TWI475251B - Image capturing lens assembly, image capturing device and mobile terminal - Google Patents

Description

Image system lens group, image capturing device and portable device

The invention relates to an image system lens group, an image capturing device and a portable device, in particular to a miniaturized image system lens group, an image capturing device and a portable device.

In recent years, with the rapid development of miniaturized photographic lenses, the demand for miniature imaging modules has been increasing, and the photosensitive elements of general photographic lenses are nothing more than photosensitive coupled devices (CCDs) or complementary oxidized metal semiconductors. Complementary Metal-Oxide Semiconductor Sensor (CMOS Sensor), and with the advancement of semiconductor process technology, the pixel size of the photosensitive element is reduced, and today's electronic products are developed with a good function, light and thin appearance. Trends, therefore, miniaturized photographic lenses with good image quality have become the mainstream in the market.

An optical lens assembly having a three-lens structure is generally designed from the object side to the image side as a three-piece front aperture system with positive refractive power, negative refractive power and positive refractive power, but the conventional refractive power and The aperture configuration method is easy to cause limited image capturing range, and it is impossible to effectively balance the expansion of the viewing angle and the shortening of the total length.

The invention provides an image system lens group, an image capturing device and a portable device. The first lens is designed as a lenticular lens, which not only can shorten the total length, but also meets the requirements of lightness and thinness of the product. this In addition, the image system lens group, the image capturing device and the portable device can also bring the aperture closer to the imaging surface, thereby increasing the angle of view, thereby making the image system lens group, the image capturing device and the portable device within a limited shooting distance. Take enough image range.

The invention provides an image system lens group comprising a first lens, a second lens and a third lens in sequence from the object side to the image side. The first lens has a positive refractive power, and the object side surface is a convex surface, and the image side surface thereof is a convex surface, and both the object side surface and the image side surface are aspherical. The second lens has a positive refractive power, and the object side surface is a concave surface, the image side surface thereof is a convex surface, and the object side surface and the image side surface are both aspherical surfaces. The third lens has a negative refractive power, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both aspherical. The lens with refractive power in the lens system of the imaging system is three. The image system lens group further includes an aperture disposed between the first lens and the second lens. Wherein, the focal length of the lens group of the image system is f, the focal length of the second lens is f2, the focal length of the third lens is f3, and the distance from the aperture to the side of the image side of the third lens image on the optical axis is SD, and the first lens side surface The distance from the side surface of the third lens image to the optical axis is TD, the thickness of the first lens on the optical axis is CT1, the thickness of the second lens on the optical axis is CT2, and the entrance pupil diameter of the lens group of the imaging system is EPD. (Entrance Pupil Diameter) which satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; 0.20 < CT2 / CT1 < 0.85; and 1.20 < f / EPD < 2.80.

The present invention further provides a lens system for an image system, comprising a first lens, a second lens and a third lens in sequence from the object side to the image side. The first lens has a positive refractive power, and the object side surface is a convex surface, and the image side surface thereof is a convex surface, and both the object side surface and the image side surface are aspherical. The second lens has a positive refractive power, The object side surface is a concave surface, and the image side surface is a convex surface, and both the object side surface and the image side surface are aspherical. The third lens has a negative refractive power, and the object side surface is a convex surface, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both Aspherical. The lens with refractive power in the lens system of the imaging system is three. The image system lens group further includes an aperture disposed between the first lens and the second lens. Wherein, the focal length of the second lens is f2, the focal length of the third lens is f3, the distance from the aperture to the side of the third lens image side on the optical axis is SD, and the first lens object side surface to the third lens image side surface is light. The distance on the shaft is TD, the radius of curvature of the first lens object side surface is R1, and the radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -0.90<f2/f3<0; 0.58<SD/TD <0.82; and -3.0<R2/R1<-0.2.

The present invention further provides an image system lens group comprising a first lens, a second lens and a third lens in sequence from the object side to the image side. The first lens has a positive refractive power, and the object side surface is a convex surface, and the image side surface thereof is a convex surface, and both the object side surface and the image side surface are aspherical. The second lens has a positive refractive power, and the object side surface is a concave surface, the image side surface thereof is a convex surface, and the object side surface and the image side surface are both aspherical surfaces. The third lens has a negative refractive power, and the object side surface is a convex surface, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both Aspherical. The lens with refractive power in the lens system of the imaging system is three. The image system lens group further includes an aperture disposed between the first lens and the second lens. Wherein, the focal length of the second lens is f2, the focal length of the third lens is f3, the distance from the aperture to the side of the third lens image side on the optical axis is SD, and the first lens object side surface to the third lens image side surface is light. The distance on the axis is TD, and the distance from the first lens object side surface to the imaging surface on the optical axis is TL, which satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; and 1.0 mm < TL < 2.3 mm.

The invention provides an image capturing device comprising an image system lens group and an electronic photosensitive element in sequence from the object side to the image side. The image system lens group sequentially includes a first lens, a second lens, and a third lens from the object side to the image side. The first lens has a positive refractive power, and the object side surface is a convex surface, and the image side surface thereof is a convex surface, and both the object side surface and the image side surface are aspherical. The second lens has a positive refractive power, and the object side surface is a concave surface, the image side surface thereof is a convex surface, and the object side surface and the image side surface are both aspherical surfaces. The third lens has a negative refractive power, and the object side surface is a convex surface, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both Aspherical. The lens with refractive power in the lens system of the imaging system is three. The image system lens group further includes an aperture disposed between the first lens and the second lens. Wherein, the focal length of the second lens is f2, the focal length of the third lens is f3, the distance from the aperture to the side of the third lens image side on the optical axis is SD, and the first lens object side surface to the third lens image side surface is light. The distance on the shaft is TD, and the distance from the first lens object side surface to the imaging plane on the optical axis is TL, which satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; and 1.0 mm <TL<2.3mm.

