Non-canting VCM-actuated autofocus
AssigneeGoogle Inc.
InventorsPhilip Sean Stetson, Guangxun Liao
Life of this patent
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Abstract
Techniques and apparatuses are described that enable non-canting VCM-actuated autofocus. These techniques and apparatuses enable multiple focal distances that are substantially free of imaging errors caused by canting of a lens housing. These multiple focal distances are provided by multiple positions of a lens housing relative to an image sensor. These positions can be free of cant through use of mechanical stops and corresponding mechanical stop-mates. By so doing, lower cost, faster focusing, higher image quality, lower power, or lower settling time can be achieved.
Claims20
A camera system comprising:
- an image sensor;
- a lens housing having:
- a lens-retention section configured to retain one or more lenses capable of focusing light from a scene onto the image sensor;
- and
- a mechanical stop-mate configured to mate with a mechanical stop;
- one or more springs;
- one or more electromagnets;
- and
- the mechanical stop, the mechanical stop configured to mate with the mechanical stop-mate effective to prevent cant of the lens housing relative to a planar cross section of at least one of the lenses, the planar cross section parallel to a plane of the image sensor, and further effective to prevent non-cant movement of an image center of the scene on the image sensor, the mechanical stop having a convex or concave structure and the mechanical stop-mate having another of the convex or concave structure.
A method comprising:
- receiving distance data for a scene;
- determining an autofocus focal position based on the distance data;
- and
- applying a force effective to move a mechanical stop-mate of a lens housing to mate with a mechanical stop, the move positioning a lens or lens stack of the lens housing into the autofocus focal position to focus the scene on an image sensor, the mate of the mechanical stop and the mechanical stop-mate prohibiting:
- cant of the lens housing;
- and
- movement of an image center of the scene on the image sensor.
A camera system configured to provide three focal positions, the camera system comprising:
- a first focal position prohibiting cant of lenses within a lens housing relative to a plane of an image sensor using a first mechanical stop and a first mechanical stop-mate, the first mechanical stop including three or more projections, the three or more projections arranged effective to define a stop plane, the stop plane parallel to the plane of the image sensor and configured to contact the first mechanical stop-mate;
- a second focal position prohibiting cant of the lenses within the lens housing relative to the plane of the image sensor using a second mechanical stop and a second mechanical stop-mate;
- and
- a third focal position between the first and second focal position, the third focal position enabling focus of a scene on the image sensor at focal distances less that the first position and greater than the second position.
Dependencies are inferred from the claim text.