Camera Module with EMI Shield

• US 20140043519A1
• Filed: 08/10/2012
• Published: 02/13/2014
• Est. Priority Date: 08/10/2012
• Status: Active Grant

• Current Assignee: Nanchang Oufei Photoelectric Technology Company Limited
• Original Assignee: DigitalOptics Corporation (Adeia, Inc.)
• Inventors: Azuma, Eddie, Liu, Chih Yen, Yu, Emerson, Hsieh, David, Tsai, Josh
• Granted Patent: US 9,007,520 B2
• Time in Patent Office: Days
• US Class Current: 348/345
• CPC Class Codes: G02B 7/09 adapted for automatic focusing or varying magnification
• CPC Class Codes: G02B 7/102 controlled by a microcomputer cameras with interchangeable lenses G03B17/14
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04N 23/51 Housings
• 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: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices

Abstract

A compact camera module has an EMI housing configured to shield camera module components from electromagnetic interference and having defined therein a focus-adjustment aperture to permit an optical train to extend to at one end of an auto-focus range, and a light leak baffle partially overlaps the focus-adjustment aperture along the optical path outside the auto-focus range.

Claims

1. A compact camera module, comprising

an image sensor configured to couple to a flexible printed circuit to power the camera module and transmit images captured at the image sensor;

an optical train aligned with the image sensor that includes multiple lenses including at least one movable lens coupled to an actuator to form an optical system that is configured to automatically adjust a position of the at least one movable lens along the optical path to focus an object disposed within an auto-focus range of the camera module onto the image sensor;

an EMI housing configured to contain the optical train and to shield camera module components from electromagnetic interference (EMI), the EMI housing having defined therein a focus-adjustment aperture that is large enough to permit an object end of the optical train to at least partially protrude therethrough at one end of the auto-focus range; and

a light leak baffle that has a baffle aperture defined therein that partially overlaps the focus-adjustment aperture along said optical path, the light leak baffle comprising EMI shield material that partially overlaps the focus adjustment aperture in the direction of the optical path but outside said one end of the auto-focus range.

2. The compact camera module of claim 1, further comprising a lens barrel containing therein one or more of the multiple lenses including the at least one movable lens.

3. The compact camera module of claim 1, wherein the EMI housing comprises an EMI coating.

4. The compact camera module of claim 1, wherein the light leak baffle comprises a conductive material that provides EMI shielding for camera module components.

5. The compact camera module of claim 4, wherein the conductive material of the light leak baffle comprises carbon.

6. The compact camera module of claim 1, further comprising a conductive glue for coupling the light leak baffle to the housing.

7. The compact camera module of claim 1, wherein the light leak baffle is disposed outside the housing.

8. The compact camera module of claim 1, further comprising a pair of conductive traces inside the EMI housing electrically connecting a pair of contact pads of said actuator with a pair of contact pads on said flexible printed circuit.

9. The compact camera module of claim 8, wherein a FPC segment adjacent the segment to which the sensor is coupled is folded to enclose a side wall of the compact camera module.

10. The compact camera module of claim 1, further comprising a flexible printed circuit (FPC) extension coupled to the light leak baffle and having a pair of contact pads that electrically connect to a pair of contact pads of said actuator when the FPC is folded around said compact camera module.

11. The compact camera module of claim 10, wherein a middle FPC segment between the segment to which the sensor is coupled and the FPC extension segment encloses a side wall of the compact camera module when the FPC is folded around said compact camera module.

12. The compact camera module of claim 1, further comprising one or more shock absorbing sponges including shock absorbing sponge material disposed between the EMI housing and an interior housing that contains the optical train on at least two sides of the interior housing;

and wherein one or more sponge compression gaps are defined between the EMI housing and the interior housing in a Z-direction approximately parallel to the optical path to permit relative movement of the EMI housing towards the interior housing without contact during compression of the one or more shock absorbing sponges due to a Z-component of an external shock to the compact camera module.

13. A compact camera module, comprising

a compact optical module coupled to a sensor module,

wherein the compact optical module comprises

an optical train including multiple lenses and including at least one movable lens coupled to an actuator to form an optical system that is configured to automatically adjust a position of the at least one movable lens along the optical path to focus an object disposed within an auto-focus range of the camera module onto an image sensor that is aligned with the optical train;

an EMI housing configured to contain the optical train and to shield camera module components from electromagnetic interference (EMI), the EMI housing having defined therein a focus-adjustment aperture that is large enough to permit an object end of the optical train to at least partially protrude therethrough at one end of an auto-focus range; and

a light leak baffle including a baffle aperture defined therein that overlaps the focus-adjustment aperture along said optical path, the light leak baffle comprising EMI shield material that partially overlaps the focus adjustment aperture outside said one end of the auto-focus range; and

wherein the sensor module comprises an image sensor that is aligned with the compact optical module and is coupled to or is configured to couple to a flexible printed circuit to power the camera module and transmit images captured at the image sensor.

14. The compact camera module of claim 13, wherein the sensor module comprises a fixed lens coupled along the optical path just before the image sensor.

