TWI477802B - Micro-lens module - Google Patents

Description

Micro lens module

The present invention relates to a lens module, and more particularly to a miniature lens module.

With the advancement of technology, various portable electronic products such as mobile phones and personal digital assistants (PDAs), notebook computers (notebook PCs), tablet PCs, etc. are usually equipped with miniature camera lenses. Allow users to record the glimpses of life. Camera performance has become a common and basic feature of portable electronics as performance continues to increase and prices continue to fall.

In general, miniature camera lenses are usually equipped with image sensing components, such as a Charge Coupled Device (CCD) or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor), which are becoming smaller and smaller. In addition, the lens that the portable electronic product is equipped with must be reduced in size to meet the portable requirements. In terms of current technology, although the lens of the portable electronic product has the advantage of small size, the interface reflection problem between different materials is serious, and the imaging quality is not good.

The present invention provides a miniature lens module which can simultaneously improve image quality and have a miniaturized volume while achieving convenience in manufacturing.

The present invention provides a miniature lens module that includes a plurality of lens groups. The lens group is disposed between the object side and the image side, wherein at least one of the lens groups is composed of a compound lens. The composite lens includes a plurality of lenses that are attached to each other, and at least one of the lenses has a different refractive index from the other lenses.

In an embodiment of the invention, the lens group comprises a first lens group. The first lens group is disposed between the object side and the image side, wherein the first lens group is composed of a compound lens. The composite lens includes a first lens and a second lens. The first lens is disposed between the object side and the image side. The second lens is disposed between the first lens and the image side. One of the planes of the second lens serves as an aperture diaphragm of the micro lens module.

In an embodiment of the invention, the first lens group has positive refractive power.

In an embodiment of the invention, the first lens is a plano-concave lens. The concave surface of the first lens faces the object side, and the plane of the first lens faces the image side and fits with the first plane of one of the second lenses to form an aperture stop.

In an embodiment of the invention, the first lens is a plano-convex lens. The convex surface of the first lens faces the object side, the plane of the first lens faces the image side and fits with the first plane of one of the second lenses, and the second plane of the second lens serves as the aperture diaphragm.

In an embodiment of the invention, the second lens is a light transmissive plate.

In an embodiment of the invention, the first lens and the second lens have different refractive indices.

In an embodiment of the invention, the composite lens further includes a third lens disposed between the second lens and the image side.

In an embodiment of the invention, the third lens is a plano-convex lens. The convex surface of the third lens faces the image side, and the plane of the third lens faces the object side and is attached to the second lens.

In an embodiment of the invention, the third lens and the second lens have different refractive indices.

In an embodiment of the invention, the lens group further includes a second lens group disposed between the first lens group and the image side.

In an embodiment of the invention, the second lens group has a negative refracting power.

In an embodiment of the invention, the second lens group includes a meniscus lens. The convex surface of the meniscus lens faces the object side, and the concave surface of the meniscus lens faces the image side.

In an embodiment of the invention, the second lens group has a positive power.

In an embodiment of the invention, the second lens group includes a meniscus lens. The concave surface of the meniscus lens faces the object side, and the convex surface of the meniscus lens faces the image side.

In an embodiment of the invention, the lens group further includes a third lens group disposed between the second lens group and the image side.

In an embodiment of the invention, the third lens group has a negative refracting power.

In an embodiment of the invention, the third lens group comprises a biconcave lens.

Based on the above, in the exemplary embodiment of the present invention, the micro lens module can simultaneously improve the image quality and have a miniaturized volume by combining the lens group and other lens groups in consideration of manufacturing convenience.

The above described features and advantages of the present invention will be more apparent from the following description.

In an exemplary embodiment of the present invention, the micro lens module includes a plurality of lens groups arranged on the object side toward the image side. Wherein at least one of the groups of lenses consists of a composite lens. The composite lens includes a plurality of lenses that are attached to each other, and at least one of them has a different refractive index from the other lenses.

