made of plastic, and has a concave object-side surface and a convex image-side surface, and both object-side surface and image-side surface are aspheric; the fifth lens element with negative refractive power is made of plastic and has a concave image-side surface, and both object-side surface and image-side surface are aspheric, and at least one of the object-side surface and image-side surface has at least one inflection point, and the following relations are satisfied:
0.25 mm<CTmax<0.6 mm  (8)
0.14 mm<CTmin<0.25 mm  (9)

Wherein, CTmaxis the central thickness of the thickest lens element of the optical lens assembly for imaging pickup, and CTminis the central thickness of the thinnest lens element of the optical lens assembly for imaging pickup.

On the other hand, the present invention provides an optical lens assembly for imaging pickup, as described above, and further comprises a stop and an image plane, and the optical lens assembly for imaging pickup satisfies one or more of the following relations in addition to the relations (8) and (9):
0.2<f4/f<0.65;  (5)
−0.65<f5/f<−0.2;  (6)
30<v1−v2<42;  (3)
0.85<SD/TD<1.15;  (2)
0.45<CTmin/CTmax<0.95;  (10)
0.15 mm<ET3<0.25 mm;  (7)
1.7 mm<(TTL/f)*TD<2.8 mm;  (11)

wherein, f is the focal length of the optical lens assembly for imaging pickup, f4is the focal length of the fourth lens element, f5is the focal length of the fifth lens element, v1is the Abbe number of the first lens element, v2is the Abbe number of the second lens element, SDis the axial distance between the stop and the image-side surface of the fifth lens element, TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element, CTminis the central thickness of the thinnest lens element of the optical lens assembly for imaging pickup, CTmaxis the central thickness of the thickest lens element of the optical lens assembly for imaging pickup, ET3is the edge thickness of the third lens element at the maximum effective diameter, and TTL is the axial distance between the object-side surface of the first lens element and the image plane.

Another objective of the present invention is to provide an optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along the optical axis, comprising: the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element, wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element has negative refractive power; the third lens element with refractive power is made of plastic and has both aspheric object-side surface and image-side surface; the fourth lens element with positive refractive power is made of plastic and has a concave object-side surface and a convex image-side surface, and both object-side surface and image-side surface are aspheric; the fifth lens element with negative refractive power is made of plastic and has a concave image-side surface and both aspheric object-side surface and image-side surface, and at least one of the object-side surface and image-side surface has at least one inflection point, and the following relations are satisfied:
0.3 mm<(CT2+CT3)<0.55 mm;  (12)
1.15 mm<ΣCT<1.65 mm;  (13)

wherein, CT2is the central thickness of the second lens element, CT3is the central thickness of the third lens element, and ΣCT is the summation of the central thickness of each lens element of the optical lens assembly for imaging pickup.

On the other hand, the present invention provides an optical lens assembly for imaging pickup, as described above, and further comprises a stop, wherein the second lens element has a concave image-side surface, and the optical lens assembly for imaging pickup satisfies one or more of the following relations in addition to the relations (12) and (13):
0.85<SD/TD<1.15;  (2)
0.2<f4/f<0.65;  (5)
−0.65<f5/f<−0.2;  (6)
30<v1−v2<42;  (3)
|f/f3|<0.3;  (4)
0.15 mm<ET3<0.25 mm;  (7)

wherein, SDis the axial distance between the stop and the image-side surface of the fifth lens element, TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element, f is the focal length of the optical lens assembly for imaging pickup, f3is the focal length of the third lens element, f4is the focal length of the fourth lens element, f5is the focal length of the fifth lens element, v1is the Abbe number of the first lens element, v2is the Abbe number of the second lens element, and ET3is the edge thickness of the third lens element at the maximum effective diameter.

Another objective of the present invention is to provide an optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along the optical axis, comprising: the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element; wherein the first lens element has positive refractive power; the second lens element has negative refractive power; the third lens element with refractive power is made of plastic and has both aspheric object-side surface and image-side surface; the fourth lens element with positive refractive power is made of plastic and has a concave object-side surface and a convex image-side surface, and both object-side surface and image-side surface are aspheric; the fifth lens element with negative refractive power is made of plastic and has both aspheric object-side surface and image-side surface, and at least one of object-side surface and image-side surface has at least one inflection point; and the optical lens assembly for imaging pickup further comprises an image plane, and the following relation is satisfied:
1.7 mm<(TTL/f)*TD<2.8 mm;  (11)

wherein TTL is the axial distance between the object-side surface of the first lens element and the image plane, f is the focal length of the optical lens assembly for imaging pickup, and TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element.

