MEMS auto focus miniature camera module with fixed and movable lens groups

• US 9,817,206 B2
• Filed: 03/21/2016
• Issued: 11/14/2017
• Est. Priority Date: 03/10/2012
• Status: Active Grant

• Current Assignee: DigitalOptics Corporation (Adeia Inc.)
• Original Assignee: DigitalOptics Corporation (Adeia Inc.)
• Inventors: Lipson, Ariel, Kinrot, Uri, Bahar, Dalit, Kriman, Moshe, Levy, Moshe, Ward, Ocie, Harland, Mark
• Primary Examiner(s): HSU, AMY R
• Application Number:
  US15/076,467
• Publication Number:
  US 20160202449A1
• Time in Patent Office: 603 Days
• 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 13/009 having zoom function
• 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: G02B 7/10 by relative axial movement of several lenses, e.g. of varifocal objective lens
• CPC Class Codes: G02B 7/282 Autofocusing of zoom lenses
• CPC Class Codes: G03B 2205/0046 Movement of one or more optical elements for zooming for optical zoom lenses in general G02B7/10
• CPC Class Codes: G03B 2205/0053 Driving means for the movement of one or more optical element
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A MEMS auto focus miniature camera module includes an image sensor and an optical train including at least one movable lens and one or more fixed lenses or fixed lens groups on either side of the movable lens. The movable lens provides an auto focus feature of the camera module. A MEMS actuator translates the movable lens through an auto focus range to adjust focus.

Claims

1. A camera module comprising:

a housing;

an image sensor disposed within said housing;

an actuator disposed within said housing; and

an optical train at least partially disposed within said housing, said optical train including

a first fixed lens group,

a second fixed lens group comprising a special lens nearest said image sensor, said special lens having different magnification near its center than near its periphery, and

at least one movable lens disposed between said first and said second fixed lens groups and being coupled to said actuator; and

wherein

said actuator is fixedly aligned to said first and said second fixed lens groups; and

said actuator is configured to move said at least one movable lens relative to said image sensor and said first and said second fixed lens groups in an auto-focus operation of said camera module.

2. The camera module of claim 1, wherein said first fixed lens group comprises at least two fixed lenses.

3. The camera module of claim 2, wherein said second fixed lens group comprises at least two fixed lenses.

4. The camera module of claim 3, wherein said at least one movable lens is disposed in the middle between two pairs of fixed lenses.

5. The camera module of claim 1, wherein said actuator is fabricated in silicon.

6. The camera module of claim 1, wherein said actuator has a range of motion of not more than 350 μ

m.

7. The camera module of claim 1, further comprising:

a substrate having said image sensor mounted thereon; and

a lens holder having said optical train and said actuator mounted therein; and

wherein

said housing comprises a sleeve mounted on said substrate; and

said sleeve is disposed around said image sensor and is configured to adjustably receive said lens holder therein.

8. The camera module of claim 1, wherein:

said actuator is fixedly aligned to one of said first and said second fixed lens groups using passive alignment features; and

said actuator is affixed to the other of said first and said second fixed lens groups following an active alignment process therebetween.

9. The camera module of claim 8, wherein said at least one movable lens is passively aligned to said actuator.

10. The camera module of claim 9, wherein:

said actuator is actively aligned with said second fixed lens group; and

said second fixed lens group is disposed on a side of said at least one movable lens nearest said image sensor.

11. The camera module of claim 1, wherein:

said first fixed lens group comprises a lens L1 and a lens L2, said at least one movable lens comprises a single lens L3, and said second fixed lens group comprises a lens L4 and a lens L5;

said optical train further includes

a first optical stop on an image side of said lens L1 and

second optical stops on a scene side of each of said lenses L3, L4, and L5; and

said second optical stop provided on said lens L3 is configured to move in tandem with said lens L3.

12. The camera of claim 1, wherein said special lens comprises a complex meniscus lens.

13. The camera of claim 1, wherein said optical train is configured to be installed in said housing as a pre-aligned, unitary component.

14. An auto-focus camera module comprising:

a housing;

an image sensor disposed within said housing;

a micro-electro-mechanical systems (MEMS) actuator disposed within said housing; and

an optical train at least partially disposed within said housing, said optical train including

a first fixed lens group,

a second fixed lens group nearest said image sensor, said second fixed lens group comprising a special lens nearest said image sensor, said special lens having different magnification near its center than near its periphery, and

a movable lens group disposed between said first and said second fixed lens groups, said movable lens group being coupled to said MEMS actuator; and

wherein

said MEMS actuator is configured to move said movable lens group relative to said image sensor and said first and said second fixed lens groups in an auto-focus operation of said camera module; and

said MEMS actuator has a rest position and is driven from said rest position in only one dimension.

15. The auto-focus camera module of claim 14, wherein said optical train comprises an even number of fixed lenses.

16. The auto-focus camera module of claim 14, wherein said MEMS actuator is fabricated in silicon.

17. The auto-focus camera module of claim 16, wherein said MEMS actuator and at least a portion of said optical train define a pre-aligned, unitary component.

18. A camera module comprising:

a housing;

an image sensor disposed within said housing;

an actuator disposed within said housing; and

an optical train at least partially disposed within said housing, said optical train including

a first fixed lens group comprising a lens L1 and a lens L2,

a single movable lens L3,

a second fixed lens group comprising a lens L4 and a lens L5, said single movable lens L3 being disposed between said first and said second fixed lens groups and being coupled to said actuator,

a first optical stop on an image side of said lens L1, and

second optical stops on a scene side of each of said lenses L3, L4, and L5, said second optical stop provided on said lens L3 being configured to move in tandem with said lens L3; and

wherein

said actuator is fixedly aligned to said first and said second fixed lens groups; and

said actuator is configured to move said single movable lens L3 relative to said image sensor and said first and said second fixed lens groups in an auto-focus operation of said camera module.

19. The camera module of claim 18, further comprising:

a substrate having said image sensor mounted thereon; and

a lens holder having said optical train and said actuator mounted therein; and

wherein

said housing comprises a sleeve mounted on said substrate; and

said sleeve is disposed around said image sensor and is configured to adjustably receive said lens holder therein.

20. The camera module of claim 18, wherein:

said actuator is fixedly aligned to one of said first and said second fixed lens groups using passive alignment features; and

said actuator is affixed to the other of said first and said second fixed lens groups following an active alignment process therebetween.