Polaroid Corporation

John W Stempeck

Seymour Ellin

Richard J Coppa

An electronic viewfinder for an electronic imaging still camera may be selectively operated in either an electronic viewfinder mode in which electronic image data sensed by the photoresponsive sensing elements of the camera is transmitted to provide a video display of the scene within the field of view of the camera or, alternatively, an optic viewfinder mode in which the image defining scene light rays are optically transmitted for direct viewing of the scene within the field of view of the camera by the camera operator. The optic viewfinder mode of operation is automatically initiated during the time in which the image defining data is transmitted from the image sensing elements to the image data storing elements and the viewfinder is inoperative to provide its video display.

Electronic viewfinder

A photographic camera having both automatic and manual focusing modes of operation includes apparatus for establishing an electrical signal representative of lens focus position for lens focusing related purposes when in its automatic focusing mode of operation, is capable of generating this electrical signal for camera functions other than lens focusing by automatically positioning the lens from its initial manually focused position to a reference position and then back to its initial position, when the camera is operated in its manual focus control mode.

Auto/manual camera employing common lens focusing data

A safety switch arrangement is provided for an electronic flash for automatically discharging the main storage capacitor in response to the user deliberately or inadvertently removing the cover from the flash housing. The electronic flash is of any ordinary type comprising a DC-to-DC converter with a step-up transformer and the safety switch arrangement is connected to discharge the main storage capacitor through the secondary winding of the DC-to-DC converter transformer thereby eliminating the need for a separate bleeder resistor.

Electronic flash with safety switch feature

A system for automatically controlling the charging operation of an electronic flash in a photographic apparatus operates to enable the electronic flash to charge in response to readying the camera in anticipation to implementing a photographic exposure cycle and thereafter disabling the charging of the electronic flash as soon as the electronic flash reaches its full charge condition. The control system responds to the subsequent actuation of the camera to initiate a photographic exposure cycle to reenable the electronic flash to again become fully charged. After the electronic flash is fully charged, it is again disabled from further charging during the remainder of the photographic exposure cycle.

Photographic system for automatically charging electronic flash

A photographic camera exposure and flash fire control system provides for a proportional fill flash by firing an electronic flash or strobe at an aperture appropriate for the camera-to-subject range. The flash is fired during the closing movement of the shutter blade mechanism and subsequent to the integration of ambient scene light to a select proportion of the optimum film exposure value whereby the remaining proportion of the optimum film exposure value is provided by the artificial illumination from the flash during the closing of the shutter blades.

Follow focus flash arrangement

An exposure control system for photographic apparatus of a variety utilizing a pulse driven stepper motor to drive the light regulating elements of an exposure mechanism. The control system utilizes an exposure evaluating network, the output signal from which is converted to binary form and compared against the count output of counter means driven at a predetermined frequency. The system operates to count at one pulse frequency while simultaneously driving the stepper motor at a submultiple frequency until equality is reached with the binary representation. Supplementary counting continues at the one frequency in response to any deviation between the value of exposure derived by the exposure mechanism elements and the value of exposure represented by the binary representation. The deviation is accommodated for by a digitally derived delay corresponding therewith. In effect, a vernier form of binary regulation of exposure is provided.

Growing community of inventors

Reading, MA, United States of America

John W Stempeck