Carrier frame and circuit board for an electronic device with lens backlash reduction

• US 9,513,458 B1
• Filed: 12/06/2013
• Issued: 12/06/2016
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Cognex Corporation
• Inventors: Flgge, Kai, Nunnink, Laurens
• Primary Examiner(s): Haskins, Twyler
• Assistant Examiner(s): Tejano, Dwight C
• Application Number:
  US14/098,905
• Time in Patent Office: 1,096 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G02B 7/022 lens and mount having complementary engagement means, e.g. screw/thread
• CPC Class Codes: G02B 7/04 with mechanism for focusing or varying magnification
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G03B 17/02 Bodies
• CPC Class Codes: G03B 17/12 with means for supporting objectives, supplementary lenses, filters, masks, or turrets
• CPC Class Codes: G03B 2215/0567 Solid-state light source, e.g. LED, laser
• CPC Class Codes: G03B 2217/002 Details of arrangement of components in or on camera body
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: Y10T 29/49769 Using optical instrument [excludes mere human eyeballing]
• CPC Class Codes: Y10T 29/49863 with prestressing of part

Abstract

An electronic device includes a threaded spacer and a biasing element to reduce backlash. The threaded spacer includes a thread end point that is offset from the thread start point of the carrier frame. The offset thread ending and starting points create a gap between the threaded spacer and the carrier frame. The biasing element applies a force to the threaded spacer, thereby reducing the backlash between the lens and the carrier frame, while at the same time allowing the lens to be rotated for focus adjustments.

Claims

1. A lens backlash reduction apparatus comprising:

a lens, the lens including a threaded lens base;

a carrier frame, the carrier frame including a threaded aperture, the threaded aperture being sized to threadably receive the threaded lens base;

a biasing element coupled to the carrier frame, the biasing element including a base and at least one spring extending outwardly from the base, the spring having a bias end; and

a threaded spacer, the threaded spacer being sized to threadably receive the threaded lens base, such that when the threaded lens base is threaded into and through the threaded spacer and into the threaded aperture, the threaded spacer does not rotate and a gap is formed between the threaded spacer and the carrier frame, and the bias end of the spring applies a force to the threaded spacer.

2. The lens backlash reduction apparatus according to claim 1:

further including a thread end point on the threaded spacer and a thread start point on the threaded aperture, the thread end point on the threaded spacer being rotationally offset by a predetermined angle from the thread start point on the threaded aperture.

3. The lens backlash reduction apparatus according to claim 1:

wherein the threaded aperture includes a recessed rim, the threaded spacer being sized to fit at least partially within a space defined by the recessed rim, and the threaded spacer being non-rotatable within the space defined by the recessed rim.

4. The lens backlash reduction apparatus according to claim 3:

further including a thread end point on the threaded spacer and a thread start point on the threaded aperture, the thread end point on the threaded spacer being rotationally offset by a predetermined angle from the thread start point on the threaded aperture when the threaded spacer is positioned within the space defined by the recessed rim.

5. The lens backlash reduction apparatus according to claim 3:

wherein the recessed rim includes at least one cutout, the threaded spacer further including at least one tab sized to be positioned in the cutout, the tab positioned in the cutout to cause the threaded spacer to be non-rotatable within the space defined by the recessed rim.

6. The lens backlash reduction apparatus according to claim 3:

wherein the biasing element includes a first spring and a second spring extending from the base; and

wherein the first spring and the second spring extend from the base and at least partially extend within the space defined by the recessed rim.

7. The lens backlash reduction apparatus according to claim 1:

wherein the biasing element interacts with the threaded spacer to cause the threaded spacer to be non-rotatable.

8. The lens backlash reduction apparatus according to claim 1:

wherein the bias end of the spring applies a force to the threaded spacer on an opposite site of the threaded spacer where the gap is formed between the threaded spacer and the carrier frame.

9. The lens backlash reduction apparatus according to claim 1:

wherein the biasing element includes a first spring and a second spring extending from the base.

10. The lens backlash reduction apparatus according to claim 1:

wherein the biasing element includes at least three or more springs.

11. The lens backlash reduction apparatus according to claim 1:

wherein the biasing element is coupled to the carrier frame away from the threaded aperture.