15. The compact camera module of claim 13, further comprising a lens barrel containing the optical train including the at least one movable lens.

16. The compact camera module of claim 13, wherein the EMI housing comprises an EMI coating.

17. The compact camera module of claim 13, wherein the light leak baffle comprises a conductive material that provides EMI shielding for camera module components.

18. The compact camera module of claim 17, wherein the conductive material of the light leak baffle comprises carbon.

19. The compact camera module of claim 13, further comprising a conductive glue for coupling the light leak baffle to the housing.

20. The compact camera module of claim 13, wherein the light leak baffle is disposed outside the housing.

21. The compact camera module of claim 13, further comprising a pair of conductive traces inside the EMI housing electrically connecting a pair of contact pads of said actuator with a pair of contact pads on said flexible printed circuit.

22. The compact camera module of claim 21, wherein a FPC segment adjacent the segment to which the sensor is coupled is folded to enclose a side wall of the compact camera module.

23. The compact camera module of claim 13, further comprising a flexible printed circuit (FPC) extension coupled to the light leak baffle and having a pair of contact pads that electrically connect to a pair of contact pads of said actuator when the FPC is folded around said compact camera module.

24. The compact camera module of claim 23, further comprising a middle FPC segment, disposed between the segment to which the sensor is coupled and the FPC extension segment, that encloses a side wall of the compact camera module when the FPC is folded around said compact camera module.

25. The compact camera module of claim 13, further comprising one or more shock absorbing sponges, disposed between the EMI housing and an interior framework containing the optical train, that include shock absorbing sponge material on at least two interior sides of the EMI housing;

and wherein one or more sponge compression gaps are defined between the EMI housing and the interior framework in a Z-direction approximately parallel to the optical path of the camera module, said one or more gaps being configured to permit relative movement of the EMI housing towards the interior framework during compression of the one or more shock absorbing sponges which thereby absorb a Z-direction component of an external shock to the camera module without overlapping the optical train nor the interior framework.

26. A compact optical module configured for coupling with an image sensor component of an auto focus digital camera module, the compact optical module comprising:

an optical train of multiple lenses disposed within a lens barrel and including at least one movable lens coupled to an actuator to form an optical system that is configured to automatically adjust a position of the at least one movable lens along the optical path to focus an object disposed within an auto-focus range of the camera module onto an image sensor component to which the compact optical module is coupled;

an EMI housing configured to contain the optical train and to shield camera module components from electromagnetic interference (EMI) and defining a focus-adjustment aperture that is large enough to permit an object end of the lens barrel to at least partially protrude therethrough at one end of an auto-focus range; and

a light leak baffle that has a baffle aperture defined therein that overlaps the focus-adjustment aperture along the optical path and that includes EMI shield material that partially overlaps the focus adjustment aperture outside of said one end of the auto-focus range of the lens barrel.

27. The compact optical module of claim 26, wherein the compact optical module comprises one or more passive alignment features configured to couple with one or more complementary features of an image sensor module to couple and align the compact optical module and the image sensor module.

28. The compact optical module of claim 26, wherein the EMI housing comprises an EMI coating.

29. The compact optical module of claim 26, wherein the light leak baffle comprises a conductive material that provides EMI shielding for optical module components.

30. The compact optical module of claim 29, wherein the conductive material of the light leak baffle comprises carbon.

31. The compact optical module of claim 26, further comprising a conductive glue for coupling the light leak baffle to the EMI housing.

32. The compact optical module of claim 26, wherein the light leak baffle is disposed outside the housing.

33. The compact optical module of claim 26, further comprising a pair of conductive traces inside the EMI housing configured for electrically connecting a pair of contact pads of said actuator with a pair of contact pads on a flexible printed circuit (FPC) when a sensor component that is coupled to the compact optical module, to form a compact camera module, is itself coupled to the FPC.

34. The compact optical module of claim 33, wherein an open side wall is defined in the compact optical module that is configured to be enclosed by a folded FPC segment adjacent the segment to which the sensor is coupled.

35. The compact optical module of claim 26, wherein the actuator comprises a pair of contact pads configured to electrically connect to a pair of contact pads on a flexible printed circuit (FPC) extension segment that is coupled to the light leak baffle when the FPC is folded around a compact camera module formed by coupling a sensor module to the compact optical module and when the sensor module is coupled to the FPC at a different segment spaced apart from the FPC extension segment.

36. The compact optical module of claim 35, wherein an open side wall is defined in the compact optical module that is configured to be enclosed by a folded middle FPC segment, disposed between the segment to which the sensor is coupled and the FPC extension segment, when the FPC is folded around said compact camera module formed by coupling said sensor module with said compact optical module.

37. The compact optical module of claim 26, further comprising one or more shock absorbing sponges disposed between the EMI housing and a molded framework containing the lens barrel, including shock absorbing sponge material on at least two sides of the lens barrel;

and wherein one or more sponge compression gaps are defined between the EMI housing and the molded framework permitting relative movement of the EMI housing in the Z-direction during sponge compression due to an external shock without sponge material overlapping the optical train nor molded framework.