The present invention provides a portable device that includes an imaging device. The image capturing device sequentially includes an image system lens group and an electronic photosensitive element from the object side to the image side. The image system lens group sequentially includes a first lens, a second lens, and a third lens from the object side to the image side. The first lens has a positive refractive power, and the object side surface is a convex surface, and the image side surface thereof is a convex surface, and both the object side surface and the image side surface are aspherical. Second lens It has a positive refractive power, and its object side surface is a concave surface, and its image side surface is a convex surface, and both the object side surface and the image side surface are aspherical. The third lens has a negative refractive power, and the object side surface is a convex surface, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both Aspherical. The lens with refractive power in the lens system of the imaging system is three. The image system lens group further includes an aperture disposed between the first lens and the second lens. Wherein, the focal length of the second lens is f2, the focal length of the third lens is f3, the distance from the aperture to the side of the third lens image side on the optical axis is SD, and the first lens object side surface to the third lens image side surface is light. The distance on the shaft is TD, and the distance from the first lens object side surface to the imaging plane on the optical axis is TL, which satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; and 1.0 mm <TL<2.3mm.

The image system lens group, the image capturing device and the portable device provided by the invention are designed as lenticular lenses by the first lens, which is advantageous for shortening the total length to meet the requirements of lightening and thinning of the product.

When f2/f3 satisfies the above conditions, the total optical length can be effectively enhanced.

When the SD/TD meets the above conditions, the aperture can be approached to the imaging surface, thereby increasing the angle of view, so that the image system lens group, the image capturing device, and the portable device can capture a sufficient image range within a limited shooting distance.

When CT2/CT1 satisfies the above conditions, it can contribute to lens assembly and improve manufacturing yield.

When f/EPD satisfies the above conditions, the amount of light entering the system can be increased, thereby improving the resolution.

When R2/R1 satisfies the above conditions, it can be beneficial to the correction of the spherical aberration.

When the TL satisfies the above conditions, it is advantageous for the image system lens group and the image capturing device to be miniaturized, and is suitable for being mounted on a thin and portable device.

10‧‧‧Image capture device

100, 200, 300, 400, 500, 600, 700, 800‧ ‧ aperture

110, 210, 310, 410, 510, 610, 710, 810 ‧ ‧ first lens

111, 211, 311, 411, 511, 611, 711, 811 ‧ ‧ ‧ side surface

112, 212, 312, 412, 512, 612, 712, 812‧‧‧ image side surface

120, 220, 320, 420, 520, 620, 720, 820‧‧‧ second lens

121, 221, 321, 421, 521, 621, 721, 821‧‧ ‧ side surfaces

122, 222, 322, 422, 522, 622, 722, 822 ‧ ‧ side surface

130, 230, 330, 430, 530, 630, 730, 830 ‧ ‧ third lens

131, 231, 331, 431, 531, 631, 731, 831 ‧ ‧ ‧ side surface

132, 232, 332, 432, 532, 632, 732, 832‧‧‧ side surface

140, 240, 340, 440, 540, 640, 740, 840 ‧ ‧ infrared filter

150, 250, 350, 450, 550, 650, 750, 850 ‧ ‧ imaging surface

160, 260, 360, 460, 560, 660, 760, 860‧‧‧ electronic photosensitive elements

CT1‧‧‧ thickness of the first lens on the optical axis

CT2‧‧‧ thickness of the second lens on the optical axis

Incident aperture of the EPD‧‧ ‧ imaging system lens

f‧‧‧Focus of the lens system of the imaging system

F2‧‧‧The focal length of the second lens

f3‧‧‧The focal length of the third lens

Aperture value of Fno‧‧‧ image system lens group

Maximum viewing angle of the FOV‧‧‧ imaging system lens group

Half of the maximum viewing angle of the HFOV‧‧ image system lens group

ImgH‧‧‧Maximum image height

R1‧‧‧The radius of curvature of the side surface of the first lens object

R2‧‧‧ radius of curvature of the side surface of the first lens image

R3‧‧‧ radius of curvature of the side surface of the second lens

R4‧‧‧ radius of curvature of the side surface of the second lens image

R5‧‧‧ radius of curvature of the side surface of the third lens

R6‧‧‧ radius of curvature of the side surface of the third lens image

SD‧‧‧ aperture to the distance of the side surface of the third lens image on the optical axis

TD‧‧‧Distance from the first lens object side surface to the third lens image side surface on the optical axis

TL‧‧‧Distance from the side surface of the first lens to the optical axis of the imaging surface

FIG. 1 is a schematic view of an image taking device according to a first embodiment of the present invention.

Fig. 2 is a spherical aberration, astigmatism, and distortion curve of the first embodiment from left to right.

FIG. 3 is a schematic view of an image taking device according to a second embodiment of the present invention.

Fig. 4 is a spherical aberration, astigmatism, and distortion curve of the second embodiment, from left to right.

FIG. 5 is a schematic view of an image taking device according to a third embodiment of the present invention.

Fig. 6 is a spherical aberration, astigmatism, and distortion curve of the third embodiment, from left to right.

FIG. 7 is a schematic view of an image taking device according to a fourth embodiment of the present invention.

Fig. 8 is a spherical aberration, astigmatism, and distortion curve of the fourth embodiment, from left to right.

FIG. 9 is a schematic view of an image taking device according to a fifth embodiment of the present invention.

Fig. 10 is a spherical aberration, astigmatism, and distortion curve of the fifth embodiment from left to right.

11 is a schematic view of an image capturing apparatus according to a sixth embodiment of the present invention.

Fig. 12 is a spherical aberration, astigmatism, and distortion curve of the sixth embodiment, from left to right.

Figure 13 is a schematic view showing an image taking device according to a seventh embodiment of the present invention.