[First Embodiment]

FIG. 1A is a schematic structural view of a micro lens module according to a first embodiment of the present invention. Referring to FIG. 1A , in the embodiment, the micro lens module 100 includes a first lens group 110 and a second lens group 120 . The first lens group 110 is disposed between the object side and the second lens group 120, is composed of a compound lens, and has positive refractive power. The composite lens includes a first lens 112, a second lens 114 and a third lens 116 arranged in sequence from the object side to the image side. In an exemplary embodiment of the present invention, a composite lens refers to a lens composed of a plurality of lenses that are attached to each other, and at least one of which has a different refractive index from the other lenses. For example, the second lens 114 of the present embodiment has different refractive indices from the first lens 112 and the third lens 116, and the three are attached to each other to form the composite lens.

Specifically, in the present embodiment, the first lens 112 is a plano-concave lens having a concave surface S1 facing the object side, and the plane S2 facing the image side and conforming to the plane of the second lens 114 to form an aperture stop. The second lens 114 is, for example, a light-transmissive flat plate made of glass, and is bonded to the first lens 112 in a plane facing the object side, and is bonded to the third lens 116 on a plane facing the image side. The third lens 116 is a plano-convex lens whose plane S3 faces the object side and is in contact with the plane of the second lens 114, and the convex surface S4 faces the image side. In other words, one of the planes of the second lens 114 (ie, the light transmissive plate) of the present embodiment is in contact with the plane S2 of the first lens 112 to serve as the aperture diaphragm of the micro lens module 100, and the other plane is The plane S3 of the third lens 116 is fitted.

The second lens group 120 is disposed between the first lens group 110 and the image side and has a negative refracting power. The second lens group 120 includes a meniscus lens 122. The convex surface S5 of the meniscus lens 122 faces the object side, and the concave surface S6 of the meniscus lens 122 faces the image side.

In the present embodiment, the micro lens module 100 further includes a protective cover 70 disposed between the second lens group 120 and the image side for protecting the image sensor 60 between the surface S8 and the image side. The protective cover 70 has two surfaces S7, S8 with the surface S7 facing the object side and the surface S8 facing the image side. In this embodiment, the material of the protective cover 70 is a light transmissive material, such as glass, transparent resin, etc., and the image sensor 60 can be a charge coupled device (CCD), a complementary MOS sensing device. Complementary metal-oxide-semiconductor sensor (CMOS sensor).

One embodiment of the micro lens module 100 will be exemplified below. It should be noted that the following data sheets and the data listed in Tables 1 and 2 are not intended to limit the present invention, and any one of ordinary skill in the art may refer to the present invention after appropriate parameters or settings thereof. The change, but it should still fall within the scope of the present invention.

In Table 1, the pitch refers to the linear distance between two adjacent surfaces on the optical axis A. For example, the distance between the surfaces S3, that is, the linear distance between the surface S3 and the surface S4 on the optical axis A. For the thickness, refractive index, and Abbe number of each optical element in the remark column, refer to the values corresponding to the pitch, refractive index, and Abbe number in the same column. Further, in Table 1, the surfaces S1, S2 are the two surfaces of the first lens 112, the surfaces S3, S4 are the two surfaces of the third lens 116, and the surfaces S5, S6 are the both surfaces of the meniscus lens 122 of the second lens group 120. The surfaces S7 and S8 are the two surfaces of the protective cover 70, wherein the spacing in the row of the surface S8 is the distance from the surface S8 to the image sensor 60.

For the parameter values such as the radius of curvature and the spacing of each surface, please refer to Table 1, and will not be repeated here.

The above-mentioned surfaces S1, S4, S5, and S6 are even-order aspheric surfaces, and they can be expressed by the following formula:

Where Z is the offset (sag) in the direction of the optical axis A, and c is the reciprocal of the radius of the osculating sphere, that is, the radius of curvature near the optical axis A (as shown in Table 1, S1, S4, S5) The reciprocal of the radius of curvature of S6. k is a quadric coefficient (conic), r is an aspherical height, that is, a height from the center of the lens toward the edge of the lens, and α ₁ to α _{8 are} aspheric coefficients, and in this embodiment, the coefficient α ₁ is 0. Listed in Table 2 are the parameter values of the surfaces S1, S4, S5, and S6.

In addition, in the present embodiment, the micro lens module 100 has a numerical aperture (F number) of 2.8, an effective focal length of 1 cm (mm), and a field of view (FOV) of 60 degrees. The equivalent focal length of the first lens group is 1.05 cm, and the equivalent focal length of the second lens group 120 is -12.01 cm. However, the invention is not limited to the above.