On the other hand, the present invention provides an optical lens assembly for imaging pickup, as described above, and further comprises a stop, wherein the second lens element has a concave image-side surface, and the optical lens assembly for imaging pickup satisfies one or more of the following relations in addition to the relation (11):
0.85<SD/TD<1.15;  (2)
|f/f3|<0.3;  (4)
0.2<f4/f<0.65;  (5)
−0.65<f5/f<−0.2;  (6)
0.45<CTmin/CTmax<0.95;  (10)
0.15 mm<ET3<0.25 mm;  (7)

wherein, SDis the axial distance between the stop and the image-side surface of the fifth lens element, TDis the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element, f is the focal length of the optical lens assembly for imaging pickup, f3is the focal length of the third lens element, f4is the focal length of the fourth lens element, f5is the focal length of the fifth lens element, CTminis the central thickness of the thinnest lens element of the optical lens assembly for imaging pickup on the optical axis, CTmaxis the central thickness of the thickest lens element of the optical lens assembly for imaging pickup on the optical axis, and ET3is the edge thickness of the third lens element at the maximum effective diameter.

With the arrangement of the aforementioned first lens element, second lens element, third lens element, fourth lens element and fifth lens element with an appropriate interval apart from one another on the optical axis, the present invention can provide a good aberration correction and an advantageous modulation transfer function (MTF) in a greater field of view.

In the optical lens assembly for imaging pickup of the present invention comprised of the first lens element, second lens element, third lens element, fourth lens element and fifth lens element, the first lens element with positive refractive power provides most of the refractive power required by the system, and the second lens element with negative refractive power can correct aberrations produced by the positive refractive power effectively and correct the Petzval sum of the system to make the image surface on the edge flatter. If the second lens element has a concave image-side surface, the intensity of negative refractive power of the second lens element can be adjusted appropriately according to the surface shape to provide a good aberration correction effect to the system. If the fourth lens element has a concave object-side surface and a convex meniscus image-side surface, the aberration correction can be improved. If the curvature at the periphery of the image-side surface is greater than that at the center, the angle of projecting the light onto the sensor can be suppressed to enhance the light sensitivity of the image sensor. By having the complementary lens set of the fourth lens element with positive refractive power and the fifth lens element with negative refractive power, the telecentric effect can be achieved to reduce the back focal length, so as to shorten the total length. If the fifth lens element has a concave image-side surface, the principal point of the optical lens assembly for imaging pickup will be far away from the image plane to reduce the total length of the optical lens assembly for imaging pickup, so as to produce a compact design of a lens system.

In the optical lens assembly for imaging pickup of the present invention, the combination of the first lens element with positive refractive power, the second lens element with negative refractive power and the third lens element with positive or negative refractive power, and the mutual compensation of the fourth lens element with positive refractive power and the fifth lens element with negative refractive power can reduce the total length of the optical lens assembly for imaging pickup effectively, so that the image sensor can have a larger effective pixel range within the same total length. In other words, a shorter optical imaging system for pickup can be designed with the same effective pixel range of the image sensor.

If the fifth lens element has an inflection point, the inflection point can be used for guiding light of an image with an angle out from the edges of the fifth lens element, such that the light of an image at the off-axis view angle is guided and received by the image sensor. In addition, the third lens element, fourth lens element and fifth lens element are made of plastic to facilitate lower manufacture costs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference toFIG. 1Afor an optical lens assembly for imaging pickup of the present invention, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along the optical axis, comprises: the first lens element110, the second lens element120, the third lens element130, the fourth lens element140and the fifth lens element150; wherein, the first lens element110with positive refractive power has a convex object-side surface111; the second lens element120has negative refractive power; the third lens element130with refractive power is made of plastic and has both aspheric object-side surface131and image-side surface132; the fourth lens element140with positive refractive power is made of plastic, and has a concave object-side surface141and a convex image-side surface142, and both object-side surface141and image-side surface142are aspheric; the fifth lens element150with negative refractive power is made of plastic and has a concave image-side surface152, and both object-side surface151and image-side surface152are aspheric, and at least one of the object-side surface151and image-side surface152has at least one inflection point. The optical lens assembly for imaging pickup further comprises a stop and an IR-filter160, the stop can be an aperture stop100, which is a front aperture stop installed between a photographed object and the first lens element110. The IR-filter160is installed between the fifth lens element150and the image plane170and generally made of panel glass without affecting the focal length of the optical lens assembly for imaging pickup of the present invention. The aspheric surfaces of the first lens element110, second lens element120, third lens element130, fourth lens element140and fifth lens element150comply with the aspherical surface formula as given in Equation (14).

