TWI471586B - Four-piece optical lens system - Google Patents

Description

Four-piece imaging lens set

The present invention relates to optical lenses, and more particularly to a four-piece imaging lens set.

In recent years, with the rise of mobile phone cameras, the demand for miniaturized photographic lenses has been increasing, and the photosensitive elements of general photographic lenses are nothing more than a Charge Coupled Device (CCD) or a Complementary Metallic Semiconductor (Complementary Metal). -Oxide Semiconductor (CMOS), due to the advancement of semiconductor process technology, the pixel area of the photosensitive element is reduced, and the miniaturized photographic lens is gradually developing into the high-pixel field. Therefore, the requirements for image quality are increasing.

The common mobile phone camera lens adopts a three-piece imaging lens group, and the imaging lens group sequentially has a first lens with positive refractive power, a second lens with negative refractive power, and a positive refractive lens from the object side to the image side. The third lens of the force, however, as the pixel area of the photosensitive element is gradually reduced, the system's requirements for image quality are improved, and the common three-piece imaging lens set will not be able to satisfy the higher-order photographic lens module.

To this end, the mobile phone camera lens is equipped with a four-piece imaging lens set to solve the problem that the three-piece imaging lens cannot meet the requirements of the higher-order photographic lens module. However, since the pixel of the mobile phone camera climbs very rapidly, the sensitization The pixel area of the component is gradually reduced, and in the case of increasing requirements for the imaging quality of the system, how to develop a four-piece imaging lens group with a large angle of painting, high number of pictures, high resolution, and low lens height, ie It is the motivation for the development of the present invention.

It is an object of the present invention to provide a four-piece imaging lens set that can be applied to a high-resolution mobile phone camera without causing the total length of the lens to be too long, while having a large picture angle, high number of pictures, high resolution, and low A four-piece imaging lens set with lens height.

The present invention provides a four-piece imaging lens set comprising, from the object side to the image side, a first lens having a positive refractive power, the image side surface being a convex surface, and the object side surface and the image side of the first lens At least one side of the surface is aspherical; a diaphragm; a second lens having a negative refractive power, the image side surface is concave, and the object side surface and the image side surface of the second lens are at least one aspherical surface; a third lens of refractive power, wherein the image side surface is convex, and the object side surface and the image side surface of the third lens are at least one aspherical surface; and the fourth lens having a negative refractive power, the object side surface is concave. And at least one side of the object side surface and the image side surface of the fourth lens is aspherical, the distance from the object side surface of the first lens to the imaging surface is TL, and an electronic photosensitive element is disposed on the imaging surface, the electron The half of the diagonal length of the effective pixel area of the photosensitive element is ImgH, and both satisfy the following relationship: both satisfy the following relationship: TL/ImgH<1.6.

In the four-piece imaging lens set of the present invention, the focal length of the first lens is f1, and the focal length of the second lens is f2, and both satisfy the following relationship: 0.3<|f1|/|f2|<0.8. When |f1|/|f2| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Otherwise, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

In the four-piece imaging lens set of the present invention, the focal length of the second lens is f2, and the focal length of the third lens is f3, and both satisfy the following relationship: 1.3<|f2|/|f3|<2.0. When |f2|/|f3| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Otherwise, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

In the four-piece imaging lens set of the present invention, the focal length of the third lens is f3, and the focal length of the fourth lens is f4, and the two satisfy the following relationship: 0.8<|f3|/|f4|<1.5. When |f3|/|f4| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Otherwise, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

In the four-piece imaging lens set of the present invention, the composite focal length of the first lens and the second lens is f12, and the combined focal length of the third lens and the fourth lens is f34, and the two satisfy the following relationship: |f12|/ |f34|<0.06. When |f12|/|f34| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Conversely, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

In the four-piece imaging lens set of the present invention, the focal length of the first lens is f1, and the combined focal length of the second lens, the third lens and the fourth lens is f234, and the two satisfy the following relationship: 0.4<|f1| /|f234|<0.9. When |f1|/|f234| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Otherwise, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

In the four-piece imaging lens set of the present invention, the composite focal length of the second lens and the third lens is f23, and the overall composite focal length of the four-piece imaging lens set is f, and the two satisfy the following relationship: 0.6<|f23| /|f|<1.2. When |f23|/|f| satisfies the foregoing relationship, the imaging lens group can have a large picture angle, a high number of pictures, and a low lens height, and the image resolution capability is remarkably improved. Otherwise, if the above optical data is exceeded The range of values results in problems with the performance, low resolution, and insufficient yield of the four-piece imaging lens set.