1B and 1C are diagrams of imaging optical simulation data of the micro lens module 100 of FIG. 1A. Please refer to FIG. 1B, in which FIG. 1B is a graph of field curvature and distortion from left to right. In addition, FIG. 1C is a transverse ray fan plot of the image. As can be seen from the graphs shown in FIG. 1B and FIG. 1C, the micro lens module 100 of the present embodiment can exhibit good image quality with a miniaturized volume.

[Second embodiment]

2A is a schematic structural view of a micro lens module 200 according to a second embodiment of the present invention. Referring to FIG. 2A, the micro lens module 200 of the present embodiment is similar to the micro lens module 100 of FIG. 1A. The following is a description of the differences between the two, and the same points will not be repeated.

Specifically, in the embodiment, the micro lens module 200 includes a first lens group 210, a second lens group 220, and a third lens group 230. The first lens group 210 is disposed between the object side and the second lens group 220, and is composed of a compound lens and has positive refractive power. The composite lens includes a first lens 212 and a second lens 214 arranged in sequence from the object side to the image side. In an exemplary embodiment of the present invention, a composite lens refers to a lens composed of a plurality of lenses that are attached to each other, and at least one of which has a different refractive index from the other lenses. For example, the second lens 214 of the present embodiment has a different refractive index than the first lens 212, and the two are attached to each other to form the composite lens.

In detail, in the present embodiment, the first lens 212 is a plano-convex lens having a convex surface S1 facing the object side, and a plane S2 facing the image side and conforming to the plane of the second lens 214. The second lens 214 is, for example, a light-transmissive flat plate made of glass, and is bonded to the first lens 212 in a plane facing the object side, and a plane S3 facing the image side serves as an aperture diaphragm of the micro lens module 200. In other words, one of the planes of the second lens 214 (ie, the light transmissive plate) of the present embodiment is in contact with the plane S2 of the first lens 212, and the other plane S3 serves as the aperture diaphragm of the micro lens module 200.

The second lens group 220 is disposed between the first lens group 210 and the third lens group 230 and has a positive refractive power. The second lens group 220 includes a meniscus lens 222. The concave surface S4 of the meniscus lens 222 faces the object side, and the convex surface S5 of the meniscus lens 222 faces the image side.

The third lens group 230 is disposed between the second lens group 220 and the image side and has a negative refracting power. The third lens group 230 includes a double concave lens 232. One concave surface S6 of the double concave lens 232 faces the object side, and the other concave surface S7 of the double concave lens 232 faces the image side.

One embodiment of the micro lens module 200 will be exemplified below. It should be noted that the data sheets listed below and in Tables 3 and 4 are not intended to limit the present invention, and any one of ordinary skill in the art may refer to the present invention after appropriate parameters or settings thereof. The change, but it should still fall within the scope of the present invention.

In Table 3, the pitch refers to the linear distance between the two adjacent surfaces on the optical axis A. For example, the distance between the surfaces S2, that is, the linear distance between the surface S2 and the surface S3 on the optical axis A. For the thickness, refractive index, and Abbe number of each optical element in the remark column, refer to the values corresponding to the pitch, refractive index, and Abbe number in the same column. Further, in Table 3, the surfaces S1, S2 are the both surfaces of the first lens 212, and the surface S3 is the surface of the second lens 214 facing the image side. The surfaces S4, S5 are the two surfaces of the meniscus lens 222 of the second lens group 220, and the surfaces S6, S7 are the two surfaces of the biconcave lens 232 of the third lens group 230, wherein the pitch in the row of the surface S7 is filled. It is the pitch of the surface S7 to the image sensor 60. For the parameter values such as the radius of curvature and the spacing of each surface, please refer to Table 1, and will not be repeated here.

The above-mentioned surfaces S1, S4 to S7 are even-order aspheric surfaces, and they can be expressed by the following formula:

Where Z is the offset (sag) in the direction of the optical axis A, and c is the reciprocal of the radius of the osculating sphere, that is, the radius of curvature near the optical axis A (see S1, S4~S7 in Table 3). The reciprocal of the radius of curvature). k is a quadric coefficient (conic), r is an aspherical height, that is, a height from the center of the lens toward the edge of the lens, and α ₁ to α _{8 are} aspheric coefficients, and in this embodiment, the coefficient α ₁ is 0. Table 4 lists the parameter values of the surfaces S1, S4~S7.

