West Electric Co., Ltd.

Toshitsugu Kashihara

Hiroshi Iwata

Tsunemi Yoshino

Akitoshi Morioka

Nobuo Yamashita

Youichi Iwai

Toshihiko Taniguchi

Kazuo Tanaka

Hirohiko Ina

Electric zoom camera wherein zooming speed is not influenced even by drop of power source voltage, by driving its zooming electric motor by an electric pulse current such that the period (T.sub.0, T.sub.1, T.sub.2, - - -) is defined by present period of a lens position signal 'b' from a lens position detector (2) which consists of a photo-interrupter and a photo-coupler, and each of the period length is divided into a first portion (Po) (off-portion) wherein motor current is off and a second portion (Pd) (duty portion) wherein the motor current is on, the length of the first portion (Po) being adjusted responding to the present zooming speed obtained from the lens position signal outputted from the lens position detector (2).

Electric zoom camera

A zoom lens apparatus comprising a moving construction for moving a zoom-ratio adjusting barrel composed of a variator-lens amount and a compensator-lens mount by the rotation along the direction of the optical axis within the fixed barrel; a stepping motor, which is coupled to the moving construction is composed of a rotor having a hollow portion as a light path including the optical axis and a stator to be combined with the rotor, and reversibly rotates in accordance with the pulse signal to be applied; and a circuit means for controlling the operation of the stepping motor with providing advantages and that the reduction gear and clutch mechanism are not required, the outer shape is kept cylindrical, but is not required bigger in size and the price can be made lower.

Zoom lens apparatus

A lens drive mechanism comprising a lens mount, a basic barrel having a compartment defined therein for accommodating the lens mount for movement in a direction parallel to the optical axis, a pin member, and a generally semicircular cross-sectioned cam member mounted so as to cover the basic barrel for rotation about the optical axis and having a cam groove defined therein with the free end of the pin member engaged in the cam groove.

Lens drive device and optical lens assembly utilizing the same

A photographic lens device with a built-in electronic aperture-stop control system or mechanism comprising a step motor and an aperture-stop setting device which are spaced apart from each other by a suitable distance in the direction of the optical axis of the photographic lens system and are coupled to each other through a coupling means. In one embodiment, the aperture-stop control system can be incorporated in the lens device simply by slightly enlarging the diameter of the lens device or barrel without increasing its axial length because of full possible use of a heretofore unused dead space available in the lens device.

Photographic lens device having a step motor mounted on the lens barrel

So far, the windows for displaying the number of frames exposed, a film speed, an aperture, a shutter speed and the like have been located at various positions on a camera body, but according to the present invention such photographic information can be displayed at the same place in the vicinity of a viewfinder or in the field of view thereof by a display device comprising an electro-optical display unit and a display information selection means adapted to cause the display unit to display the desired information.

Photographic information display device

A focus state indicator for a camera is provided such that the photographer may know a focus state in accordance with electrical signals respectively corresponding to the lens position in the previous focusing operation and a distance between a camera and a subject to be photographed. A circuit is arranged to generate a differential signal between the output electrical signals. The alarm operation of an alarm element is continuously changed between focused and out of focused states in accordance with the differential signal, so that the photographer can know the focus state.

Focus state indicator

A photographic equipment provided with a focal-length sensing means for sensing the focal length of a photographic lens mounted on a camera body and generating the electrical output signal representative of the detected focal length and a beam-angle control means responsive to the output signal from the focal-length sensing means for changing, in response to the detected focal length, the beam angle of an electronic flash unit mounted on the camera body.

Photographic equipment

Image focusing device especially adapted for use in single-lens reflex cameras. A light-beam emission or projection means is incorporated in each interchangeable photographic lens in such a way that the direction of the light beam emitted or projected therefrom can be varied in response to the axial displacement of a lens group for focusing an object. The light rays which are reflected from the object and pass through the photographic lens along and in the vicinity of its optical axis are intercepted by a photodetection means disposed within a camera body, whereby whether or not the photographic lens is sharply focused at the object can be detected.

Device for detecting sharp focusing

A photographing lens, which is to be mounted on a camera in an interchangeable manner is provided with a focus-informing means, which informs the photographer of focussings of the photographing lens during manual focussing operation thereof by buzzer or by small lamp, thereby enabling to provide a semi-automatic focussing for a conventional camera body without provision of an automatic focus adjusting means.

Photographing lens system with focus informing means

A photographic flash device comprising a main capacitor for flashing a flash discharge tube, a DC-DC converter, a constant-voltage circuit for controlling the oscillation function of the DC-DC converter and an indication means capable of discriminatively indicating states of the voltage of the main capacitor in three different voltage ranges, first range being from zero to a first predetermined voltage above which flashing is possible, second range being from a first predetermined voltage to a second predetermined voltage, the third range being from the second predetermined voltage to a third predetermined maximum voltage, respectively.

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Nara, Japan

Toshitsugu Kashihara