12. The lens backlash reduction apparatus according to claim 1:

wherein the biasing element is adjustable.

13. The lens backlash reduction apparatus according to claim 12:

wherein the biasing element is adjustable using a mechanism to adjust a force of the biasing element.

14. The lens backlash reduction apparatus according to claim 2:

wherein the threaded spacer is an injection molded part so the thread end point on the threaded spacer is consistent during manufacture of quantities of the threaded spacer.

15. The lens backlash reduction apparatus according to claim 1:

wherein the threaded lens base includes a thread start point, the thread start point of the threaded lens base first to engage the threaded spacer and a thread end point and being rotated through a predetermined angle before engaging a thread start point of the threaded aperture.

16. The lens backlash reduction apparatus according to claim 1:

further including a lens focus fix, the lens focus fix including a ratchet portion and a lens retainer portion, the lens focus fix being rotatable to adjust a focal position of the lens.

17. A lens backlash reduction apparatus comprising:

a lens including a threaded lens base;

a carrier frame including a threaded aperture, the threaded aperture being sized to threadably receive the threaded lens base, the threaded aperture including a thread start point on the threaded aperture, and the threaded aperture including a recessed rim;

a biasing element coupled to the carrier frame, the biasing element including a base and at least one spring extending outwardly from the base, the spring having a bias end; and

a threaded spacer sized to threadably receive the threaded lens base, the threaded spacer being sized to fit at least partially within a space defined by the recessed rim, the threaded spacer being non-rotatable within the space defined by the recessed rim, the threaded spacer including a thread end point on the threaded spacer, the thread end point on the threaded spacer being rotationally offset by a predetermined angle from the thread start point on the threaded aperture when the threaded spacer is positioned within the space defined by the recessed rim.

18. The lens backlash reduction apparatus according to claim 17:

wherein when the threaded lens base is threaded into and through the threaded spacer and into the threaded aperture, a gap is formed between the threaded spacer and the carrier frame, and the bias end of the spring applies a force to the threaded spacer on an opposite site of the threaded spacer where the gap is formed between the threaded spacer and the carrier frame.

19. The lens backlash reduction apparatus according to claim 18:

wherein the bias end of the spring applies a symmetrical force to the threaded spacer.

20. The lens backlash reduction apparatus according to claim 17:

wherein the threaded lens base includes a thread start point, the thread start point of the threaded lens base first to engage the threaded spacer and the thread start point and being rotated through the threaded spacer and through a predetermined angle before engaging the thread start point of the threaded aperture.

21. The lens backlash reduction apparatus according to claim 17:

wherein the lens backlash reduction apparatus is an imaging device, the imaging device further including a vision sensor and a processor to process an image acquired by the imaging device.

22. A method for reducing lens backlash in an imaging device, the method comprising:

providing a lens including a threaded lens base;

providing a carrier frame, the carrier frame including a threaded aperture, the threaded aperture being sized to threadably receive the threaded lens base;

positioning a threaded spacer over the threaded aperture, the threaded spacer being sized to threadably receive the threaded lens base;

coupling a biasing element to the carrier frame, the biasing element including a base and at least one spring extending outwardly from the base, the spring having a bias end;

threading the threaded lens base into and through the threaded spacer and into the threaded aperture;

forming a gap between the threaded spacer and the carrier frame; and

using the bias end of the spring for applying a force to the threaded spacer on an opposite site of the threaded spacer where the gap is formed between the threaded spacer and the carrier frame, the force applied to the threaded spacer reducing the lens backlash.

23. The method according to claim 22:

further including restraining the lens with a lens focus fix, the lens focus fix contacting the lens and the carrier frame, such that rotating the lens focus fix a first distance in a first direction causes the lens to rotate a second distance in the first direction.

24. The method according to claim 22:

further including acquiring image data, and using a processor for decoding the acquired image data into a decoded image.

25. The method according to claim 22:

further including providing a thread end point on the threaded spacer and a thread start point on the threaded aperture; and

rotationally offsetting the thread end point on the threaded spacer from the thread start point on the threaded aperture by a predetermined angle.