Minolta Company, Ltd.

Junji Takahata

Koutaro Kawabe

Hiroshi Ueda

Toshihito Kido

Masayuki Nakasa

Hironori Kamishita

A driving apparatus, employing a piezoelectric element, for smoothly and silently driving a focus lens of a camera over a wide range of its driving speed. The driving apparatus includes a control system for controlling the piezoelectric element in such a manner that a continuous supply of a certain number of drive pulses to the piezoelectric element and a non-supply thereof during a certain period of time are repeated by a &ldquo;block pulse drive&rdquo; at time of slow speed driving, and that the continuous supply thereof are continuously supplied to the piezoelectric element by a &ldquo;continuous pulse drive&rdquo; at time of high speed driving.

Drive mechanism employing electromechanical transducer, photographing lens with the drive mechanism, and its drive circuit

In addition to a focus detecting sensor for phase difference detection, a camera is provided with a light source or a generator for emitting light or ultrasonic waves, and a light receiver or a receiver for receiving the light or the ultrasonic waves reflected from the object. The distance to the object is detected from the intensity of the reflected light or ultrasonic waves and the focusing lens is set at a position close to the in-focus position. Then, the driving range of the focusing lens is limited in accordance with the detected distance, and from the set focusing lens position, focusing by the phase difference detection method is performed within the limited driving range.

Camera

An apparatus provided with a magnetic head including a core, a writing coil and a reading coil wound around the core; a writing circuit connected with the writing coil for driving the writing coil; a reading circuit connected with the reading coil for generating a read signal based on an output of the reading coil; a power source for supplying an electric power to the writing circuit; and a controller for suspending the supply of electric power to the writing circuit when the reading circuit is in operation.

Growing community of inventors

Sakai, Japan

Junji Takahata