X is the relative height from a point on the aspherical surface with a distance Y between the optical axis and a tangent plane at the tip of the optical axis of the aspherical surface;

Y is the distance between a point on the curve of the aspherical surface and the optical axis;

R is the curvature radius;

K is the conic coefficient; and

In the optical lens assembly for imaging pickup of the present invention, the first lens element110and second lens element120have spheric or aspheric surfaces. If aspheric optical surfaces are adopted, then the curvature radius of the optical surfaces can be used for changing the refractive power to reduce or eliminate aberrations, so as to reduce the total length of the optical lens assembly for imaging pickup. With the arrangement of the first lens element110, second lens element120, third lens element130, fourth lens element140and fifth lens element150, the optical lens assembly for imaging pickup of the present invention satisfies the relation (1).

In the optical lens assembly for imaging pickup of the present invention, if the relation (1) is satisfied, the distance between the object-side surface111of the first lens element110and the image-side surface152of the fifth lens element150can be limited, so that the optical lens assembly for imaging pickup of the present invention can be installed into a thin digital camera, a mobile phone camera or a compact electronic device for different applications.

If the relations (2) and (11) are satisfied, the position of the aperture stop and the distance between the first lens element110and the image plane170can be adjusted to shorten the length of the optical lens assembly for imaging pickup. Similarly, if the relation (13) is satisfied, the allocation of thickness for each lens element and the length of the traveling light path of the optical lens assembly for imaging pickup can be limited to adjust the total length of the optical lens assembly for imaging pickup.

If the relations (8), (9) and (10) are satisfied, the thickness of each lens element of the optical lens assembly for imaging pickup can be adjusted appropriately. If the thickness of each lens element is excessive, it will be unfavorable to reduce the total length of the optical lens assembly for imaging pickup. If the thickness of each lens element is insufficient, the resolution of each lens element will be insufficient and unfavorable for the manufacture, and may lower the manufacturing yield rate. If the second lens element120and the third lens element130constitute a lens group with negative refractive power and the relation (12) is limited, the thickness of the second lens element120and third lens element130can be adjusted more appropriately to facilitate reducing the total length of the optical lens assembly for imaging pickup and limit the total length of the optical path of the lens group with negative refractive power and facilitate the aberration correction.

If the relations (5) and (6) are satisfied, the negative refractive power of the fourth lens element140can be adjusted appropriately to be complementary with the positive refractive power of the fifth lens element150to reduce the back focal length and shorten the total length. In the meantime, the refractive power of the fourth lens element140can be adjusted appropriated to be complementary with the refractive power of the fifth lens element150to produce the telecentric effect, so as to facilitate reduction of the back focal length and the total length and achieve the effect of a compact lens assembly. If the ratio of the focal length f3of the third lens element130to the focal length f of the optical lens assembly for imaging pickup is limited according to the relation (4), the refractive power of the third lens element130can be adjusted appropriately to assist reducing the sensitivity of the system in manufacturing tolerance. Similarly, if the relation (7) is satisfied, the thickness of the third lens element130at the maximum effective diameter can be adjusted appropriately to facilitate correcting high-level aberrations. If the effective diameter of the lens is undersized, the formation and manufacture of lenses may be affected by the stress at the periphery of the lens.

If the relation (3) is satisfied, meaning the difference between the Abbe number v1of the first lens element110and the Abbe number v2of the second lens element120will fall within a desirable range, the chromatic aberration produced by the first lens element110and the second lens element120can be improved by the chromatic aberration compensation ability of the second lens element120.

The optical lens assembly for imaging pickup of the present invention is described by means of preferred embodiments with relevant drawings as follows.

