Canon Kabushiki Kaisha

Takashi Kobe

Takayuki Tsuboi

Ryuji Tokuda

Yoshihiro Harunari

Masanori Ohtsuka

A device for braking an electric motor as the drive source of an operating mechanism in camera by means of an electrical circuit is disclosed. This circuit includes a detector for levels of the rotation speed of the motor or of factors of influencing the rotation speed sensed when the motor is supplied with current flowing in a direction to activate the operating mechanism, and control means responsive to the output of the detector for altering the time for which a current flow of reversed direction is supplied to brake the motor.

Brake device for motor in camera

A camera including shutter blades; a driving device which, upon receipt of electric energy, drives the shutter blades to open; an optical detecting device for optically detecting the operating state of the shutter blades; and a control circuit which controls the opening speed of the shutter blades by changing the amount of electric energy supplied to the driving device in response to the output of the optical detecting device.

Camera

The present invention relates to an exposure control automatic device for a camera. A shutter controls the amount of the exposure; a detector detects the operation speed of the shutter and calculator device compares an output of the detector with a predetermined speed information to determine the exposure time.

Automatic exposure control device

In a distance measuring device which has a semiconductor position sensor or the like employed as a light receiving element and which produces two different signals corresponding to the incident angles of a light coming from an object, the signals from the light receiving element are supplied, one after another, to a dual-slope type integrator such as a Miller integrator. A length of time required for reverse integration of the dual-slope type integrator is measured. Distance to the object is computed on the basis of the measured time.

Distance measuring device

An input circuit which converts currents produced from a plurality of photo-sensitive elements arranged in a distance measuring apparatus. The input circuit has a switching element series connected to at least one of the photo-sensitive elements. When the switching element is operated, the output current of one of the photo-sensitive elements is supplied to a converting circuit which converts current into a voltage. Only one converting circuit is present. The output of the converting circuit is produced in a time series to a computing circuit. The computing circuit processes the signal thus received and produces a signal corresponding to an object distance.

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Yokohama, Japan

Takashi Kobe