Focusing control and indication of information relating to an object
First Claim
1. A video camera with an optical system including a zoom lens system and a rear lens system wherein focusing is performed by varying the distance between said rear lens system and an imaging pickup device of said video camera, comprising:
- first sensor means for sensing the position of said rear lens system to detect a relative distance between said rear lens system and said image pickup device and for producing a first detection signal indicative of the detected relative distance;
second sensor means for sensing the position of said zoom lens system to detect a focal length of said optical system and for producing a second detection signal indicative of the detected focal length;
drive means for driving said rear leans system; and
control means responsive to said first and second detection signals from said first and second sensor means for calculating a distance to an object on the basis of the detected relative distance and the detected focal length, detecting a zooming operation of said optical system on the basis of the second signal produced by said second sensor means, and, in response to the detection of the zooming operation, calculating a relative distance between said rear lens system and said image pickup device on the basis of the calculated distance to said object and the focal length detected by said second sensor means, said control means generating a control signal to supplying it to said drive means to move said rear lens system so that the relative distance obtained by the signal from said first sensor means becomes equal to the calculated relative distance.
1 Assignment
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Accused Products
Abstract
A video camera with an optical system including a zoom lens system and a rear lens system provided therebetween wherein focusing is performed by varying the distance between the rear lens system and an imaging pickup device of the video camera. The video camera further includes a first sensor for sensing the position of the rear lens system to detect a relative distance between the rear lens system and the image pickup device, a second sensor for sensing the position of the zoom lens system to detect a focal length of the optical system. An arithmetic unit provided in the video camera calculates a distance to an object on the basis of the detected relative distance and the detected focal length and, in response to zooming operation, calculates a relative distance between the rear lens system and the image pickup device on the basis of the calculated distance to the object and the focal length detected by the second sensor. The arithmetic unit generates an error signal on the basis of the difference between the calculated relative distance and the relative distance detected by the first sensor and controls the position of the rear lens system on the basis of the generated error signal.
65 Citations
9 Claims
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1. A video camera with an optical system including a zoom lens system and a rear lens system wherein focusing is performed by varying the distance between said rear lens system and an imaging pickup device of said video camera, comprising:
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first sensor means for sensing the position of said rear lens system to detect a relative distance between said rear lens system and said image pickup device and for producing a first detection signal indicative of the detected relative distance; second sensor means for sensing the position of said zoom lens system to detect a focal length of said optical system and for producing a second detection signal indicative of the detected focal length; drive means for driving said rear leans system; and control means responsive to said first and second detection signals from said first and second sensor means for calculating a distance to an object on the basis of the detected relative distance and the detected focal length, detecting a zooming operation of said optical system on the basis of the second signal produced by said second sensor means, and, in response to the detection of the zooming operation, calculating a relative distance between said rear lens system and said image pickup device on the basis of the calculated distance to said object and the focal length detected by said second sensor means, said control means generating a control signal to supplying it to said drive means to move said rear lens system so that the relative distance obtained by the signal from said first sensor means becomes equal to the calculated relative distance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification