Konishiroku Photo Industry Co., Ltd.

Hitachi, Ltd.

Other

Kijiro Suzuki

Kazuo Shiozawa

Haruji Ishihara

Michio Yagi

Ryushi Shimokawa

Kazuhisa Aratame

Yoshiharu Takahashi

A method and device for an automatic exposure control by programs, characterized in that the exposure for an object located at a long distance is controlled by a first automatic exposure control program wherein a stop varies in a range of stop value including open stop value while the exposure for an object located at a close-up distance is controlled by a second automatic exposure control program wherein the stop varies in a range of stop value exceeding a predetermined stop value. The two automatic exposure control programs are selected on the basis of an information on the distance to an object which is set manually, or on the basis of a signal delivered from a range-finder.

Method and device for automatic exposure control by programs

The present invention generally concerns an automatic exposure camera and, more particularly, one incorporating a so-called AE locking device or circuit. In such a camera, the proper or optimum exposure values are automatically determined by electronic circuitry and the exposure operation is controlled in accordance with that determination. In addition, the control circuitry by which the exposure operation is accomplished is 'locked' during the exposure so as to hold--as in a memory device--the proper exposure values determined immediately prior to the exposure operation by automatically actuating the AE locking device. The present invention provides for connection between the AE locking circuit and the warning device so as to inhibit the output of the warning device--and prevent an erroneous indication by the indicating unit--on actuation of the AE locking circuit. In the absence of this particularly advantageous feature, the 'low light' indicator would likely be actuated each time an exposure was carried out as the return mirror in the camera was upwardly pivotted. Other erroneous indications would similarly occur when the AE locking circuit was selectively used to retain an exposure determination for a subsequent photographing operation.

Automatic exposure camera

Battery voltage level warning is made according to the output signals of two detecting circuits. A first detecting circuit detects the power supply voltage having lowered to a value somewhat above the lower limit of the operation power supply voltage of an electronic system. The output thereof supplies weak battery warning. The second detecting circuit detects the power supply voltage having lowered to the lower limit level of said operation power-supply voltage. The output thereof prohibits the operation of said electronic system. Thereby, desirable battery-replacement times becomes clarified and the malfunction of said electronic system is prevented.

Battery level warning device

A camera in which the automatic exposure control is conducted on the basis of measured light information obtained in accordance with the illumination of an object to be photographed. In the camera, a type of exposure control information that is predetermined irrespective of measured light information is supplied as first exposure control information into an exposure control circuit including an analog to digital converter. Subsequently, measured light information obtained through the operation of a shutter release of the camera is supplied thereinto as second exposure control information.

Camera having an automatic exposure control means

The power supply resetting circuit of the invention is adapted to be used in such a type of camera that the shutter release action comprises two steps of strokes: a first stroke by which a power supply circuit for electric circuits mounted in the camera, such as a light measuring circuit, is closed, and a second stroke by which at least the operation of the circuits mounted in the camera is started. The power supply resetting circuit has a self-holding circuit for closing the power supply circuit and additionally mounted to the electric circuits in the camera. The self-holding circuit is adapted to be turned into operation by the second stroke of the shutter release action, substantially simultaneously with the starting of operation of the circuits mounted in the camera, and to be turned inoperative, so as to break the power supply circuit, at the instant at which the photographing sequence is completed or with a certain time lag to that instant.

Growing community of inventors

Tokyo, Japan

Kijiro Suzuki