Lens module

The present invention relates to a lens module with lens group, particularly to a miniature lens module applicable to a camera module or a photographing module in a mobile device, such as a tablet PC, a mobile phone, or a personal digital assistant (PDA) and etc.

With the rapid development of technologies, electronic devices having image pick-up functions, such as cameras, mobile phones, portable computers, tablets, are equipped with lens modules. For satisfying the demands of high quality pictures, lens modules are designed and manufactured with high accuracies. As one of the key characters of a lens module, concentricity is much important for performing high quality pictures.

Generally, a lens module comprises a lens supporter for receiving a plurality of lens groups therein. The lens group should be provided with high concentricity to be concentric with each other, and the combination of the lens group should be concentric with the supporter. During actual manufacturing process, the concentricity between the lens group, or between the lens group and the lens supporter is difficult to be controlled. Thus, this disclosure provides a lens module provided with a special configuration for ensuring the concentricity thereof.

Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an illustrative cross-sectional view of a lens module in accordance with an first exemplary embodiment of the present disclosure.

FIG. 2 is an illustrative cross-sectional view of a lens supporter of the lens module in FIG. 1 .

FIG. 3 is an illustrative cross-sectional view of a first lens used in the lens module in FIG. 1 .

FIG. 4 is an illustrative cross-sectional view of the first lens in FIG. 3 assembled with the lens supporter in FIG. 2 .

FIG. 5 is an illustrative cross-sectional view of a second lens used in the lens module in FIG. 1 .

FIG. 6 is an illustrative cross-sectional view of the second lens in FIG. 5 stacked on the first lens in FIG. 3 .

FIG. 7 is an illustrative cross-sectional view of a third lens used in the lens module in FIG. 1 .

FIG. 8 is an illustrative cross-sectional view of the third lens in FIG. 7 stacked on the second lens in FIG. 5 .

FIG. 9 is an illustrative cross-sectional view of a fourth lens used in the lens module in FIG. 1 .

FIG. 10 is an illustrative cross-sectional view of the fourth lens in FIG. 9 stacked on the third lens in FIG. 7 .

FIG. 11 is an illustrative cross-sectional view of a lens module in accordance with a second exemplary embodiment of the present disclosure.

The present invention will hereinafter be described in detail with reference to exemplary embodiments. The first exemplary embodiment of the present disclosure provides a lens module that could be used in a mobile phone, a tablet PC, or a digital camera. Referring to FIGS. 1 and 2 , a lens module 100 comprises a lens supporter 10 and a lens group 20 supported by the lens supporter 10 . The lens supporter 10 includes an aperture plate 11 , a main body 12 extending vertically from an edge of the aperture plate 11 , and a receiving space 30 formed by the aperture plate 11 and the main body 12 . In this embodiment, the main body 12 is integrated with the aperture plate 11 . The lens group 20 is received in the receiving space 30 . The lens group 20 comprises a first lens 21 , a second lens 22 stacked on the first lens 21 , a third lens 23 stacked on the second lens 22 , and a fourth lens 24 stacked on the third lens 23 . The first lens 21 locates in the main body 12 and partially extending into the aperture plate 11 . The lens group 10 has an optical axis 40 . The first lens 21 , the second lens 22 , the third lens 23 , and the fourth lens 24 are aligned sequentially along the optical axis 40 .

The aperture plate 11 comprises an top surface 111 , a bottom surface 112 opposite and parallel to the top surface 111 , and a light aperture 13 with a central axis 40 ′ drilled through the aperture plate 11 , for passing lights into the lens supporter 10 . Specifically, the light aperture 13 is a cylindrical-shaped hole drilled perpendicularly in the aperture plate 11 . The bottom surface 112 of the aperture plate 11 has a first bottom surface 112 A surrounding the light aperture 13 , a second bottom surface 112 B connecting to the main body 12 , and a first engaging portion 113 connecting the first bottom surface 112 A with the second bottom surface 112 B and surrounding the central axis 40 ′. Therefore, the first bottom surface 112 A, the first engaging portion 113 , and the second bottom surface 112 B are arranged sequentially away from the central axis 40 ′. The main body 12 comprises an internal surface bounding the receiving space 30 , including a first inner surface 121 jointing with and perpendicular to the bottom surface 112 , a second inner surface 123 parallel with the first inner surface 121 and a sloping surface 122 connecting the first inner surface 121 with the second inner surface 123 . The sloping surface 122 extends from the first inner surface 121 to the second inner surface 123 in a direction away from the central axis 40 ′. The receiving space 30 is formed by the first inner surface 121 , the sloping surface 122 , and second inner surface 123 and the bottom surface 112 cooperatively for receiving the lens group 20 .