Fig. 14 is a spherical aberration, astigmatism, and distortion curve of the seventh embodiment, from left to right.

Figure 15 is a schematic view showing an image taking device according to an eighth embodiment of the present invention.

Fig. 16 is a spherical aberration, astigmatism, and distortion curve of the eighth embodiment, from left to right.

Figure 17 is a schematic view showing a portable device in accordance with a first embodiment of the present invention.

Figure 18 is a schematic view of a portable device in accordance with a second embodiment of the present invention.

Figure 19 is a schematic view showing a portable device in accordance with a third embodiment of the present invention.

The image system lens group sequentially includes a first lens, a second lens, and a third lens from the object side to the image side. Among them, there are three lenses with refractive power in the lens group of the image system.

The first lens has a positive refractive power. Thereby, the total optical length of the lens group of the image system can be effectively shortened. The first lens object side surface is a convex surface, and the first lens image side surface is a convex surface, which can help to strengthen the shortened total length to meet the demand for thinning and thinning of the product.

The second lens has a positive refractive power. Thereby, the sensitivity of the lens system of the image system can be reduced. The second lens object side surface is a concave surface, and the second lens image side surface is a convex surface, which is advantageous for correcting astigmatism.

The third lens has a negative refractive power. This can effectively correct aberrations. The third lens object side surface may be a convex surface at the near optical axis, and may have at least one concave surface at the off-axis, the third lens image side surface is concave at the near optical axis, and has at least one convex surface at the off-axis, except Helping to repair the astigmatism, it can help to correct the aberration of the off-axis field of view.

The focal length of the second lens is f2, and the focal length of the third lens is f3, which satisfies the following conditional expression: -3.0 < f2 / f3 < 0. Thereby, the total length of the short optical can be effectively reduced. Preferably, the following conditions are satisfied: -1.5 < f2 / f3 < 0. More preferably, the following conditions are satisfied: -0.90 < f2 / f3 < 0.

The distance from the aperture to the side surface of the third lens image on the optical axis is SD, and the distance from the first lens object side surface to the third lens image side surface on the optical axis is TD, which satisfies the following condition: 0.58<SD/TD< 0.82. Thereby, the aperture can be approached to the imaging surface, thereby increasing the angle of view, so that the image system lens group can capture a sufficient image range within a limited shooting distance.

The thickness of the first lens on the optical axis is CT1, and the thickness of the second lens on the optical axis is CT2, which satisfies the following conditional formula: 0.20 < CT2 / CT1 < 0.85. Thereby, it can contribute to the assembly of the lens and improve the manufacturing yield. Preferably, the following conditions are satisfied: 0.30 < CT2 / CT1 < 0.75.

The focal length of the image system lens group is f, and the incident pupil diameter of the image system lens group is EPD, which satisfies the following conditions: 1.20<f/EPD<2.80. Thereby, the amount of light entering the system can be increased, thereby improving the resolution capability. Preferably, the following conditions are satisfied: 1.60 < f / EPD < 2.45.

The radius of curvature of the first lens object side surface is R1, and the radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -3.0 < R2 / R1 < - 0.2. Thereby, it can be beneficial to the correction of the spherical aberration. Preferably, the following conditions are satisfied: -2.0 < R2 / R1 < - 0.2.

The distance from the first lens object side surface to the imaging surface on the optical axis is TL, which satisfies the following condition: 1.0 mm < TL < 2.3 mm. Thereby, the image system lens group and the image capturing device can be advantageously miniaturized, and it is suitable for being mounted on a thin and portable device. Preferably, the following conditions are satisfied: 1.0 mm < TL < 2.0 mm.

The maximum viewing angle of the image system lens group is FOV, which satisfies the following conditions: 76 degrees < FOV < 120 degrees. Thereby, an appropriate field of view angle can be obtained to obtain a wide image capturing range.

The radius of curvature of the third lens object side surface is R5, and the radius of curvature of the third lens image side surface is R6, which satisfies the following condition: |(R5-R6)/(R5+R6)|<0.35. Thereby, it is advantageous to correct the aberration. Preferably, the following conditions are satisfied: |(R5-R6)/(R5+R6)|<0.25.

The focal length of the image system lens group is f, and the focal length of the second lens is f2, which satisfies the following condition: 0.4 < f / f2 < 1.0. Thereby, it is advantageous to reduce the sensitivity.

The radius of curvature of the second lens object side surface is R3, and the radius of curvature of the second lens image side surface is R4, which satisfies the following condition: |(R3-R4)/(R3+R4)|<0.15. Thereby, it can contribute to the correction of astigmatism in the lens group of the image system.

The maximum image height is ImgH (that is, half of the diagonal length of the effective sensing area of the electronic photosensitive element), and the distance from the first lens object side surface to the imaging surface on the optical axis is TL, which satisfies the following condition: TL/ImgH <1.90. Thereby, it is advantageous to maintain the miniaturization of the lens system of the image system for mounting on a portable electronic product.

The distance from the first lens object side surface to the imaging surface on the optical axis is TL, and the maximum viewing angle of the image system lens group is half HFOV, which satisfies the following condition: 1.0 mm < TL / tan (HFOV) < 3.0 mm. Thereby, the image system lens group can be kept compact and have an appropriate range of viewing angles.

In the lens system of the image system of the present invention, the material of the lens may be plastic or glass. When the lens is made of glass, the degree of freedom in the configuration of the refractive power can be increased. In addition, when the lens material is plastic, the production cost can be effectively reduced. In addition, an aspherical surface can be disposed on the surface of the lens, and the aspherical surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration, thereby reducing the number of lenses required, thereby effectively reducing the total optical length. degree.

In the lens system of the image system of the present invention, if the lens surface is convex and the convex surface is not defined, the lens surface is convex at the near optical axis; if the lens surface is Concave and undefined the concave position indicates that the lens surface is concave at the near optical axis.

