The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 1978
Filed:
May. 20, 1976
Keisuke Maeda, Osaka, JA;
Akira Yamanaka, Sakai, JA;
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
A camera accommodating film cartridges having structural signals differently configured according to the corresponding film speeds and selectively accepting a photoflash unit with a predetermined high guide number and a photoflash unit with a predetermined low guide number is provided with an automatic diaphragm mechanism which, in flashbulb photography, adjusts the aperture according to the object to camera distance. The camera includes a luminosity attenuator for guide number compensation and a luminosity attenuator for film speed compensation, each attenuator being displaceable between a nonattenuating position displaced from the camera objective light path and an attenuating position in said light path. Internal of the camera is a first sensor for differential detection of the guide number classification of a photoflash unit to be mounted on the camera for flashbulb photography. The luminosity attenuator for guide number compensation is operatively associatable with the first sensor and assumes the attenuating position only when the sensor has detected the mounting of a photoflash unit with the predetermined high guide number. The camera includes a second sensor for reading the film speed of the cartridge loaded in the camera from the cartridge signal structure. The light attenuator for film speed compensation is operatively associated with the second sensor so that the former assumes the luminosity attenuating position when the second sensor has detected a film speed higher than the preset camera speed rating or when, with a photoflash unit mounted, the second sensor has detected a higher film speed. The camera is such that both the guide number and film speed setting or compensating functions are automatically performed in flashbulb photography.