Autofocus camera systems and methods

• US 9,625,673 B2
• Filed: 03/21/2016
• Issued: 04/18/2017
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: DigitalOptics Corporation MEMS (Adeia Inc.)
• Original Assignee: DigitalOptics Corporation MEMS (Adeia Inc.)
• Inventors: Gutierrez, Roman C., Calvet, Robert J., Harrington, Darrell, Wang, Guiqin, Jayaraj, Kumaraswamy
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): Fenwick, Warren K
• Application Number:
  US15/076,383
• Publication Number:
  US 20160202447A1
• Time in Patent Office: 393 Days
• Field of Search: 396133, 359694, 359824
• CPC Class Codes: G02B 13/001 Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras G02B23/243 takes precedence
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G02B 7/09 adapted for automatic focusing or varying magnification
• CPC Class Codes: G03B 13/36 Autofocus systems
• CPC Class Codes: G03B 17/02 Bodies
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A method for focusing a miniature camera includes providing a current through a coil, moving a lens of a camera based on the current to adjust a focus of the camera, and limiting movement of the lens along an optical path of the camera.

Claims

1. A method, comprising:

providing a variable current through a coil; and

moving an optical element, based on the current, with respect to an image sensor, the optical element being disposed on a stage comprising a magnet resiliently suspended adjacent to the coil for movement relative to the coil; and

wherein

the coil is wound around an axis that is perpendicular to a direction of movement of the optical element; and

the direction of movement of the optical element comprises a direction of movement toward and/or away from the image sensor along an optical axis of the optical element.

2. The method of claim 1, wherein:

the optical element comprises a lens disposed on a ring shaped lens mount;

the lens mount is disposed on the stage; and

the stage is constrained by a snubber mechanism against movement other than rectilinear movement along an axis that is parallel to an optical axis of the lens.

3. The method of claim 1, wherein the stage comprises a micro

electromechanical systems (MEMS) stage.

4. The method of claim 1, wherein

the stage moves with the optical element;

and

the stage remains within a plane defined by the stage itself when the stage moves.

5. The method of claim 4, wherein the magnet and the optical element are disposed on opposite sides of the stage.

6. The method of claim 1, further comprising:

providing a housing around the optical element; and

attaching the coil to the housing, whereby the coil is aligned relative to the magnet by the housing.

7. The method of claim 1, further comprising controlling the current through the coil using a processor to adjust the focus of an image on the image sensor.

8. A device, comprising:

an imaging sensor;

a coil;

circuitry for providing a variable current through the coil; and

an optical element disposed on a stage comprising a magnet resiliently suspended adjacent to the coil for movement relative to the coil; and

wherein

the coil is wound around an axis that is perpendicular to a direction of movement of the optical element; and

the direction of movement of the optical element comprises a direction of movement toward and/or away from the imaging sensor along an optical axis of the optical element.

9. The device of claim 8, wherein the optical element comprises a lens disposed on a ring shaped lens mount, wherein the lens mount is disposed on the stage, and wherein the stage is constrained by a snubber mechanism against movement other than rectilinear movement along an axis that is parallel to an optical axis of the lens.

10. The device of claim 8, wherein the stage comprises a micro electromechanical systems (MEMS) stage.

11. The device of claim 8, wherein:

the stage moves with the optical element; and

the stage remains within a plane defined by the stage itself when the stage moves.

12. The device of claim 8, wherein the magnet and the optical element are attached to the stage in a planar fashion.

13. The device of claim 12, wherein the magnet and the optical element are disposed on opposite sides of the stage.

14. The device of claim 8, further comprising:

a housing around the optical element; and

wherein

the housing holds the coil and aligns the coil relative to the magnet.

15. A method, comprising:

coupling an optical element to a magnet via a stage; and

suspending the magnet adjacent to a coil via the stage so that the optical element and the magnet move conjointly in response to a variable current through the coil; and

wherein

the coil is wound around an axis that is perpendicular to a direction of movement of the optical element; and

the direction of movement of the optical element comprises a direction of movement toward and/or away from an imaging sensor along an optical axis of the optical element.

16. The method of claim 15, wherein:

the optical element comprises a lens disposed on a ring shaped lens mount;

the lens mount is disposed on the stage; and

the stage is constrained by a snubber mechanism against movement other than rectilinear movement along an axis that is parallel to an optical axis of the lens.

17. The method of claim 15, wherein the stage comprises a micro electromechanical systems (MEMS) stage.

18. The method of claim 15, wherein the stage remains within a plane defined by the stage itself when the stage moves conjointly with the magnet and the optical element.

19. The method of claim 15, wherein the step of coupling the optical element to the magnet via the stage comprises assembling the stage, the magnet, and the optical element in a stacked fashion.

20. The method of claim 19, wherein the magnet and the optical element are disposed on opposite sides of the stage.

21. The method of claim 15, further comprising:

providing a housing around the optical element; and

attaching the coil to the housing, whereby the coil is aligned relative to the magnet by the housing.