Referring to FIGS. 1-4 , the first lens 21 comprises a first object-side surface 21 A, a first image-side surface 21 B opposite to the first object-side surface 21 A, and a first lateral surface 21 C connecting the first object-side surface 21 A with the first image-side surface 21 B. The first lateral surface 21 C abuts against the inner surface 121 of the main body 12 . The first lens 21 further has a first concave part 215 concave from the first image-side surface 21 B towards the first object-side surface 21 A and a second engaging portion 205 protruding from the first object-side surface 21 A towards the aperture plate 11 and surrounding the optical axis 40 for engaging with the first engaging portion 113 . Specifically, the first engaging portion 113 is an arc shaped groove, and the second engaging portion 205 is accordingly an arc shaped protrusion.

The first object-side surface 21 A has a first connecting portion 203 connecting the first lateral surface 21 C with one end of the second engaging portion 205 , and a first object-side extending portion 210 connecting to the other end of the second engaging portion 205 . The first object-side extending portion 210 includes a first object-side optical surface 201 arranged in a middle thereof and centered about the optical axis 40 for serving as an optical zone, and a first abutting portion 202 connecting the first object-side optical surface 201 with the second engaging portion 205 . When assembled, the first bottom surface 112 A abuts against the first abutting portion 202 , the second bottom surface 112 B abuts against first connecting portion 203 , the first engaging portion 113 abuts against the second engaging portion 205 , and the first lateral surface 21 C at least partially abuts against the inner surface 121 of the main body 12 , thereby forming a first alignment accuracy for ensuring the central axis 40 ′ is coaxial with the optical axis 40 and the misalignment between the lens group 20 and the lens supporter 10 can be prevented. The first engaging portion 113 is a concave shape and the second engaging portion 205 is a convex shape for mating the first engaging portion 113 .

The first image-side surface 21 B has a first image-side connecting portion 211 connecting the first lateral surface 21 C and one end of the first concave part 215 and a first image-side extending portion 210 ′ connecting to the other end of the first concave part 215 . The first image-side extending portion 210 ′ has a first image-side optical surface 216 arranged in the middle thereof and centered about the optical axis 40 for serving as an optical zone, a first inclining surface 214 connecting to the first image-side optical surface 216 and surrounding the optical axis 40 , and a first plane 213 connecting the first concave part 215 with the first inclining surface 214 .

Referring to FIGS. 3-6 , the second lens 22 includes a second object-side surface 22 A, an second image-side surface 22 B opposite the second object-side surface 22 A, and a second lateral surface 22 C connecting the second object-side surface 22 A and the second image-side surface 22 B. The second lateral surface 22 C keeps a distance from the second inner surface 123 and the sloping surface 122 . The second lens 22 further has a first convex part 225 protruding from the second object-side surface 22 A and away from the second image-side surface 22 B for engaging with the first concave part 215 of the first lens 21 and a second concave part 224 concave from the second image-side surface 22 B and towards the second object-side surface 22 A. The second object-side surface 22 A has a second object-side connecting portion 221 connecting the second lateral surface 22 C and one end of the first convex part 225 , and a second object-side extending portion 220 connecting the other end of the first convex part 225 . The second object-side extending portion 220 has a second object-side optical surface 226 arranged in the middle thereof and centered about the optical axis 40 for serving as an optical zone and a second object-side plane 223 connecting the first convex part 225 and the second object-side optical surface 226 .

The second image-side surface 22 B has a second image-side connecting portion 227 connecting the second lateral surface 22 C with one end of the second concave part 224 and a second image-side extending portion 220 ′ connecting to the other end of the second concave part 224 . The second image-side extending portion 220 ′ has a second image-side optical surface 229 arranged in the middle thereof and centered about the optical axis 40 for serving as an optical zone and a second image-side plane 228 connecting the second concave part 224 and the second image-side optical surface 229 .