The four-piece imaging lens set of the present invention has an overall composite focal length f, and the distance from the object side surface of the first lens to the imaging surface is TL, and the two satisfy the following relationship: 0.75< |f/TL|<0.95. When |f/TL| satisfies the foregoing relationship, it can have a shorter optical total length and is smaller and lighter.

The present invention has been described with reference to the preferred embodiments of the present invention in accordance with the accompanying drawings.

"First Embodiment"

For a four-piece imaging lens set provided by the first embodiment of the present invention, please refer to FIGS. 1A and 1B. FIG. 1A is a schematic view showing a configuration of a four-piece imaging lens unit according to a first embodiment of the present invention, and FIG. In the aberration diagram of the first embodiment of the present invention, the first embodiment includes from the object side A to the image side B:

A first lens 100 having a positive refractive power is made of plastic. The object side surface 101 of the first lens 100 is a convex surface, and the image side surface 102 is a convex surface. The object side surface 101 and the image side of the first lens 100 are The surface 102 is set to be aspherical.

A light bar 110.

A second lens 120 having a negative refractive power is made of plastic, the object side surface 121 of the second lens 120 is a concave surface, the image side surface 122 is a concave surface, and the object side surface 121 and the image side of the second lens 120 are The surface 122 is set to be aspherical.

A third lens 130 having a positive refractive power is made of plastic. The object side surface 131 of the third lens 130 is a concave surface, and the image side surface 132 is a convex surface. The object side surface 131 and the image side of the third lens 130 are The surface 132 is set to be aspherical.

A fourth lens 140 having a negative refractive power is made of plastic, the object side surface 141 of the fourth lens 140 is a concave surface, the image side surface 142 is a concave surface, and the object side surface 141 and the image side of the fourth lens 140 are The surface 142 is set to be aspherical.

An infrared filter (IR-filter) 150 is disposed between the image side surface 142 of the fourth lens 140 and an imaging surface 160. The infrared filter filter 150 is made of glass and does not affect the image. The focal length of the four-piece imaging lens set.

The equation for the above aspheric curve is expressed as follows:

Where z is the position value at the height h of the position along the optical axis 170 with reference to the surface apex; k is the cone constant metric; c is the reciprocal of the radius of curvature; A, B, C, D, E, G, .. .... is a high order aspheric coefficient.

In the first embodiment, the overall composite focal length of the four-piece imaging lens set is f, and the relationship is: f=2.95 mm.

In the first embodiment, the overall aperture value (f-number) of the four-piece imaging lens group is Fno, and the relationship is Fno=2.8.

In the first embodiment, the four-piece imaging lens group has an angle of 2ω, and the relationship is: 2ω=79°.

In the first embodiment, the distance between the object side surface 101 of the first lens 100 and the imaging surface 160 is TL, and an electronic photosensitive element (not shown) is disposed on the imaging surface 160. The electronic photosensitive element is effective. Half of the diagonal length of the pixel area is ImgH, and both satisfy the following relationship: TL/ImgH=1.512.

In the first embodiment, the focal length of the first lens 100 is f1, and the focal length of the second lens 120 is f2, and the relationship is: |f1|/|f2|=0.594.

In the first embodiment, the focal length of the second lens 120 is f2, and the focal length of the third lens 130 is f3, and the relationship is: |f2|/|f3|=1.696.

In the first embodiment, the focal length of the third lens 130 is f3, and the focal length of the fourth lens 140 is f4, and the relationship is: |f3|/|f4|=1.196.

In the first embodiment, the composite focal length of the first lens 100 and the second lens 120 is f12, and the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the relationship is: |f12|/| F34|=0.044.

In the first embodiment, the focal length of the first lens 100 is f1, and the combined focal length of the second lens 120, the third lens 130, and the fourth lens 140 is f234, and the relationship is: |f1|/|f234 |=0.729.