In the lens system of the image system of the present invention, at least one aperture may be disposed, and the position may be set before the first lens, between the lenses or after the last lens, and the type of the aperture is such as a flare (Glare) Stop) or Field Stop, etc., to reduce stray light and help improve image quality.

In the lens system of the image system disclosed in the present invention, the aperture can be disposed between the first lens and the second lens (ie, the center aperture), which helps to expand the angle of view and make the lens system of the imaging system wide. The advantage of the angular lens.

The invention further provides an image capturing device comprising the image system lens group and the electronic photosensitive element, wherein the electronic photosensitive element is disposed on an imaging surface of the image system lens group. It can help shorten the total length to meet the needs of thin and light products. In addition, the aperture can be brought closer to the imaging surface to increase the angle of view, thereby allowing a sufficient image range to be captured within a limited shooting distance. Preferably, the image capturing device may further comprise a barrel (Barrel Member), a support device (Holder Member) or a combination thereof.

The invention further provides a portable device comprising the aforementioned image capturing device. Referring to Figures 17, 18 and 19, the image taking device 10 can be applied in various aspects to a smart phone (as shown in Fig. 17), a tablet (as shown in Fig. 18) and a wearable device (such as Fig. 19). Shown) and so on. It can help shorten the total length to meet the needs of thin and light products. In addition, the aperture can be brought closer to the imaging surface to increase the angle of view, thereby allowing a sufficient image range to be captured within a limited shooting distance. Preferably, the portable device may further include a control unit, a display unit, a storage unit (ROM), a temporary storage unit (RAM), or a combination thereof.

The foregoing portable device is merely illustrative of the practical application of the present invention and does not limit the scope of application of the imaging device of the present invention.

The image system lens group of the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good image quality, and can be applied to 3D (3D) image capture, digital camera, and action in various aspects. In portable devices such as devices, digital tablets and wearable devices.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the light of the above-described embodiments, the specific embodiments are described below in detail with reference to the drawings.

<First Embodiment>

Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram of an image capturing apparatus according to a first embodiment of the present invention. FIG. 2 is a left-to-right sequence of spherical aberration, astigmatism and the first embodiment. Distortion curve. As can be seen from Fig. 1, the image taking device includes an image system lens group and an electron light sensing element 160. The image system lens group sequentially includes a first lens 110, a diaphragm 100, a second lens 120, a third lens 130, an IR-Cut Filter 140, and an imaging surface 150 from the object side to the image side. The electronic photosensitive element 160 is disposed on the imaging surface 150. The lens with refractive power in the lens system of the imaging system is three.

The first lens 110 has a positive refractive power and is made of a plastic material. The object side surface 111 is a convex surface, and the image side surface 112 is a convex surface, and both surfaces thereof are aspherical.

The second lens 120 has a positive refractive power and is made of a plastic material. The object side surface 121 is a concave surface, and the image side surface 122 is a convex surface, and both surfaces thereof are aspherical.

The third lens 130 has a negative refractive power and is made of a plastic material. The object side surface 131 is convex at the near optical axis, and the object side surface 131 has at least one concave surface at an off-axis, and the image side surface 132 is at the near optical axis. The concave surface has an image side surface 132 having at least one convex surface at an off-axis, and both surfaces thereof are aspherical.

The material of the infrared filter filter 140 is glass, which is disposed between the third lens 130 and the imaging surface 150, and does not affect the focal length of the lens group of the image system.

The aspherical curve equations of the above lenses are expressed as follows: Where: X: the relative distance of the point on the aspherical surface from the optical axis to the Y, which is tangent to the intersection of the intersection on the aspherical optical axis; Y: the vertical distance between the point on the aspherical curve and the optical axis; R: Curvature radius; k: cone coefficient; and Ai: i-th order aspheric coefficient.

In the image system lens group of the first embodiment, the focal length of the image system lens group is f, the aperture value (F-number) of the image system lens group is Fno, and the half angle of the maximum viewing angle in the image system lens group is HFOV, and the values are as follows: : f = 1.21 mm; Fno = 2.40; and HFOV = 42.8 degrees.

In the image system lens group of the first embodiment, the thickness of the first lens 110 on the optical axis is CT1, and the thickness of the second lens 120 on the optical axis is CT2, which satisfies the following condition: CT2/CT1=0.61.

The radius of curvature of the first lens object side surface 111 is R1, and the radius of curvature of the first lens image side surface 112 is R2, which satisfies the following condition: R2/R1 = -1.48.

The radius of curvature of the second lens object side surface 121 is R3, and the radius of curvature of the second lens image side surface 122 is R4, which satisfies the following conditional expression: |(R3-R4)/(R3+R4)|=0.11.

The radius of curvature of the third lens object side surface 131 is R5, and the radius of curvature of the third lens image side surface 132 is R6, which satisfies the following condition: |(R5-R6)/(R5+R6)|=0.31.

The focal length of the image system lens group is f, and the focal length of the second lens 120 is f2, which satisfies the following condition: f/f2 = 0.95.

The focal length of the second lens 120 is f2, and the focal length of the third lens 130 is f3, which satisfies the following condition: f2/f3 = -0.74.

The focal length of the lens system of the image system is f, and the entrance pupil diameter of the lens group of the image system is EPD, which satisfies the following condition: f/EPD=2.40.

The distance from the aperture 100 to the third lens image side surface 132 on the optical axis is SD, and the distance from the first lens object side surface 111 to the third lens image side surface 132 on the optical axis is TD, which satisfies the following condition: SD/ TD = 0.68.

The distance from the first lens object side surface 111 to the imaging surface 150 on the optical axis is TL, which satisfies the following condition: TL = 1.82 mm.

