Electronic still camera having mechanically adjustable CCD to effect focus
AssigneePolaroid Corporation
InventorsPaul W. Ernest, John C. Ostrowski, Massimo A. Russo
Life of this patent
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Abstract
An electronic still camera is disclosed which adjusts focus to an object image by mechanically moving an electronic sensor within the electronic still camera. The electronic sensor is moved along an optical path of the electronic still camera. In this way, the sensor follows the focal plane of the image, thus tracking a focused image.
Claims14
An electronic still camera having an optical system for focusing image-bearing light reflected from a subject along an optical path onto a sensor which converts the image-bearing light into signals representative of the subject, said electronic camera comprising:
- a sonar ranging system for producing a ranging signal representative of the distance from the subject to the sensor;
- and
- adjustment means, responsive to said ranging signal, for moving the sensor along the optical path relative to the optical system such that focus of the subject is effected, said adjustment means comprising
- a lead screw in mechanical communication with the sensor such that rotation of said lead screw about a longitudinal axis produces motion of both said lead screw and the sensor alone said longitudinal axis;
- and
- alignment means for maintaining rotational alignment of the sensor with the optical path.
A focusing system for use in an apparatus having optics through which image-bearing light from a subject passes to an electronic sensor disposed within a housing, said focusing system comprising:
- sonar ranging means for determining the range to the subject;
- processing means in electrical communication with said ranging means for determining the focal plane as a function of the range to the subject;
- a motor in electrical communication with said processing means for moving the sensor to the position of the focal plane in response to a signal from said processing means;
- and,
- a lead screw in mechanical communication with the housing such that rotation of said lead screw about a longitudinal axis produces motion of both said lead screw and the sensor along said longitudinal axis, rotation of the lead screw in a first direction applies a drive force to drive the housing toward the optics, and rotation of the lead screw in a second direction removes said drive force from the housing.
A method of focusing an electronic still camera which uses a sensor to capture image-bearing light reflected from a subject through camera optics, said method comprising the steps of:
- using sonar means to determine a range to the subject;
- determining the focal plane as a function of the range to the subject;
- and
- electrically moving the sensor to the position of the focal plane by actuating a lead screw to move both said lead screw and the sensor so as to bias the sensor against the bias of an elastic means.
Dependencies are inferred from the claim text.