In the first embodiment, the combined focal length of the second lens 120 and the third lens 130 is f23, and the overall composite focal length of the four-piece imaging lens group is f, and the relationship is: |f23|/|f|=0.847 .

In the first embodiment, the overall composite focal length of the four-piece imaging lens set is f, and the distance between the object side surface 101 of the first lens 100 and the imaging surface 160 is TL, and the relationship is: |f/TL |=0.85.

The detailed structural data of the first embodiment is as shown in Table 1 of FIG. 1C, and the aspherical data is as shown in Table 2 of FIG. 1D, wherein the unit of curvature radius, thickness and focal length is in mm (mm), and The surfaces 1 and 2 shown in Tables 1 and 2 are respectively the object of the first lens 100, the image side surfaces 101 and 102, and the surfaces 4 and 5 are the objects of the second lens 120 and the image side surfaces 121 and 122, respectively. The surfaces 6, 7 are the objects of the third lens 130, the image side surfaces 131, 132, respectively, and the surfaces 8, 9 are the objects of the fourth lens 140, the image side surfaces 141, 142, respectively.

Second Embodiment

For a four-piece imaging lens set according to a second embodiment of the present invention, please refer to FIGS. 2A and 2B. FIG. 2A is a schematic view showing the configuration of a four-piece imaging lens unit according to a second embodiment of the present invention, and FIG. According to a second embodiment of the present invention, the second embodiment includes: a first lens 200 having a positive refractive power, the material is plastic, and the first mirror is from the object side A to the image side B. The object side surface 201 of the sheet 200 is a convex surface, and the image side surface 202 is a convex surface. The object side surface 201 and the image side surface 202 of the first lens 200 are both aspherical.

A light bar 210.

A second lens 220 having a negative refractive power is made of plastic. The object side surface 221 of the second lens 220 is a concave surface, the image side surface 222 is a concave surface, and the object side surface 221 and the image side of the second lens 220 are The surface 222 is set to be aspherical.

A third lens 230 having a positive refractive power is made of plastic. The object side surface 231 of the third lens 230 is a concave surface, the image side surface 232 is a convex surface, and the object side surface 231 and the image side of the third lens 230 are The surface 232 is set to be aspherical.

A fourth lens 240 having a negative refractive power is made of plastic, the object side surface 241 of the fourth lens 240 is a concave surface, the image side surface 242 is a concave surface, and the object side surface 241 and the image side of the fourth lens 240 are The surface 242 is set to be aspherical.

An infrared filter (IR-filter) 250 is disposed between the image side surface 242 of the fourth lens 240 and an imaging surface 260. The material of the infrared filter filter 250 is glass and does not affect the The focal length of the four-piece imaging lens set.

The equation for the above aspheric curve is expressed as follows:

Where z is the position value at the height h of the position along the optical axis 270 with reference to the surface apex; k is the cone constant metric; c is the reciprocal of the radius of curvature; A, B, C, D, E, G, .. .... is a high order aspheric coefficient.

In the second embodiment, the overall composite focal length of the four-piece imaging lens set is f, and the relationship is: f=2.95 mm.

In the second embodiment, the overall aperture value (f-number) of the four-piece imaging lens group is Fno, and the relationship is Fno=2.8.

In the second embodiment, the four-piece imaging lens group has an angle of 2ω, and the relationship is: 2ω=79°.

In the first embodiment, the distance between the object side surface 201 of the first lens 200 and the imaging surface 260 is TL, and an electronic photosensitive element (not shown) is disposed on the imaging surface 260, and the electronic photosensitive element is effective. Half of the diagonal length of the pixel area is ImgH, and both satisfy the following relationship: TL/ImgH=1.525.

In the second embodiment, the focal length of the first lens 200 is f1, and the focal length of the second lens 220 is f2, and the relationship is: |f1|/|f2|=0.567.

In the second embodiment, the focal length of the second lens 220 is f2, and the focal length of the third lens 230 is f3, and the relationship is: |f2|/|f3|=1.621.