The maximum viewing angle of the image system lens group is FOV, which satisfies the following condition: FOV=85.6 degrees.

The distance from the first lens object side surface 111 to the imaging surface 150 on the optical axis is TL, and the maximum viewing angle of the image system lens group is half HFOV, which satisfies the following condition: TL/tan(HFOV)=1.97 mm.

The maximum image height is ImgH (in the embodiment, half of the diagonal length of the effective sensing region of the electronic photosensitive element 160), and the distance from the first lens object side surface 111 to the imaging surface 150 on the optical axis is TL. The following conditions were met: TL/ImgH = 1.66.

Refer to Table 1 and Table 2 below.

Table 1 is the detailed structural data of the first embodiment of Fig. 1, in which the unit of curvature radius, thickness and focal length is mm, and the surfaces 0 to 10 sequentially represent the surface from the object side to the image side. Table 2 is the aspherical data in the first embodiment, in which the taper coefficients in the equation of the aspherical curve of k, and A4 to A14 represent the aspheric coefficients of the 4th to 14th order of each surface. In addition, the following table of the embodiments corresponds to the schematic diagrams and the aberration diagrams of the respective embodiments, and the definitions of the data in the table are the same as those of the first embodiment and the second embodiment, and are not described herein.

<Second embodiment>

Please refer to FIG. 3 and FIG. 4 , wherein FIG. 3 is a schematic diagram of the image capturing apparatus according to the second embodiment of the present invention, and FIG. 4 is a spherical aberration and astigmatism of the second embodiment from left to right. Distortion curve. As can be seen from FIG. 3, the image taking device includes an image system lens group and an electron photosensitive element 260. The image system lens group sequentially includes the first lens 210 from the object side to the image side, The aperture 200, the second lens 220, the third lens 230, the infrared filter filter 240, and the imaging surface 250. The electronic photosensitive element 260 is disposed on the imaging surface 250. The lens with refractive power in the lens system of the imaging system is three.

The first lens 210 has a positive refractive power and is made of a plastic material. The object side surface 211 is a convex surface, and the image side surface 212 is a convex surface, and both surfaces thereof are aspherical.

The second lens 220 has a positive refractive power and is made of a plastic material. The object side surface 221 is a concave surface, and the image side surface 222 is a convex surface, and both surfaces thereof are aspherical.

The third lens 230 has a negative refractive power and is made of a plastic material. The object side surface 231 is convex at the near optical axis, and the object side surface 231 has at least one concave surface at the off-axis, and the image side surface 232 is at the near optical axis. It is a concave surface, and its image side surface 232 has at least one convex surface at an off-axis, and both surfaces thereof are aspherical.

The material of the infrared filter filter 240 is glass, which is disposed between the third lens 230 and the imaging surface 250, and does not affect the focal length of the lens group of the image system.

Please refer to Table 3 and Table 4 below.

In the second embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Third embodiment>

Please refer to FIG. 5 and FIG. 6 , wherein FIG. 5 is a schematic diagram of an image capturing apparatus according to a third embodiment of the present invention. FIG. 6 is a left-to-right sequence of spherical aberration, astigmatism and the third embodiment. Distortion curve. As can be seen from FIG. 5, the image taking device includes an image system lens group and an electronic photosensitive element 360. Shadow The image lens group sequentially includes a first lens 310, a diaphragm 300, a second lens 320, a third lens 330, an infrared filter 340, and an imaging surface 350 from the object side to the image side. The electronic photosensitive element 360 is disposed on the imaging surface 350. The lens with refractive power in the lens system of the imaging system is three.

The first lens 310 has a positive refractive power and is made of a plastic material. The object side surface 311 is a convex surface, and the image side surface 312 is a convex surface, and both surfaces thereof are aspherical.

The second lens 320 has a positive refractive power and is made of a plastic material. The object side surface 321 is a concave surface, and the image side surface 322 is a convex surface, and both surfaces thereof are aspherical.

The third lens 330 has a negative refractive power and is made of a plastic material. The object side surface 331 is convex at the near optical axis, and the object side surface 331 has at least one concave surface at the off-axis, and the image side surface 332 is at the near optical axis. The concave surface has an image side surface 332 having at least one convex surface at an off-axis, and both surfaces thereof are aspherical.

The material of the infrared filter 340 is glass, which is disposed between the third lens 330 and the imaging surface 350, and does not affect the focal length of the lens group of the image system.

Please refer to Table 5 and Table 6 below.

In the third embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Fourth embodiment>

Please refer to FIG. 7 and FIG. 8 , wherein FIG. 7 is a schematic diagram of an image capturing apparatus according to a fourth embodiment of the present invention, and FIG. 8 is a spherical aberration, astigmatism and the fourth embodiment from left to right. Distortion curve. As can be seen from FIG. 7, the image taking device includes an image system lens group and an electronic photosensitive element 460. The image system lens group sequentially includes a first lens 410, a diaphragm 400, a second lens 420, a third lens 430, an infrared filter 440, and an imaging surface 450 from the object side to the image side. The electronic photosensitive element 460 is disposed on the imaging surface 450. The lens with refractive power in the lens system of the imaging system is three.

The first lens 410 has a positive refractive power and is made of a plastic material. The object side surface 411 is a convex surface, and the image side surface 412 is a convex surface, and both surfaces thereof are aspherical.

The second lens 420 has a positive refractive power and is made of a plastic material. The object side surface 421 is a concave surface, and the image side surface 422 is a convex surface, and both surfaces thereof are aspherical.

The third lens 430 has a negative refractive power and is made of a plastic material. The object side surface 431 is convex at the near optical axis, and the object side surface 431 has at least one concave surface at the off-axis, and the image side surface 432 is at the near optical axis. The concave surface has an image side surface 432 having at least one convex surface at an off-axis, and both surfaces are aspherical.

