High speed multi-focal camera
AssigneeDell Products L.P.
InventorsYi-Hsien Lin, Chih-Hao Kao, Ghee Beng Ooi
Life of this patent
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Abstract
A camera captures a visual image of an object in a rapid manner by determining a distance to the object with a time-of-flight sensor and looking up an actuator position for actuating the camera lens to a focus based upon the distance. The actuator position set by the look up table adjusts for temperature effects on focus based upon a temperature measurement associated with the lens. Visual image capture may be accomplished without image-based focus analysis, such as contrast and phase detection autofocus, by validating the distance captured with the time-of-flight sensor.
Claims18
An information handling system comprising:
- a processor operable to execute instructions to process information;
- a memory interfaced with the processor and operable to store the instructions and information;
- a time-of-flight sensor operable to detect distance to an object;
- an image sensor operable to capture light as visual information;
- an image signal processor interfaced with the image sensor and operable to define a visual image as an array of pixel values from the visual information;
- a lens aligned with the image sensor to direct light at the image sensor;
- an actuator coupled to the lens to adjust the lens position relative to the image sensor to focus the light at the image sensor;
- and
- a non-transitory memory storing instructions that when executed cause:
- detection by the time-of-flight sensor of a distance to the object;
- validation of the distance to the object;
- lookup in focal point table of an actuator position associated with focus by the lens on the object for the distance;
- actuation of the actuator to the actuator position;
- and
- capture of a visual image at the image sensor by the image signal processor;
- wherein the validation comprises analysis of the distance of the time-of-flight sensor compared against expected time-of-flight distances of facial features.
A method for capturing a visual image with a camera comprising:
- detecting by a time-of-flight sensor of a distance to an object;
- validating the distance to the object, the validating including at least analysis of a size of the object indicated by the time-of-flight sensor compared against an amount of a field of view of the lens of the object;
- looking up in a focal point table of an actuator position associated with focus by a lens on the object for the distance;
- actuating of the actuator to the actuator position;
- and
- capturing a visual image at an image sensor by an image signal processor of light passing through the lens focused on the object.
A camera comprising:
- a time-of-flight sensor operable to detect distance to an object;
- an image sensor operable to capture light as visual information;
- an image signal processor interfaced with the image sensor and operable to define a visual image as an array of pixel values from the visual information;
- a lens aligned with the image sensor to direct light at the image sensor;
- an actuator coupled to the lens to adjust the lens position relative to the image sensor to focus the light at the image sensor;
- and
- a non-transitory memory storing instructions that when executed cause:
- detection by the time-of-flight sensor of a distance to the object;
- validation of the distance to the object;
- lookup in focal point table of an actuator position associated with focus by the lens on the object for the distance;
- actuation of the actuator to the actuator position;
- and
- capture of a visual image at the image sensor by the image signal processor;
- wherein the instructions further:
- select a first actuator position within a first predetermined portion of the lens depth of field;
- capture first visual information;
- select a second actuator position within a second predetermined portion of the lens depth of field;
- capture second visual information;
- and
- compare the first visual information and the second visual information by phase detection autofocus to confirm lens focus.
Dependencies are inferred from the claim text.