Focus detection device and method

Details Focus detection device and method Focus detection device and method

1997-03-26

1998-06-09

Blankenship, Howard B.

Photography

Having variable focal length of camera objective

Power zoom

396 85, 396 86, 396 81, 396104, 396135, 396 95, 2502012, G03B 1336, G03B 300

Patent

active

057650519

ABSTRACT:
A focus detection device and method permits the shooting lens to follow the movement of the photographic object without a focussing delay due to the calculation time and the movement of the object. The system includes a camera, a shooting lens, a focus detection device for detecting a desired focussing position of the shooting lens for an object, and a communications circuit. The lens includes a shooting lens driving circuit moving the shooting lens to focus, a shooting lens driving control circuit that controls the shooting lens driving circuit, a monitoring circuit that monitors the shooting lens movement by the shooting lens driving circuit, and a shooting lens data memory circuit that stores camera data. The camera includes a focal point detection circuit detecting a position of the shooting lens that matches the desired focussing position, a delay amount correction circuit updating the control amount of the amount calculation circuit to an updated control amount as a result of a delay in calculating the shooting lens control amount, and a shooting lens control amount calculation circuit calculating a control amount to drive the shooting lens to the desired focussing state, the control amount based on the focal point detection circuit detecting when the focussing position the shooting lens matches the desired focussing position and the shooting lens movement. The communications circuit communicates the lens to the with the camera. Focussing is accomplished by transmitting the updated control amount to the shooting lens and moving the shooting lens accordingly.

REFERENCES:
patent: 4967224 (1990-10-01), Hamada et al.
patent: 4969003 (1990-11-01), Ohnuki et al.
patent: 5005040 (1991-04-01), Norita et al.
patent: 5065175 (1991-11-01), Suzuki et al.
patent: 5079581 (1992-01-01), Kadohara et al.
patent: 5179407 (1993-01-01), Kusaka et al.
patent: 5208625 (1993-05-01), Suekane
patent: 5448051 (1995-09-01), Yamano
patent: 5448329 (1995-09-01), Nakata

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