The material of the infrared filter 440 is made of glass, which is disposed between the third lens 430 and the imaging surface 450, and does not affect the focal length of the lens group of the image system.

Please refer to Table 7 and Table 8 below.

In the fourth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Fifth Embodiment>

Please refer to FIG. 9 and FIG. 10 , wherein FIG. 9 is a schematic diagram of an image capturing apparatus according to a fifth embodiment of the present invention. FIG. 10 is a spherical aberration and astigmatism of the fifth embodiment from left to right. Distortion curve. As can be seen from FIG. 9, the image capturing device includes an image system lens group and an electronic photosensitive element. 560. The image system lens group sequentially includes a first lens 510, a diaphragm 500, a second lens 520, a third lens 530, an infrared filter 540, and an imaging surface 550 from the object side to the image side. The electronic photosensitive element 560 is disposed on the imaging surface 550. The lens with refractive power in the lens system of the imaging system is three.

The first lens 510 has a positive refractive power and is made of a plastic material. The object side surface 511 is a convex surface, and the image side surface 512 is a convex surface, and both surfaces thereof are aspherical.

The second lens 520 has a positive refractive power and is made of a plastic material. The object side surface 521 is a concave surface, and the image side surface 522 is a convex surface, and both surfaces thereof are aspherical.

The third lens 530 has a negative refractive power and is made of a plastic material. The object side surface 531 is convex at the near optical axis, and the object side surface 531 has at least one concave surface at an off-axis, and the image side surface 532 is at a near optical axis. The concave surface has an image side surface 532 having at least one convex surface at an off-axis, and both surfaces thereof are aspherical.

The material of the infrared filter 540 is glass, which is disposed between the third lens 530 and the imaging surface 550, and does not affect the focal length of the lens group of the image system.

Please refer to the following list IX and Table 10.

In the fifth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Sixth embodiment>

Please refer to FIG. 11 and FIG. 12 , wherein FIG. 11 is a schematic diagram of an image capturing apparatus according to a sixth embodiment of the present invention. FIG. 12 is a spherical aberration, astigmatism and the sixth embodiment from left to right. Distortion curve. As can be seen from FIG. 11, the image capturing device includes an image system lens group and an electronic photoreceptor. Piece 660. The image system lens group sequentially includes a first lens 610, a diaphragm 600, a second lens 620, a third lens 630, an infrared filter 640, and an imaging surface 650 from the object side to the image side. The electronic photosensitive element 660 is disposed on the imaging surface 650. The lens with refractive power in the lens system of the imaging system is three.

The first lens 610 has a positive refractive power and is made of a plastic material. The object side surface 611 is a convex surface, and the image side surface 612 is a convex surface, and both surfaces thereof are aspherical.

The second lens 620 has a positive refractive power and is made of a plastic material. The object side surface 621 is a concave surface, and the image side surface 622 is a convex surface, and both surfaces thereof are aspherical.

The third lens 630 has a negative refractive power and is made of a plastic material. The object side surface 631 is convex at the near optical axis, and the object side surface 631 has at least one concave surface from the off axis, and the image side surface 632 is on the near optical axis. The concave surface has an image side surface 632 having at least one convex surface at an off-axis, and both surfaces are aspherical.

The material of the infrared filter 640 is glass, which is disposed between the third lens 630 and the imaging surface 650, and does not affect the focal length of the lens group of the image system.

Please refer to Table 11 and Table 12 below.

In the sixth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Seventh embodiment>

Please refer to FIG. 13 and FIG. 14 , wherein FIG. 13 is a schematic diagram of an image capturing apparatus according to a seventh embodiment of the present invention, and FIG. 14 is a spherical aberration, astigmatism, and the seventh embodiment sequentially from left to right. Distortion curve. As can be seen from FIG. 13, the image capturing device includes an image system lens group and an electronic photoreceptor. Piece 760. The image system lens group sequentially includes a first lens 710, a diaphragm 700, a second lens 720, a third lens 730, an infrared filter filter 740, and an imaging surface 750 from the object side to the image side. The electronic photosensitive element 760 is disposed on the imaging surface 750. The lens with refractive power in the lens system of the imaging system is three.

The first lens 710 has a positive refractive power and is made of a plastic material. The object side surface 711 is a convex surface, and the image side surface 712 is a convex surface, and both surfaces thereof are aspherical.

The second lens 720 has a positive refractive power and is made of a plastic material. The object side surface 721 is a concave surface, and the image side surface 722 is a convex surface, and both surfaces thereof are aspherical.

The third lens 730 has a negative refractive power and is made of a plastic material. The object side surface 731 is convex at the near optical axis, and the object side surface 731 has at least one concave surface at an off-axis, and the image side surface 732 is at the near optical axis. It is a concave surface, and its image side surface 732 has at least one convex surface at an off-axis, and both surfaces thereof are aspherical.

The material of the infrared filter 740 is glass, which is disposed between the third lens 730 and the imaging surface 750, and does not affect the focal length of the lens group of the image system.

Please refer to Table 13 and Table 14 below.

In the seventh embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

<Eighth Embodiment>

Referring to FIG. 15 and FIG. 16 , FIG. 15 is a schematic diagram of an image capturing apparatus according to an eighth embodiment of the present invention. FIG. 16 is a spherical aberration, astigmatism, and the like of the eighth embodiment from left to right. Distortion curve. As can be seen from Fig. 15, the image taking device includes an image system lens group and an electronic photosensitive element 860. The image system lens group sequentially includes a first lens 810, a diaphragm 800, a second lens 820, a third lens 830, an infrared filter 840, and an imaging surface 850 from the object side to the image side. The electronic photosensitive element 860 is disposed on the imaging surface 850. The lens with refractive power in the lens system of the imaging system is three.

