# Patent

## Title
Lens module

## Abstract

A lens module includes a lens holder having a top wall that has a bottom surface, and a lens unit received by the lens holder. The lens unit includes a first lens adjacent to the top wall and a second lens attached to the first lens. The first lens includes a first object-side surface abutting against the bottom surface and a side surface abutting against an inner surface of the lens holder. The second lens includes a second object-side surface engaging with the first lens, and a jointing surface also abutting against the inner surface.

## Background
FIELD OF THE INVENTION
The present invention relates to optical apparatuses, and more particularly to a lens module used in a camera or other image pick-up device.
DESCRIPTION OF RELATED ART
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 precisions. As one of the key characters of a lens module, concentricity is much important for performing high quality pictures.
Generally, a lens module includes a holder for receiving a plurality of lens units therein. The lens units should be provided with high concentricity to be concentric with each other, and the combination of the lens unit should be concentric with the holder. During actual manufacturing process, the concentricity between the lens units, or between the lens unit and the holder is difficult to be controlled. Thus, this disclosure provides a lens module provided with special configuration for ensuring the concentricity thereof.



BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the embodiment 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 exemplary embodiment of the present disclosure.
FIG. 2 is an illustrative cross-sectional view of a lens holder 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 a top view of a first surface of the first lens.
FIG. 5 is a bottom view of a second surface of the first lens.
FIG. 6 is an illustrative cross-sectional view of a second lens used in the lens module in FIG. 1.
FIG. 7 is a top view of an upper surface of the second lens.
FIG. 8 is an illustrative view of the first lens ready to be attached to the second lens.



DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT
The present invention will hereinafter be described in detail with reference to an exemplary embodiment.
The present disclosure provides a lens module that could be used in a mobile phone, a tablet, or a digital camera. Referring to FIGS. 1-2, a lens module 100 includes a lens holder 101 and a lens unit 103 supported by the lens holder 101. The lens module has an optic axis 106. The lens holder 101 is symmetric about the optic axis 106, and comprises a first holder 101A and a second holder 101B extending vertically from an edge of the first holder 101A. In this embodiment, the second holder 101B is integrated with the first holder 101A. Along a direction perpendicular to the optic axis 106, a first thickness T1 of the first holder 101A is greater than a second thickness T2 of the second holder 101B. The first holder 101A includes a top surface 24, a bottom surface 25 opposed and parallel to the top surface 24, and a first inner surface 26 connecting the top surface 24 and the bottom surface 25. The first inner surface 26 forms an aperture 101C for passing lights into the holder. The second holder 101B includes a second inner surface 101D jointing with and perpendicular to the bottom surface 25 of the first holder 101A, a third inner surface 101F parallel to the second inner surface 101D, and a step 101E connecting the second inner surface 101D to the third inner surface 101F. By virtue of the step 101E, an inner diameter W1 of the second inner surface 101D is smaller than an inner diameter W2 of the third inner surface 101F. The second inner surface 101D, the third inner surface 101F, the step 101E, and the bottom surface 25 cooperatively form a receiving space 102 for receiving the lens unit 103 therein. The lens unit 103 includes a first lens 104 and a second lens 105 attached to the first lens 104. The first lens 104 locates between the first holder 101A and the second lens 105.
Referring to FIGS. 3-5, the first lens 104 includes a first object-side surface 104A, a first image-side surface 104B opposed to the first object-side surface 104A, and a side surface 104C connecting the first object-side surface 104A to the first image-side surface 104B. A distance between the first object-side surface 104A and the first image-side surface determines a thickness of the first lens 104. The first object-side surface 104A comprises, from a periphery to a center, a first plane 107 and a first optic surface 108 connecting with the first plane 107. The first plane 107 is perpendicular to the optic axis 106.
The first image-side surface 104B comprises, from the periphery to the center, a second plane 109 perpendicular to the optic axis, a first arc surface 110 connecting with the second plane 109, a third plane 111 connecting with the first arc surface 110 and perpendicular to the optic axis, and a second optic surface 112 connecting with the third plane 111. The first arc surface 110 is thus configured that the third plane 111 is closer to the first object-side surface 104A than the second plane 109. Alternatively, the first arc surface 110 can also be thus configured that the third plane 111 is farther from the first object-side surface 104A than the second plane 109.
Referring to FIGS. 6-7, the second lens 105 comprises a second object-side surface 105A, a second image-side surface 105B opposed to the second object-side surface 105A, and a jointing surface 105C connecting the second object-side surface 105A to the second image-side surface 105B. A distance between the second object-side surface 105A and the second image-side surface 105B determines a thickness of the second lens 105. The second object-side surface 105A comprises, from a periphery to a center, a first carrying surface 113 perpendicular to the optic axis, a second arc surface 114, a second carrying surface 115 perpendicular to the optic axis, a fourth plane 117, and a third optic surface 118. By virtue of the second arc surface 114, the second carrying surface 115 is closer to the second image-side surface 105B than the first carrying surface 113. Alternatively and corresponding to the first arc surface, the second arc surface can also be thus configured that the second carrying surface 115 is farther from the second image-side surface 105B than the first carrying surface 113, which means actually that the first arc surface and the second arc surface are complementary structures. And, the second carrying surface 115 and the fourth plane 117 form a fall so that the fourth plane 117 farther from the third plane 111 than the second carrying surface 115.
Referring to FIG. 8, and also referring to FIG. 1, while assembled, the second plane 109 abuts against the first carrying surface 113, the first arc surface 110 abuts against the second arc surface 114, and the third plane 111 spaces from the second carrying surface 115. In addition, a space is accordingly formed between the second optic surface 112 and the third optic surface 118 for arranging a filter 50 therebetween. The fall formed between the second carrying surface 115 and the fourth plane 117 is used for expanding the space formed between the second optic surface 112 and the third optic surface 118
Referring back to FIG. 1, also referring to FIGS. 2-8, when the combination of the first lens 104 and the second lens 105, i.e., the lens unit 103 is assembled with the lens holder 101, the first plane 107 abuts against the bottom surface 25 of the first holder 101A, and the side surface 104C abuts against the second inner surface 101D of the second holder 101B. Further, the jointing surface 105C abuts against the third inner surface 101F of the second holder 101B. Be noted that the first carrying surface 113 keeps a distance from the step 101E.
The cooperation or engagement between the first arc surface 110 and the second arc surface 114 ensures the concentricity between the first lens 104 and the second lens 105. The engagement between the side surface 104C and the second inner surface 101D ensures the concentricity between the lens unit 103 and the lens holder 101. Further, the jointing surface 105C of the second lens 105 engages with the third inner surface 101F of the second holder 101B, the concentricity between the lens unit 103 and the lens holder 101 is determined cooperatively by the engagement between the first lens 104 and the lens holder 101, and the engagement between the second lens 105 and the lens holder 101. And, the concentricity between the first lens 104 and the second lens 105 is determined by the engagement between the first arc surface 110 and the second arc surface 114. Another word, the first arc surface 110 of the first lens and the second arc surface 114 of the second lens define a first assembling precision, and the side surface 104C and the second inner surface 22 defines a second assembly precision. The first assembly precision ensures the concentricity between the first lens and the second lens, and the second assembly precision ensures the concentricity between the lens unit 103 and the lens holder 101.
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiment have been set forth in the foregoing description, together with details of the structures and functions of the embodiment, 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.

## Claims

1. A lens module, having an optic axis and comprising:
a lens holder having a top surface perpendicular to the optic axis, a first inner surface connecting with and perpendicular to the top surface forming an aperture, a bottom surface jointing with the first inner surface and parallel to the top surface, a second inner surface jointing with and perpendicular to the bottom surface, a step jointing with and perpendicular to the second inner surface, and a third inner surface jointing with and perpendicular to the step;
a first receiving space formed by the second inner surface and having a first diameter;
a second receiving space formed by the third inner surface and having a second diameter greater than the first diameter;
a first lens at least partially received in the first receiving space, the first lens including a first object-side surface having a first plane abutting against the bottom surface of the lens holder, a side surface positioned by the second inner surface, and a first image-side surface; and
a second lens received in the second receiving space, the second lens including a second object-side surface engaging with the first image-side surface and keeping a distance from the step, and a jointing surface positioned by the third inner surface;
wherein the first image-side surface of the first lens includes a second plane, a first arc surface and a third plane connected to the second plane via the arc surface, and the second object-side surface of the second lens includes a first carrying surface abutting against the second plane, a second arc surface engaging with the first arc surface; and
wherein the second object-side surface of the second lens further includes a second carrying surface connecting with the second arc surface and keeping a distance from the third plane of the first lens.

2. The lens module as described in claim 1, wherein the second object-side of the second lens further includes a fourth plane forming a fall relative to the second carrying surface.

3. The lens module as described in claim 1, wherein the first image-side surface keeps a distance from the second object-side surface for receiving a filter therein.