Fuji Photo Film Company, Limited

Hiroshi Saito

Mineo Kubota

Satoshi Mikajiri

Tsuneo Yokoyama

Naoki Takatori

Kazukiyo Tamada

Kazukyo Tamada

An automatic focussing adjusting device which controls properly an integration time necessary to integrate the amount of light received by a CCD line sensor for measuring the light of an object to detect a focal position. In the automatic focussing adjusting device, when the average value of the output data of the CCD line sensor is a value existing out of the stable operation region of the CCD line sensor, the integration in time for the amount of the light received from the object by the CCD line sensor is controlled so that the average value of the next output data of the CCD line sensor converges rapidly to the reference value of the output data to be selected in the CCD line sensor stable operation region. For the average value existing in the stable operation region, the integration time is controlled so that the average value of the next output data converges slowly to the reference value. Therefore, stable output data of the CCD line sensor can be obtained and can follow accurately the variations of the brightness of the object.

Automatic focussing adjusting device

An automatic focussing adjusting device which detects the amount of de-focussing of an image of an object to perform an automatic focussing adjustment of a taking lens of a camera including a zoom lens. The magnification m of a group of magnification varying lenses in the zoom lens is corrected and the amount of movement .DELTA.X of a group of focus lenses necessary for focussing is calculated based on a corrected magnification .alpha..multidot.m, so that a focussing adjustment can be executed. Also, an error in the amount of de-focussing, caused by manufacturing errors in dimensions defining a positional relationship between line sensors and a group of microscopic lenses in a focus detect element is corrected, and based on a correctively calculated amount of de-focussing .beta..multidot..DELTA.P, a focussing adjustment is performed.

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Kofu, Japan

Hiroshi Saito