With reference toFIGS. 1A and 1Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the first preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop100and an IR-filter160. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop100; a plastic first lens element110with positive refractive power has a convex object-side surface111and a concave image-side surface112, and both object-side surface111and image-side surface112are aspheric; a plastic second lens element120with negative refractive power has a concave object-side surface121and a concave image-side surface122, and both object-side surface121and image-side surface122are aspheric; a plastic third lens element130with positive refractive power has a convex object-side surface131and a concave image-side surface132, and both object-side surface131and image-side surface132are aspheric; a plastic fourth lens element140with positive refractive power has a concave object-side surface141and a convex image-side surface142, and both object-side surface141and image-side surface142are aspheric; a plastic fifth lens element150with negative refractive power has a concave object-side surface151and a concave image-side surface152, and both object-side surface151and image-side surface152being aspheric and having at least one inflection point; and an IR-filter160made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor180at an image plane170. With the combination of the five lens elements, the aperture stop100and the IR-filter160, an image of the photographed object can be formed at the image sensor180.

The optical data of this preferred embodiment are listed in Table 1, wherein the object-side surface and the image-side surface of the first lens element110to the fifth lens element150comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 2 as follows:

With reference to Table 1 andFIG. 1Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.95 (mm), an f-number Fno=2.45, and a half of the maximum view angle HFOV=33.1°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 3 below, and the related symbols have been described above and thus will not be described again.

TABLE 3Data of related relations of the first preferred embodimentRelationDatav1− v232.6(CT2+ CT3) [mm]0.35CTmin[mm]0.15CTmax[mm]0.42CTmin/CTmax0.36ΣCT [mm]1.34ET3[mm]0.20TD[mm]1.67(TTL/f)*TD[mm]2.00|f/f3|0.05f4/f0.53f5/f−0.49SD/TD0.95

According to the optical data as shown in Table 1 and the series of aberration curves as shown inFIG. 1B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 2A and 2Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the second preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop200and an IR-filter260. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop200; a plastic first lens element210with positive refractive power has a convex object-side surface211and a concave image-side surface212, and both object-side surface211and image-side surface212are aspheric; a plastic second lens element220with negative refractive power has a convex object-side surface221and a concave image-side surface222, and both object-side surface221and image-side surface222are aspheric; a plastic third lens element230with positive refractive power has a convex object-side surface231and a concave image-side surface232, and both object-side surface231and image-side surface232are aspheric; a plastic fourth lens element240with positive refractive power has a concave object-side surface241and a convex image-side surface242, and both object-side surface241and image-side surface242are aspheric; a plastic fifth lens element250with negative refractive power has a concave object-side surface251and a concave image-side surface252, and both object-side surface251and image-side surface252are aspheric, and having at least one inflection point; and an IR-filter260made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor280at an image plane270. With the combination of the five lens elements, the aperture stop200and the IR-filter260, an image of the photographed object can be formed at the image sensor280.

The optical data of this preferred embodiment are listed in Table 4, wherein the object-side surface and the image-side surface of the first lens element210to the fifth lens element250comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 5 as follows:

With reference to Table 4 andFIG. 2Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.76 (mm), an f-number Fno=2.60, and a half of the maximum view angle HFOV=35.9°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 6 below, and the related symbols have been described above and thus will not be described again.

TABLE 6Data of related relations of the second preferred embodimentRelationDatav1− v234.5(CT2+ CT3) [mm]0.42CTmin[mm]0.20CTmax[mm]0.33CTmin/CTmax0.60ΣCT [mm]1.30ET3[mm]0.16TD[mm]1.64(TTL/f)*TD[mm]2.00|f/f3|0.17f4/f0.52f5/f−0.46SD/TD0.96

According to the optical data as shown in Table 4 and the series of aberration curves as shown inFIG. 2B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 3A and 3Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the third preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop300and an IR-filter360. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop300; a plastic first lens element310with positive refractive power has a convex object-side surface311and a convex image-side surface312, and both object-side surface311and image-side surface312are aspheric; a plastic second lens element320with negative refractive power has a concave object-side surface321and a concave image-side surface322, and both object-side surface321and image-side surface322are aspheric; a plastic third lens element330with positive refractive power has a convex object-side surface331and a convex image-side surface332, and both object-side surface331and image-side surface332are aspheric; a plastic fourth lens element340with positive refractive power has a concave object-side surface341and a convex image-side surface342, and both object-side surface341and image-side surface342being aspheric; a plastic fifth lens element350with negative refractive power has a concave object-side surface351and a concave image-side surface352, and both object-side surface351and image-side surface352are aspheric and having at least one inflection point; and an IR-filter360made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor380at an image plane370. With the combination of the five lens elements, the aperture stop300and the IR-filter360, an image of the photographed object can be formed at the image sensor380.