In addition, in the present embodiment, the micro lens module 200 has a numerical aperture (F number) of 2.8, an effective focal length of 1 cm (mm), and a field of view (FOV) of 60 degrees. The equivalent focal length of the first lens group 210 is 1.04 cm, the equivalent focal length of the second lens group 220 is 2 cm, and the equivalent focal length of the third lens group 230 is -1.56 cm. However, the invention is not limited to the above.

2B and 2C are imaging optical simulation data diagrams of the micro lens module 200 of FIG. 2A. Please refer to FIG. 2B, in which FIG. 2B is a graph of field curvature and distortion from left to right. In addition, FIG. 2C is a transverse ray fan plot of the image. 2B and 2C, it can be seen that the micro lens module 200 of the present embodiment can also exhibit good imaging quality with a miniaturized volume.

In summary, in the exemplary embodiment of the present invention, the micro lens module can simultaneously improve the imaging quality and has a miniaturized volume by combining the lens group and other lens groups in consideration of manufacturing convenience. .

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

60. . . Image sensor

70. . . protection cap

100, 200. . . Micro lens module

110, 210. . . First lens group

112, 212. . . First lens

114,214. . . Second lens

116. . . Third lens

120, 220. . . Second lens group

122, 222. . . Concave lens

230. . . Third lens group

232. . . Double concave lens

S1~S8. . . surface

A. . . Optical axis

FIG. 1A is a schematic structural view of a micro lens module according to a first embodiment of the present invention.

FIG. 1B and FIG. 1C are diagrams of imaging optical simulation data of the micro lens module of FIG. 1A.

2A is a schematic structural view of a micro lens module according to a second embodiment of the present invention.

2B and 2C are diagrams of imaging optical simulation data of the micro lens module of FIG. 2A.

60. . . Image sensor

70. . . protection cap

100. . . Micro lens module

110. . . First lens group

112. . . First lens

114. . . Second lens

116. . . Third lens

120. . . Second lens group

122. . . Concave lens

S1~S8. . . surface

A. . . Optical axis

Claims (15)

A miniature lens module includes: a plurality of lens groups disposed between an object side and an image side, wherein at least one of the lens groups is composed of a composite lens comprising a plurality of lenses The lenses are attached to each other, and at least one of the lenses has a different refractive index from the other lenses, wherein the lens groups include: a first lens group disposed on the object side and the image side The first lens group is composed of the composite lens, the composite lens includes: a first lens disposed between the object side and the image side; and a second lens disposed on the first lens Between the image sides, one of the planes of the second lens serves as an aperture diaphragm of the micro lens module, the first lens is a plano-concave lens, and the concave surface of the first lens faces the object side, and the first lens The plane faces the image side and conforms to a first plane of the second lens to form the aperture stop. The micro lens module of claim 1, wherein the first lens group has a positive refractive power. The micro lens module of claim 1, wherein the second lens is a light transmissive plate. The microlens module of claim 1, wherein the first lens and the second lens have different refractive indices. The micro lens module of claim 1, wherein the composite lens further comprises a third lens disposed between the second lens and the image side. The micro lens module of claim 5, wherein the third lens is a plano-convex lens, the convex surface of the third lens faces the image side, and the plane of the third lens faces the object side and the Two lens fits. The micro lens module of claim 5, wherein the third lens and the second lens have different refractive indices. The micro lens module of claim 1, wherein the lens groups further comprise a second lens group disposed between the first lens group and the image side. The micro lens module of claim 8, wherein the second lens group has a negative refracting power. The micro lens module of claim 9, wherein the second lens group comprises a meniscus lens having a convex surface facing the object side, and a concave surface of the meniscus lens facing the image side. The micro lens module of claim 8, wherein the second lens group has a positive refracting power. The microlens module of claim 11, wherein the second lens group comprises a meniscus lens having a concave surface facing the object side, and a convex surface of the meniscus lens facing the image side. The micro lens module of claim 8, wherein the lens groups further comprise: a third lens group disposed between the second lens group and the image side. The micro lens module of claim 13, wherein the third lens group has a negative refracting power. The micro lens module of claim 13, wherein the third lens group comprises a double concave lens.