In the second embodiment, the focal length of the third lens 230 is f3, and the focal length of the fourth lens 240 is f4, and the relationship is: |f3|/|f4|=1.138.

In the second embodiment, the composite focal length of the first lens 200 and the second lens 220 is f12, and the combined focal length of the third lens 230 and the fourth lens 240 is f34, and the relationship is: |f12|/| F34|=0.013.

In the second embodiment, the focal length of the first lens 200 is f1, and the combined focal length of the second lens 220, the third lens 230, and the fourth lens 240 is f234, and the relationship is: |f1|/|f234 |=0.65.

In the second embodiment, the combined focal length of the second lens 220 and the third lens 230 is f23, and the overall composite focal length of the four-piece imaging lens group is f, and the relationship is: |f23|/|f|=0.96 .

In the second embodiment, the overall composite focal length of the four-piece imaging lens set is f, and the distance between the object side surface 201 of the first lens 200 and the imaging surface 260 is TL, and the relationship is: |f/TL |=0.854.

The detailed structural data of the second embodiment is as shown in Table 3 of FIG. 2C, and the aspherical data is as shown in Table 4 of FIG. 2D, wherein the unit of curvature radius, thickness and focal length is in mm (mm), and The surfaces 1 and 2 contained in Tables 3 and 4 are respectively the object of the first lens 200, the image side surfaces 201 and 202, and the surfaces 4 and 5 are the objects of the second lens 220 and the image side surfaces 221 and 222, respectively. The surfaces 6, 7 are the objects of the third lens 230, the image side surfaces 231, 232, respectively, and the surfaces 8, 9 are the object, image side surfaces 241, 242 of the fourth lens 240, respectively.

It should be noted that Table 1 in FIG. 1C, Table 2 in FIG. 1D, Table 3 in FIG. 2C, and Table 4 in FIG. 2D are the embodiments of the four-piece imaging lens group of the present invention. The numerical values of the various embodiments of the present invention are experimentally obtained, and even if different values are used, the products of the same structure are still within the protection scope of the present invention. Table 5 in Fig. 5 is a correspondence table of the respective relational expressions in the respective embodiments.

In the four-piece imaging lens group of the present invention, the material of each lens may be glass or plastic. If the material of each lens is glass, the degree of freedom of the refractive power configuration of the four-piece imaging lens group may be increased, if each lens material is Plastics can effectively reduce production costs.

In the four-piece imaging lens set of the present invention, if the surface of the lens is convex, it indicates that the surface of the lens is convex at the near-optical axis; if the surface of the lens is concave, it indicates that the surface of the lens is concave at the near-optical axis.

100, 200. . . First lens

101, 201. . . Object side surface of the first lens

102, 202. . . Image side surface of the first lens

110, 210. . . Light bar

120, 220. . . Second lens

121, 221. . . Object side surface of the second lens

122, 222. . . Image side surface of the second lens

130, 230. . . Third lens

131, 231. . . Object side surface of the third lens

132, 232‧‧‧ image side surface of the third lens

140, 240‧‧‧ fourth lens

141, 241‧‧‧ object side surface of the fourth lens

142, 242‧‧‧ image side surface of the fourth lens

150, 250‧‧‧ Infrared filter (IR Filter)

160, 260‧‧‧ imaging surface

170, 270‧‧‧ optical axis

F‧‧‧ is the overall synthetic focal length

Fno‧‧‧ is the overall aperture value

2ω‧‧‧ as the corner

TL‧‧‧ is the distance from the object side surface of the first lens to the imaging surface

ImgH‧‧‧ is half of the diagonal length of the effective pixel area of the electronic photosensitive element

F1‧‧‧ is the focal length of the first lens

F2‧‧‧ is the focal length of the second lens

F3‧‧‧ is the focal length of the third lens

F4‧‧‧ is the focal length of the fourth lens

F12‧‧‧ is the composite focal length of the first lens and the second lens

F34‧‧‧ is the composite focal length of the third lens and the fourth lens

F234‧‧‧ is the composite focal length of the second lens, the third lens and the fourth lens

F23‧‧‧ is the composite focal length of the second lens and the third lens

Fig. 1A is an optical schematic view of a first embodiment of the present invention.