The optical data of this preferred embodiment are listed in Table 7, wherein the object-side surface and the image-side surface of the first lens element310to the fifth lens element350comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 8 as follows:

With reference to Table 7 andFIG. 3Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.80 (mm), an f-number Fno=2.60, and a half of the maximum view angle HFOV=35.2°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 9 below, and the related symbols have been described above and thus will not be described again.

TABLE 9Data of related relations of the third preferred embodimentRelationDatav1− v232.1(CT2+ CT3) [mm]0.52CTmin[mm]0.22CTmax[mm]0.34CTmin/CTmax0.66ΣCT [mm]1.43ET3[mm]0.18TD[mm]1.75(TTL/f)*TD[mm]2.23|f/f3|0.31f4/f0.54f5/f−0.45SD/TD0.97

According to the optical data as shown in Table 7 and the series of aberration curves as shown inFIG. 3B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 4A and 4Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the fourth preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop400and an IR-filter460. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop400; a plastic first lens element410with positive refractive power has a convex object-side surface411and a concave image-side surface412, and both object-side surface411and image-side surface412are aspheric; a plastic second lens element420with negative refractive power has a convex object-side surface421and a concave image-side surface422, and both object-side surface421and image-side surface422are aspheric; a plastic third lens element430with negative refractive power has a convex object-side surface431and a concave image-side surface432, and both object-side surface431and image-side surface432are aspheric; a plastic fourth lens element440with positive refractive power has a concave object-side surface441and a convex image-side surface442, and both object-side surface441and image-side surface442are aspheric; a plastic fifth lens element450with negative refractive power has a convex object-side surface451and a concave image-side surface452, and both object-side surface451and image-side surface452are aspheric and having at least one inflection point; and an IR-filter460made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor480at an image plane470. With the combination of the five lens elements, the aperture stop400and the IR-filter460, an image of the photographed object can be formed at the image sensor480.

The optical data of this preferred embodiment are listed in Table 10, wherein the object-side surface and the image-side surface of the first lens element410to the fifth lens element450comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 11 as follows:

With reference to Table 10 andFIG. 4Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.93 (mm), an f-number Fno=2.40, and a half of the maximum view angle HFOV=33.5°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 12 below, and the related symbols have been described above and thus will not be described again.

TABLE 12Data of related relations of the fourth preferred embodimentRelationDatav1− v232.1(CT2+ CT3) [mm]0.41CTmin[mm]0.20CTmax[mm]0.35CTmin/CTmax0.58ΣCT [mm]1.28ET3[mm]0.22TD[mm]1.65(TTL/f)*TD[mm]1.95|f/f3|0.16f4/f0.59f5/f−0.61SD/TD0.95

According to the optical data as shown in Table 10 and the aberration curves as shown inFIG. 4B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 5A and 5Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the fifth preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop500and an IR-filter560. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop500; a plastic first lens element510with positive refractive power has a convex object-side surface511and a convex image-side surface512, and both object-side surface511and image-side surface512are aspheric; a plastic second lens element520with negative refractive power has a concave object-side surface521and a concave image-side surface522, and both object-side surface521and image-side surface522are aspheric; a plastic third lens element530with negative refractive power has a concave object-side surface531and a convex image-side surface532, and both object-side surface531and image-side surface532are aspheric; a plastic fourth lens element540with positive refractive power has a concave object-side surface541and a convex image-side surface542, and both object-side surface541and image-side surface542are aspheric; a plastic fifth lens element550with negative refractive power has a convex object-side surface551and a concave image-side surface552, and both object-side surface551and image-side surface552are aspheric and having at least one inflection point; and an IR-filter560made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor580at an image plane570. With the combination of the five lens elements, the aperture stop500and the IR-filter560, an image of the photographed object that can be formed at the image sensor580.

The optical data of this preferred embodiment are listed in Table 13, wherein the object-side surface and the image-side surface of the first lens element510to the fifth lens element550comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 14 as follows:

With reference to Table 13 andFIG. 5Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.77 (mm), an f-number Fno=2.60, and a half of the maximum view angle HFOV=35.6°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 15 below, and the related symbols have been described above and thus will not be described again.