In this exemplary embodiment, the first image-side connecting portion 211 keeps a distance from the second object-side connecting portion 221 , and the first image-side extending portion 210 ′ keeps a distance from the second object-side extending portion 220 . In other words, the first image-side surface 21 B of the first lens 21 does not completely engage with the second object-side surface 22 A of the second lens 2 . Therefore, the concentricity between the first lens 21 and the second lens 22 is determined solely by the engagement between the first concave part 215 of the first lens 21 and the first convex part 225 of the second lens 2 , which reduces the assembling tolerance and improves the assembling accuracy. The first concave part 215 of the first lens 21 and the first convex part 225 of the second lens 22 define a second alignment accuracy for holding the first lens 21 and the second lens 22 in a precisely coaxial relationship. The first concave part 215 of the first lens 21 engaged with the first convex part 225 of the second lens 22 accordingly forms a first jointing portion 14 . The first jointing portion 14 has a first farthest curve 141 far away from the first image-side surface 21 B, a first outer part 143 extending from the first farthest curve 141 towards the main body 12 and a first inner part 142 extending from the first farthest curve 141 towards the optical axis 40 . The first outer part 143 and the first inner part 142 are symmetrical with a plane A passing through the first farthest curve 141 and parallel to the optical axial 40 . Optionally, a distance between the first farthest curve 141 and the first image-side surface 21 B determines a thickness of the first lens 21 .

Referring to FIGS. 5-8 , the third lens 23 comprises a third object-side surface 23 A, an third image-side surface 23 B opposite to the third object-side surface 23 A, and a third lateral surface 23 C connecting the third object-side surface 23 A and the third image-side surface 23 B. The third lateral surface 23 C keeps a distance from the second inner surface 123 . The third lens 23 further has a second convex part 235 protruding from the third object-side surface 23 A and away from the third image-side surface 23 B, for engaging with the second concave part 224 , and a third concave part 238 concave from the third image-side surface 23 B and towards the third object-side surface 23 A. In this exemplary embodiment, the second concave part 224 engages with the second convex part 235 , accordingly forming a second jointing portion 15 . The second jointing portion 15 includes a second farthest curve 151 far away from the second image-side surface 22 A, a second outer part 153 extending from the first farthest curve 151 towards the main body 12 and a second inner part 152 extending from the second farthest curve 151 towards the optical axis 40 .

The third object-side surface 23 A has a third object-side connecting portion 231 connecting the third lateral surface 23 C with one end of the second convex part 235 and a third object-side extending portion 230 connecting to the other end of the second convex part 235 . The third object-side extending portion 230 includes a third object-side optical surface 234 arranged in the middle thereof and centered about the optical axis 40 for serving as an optical zone, a third object-side inclining surface 232 extending from the third object-side optical surface 234 and away from the third image-side surface 23 A and a third object-side plane 233 connecting the second convex part 235 with the third object-side inclining surface 232 . The third image-side surface 23 A has a third image-side connecting portion 237 connecting the third lateral surface 23 C and one end of the third concave part 238 and a third image-side extending portion 230 ′ connecting to the other end of the third concave part 238 . The third image-side extending portion 230 ′ includes a third image-side optical surface 239 arranged in the middle thereof and centered about the optical axis 40 , for serving as an optical zone, and a third image-side plane 236 connecting the third concave part 238 with the third image-side optical surface 239 .

The second image-side connecting portion 227 keeps a distance from the third object-side connecting portion 231 and the second image-side extending portion 220 ′ keeps a distance from the third object-side extending portion 230 . Therefore, upon assembly, the concentricity between the second lens 22 and the third lens 23 is determined solely by the engagement between the second concave part 224 of the second lens 22 and the second convex part 235 of the third lens 23 , which reduces the assembling tolerance and improves the assembling accuracy.

Referring to FIGS. 7-10 , the fourth lens 24 comprises a fourth object-side surface 24 A, an fourth image-side surface 24 B opposite to the fourth object-side surface 24 A, and a fourth lateral surface 24 C connecting the fourth object-side surface 24 A with the fourth image-side surface 24 B. The fourth lateral surface 24 C abuts against the second inner surface 123 of the main body 12 , for ensuring the central axis 40 ′ is coaxial with the optical axis 40 . The fourth lens 24 further has a third convex part 245 protruding from the fourth object-side surface 24 A and away from the fourth image-side surface 24 B, for engaging with the third concave part 238 . In this exemplary embodiment, the third concave part 238 engages with the third convex part 245 , accordingly forming a third jointing portion 16 . The third jointing portion 16 include a third farthest curve 161 far away from the third image-side surface 24 B, a third outer part 163 extending from the third farthest curve 161 towards the main body 12 , and a third inner part 162 extending from the third farthest curve 161 towards the optical axis 40 .