Fig. 1B is a diagram showing the spherical, non-dot and distortion line of the first embodiment of the present invention.

Figure 1C is a first embodiment of the optical data of the first embodiment.

The first 1D diagram is Table 2, which is the aspherical data of the first embodiment.

Fig. 2A is an optical schematic view of a second embodiment of the present invention.

Fig. 2B is a diagram showing the spherical, non-dot and distortion line of the second embodiment of the present invention.

Figure 2C is a third embodiment of the optical data of the second embodiment.

The second chart is Table 4, which is the aspherical data of the second embodiment.

Figure 3 is a table showing the numerical data of the correlation equation of the present invention.

100. . . First lens

101. . . Object side surface of the first lens

102. . . Image side surface of the first lens

110. . . Light bar

120. . . Second lens

121. . . Object side surface of the second lens

122. . . Image side surface of the second lens

130. . . Third lens

131. . . Object side surface of the third lens

132. . . Image side surface of the third lens

140. . . Fourth lens

141. . . Object side surface of the fourth lens

142. . . Image side surface of the fourth lens

150. . . Infrared filter (IR Filter)

160. . . Imaging surface

170. . . Optical axis

Claims (8)

A four-piece imaging lens set comprising, from the object side to the image side, a first lens having a positive refractive power, the image side surface being convex, and the object side surface and the image side surface of the first lens at least one side a non-spherical surface; a diaphragm; a second lens having a negative refractive power, the image side surface is concave, and the object side surface and the image side surface of the second lens are at least one side aspherical; a positive refractive power a third lens whose image side surface is a convex surface, and at least one side of the object side surface and the image side surface of the third lens is aspherical; a fourth lens having a negative refractive power, the object side surface is a concave surface, and the first lens The object side surface and the image side surface of the four lenses are aspherical on at least one side; the distance between the object side surface of the first lens and the image forming surface is TL, and an electronic photosensitive element is disposed on the image forming surface, and the electronic photosensitive element is effective The half of the diagonal length of the pixel area is ImgH, and the two satisfy the following relationship: TL/ImgH<1.6; the combined focal length of the second lens and the third lens is f23, and the overall synthesis of the four-piece imaging lens group The focal length is f, and both satisfy the following relationship: 0 .6<|f23|/|f|<1.2. The four-piece imaging lens set according to claim 1, wherein the first lens has a focal length of f1 and the second lens has a focal length of f2, and the two satisfy the following relationship: 0.3<|f1|/| F2|<0.8. The four-piece imaging lens set according to claim 1, wherein the second lens has a focal length of f2 and the third lens has a focal length of f3. Column relationship: 1.3<|f2|/|f3|<2.0. The four-piece imaging lens set according to claim 1, wherein the third lens has a focal length of f3 and the fourth lens has a focal length of f4, and the two satisfy the following relationship: 0.8<|f3|/| F4|<1.5. The four-piece imaging lens set according to claim 1, wherein the first lens and the second lens have a combined focal length of f12, and the third lens and the fourth lens have a combined focal length of f34. The following relationship is satisfied: |f12|/|f34|<0.06. The four-piece imaging lens set according to claim 1, wherein the first lens has a focal length of f1, and the second lens, the third lens and the fourth lens have a combined focal length of f234, both of which satisfy The following relationship: 0.4<|f1|/|f234|<0.9. The four-piece imaging lens set according to claim 1, wherein the overall synthetic focal length of the four-piece imaging lens group is f, and the distance between the object side surface of the first lens and the imaging surface is TL. Both satisfy the following relationship: 0.75<|f/TL|<0.95. The four-piece imaging lens set according to claim 1, wherein the first lens is made of plastic, and the object side surface of the first lens is a convex surface, and the object side surface and the image side of the first lens The surface of the second lens is made of plastic, and the object side surface of the second lens is concave, and the object side surface and the image side surface of the second lens are aspherical, and the material of the third lens is Is plastic, and the object side surface of the third lens is concave, the third mirror The object side surface and the image side surface of the sheet are aspherical, the fourth lens is made of plastic, and the image side surface of the fourth lens is concave, and the object side surface and the image side surface of the fourth lens are both non-spherical. Spherical.