CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of Taiwanese Application No. 096131662, filed on Aug. 27, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for making a lens module, more particularly to a method for making a lens module in which a lens barrel is molded over a sensing element and a lens by insert molding. The invention also relates to a lens module made thereby.
2. Description of the Related Art
Referring to FIG. 1, a conventional lens module 1 includes: a first lens barrel portion 11 having an outer threaded surface 111, a central hole 112, and a receiving space 113; a second lens barrel portion 12 having an inner threaded surface 121 and threadedly engaged to the first lens barrel portion 11; and a first lens 13, a first spacer 14, a second lens 15, and a second spacer 16 received in the receiving space 113. The second lens barrel portion 12 is mounted on a circuit board 2. The lens module 1 further includes a filter 17 received within the second lens barrel portion 12, and a sensing element 18 received with the second lens barrel portion 12 and mounted on the circuit board 2. Light enters into the first lens barrel portion 11 through the central hole 112, and is transmitted to the sensing element 18 through the first lens 13, the second lens 15, and the filter 17.
Since the first lens 13, the first spacer 14, the second lens 15, the second spacer 16, and the filter 17 are respectively assembled to the first and second lens barrel portions 11, 12, they can not be assembled precisely and an assembly tolerance may occur. After assembly, the first lens barrel portion 11 and the second lens barrel portion 12 should be rotated relatively to adjust a focal distance between the first lens 13 and the second lens 15. However, grains may be produced due to the friction between the outer threaded surface 111 of the first lens barrel portion 11 and the inner threaded surface 121 of the second lens barrel portion 13 during the rotation of the first lens barrel portion 11 relative to the second lens barrel portion 12. The grains fall onto the filter 17, which in turn reduces the quantity of the light reaching the sensing element 18 and reduces the imaging quality of the lens module 1.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for making a lens module, which can overcome the aforesaid shortcomings. Another object of the present invention is to provide a lens module made by the method.
In the first aspect of this invention, a method for making a lens module includes the steps of:
(a) providing a mold with a mold cavity;
(b) mounting at least a sensing element and a lens within the mold cavity in such a manner that the sensing element and the lens are spaced apart from each other; and
(c) forming a lens barrel by injecting a molding material into the mold cavity and by molding the molding material over the sensing element and the lens.
In the second aspect of this invention, a lens module includes: a lens; a sensing element spaced apart from the lens; and a lens barrel molded over the lens and the sensing element by insert molding.
In the third aspect of this invention, an electronic device includes a main body and a lens module. The main body is formed with a receiving space and an opening communicated with the receiving space. The lens module is received in the receiving space, and includes a lens aligned with the opening, a sensing element spaced apart from the lens, and a lens barrel molded over the sensing element and the lens by insert molding.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:
FIG. 1 is a sectional view of a conventional lens module;
FIG. 2 is a fragmentary partly sectional view of an electronic device including a first preferred embodiment of a lens module according to this invention;
FIG. 3 is a sectional view of the first preferred embodiment;
FIG. 4 is a flow chart of a method for making the first preferred embodiment;
FIGS. 5 to 8 are sectional views illustrating steps of the method for making the first preferred embodiment;
FIG. 9 is a sectional view of a second preferred embodiment of a lens module according to this invention;
FIGS. 10 and 11 are sectional views illustrating steps of a method for making the second preferred embodiment;
FIG. 12 is a sectional view of a third preferred embodiment of a lens module according to this invention;
FIGS. 13 and 14 are sectional views illustrating steps of a method for making the third preferred embodiment;
FIG. 15 is a sectional view of a fourth preferred embodiment of a lens module according to this invention;
FIGS. 16 and 17 are sectional views illustrating steps of a method for making the fourth preferred embodiment;
FIG. 18 is a sectional view of a fifth preferred embodiment of a lens module according to this invention;
FIG. 19 is a flow chart of a method for making the fifth preferred embodiment;
FIGS. 20 and 21 are sectional views illustrating steps of a method for making the fifth preferred embodiment;
FIG. 22 is a sectional view of a sixth preferred embodiment of a lens module according to this invention; and
FIGS. 23 and 24 are sectional views illustrating steps of a method for making the sixth preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.
Referring to FIGS. 2 and 3, the first preferred embodiment of a lens module 300 according to this invention is installed in an electronic device 20, which is illustrated as a cellular phone. The lens module 300 can be installed in a personal digital assistant (PDA) or other portable electronic devices. The electronic device 20 includes a main body 200 and the lens module 300. The main body 200 is formed with a receiving space 21 and an opening 22 communicated with the receiving space 21. The lens module 300 is received in the receiving space 21, and includes a lens 32 aligned with the opening 22, a sensing element 36 spaced apart from the lens 32, a filter 34 mounted between the sensing element 36 and the lens 32, a masking sheet 33 mounted between the lens 32 and the filter 34 and having a central hole 331, a spacing ring 35 mounted between the filter 34 and the sensing element 36, and a lens barrel 31 molded over the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 by insert molding.