The fourth object-side surface 24 A has a fourth object-side connecting portion 241 connecting the fourth lateral surface 24 C with one end of the third convex part 245 and a fourth object-side extending portion 240 connecting to the other end of the third convex part 245 . The fourth object-side extending portion 240 has a fourth object-side optical surface 242 arranged in the middle thereof and centered about the optical axis 40 for serving as an optical zone, and a fourth object-side plane 243 connecting the third convex part 245 with the fourth object-side optical surface 242 . The third image-side connecting portion 237 keeps a distance from the fourth object-side connecting portion 241 and the third image-side extending portion 230 ′ keeps a distance from the fourth object-side extending portion 240 . Therefore, the concentricity between the third lens 23 and the fourth lens 24 is determined solely by the engagement between the third concave part 238 and the third convex part 245 , which reduces the assembling tolerance and improves the assembling accuracy.

Outlines of the concave parts 215 , 224 , 238 and the convex parts 225 , 235 , 245 are respectively configured to be a part of a circle for ensuring the concentricity between the lens group. In other words, the outlines of the convex parts 225 , 235 , 245 and the concave parts 215 , 224 , 238 are shaped as circular arc. The farther curves 141 , 151 , 161 are farther from the corresponding image-side surface 21 B, 22 B, 23 B than other portion of the jointing portions 14 , 15 , 16 for placing the outer parts 143 , 153 , 163 and the inner part 142 , 152 , 162 on two sides of the corresponding farther curves 14 , 15 , 16 respectively, thereby the concentricity between the lens group 20 is effectively enhanced, and the misalignment of the lens group 20 can be prevented.

Optionally, heights between the farthest curves 141 , 151 , 161 and the corresponding image-side surfaces 21 B, 22 B, 23 B can be changed according to different requirements. The concave parts may be interchanged with the corresponding convex parts, for example, the concave part provided on the first lens may be interchanged with the first convex part provided on the second lens. Similarly, the shape of the first and second engaging portions may be in variety, as long as the first engaging portion is shaped to match the second engaging portion for forming the first alignment accuracy to ensure the central axis is coaxial with the optical axis.

Therefore, as shown in FIG. 11 , a second embodiment, which is similar to the first embodiment of the present invention, is illustrated in FIG. 11 . Referring to FIG. 11 , a lens module 200 comprises a lens supporter 10 ′ with a central axis 41 ′ and a lens group 20 ′ supported by the lens supporter 10 ′. The lens group 20 ′ has an optical axis 41 . The lens group 20 ′ has a first lens 21 ′, a second lens 22 ′ stacked on the first lens 21 ′, a third lens 23 ′ stacked on the second lens 22 ′, and a fourth lens 24 ′ stacked on the third lens 23 ′. The lens supporter 10 ′ has a aperture plate 11 ′ and a main body 12 ′ extending vertically from an edge of the aperture plate 11 ′. The aperture plate 11 ′ has a first bottom surface 112 ′ directly abutting against the first lens 21 ′. The first lens 21 ′ has a first object-side surface 21 A′, a first image-side surface 21 B′ opposite to the first object-side surface 21 A′, and a first lateral surface 21 C′ connecting the first object-side surface 21 A′ with the first image-side surface 21 B′. The first lateral surface 21 C′ abuts against the main body 12 ′. The first image-side surface 21 B′ comprises a first object-side optical surface 201 ′ in the middle thereof and centered about the optical axis 41 for serving as an optical zone, and a first object-side extending portion 210 ′ connecting the first lateral surface 21 C′ with the first object-side optical surface 201 ′. Herein, the first object-side extending portion 210 ′ abuts against the first bottom surface 112 ′. In this embodiment, a first concave part is provided on the second lens 22 ′ and a first convex part is accordingly provided on the first lens 21 ′, for holding the first lens 21 ′ and the second lens 22 ′ in a precisely coaxial relationship. In this embodiment, engagements between the other lenses are similar with that between the first lens 21 ′ and second lens 22 ′, for ensuring the concentricity of the lens group 20 ′, so that the misalignment can be prevented.

It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.