TABLE 15Data of related relations of the fifth preferred embodimentRelationDatav1− v232.6(CT2+ CT3) [mm]0.41CTmin[mm]0.20CTmax[mm]0.34CTmin/CTmax0.58ΣCT [mm]1.34ET3[mm]0.20TD[mm]1.67(TTL/f)*TD[mm]2.12|f/f3|0.05f4/f0.60f5/f−0.57SD/TD0.97

According to the optical data as shown in Table 13 and the series of aberration curves as shown inFIG. 5B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 6A and 6Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the sixth preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop600and an IR-filter660. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop600; a plastic first lens element610with positive refractive power has a convex object-side surface611and a convex image-side surface612, and both object-side surface611and image-side surface612are aspheric; a plastic second lens element620with negative refractive power has a concave object-side surface621and a concave image-side surface622, and both object-side surface621and image-side surface622are aspheric; a plastic third lens element630with positive refractive power has a concave object-side surface631and a convex image-side surface632, and both object-side surface631and image-side surface632are aspheric; a plastic fourth lens element640with positive refractive power has a concave object-side surface641and a convex image-side surface642, and both object-side surface641and image-side surface642are aspheric; a plastic fifth lens element650with negative refractive power has a convex object-side surface651and a concave image-side surface652, and both object-side surface651and image-side surface652are aspheric and having at least one inflection point; and an IR-filter660made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor680at an image plane670. With the combination of the five lens elements, the aperture stop600and the IR-filter660, an image of the photographed object can be formed at the image sensor680.

The optical data of this preferred embodiment are listed in Table 16, wherein the object-side surface and the image-side surface of the first lens element610to the fifth lens element650comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 17 as follows:

With reference to Table 16 andFIG. 6Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=2.02 (mm), an f-number Fno=2.60, and a half of the maximum view angle HFOV=32.0°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 18 below, and the related symbols have been described above and thus will not be described again.

TABLE 18Data of related relations of the sixth preferred embodimentRelationDatav1− v229.3(CT2+ CT3) [mm]0.46CTmin[mm]0.23CTmax[mm]0.42CTmin/CTmax0.55ΣCT [mm]1.46ET3[mm]0.26TD[mm]1.78(TTL/f)*TD[mm]2.17|f/f3|0.11f4/f0.52f5/f−0.46SD/TD0.97

According to the optical data as shown in Table 16 and the series of aberration curves as shown inFIG. 6B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 7A and 7Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the seventh preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop700and an IR-filter760. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop700; a plastic first lens element710with positive refractive power has a convex object-side surface711and a convex image-side surface712, and both object-side surface711and image-side surface712are aspheric; a plastic second lens element720with negative refractive power has a concave object-side surface721and a concave image-side surface722, and both object-side surface721and image-side surface722are aspheric; a plastic third lens element730with negative refractive power has a concave object-side surface731and a concave image-side surface732, and both object-side surface731and image-side surface732are aspheric; a plastic fourth lens element740with positive refractive power has a concave object-side surface741and a convex image-side surface742, and both object-side surface741and image-side surface742are aspheric; a plastic fifth lens element750with negative refractive power has a convex object-side surface751and a concave image-side surface752, and both object-side surface751and image-side surface752are aspheric and having at least one inflection point; and an IR-filter760made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor780at an image plane770. With the combination of the five lens elements, the aperture stop700and the IR-filter760, an image of the photographed object can be formed the image sensor780.

The optical data of this preferred embodiment are listed in Table 19, wherein the object-side surface and the image-side surface of the first lens element710to the fifth lens element750comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 20 as follows:

With reference to Table 19 andFIG. 3Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.76 (mm), an f-number Fno=2.60, and a half of the maximum view angle HFOV=35.6°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 21 below, and the related symbols have been described above and thus will not be described again.