The first lens 810 has a positive refractive power and is made of glass. The object side surface 811 is a convex surface, and the image side surface 812 is a convex surface, and both surfaces thereof are aspherical.

The second lens 820 has a positive refractive power and is made of a plastic material. The object side surface 821 is a concave surface, and the image side surface 822 is a convex surface, and both surfaces thereof are aspherical.

The third lens 830 has a negative refractive power and is made of a plastic material. The object side surface 831 is convex at the near optical axis, and the object side surface 831 has at least one concave surface at an off-axis, and the image side surface 832 is at the near optical axis. The concave surface has an image side surface 832 having at least one convex surface at an off-axis, and both surfaces are aspherical.

The material of the infrared filter 840 is made of glass, which is disposed between the third lens 830 and the imaging surface 850, and does not affect the focal length of the lens group of the image system.

Please refer to Table 15 and Table 16 below.

In the eighth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not described herein.

The above imaging device can be disposed in the portable device. The portable device can be designed as a lenticular lens by the first lens of the lens system of the image system, which can shorten the total length to meet the requirements of thinning and thinning. In addition, the aperture can be brought closer to the imaging surface, and the angle of view is increased, thereby making the shooting distance limited. Take enough image range from inside.

While the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The patent protection scope of the invention is subject to the definition of the scope of the patent application attached to the specification.

100‧‧‧ aperture

110‧‧‧first lens

111‧‧‧Side side surface

112‧‧‧ image side surface

120‧‧‧second lens

121‧‧‧Side side surface

122‧‧‧ image side surface

130‧‧‧ third lens

131‧‧‧ object side surface

132‧‧‧Image side surface

140‧‧‧Infrared filter

150‧‧‧ imaging surface

160‧‧‧Electronic photosensitive element

Claims (22)