The lens barrel 31 is cylindrical or rectangular, and is made of a molding material, such as a plastic material. The lens barrel 31 has a top hole 311 aligned with the opening 22 of the main body 200 and the central hole 331 of the masking sheet 33. The filter 34 used in the preferred embodiment is an infrared (IR) filter. The spacing ring 35 has a certain thickness, and confines a through hole 351 aligned with the opening 22 of the main body 200 and the central hole 331 of the masking sheet 33. The thickness of the spacing ring 35 is adjusted according to requirements, i.e., the desired focal distance between the lens 32 and the sensing element 36. Furthermore, more than one lens 32 can be used in the lens module 300 of the present invention, if desired.
Referring to FIGS. 4 to 8, a method for making the first preferred embodiment of the lens module 300 includes the steps of:
(A) Providing a Mold 4;
- The mold 4 has a mold cavity 41, and includes an upper positioner 43, a lower positioner 42, and two opposite side positioners 44, which are movable in directions transverse to moving directions of the upper and lower positioners 43, 42. Each of the side positioners 44 has an inner abutment surface 442 with an indentation 441.
(B) Mounting the Sensing Element 36, the Spacing Ring 35, the Filter 34, the Masking Sheet 33, and the Lens 32:
- The sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 are positioned and centered sequentially or simultaneously within the mold cavity 41 so that the sensing element 36 and the lens 32 are spaced apart from each other. The upper and lower positioners 43, 42 are moved within the mold 4 to abut against the lens 32 and the sensing element 36, respectively, and the two opposite side positioners 44 are moved within the mold 4 to abut against the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32.
(C) Forming the Lens Barrel 31:
- A molding material is injected into the mold cavity 41 and is molded over the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 by insert molding. Specifically, the molding material flows between the lens 32 and the side positioners 44 at the beginning of the injecting of the molding material and before flowing between the sensing element 36 and the side positioners 44. Therefore, the molding material is allowed to flow into the indentation 441 of each of the side positioners 44 at the beginning of the injecting of the molding material (best shown in FIG. 5). When the molding material hardens in the indentation 441, the lens 32 is properly positioned against the upper positioner 43.
- Thereafter, specifically referring to FIGS. 7 and 8, the side positioners 44 are moved gradually away from the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 during the injecting of the molding material so as to permit the molding material to flow between each of the side positioners 44 and each of the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32. The lens barrel 31 is formed over the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 when the molding material is hardened.
Since the sensing element 36, the spacing ring 35, the filter 34, the masking sheet 33, and the lens 32 are positioned and centered within the mold cavity 41 by the upper and lower positioners 43, 42 during the insert molding, the occurrence of assembly tolerance and the adjustment of the focal distance can be avoided. Therefore, the aforesaid shortcomings encountered in the prior art can be overcome.
Referring to FIGS. 9 to 11, the second preferred embodiment of a lens module 310 according to this invention s shown to include a lens 32, a sensing element 36 spaced apart from the lens 32, a filter 34 mounted on the sensing element 36, a spacing ring 37 mounted between the filter 34 and the lens 32, and a lens barrel 31 molded over the sensing element 36, the filter 34, the spacing ring 37, and the lens 32 by insert molding. The spacing ring 37 has a tapered hole 371 converging along a direction from the sensing element 36 toward the lens 32.
The method for making the second preferred embodiment of the lens module 310 is substantially identical to the method for making the first preferred embodiment except that the sensing element 36, the filter 34, the spacing ring 37, and the lens 32 are positioned and centered sequentially or simultaneously within the mold cavity 41 of the mold 4 prior to the insert molding procedure.
Referring to FIGS. 12 to 14, the third preferred embodiment of a lens module 320 according to this invention is shown to include a lens 32, a sensing element 36 spaced apart from the lens 32, a filter 34 mounted between the sensing element 36 and the lens 32 and proximate to the lens 32, a masking sheet 33 mounted between the lens 32 and the filter 34 and having a central hole 331, and a lens barrel 31 molded over the sensing element 36, the filter 34, the masking sheet 33, and the lens 32 by insert molding.
The method for making the third preferred embodiment of the lens module 320 is substantially identical to the method for making the first preferred embodiment except that the side positioners 45 abut against the sensing element 36, the filter 34, the masking sheet 33, and the lens 32 in the step (b) and that each of the side positioners 45 has an inner abutment surface 451 formed with a spacer portion 452 protruding between and separating the sensing element 36 and the filter 34 in the step (b).
