Fixed-focus camera module and associated method of assembly

• US 20050036778A1
• Filed: 08/12/2003
• Published: 02/17/2005
• Est. Priority Date: 08/12/2003
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Micron Technology, Inc.
• Inventors: DeMonte, Frank J.
• Granted Patent: US 7,233,737 B2
• Time in Patent Office: Days
• US Class Current: 396/89
• CPC Class Codes: G03B 13/32 Means for focusing

Abstract

A fixed-focus camera module includes an image sensor, a lens for focusing an image onto the image sensor, and a positioning structure for maintaining an alignment of the lens and image sensor. The alignment provides a desired image quality of the image focussed onto the image sensor. The positioning structure includes a first unthreaded member coupled to the lens and a second unthreaded member coupled to the image sensor. One of the first and the second members is configured to be inserted into the other of the members to provide an adjustable relative position of the lens and the image sensor.

Claims

1. A fixed-focus camera module, comprising:

an image sensor;

a lens for focusing an image onto the image sensor; and

a positioning structure for maintaining an alignment of the lens and image sensor to provide a desired image quality, the positioning structure including a first unthreaded member coupled to the lens and a second unthreaded member coupled to the image sensor, one of the first and the second members configured to be inserted into the other of the members to provide an adjustable relative position of the lens and the image sensor.

2. The fixed-focus camera module of claim 1, wherein the positioning structure includes at least one alignment attribute for facilitating a part of the alignment of the lens and image sensor.

3. The fixed-focus camera module of claim 1, wherein the first member and the second member are adapted to adjustably couple with one another.

4. The fixed-focus camera module of claim 3, wherein the first member and the second member each include a surface, and wherein the surface of the first member is securable to the surface of the second member in at least one contact point when the alignment for the desired image quality is achieved.

5. The fixed-focus camera module of claim 3, wherein the adjustable coupling of the first member and the second member is a slip-fit between the first member and the second member.

6. The fixed-focus camera module of claim 3, wherein an adjustment of the adjustable coupling in at least one degree of freedom facilitates establishing an alignment corresponding to the desired image quality.

7. The fixed-focus camera module of claim 3, wherein the adjustable coupling of the first member and the second member is adapted to establish an alignment corresponding to the desired image quality in at least one degree of freedom.

8. The fixed-focus camera module of claim 4, wherein at least one surface of the surfaces of the first member and the second member includes a detail adapted to facilitate a process for securing the adjustable coupling.

9. The fixed-focus camera module of claim 1, wherein the positioning structure'"'"'s maintaining of the alignment is accomplished at least in part by at least one welded joint.

10. The fixed-focus camera module of claim 1, wherein the positioning structure'"'"'s maintaining of the alignment is accomplished at least in part by at least one adhesively-bonded joint.

11. The fixed-focus camera module of claim 1, wherein the positioning structure comprises at least a portion of an enclosure of the camera module.

12. A method of assembling a fixed-focus camera module having a lens and an image sensor, the method comprising:

translationally adjusting with extrinsic equipment a relative positioning of the lens and the image sensor along an axis perpendicular to a plane of the image sensor until a desired positioning has been achieved; and

securing the desired positioning of the lens and the image sensor such that the desired positioning is maintained intrinsically by the camera module.

13. The method of claim 12, wherein the extrinsic equipment is automated, and wherein the automated extrinsic equipment provides the desired positioning of the lens and the image sensor without substantial human operator involvement.

14. The method of claim 12, wherein the positioning by extrinsic equipment is based on at least one predetermined spacing along the axis perpendicular to the plane of the image sensor.

15. The method of claim 14, wherein the extrinsic equipment employs at least one datum spacer corresponding to the at least one predetermined spacing.

16. The method of claim 14, wherein the extrinsic equipment employs a feedback indication based on a spacing measurement provided by positional sensing equipment.

17. The method of claim 12, wherein the extrinsic equipment employs a feedback indication based on a measurement of image quality of an image captured by the image sensor during the positioning.

18. The method of claim 12, and further comprising:

providing a positioning structure intrinsic to the camera module that provides an alignment of the lens and the image sensor along two orthogonal axes that are parallel to the plane of the image sensor during the translational adjustment by the extrinsic equipment.

19. A method of achieving a high-accuracy alignment of a lens and an image sensor in a fixed-focus camera module, the method comprising:

providing a positional fixing structure in the camera module;

translating at least one of the lens and the image sensor with a positioning system until a desired spacing between the lens and the image sensor has been achieved; and

securing the desired spacing of the lens and the image sensor with the positional fixing structure.

20. The method of claim 19, wherein the positioning system is automated, and wherein the positional fixing structure is configured to provide an appropriate alignment of the lens and the image sensor along at least one axis parallel to a plane of the image sensor.