An image system lens group comprising: a first lens having a positive refractive power, a front side surface being a convex surface, and an image side surface being a convex surface, wherein the object side surface and the image side surface are both a second lens having a positive refractive power, the object side surface being a concave surface, the image side surface being a convex surface, the object side surface and the image side surface being aspherical surfaces, and a third lens having a negative refractive power The image side surface has a concave surface at a near optical axis, and the image side surface has at least one convex surface at an off-axis, and the object side surface and the image side surface are both aspherical surfaces; wherein the image system lens group has a refractive power The lens of the image system further includes an aperture disposed between the first lens and the second lens, the focal length of the lens group of the image system is f, and the focal length of the second lens For f2, the focal length of the third lens is f3, the distance from the aperture to the optical surface of the third lens image side is SD, and the first lens object side surface to the third lens image side surface is on the optical axis. The distance is TD, the first lens is on the optical axis The degree is CT1, the thickness of the second lens on the optical axis is CT2, and the incident pupil diameter of the lens group of the image system is EPD, which satisfies the following conditions: -3.0<f2/f3<0; 0.58<SD/TD<0.82 ;0.20<CT2/CT1<0.85; and 1.20<f/EPD<2.80. The image system lens group of claim 1, wherein the third lens object side surface is convex at a near optical axis, and the third lens object side surface has at least one concave surface at an off axis. The image system lens group of claim 1, wherein a focal length of the second lens is f2, the third through The focal length of the mirror is f3, which satisfies the following condition: -1.5 < f2 / f3 < 0. The image system lens group according to claim 1, wherein the thickness of the first lens on the optical axis is CT1, and the thickness of the second lens on the optical axis is CT2, which satisfies the following condition: 0.30<CT2/CT1< 0.75. The image system lens group of claim 1, wherein the maximum viewing angle of the image system lens group is FOV, which satisfies the following condition: 76 degrees < FOV < 120 degrees. The image system lens group according to claim 1, wherein a radius of curvature of the third lens object side surface is R5, and a radius of curvature of the third lens image side surface is R6, which satisfies the following condition: |(R5-R6) /(R5+R6)|<0.35. An image system lens group comprising: a first lens having a positive refractive power, a front side surface being a convex surface, and an image side surface being a convex surface, wherein the object side surface and the image side surface are both a second lens having a positive refractive power, the object side surface being a concave surface, the image side surface being a convex surface, the object side surface and the image side surface being aspherical surfaces, and a third lens having a negative refractive power The object side surface is a convex surface, and the image side surface is a concave surface at a near optical axis, and the image side surface has at least one convex surface at an off-axis, and the object side surface and the image side surface are both aspherical surfaces; wherein the image The lens of the system lens group has three refractive indexes; wherein the lens system of the image system further comprises an aperture, the aperture is disposed between the first lens and the second lens, and the focal length of the second lens is f2, The focal length of the third lens is f3, and the aperture is to the first The distance of the side surface of the three lens image on the optical axis is SD, the distance from the first lens object side surface to the third lens image side surface on the optical axis is TD, and the radius of curvature of the first lens object side surface is R1 The radius of curvature of the first lens image side surface is R2, the thickness of the first lens on the optical axis is CT1, and the thickness of the second lens on the optical axis is CT2, which satisfies the following condition: -0.90<f2/ F3<0; 0.58<SD/TD<0.82; -3.0<R2/R1<-0.2; and 0.20<CT2/CT1<0.85. The image system lens group according to claim 7, wherein a radius of curvature of the first lens object side surface is R1, and a radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -2.0<R2/R1 <-0.2. The image system lens group according to claim 7, wherein the focal length of the image system lens group is f, and the focal length of the second lens is f2, which satisfies the following condition: 0.4 < f / f2 < 1.0. The image system lens group according to claim 7, wherein a radius of curvature of the second lens object side surface is R3, and a radius of curvature of the second lens image side surface is R4, which satisfies the following condition: |(R3-R4) /(R3+R4)|<0.15. The image system lens group according to claim 7, wherein the maximum image height is ImgH, and the distance from the first lens object side surface to an imaging surface on the optical axis is TL, which satisfies the following condition: TL/ImgH<1.90. The image system lens group according to claim 7, wherein the focal length of the image system lens group is f, and the incident pupil diameter of the image system lens group is EPD, which satisfies the condition: 1.60<f/EPD<2.45. The image system lens group according to claim 7, wherein a radius of curvature of the third lens object side surface is R5, and a radius of curvature of the third lens image side surface is R6, which satisfies the following condition: |(R5-R6) /(R5+R6)|<0.25. The image system lens group according to claim 7, wherein a distance from the first lens object side surface to an imaging surface on the optical axis is TL, and a maximum viewing angle of the image system lens group is HFOV, which satisfies the following conditions: 1.0 mm < TL / tan (HFOV) < 3.0 mm. An image system lens group comprising: a first lens having a positive refractive power, a front side surface being a convex surface, and an image side surface being a convex surface, wherein the object side surface and the image side surface are both a second lens having a positive refractive power, the object side surface being a concave surface, the image side surface being a convex surface, the object side surface and the image side surface being aspherical surfaces, and a third lens having a negative refractive power The object side surface is a convex surface, and the image side surface is a concave surface at a near optical axis, and the image side surface has at least one convex surface at an off-axis, and the object side surface and the image side surface are both aspherical surfaces; wherein the image The lens of the system lens group has three refractive indexes; wherein the lens system of the image system further comprises an aperture, the aperture is disposed between the first lens and the second lens, and the focal length of the second lens is f2, The focal length of the third lens is f3, the distance from the aperture to the optical axis of the third lens image side is SD, and the distance from the first lens object side surface to the third lens image side surface on the optical axis is TD, the first lens side surface to an imaging surface Distance on the optical axis TL, the thickness of the first lens on the optical axis CT1, the thickness of the second lens on the optical axis CT2, which satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; 1.0 mm < TL < 2.3 mm; and 0.20 < CT2 / CT1 < 0.85. The image system lens group according to claim 15, wherein a radius of curvature of the third lens object side surface is R5, and a radius of curvature of the third lens image side surface is R6, which satisfies the following condition: |(R5-R6) /(R5+R6)|<0.35. The image system lens group according to claim 15, wherein a distance from the first lens object side surface to the imaging surface on the optical axis is TL, which satisfies the following condition: 1.0 mm < TL < 2.0 mm. The image system lens group according to claim 15, wherein a radius of curvature of the first lens object side surface is R1, and a radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -2.0<R2/R1 <-0.2. The image system lens group according to claim 15, wherein the focal length of the second lens is f2, and the focal length of the third lens is f3, which satisfies the following condition: -0.90 < f2 / f3 < 0. The image system lens group according to claim 15, wherein a distance from the first lens object side surface to the imaging surface on the optical axis is TL, and a maximum viewing angle of the image system lens group is HFOV, which satisfies the following conditions: 1.0 mm < TL / tan (HFOV) < 3.0 mm. An image capturing device comprising: an image system lens group from the object side to the image side; An electronic photosensitive element, wherein the image system lens group is sequentially included from the object side to the image side: a first lens having a positive refractive power, an object side surface being a convex surface, and an image side surface being a convex surface, and an object side surface thereof And the image side surface is aspherical; a second lens has a positive refractive power, the object side surface is a concave surface, the image side surface is a convex surface, and the object side surface and the image side surface are both aspherical surfaces; and a third The lens has a negative refractive power, and the object side surface is a convex surface, and the image side surface is concave at the near optical axis, and the image side surface has at least one convex surface at the off-axis, and the object side surface and the image side surface are both non- a spherical surface; wherein the lens of the image system lens has a refractive power of three; wherein the image system lens group further includes an aperture, the aperture is disposed between the first lens and the second lens, the second The focal length of the lens is f2, the focal length of the third lens is f3, the distance from the aperture to the optical surface of the third lens image side is SD, and the first lens object side surface to the third lens image side surface is The distance on the optical axis is TD, the first lens The distance from the side surface to an imaging surface on the optical axis is TL, the thickness of the first lens on the optical axis is CT1, and the thickness of the second lens on the optical axis is CT2, which satisfies the following condition: -3.0<f2 /f3<0; 0.58<SD/TD<0.82; 1.0 mm<TL<2.3 mm; and 0.20<CT2/CT1<0.85. A portable device comprising: an image capturing device, comprising: the object side to the image side sequentially: An image system lens group; and an electronic photosensitive element; wherein the image system lens group is sequentially included from the object side to the image side: a first lens having a positive refractive power, the object side surface being a convex surface, and an image side surface thereof The convex surface has an aspherical surface on both the object side surface and the image side surface; a second lens has a positive refractive power, the object side surface is a concave surface, and the image side surface is a convex surface, and the object side surface and the image side surface are both An aspherical surface; and a third lens having a negative refractive power, the object side surface being a convex surface, the image side surface being concave at the near optical axis, and the image side surface having at least one convex surface at the off-axis, the object side surface thereof And the image side surface is aspherical; wherein the lens of the image system lens has a refractive power of three; wherein the image system lens group further includes an aperture, the aperture is disposed on the first lens and the second Between the lenses, the second lens has a focal length of f2, the third lens has a focal length of f3, and the distance from the aperture to the third lens image side surface on the optical axis is SD, the first lens object side surface to the The third lens image side surface is on the optical axis The distance is TD, the distance from the first lens object side surface to an imaging surface on the optical axis is TL, the thickness of the first lens on the optical axis is CT1, and the thickness of the second lens on the optical axis is CT2. It satisfies the following conditions: -3.0 < f2 / f3 < 0; 0.58 < SD / TD < 0.82; 1.0 mm < TL < 2.3 mm; and 0.20 < CT2 / CT1 < 0.85.