TABLE 21Data of related relations of the seventh preferred embodimentRelationDatav1− v232.6(CT2+ CT3) [mm]0.39CTmin[mm]0.19CTmax[mm]0.33CTmin/CTmax0.57ΣCT [mm]1.31ET3[mm]0.20TD[mm]1.64(TTL/f)*TD[mm]2.06|f/f3|0.10f4/f0.59f5/f−0.57SD/TD0.97

According to the optical data as shown in Table 19 and the aberration curves as shown inFIG. 7B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

With reference toFIGS. 8A and 8Bfor a schematic view and a series of aberration curves of an optical lens assembly for imaging pickup in accordance with the eighth preferred embodiment of the present invention respectively, the optical lens assembly for imaging pickup comprises five lens elements, an aperture stop800and an IR-filter860. More specifically, the optical lens assembly for imaging pickup, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop800; a plastic first lens element810with positive refractive power has a convex object-side surface811and a convex image-side surface812, and both object-side surface811and image-side surface812are aspheric; a plastic second lens element820with negative refractive power has a concave object-side surface821and a concave image-side surface822, and both object-side surface821and image-side surface822are aspheric; a plastic third lens element830with negative refractive power has a concave object-side surface831and a concave image-side surface832, and both object-side surface831and image-side surface832are aspheric; a plastic fourth lens element840with positive refractive power has a concave object-side surface841and a convex image-side surface842, and both object-side surface841and image-side surface842are aspheric; a plastic fifth lens element850with negative refractive power has a concave object-side surface851and a concave image-side surface852, and both object-side surface851and image-side surface852are aspheric and having at least one inflection point; and an IR-filter860made of panel glass for adjusting a wavelength section of the light of an image, and an image sensor880at an image plane870. With the combination of the five lens elements, the aperture stop800and the IR-filter860, an image of the photographed object can be formed at the image sensor880.

The optical data of this preferred embodiment are listed in Table 22, wherein the object-side surface and the image-side surface of the first lens element810to the fifth lens element850comply with the aspheric surface formula as given in Equation (14), and their aspheric coefficients are listed in Table 23 as follows:

With reference to Table 22 andFIG. 8Bfor an optical lens assembly for imaging pickup of this preferred embodiment, the optical lens assembly for imaging pickup has a focal length f=1.78 (mm), an f-number Fno=2.58, and a half of the maximum view angle HFOV=35.4°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 24 below, and the related symbols have been described above and thus will not be described again.

TABLE 24Data of related relations of the eighth preferred embodimentRelationDatav1− v232.6(CT2+ CT3) [mm]0.38CTmin[mm]0.18CTmax[mm]0.33CTmin/CTmax0.55ΣCT [mm]1.33ET3[mm]0.19TD[mm]1.65(TTL/f)*TD[mm]2.04|f/f3|0.12f4/f0.54f5/f−0.49SD/TD0.97

According to the optical data as shown in Table 22 and the series of aberration curves as shown inFIG. 8B, the optical lens assembly for imaging pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion.

In the optical lens assembly for imaging pickup of the present invention, the aperture stop can be a front or middle aperture stop. If the aperture stop is a front aperture stop, a longer distance between the exit pupil of the optical lens assembly for imaging pickup and the image plane can provide the telecentric effect and improve the efficiency of receiving images by the image sensor such as a CCD or CMOS image sensor. If the aperture stop is a middle aperture stop positioned between the first lens element and the image plane, the view angle of the system can be increased, such that the optical lens assembly for imaging pickup has the advantage of a wide-angle lens.

In the optical lens assembly for imaging pickup of the present invention, the lens element can be made of glass or plastic. For the lens elements made of glass, the allocation of refractive power of the optical lens assembly for imaging pickup can have higher degree of freedom in selecting design parameters. For the lens elements made of plastic, the production cost can be lowered effectively as well as the advantages of aspheric lens production can be obtained.

In the optical lens assembly for imaging pickup of the present invention, if the lens element has a convex surface, then the surface of the lens element is convex at a position in proximity to the axis; and if the lens element has a concave surface, then the surface of the lens element is concave at a position in proximity to the axis.

In the optical lens assembly for imaging pickup of the present invention, at least one stop such as a glare stop or a field stop can be provided for reducing stray lights to improve the image quality, to limit the field size, or other functionalities.

Tables 1 to 24 show value changes of an optical lens assembly for imaging pickup in accordance with different preferred embodiments of the present invention respectively, and even if different values are used, products of the same structure are intended to be covered by the scope of the present invention. It is noteworthy to point out that the aforementioned description and the illustration of related drawings are provided for the purpose of explaining the technical characteristics of the present invention, but not intended for limiting the scope of the present invention.