Since the sensing element 36 and the filter 34 are separated by the spacer portion 452 of each of the side positioners 45, the filter 34 and the sensing element 36 of the lens module 320 are spaced apart from each other by a spacing portion 312 of the lens barrel 31 formed by insert molding. Therefore, the spacing portion 312 of the lens barrel 31 can function as a spacing ring.
Referring to FIGS. 15 to 17, the fourth preferred embodiment of a lens module 330 according to this invention is shown to include a lens 32, a sensing element 36 spaced apart from the lens 32, and a lens barrel 31 molded offer the sensing element 36 and the lens 32 by insert molding.
The method for making the fourth preferred embodiment of the lens module 330 is substantially identical to the method for making the first preferred embodiment except that the side positioners 45 abut against the sensing element 36 and the lens 32 in the step (b) and that each of the side positioners 45 has an inner abutment surface 451 formed with a spacer portion 452 protruding between and separating the sensing element 36 and the lens 32 in the step (b).
Since the sensing element 36 and the lens 32 are separated by the spacer portion 452 of each of the side positioners 45, the lens 32 and the sensing element 36 of the lens module 330 are spaced apart from each other by a spacing portion 312 of the lens barrel 31 formed by insert molding. Therefore, the spacing portion 312 of the lens barrel 31 can function as a spacing ring. Additionally, the lens 32 can be coated with a masking layer and/or a filtering coat to obtain a masking and/or filtering effect.
Referring to FIG. 18, the fifth preferred embodiment of a lens module 340 according to this invention is shown to include: a lens 32; a sensing element 36 spaced apart from the lens 32; a filter 34 disposed over the sensing element 36; a spacing ring 37 disposed over the lens 32; a supporting member 38 surrounding the lens 32, the sensing element 36, the filter 34, and the spacing ring 37; and a lens barrel 30 molded over the supporting member 38 by insert molding. The spacing ring 37 has a tapered hole 371 converging in a direction away from the lens 32. The supporting member 38 includes an upper receiving portion 381 receiving the lens 32 and the spacing ring 37, a lower receiving portion 382 communicated with the upper receiving portion 381 and receiving the sensing element 36 and the filter 34, and an inner wall formed with an inwardly projecting spacer portion 380 extending between and separating the lens 32 and the filter 34. The inwardly projecting spacer portion 380 is formed between the upper and lower receiving portions 381, 382. The inwardly projecting spacer portion 380 defines a middle communicating portion 383 converging in a direction from the lower receiving portion 382 toward the upper receiving portion 381, and extends between and separates the lens 32 and the sensing element 36. The inwardly projecting spacer portion 380 further has an upper hole 386 and a lower hole 387 having a size larger than that of the upper hole 386.
Referring to FIGS. 19 to 21, a method for making the fifth preferred embodiment of the lens module 340 includes the steps of:
(A′) Providing a Mold 4:
- The mold 4 has a mold cavity 41, and includes upper and lower positioners 43′, 42, and two positioning posts 46 at two opposite sides of the lower positioner 42. The upper positioner 43′ has two protruding portions 431 at a bottom surface thereof.
(B′) Mounting the Spacing Ring 37, the Lens 32, the Filter 34, the Sensing Element 36, and the Supporting Member 38:
- The spacing ring 37 and the lens 32 are mounted in the upper receiving portion 381 of the supporting member 38 in a manner that the spacing ring 37 and the lens 32 abut against each other. The filter 34 and the sensing element 36 are mounted in the lower receiving portion 382 of the supporting member 38. The supporting member 38 in which the spacing ring 37, the lens 32, the filter 34, and the sensing element 36 are mounted is mounted in the mold cavity 41. The upper and lower positioners 43′, 42 abut against the spacing ring 37 and the sensing element 36, respectively. The positioning posts 46 abut against two opposite sides of the supporting member 38.
(C′) Forming the Lens Barrel 30:
- A molding material is injected into the mold cavity 41 and is molded over the sensing element 36 and the supporting member 38 by insert molding. The lens barrel 30 is formed over the sensing element 36 and the supporting member 38 when the molding material is hardened.
Referring to FIG. 22, the sixth preferred embodiment of a lens module 350 according to this invention is shown to be similar to the fifth preferred embodiment except that the lens module 350 further includes a shielding element 39 sleeved around the supporting member 38 to shield the lens module 350 from electromagnetic interference.
Referring to FIGS. 23 and 24, a method for making the sixth preferred embodiment of the lens module 350 is similar to the method for making the fifth preferred embodiment except that the shielding element 39 is sleeved around the supporting member 38 before the supporting member 38 is mounted in the mold cavity 41.
While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Patent Application
20090059398
