Abstract: In a reflex camera having a penta prism positioned in the view-finder thereof, there is provided a glass member having a reflactive index equal to or larger than that of the penta prism and positioned in intimately contacting relation with the exit surface of said penta prism to utilize that portion of a view-finder image forming light beam which is directed to the exit surface of said penta prism after successive reflection from the two roof surfaces, the front reflection surface and again the roof surfaces of the penta prism such light beam portion would be otherwise subject to the total reflection from the exit surface in vain in measuring the light at a central portion of the view-finder image as well as at any portions outside thereof. In this way it being made possible to operate the camera selectively in a spot-metering mode or overall field of view light metering mode by the use of a single light value sensing means without causing the reduction of quality of the view-finder image.

Abstract: An exposure control device in which the output of a light measuring circuit which produces an electrical signal corresponding to the brightness of an object is compared with an output of a level signal circuit which produces an electrical signal of a predetermined level. When the compared value reaches a predetermined value, a flash circuit is made ready to flash, whereby the shutter time is changed over to a predetermined time suited for a flash photography and the flash circuit is made to flash in association with the shutter operation and the shutter is controlled with a constant time.

Abstract: In an image information recording apparatus which comprises a laser oscillator, means for deflecting and modulating the laser beam from the laser oscillator by an external signal, a recording medium, optical means for imaging the modulated laser beam on the recording medium and means for causing the laser beam to scan over the recording medium, the light path of the laser beam is divided into a plurality of light path sections and partition plates are provided before and behind each of the light path sections and have holes formed at the portions thereof corresponding to the center of the optical axis. Thus, the optical axis in the apparatus may be adjusted by passing the laser beam through the center of the holes in the partition plates.

Abstract: An exposure control apparatus which can set accurate shutter speed constantly irrespective of changes in ambient temperature and which can eliminate not only an error in shutter speed caused by an expansion semiconductor element but also an error in shutter speed caused by the variation in output characteristics due to variation in temperature of a compression circuit.

Abstract: An object image is formed on a screen by an objective lens. The light beam from the object image formed on the screen is guided in a direction to an eye piece by a pentagonal roof prism. Only one light measuring means is provided facing an upper part of the exit face of the pentagonal roof prism. Therefore, the light beam from the screen passing through the upper part of the pentagonal roof prism impinges into the light measuring means. Also the light beam from the screen passing through both left and right end parts of the exit face of the pentagonal roof prism is directed onto the light-measuring means through a reflective plane. A shutter means is provided at least for one of the luminous flux from the upper part of the pentagonal roof prism and the luminous flux from the both left and right end parts. The light measurement distribution in an object scene may be varied by the shutter means.

Abstract: The present invention relates to an exposure control apparatus for a camera which is so designed that the output terminal of the light measuring circuit of the brightness of the object to be photographed having a photo electric transducing means is connected to one input terminal of an operation amplifier. The output of the photographing information setting circuit, having a variable resistance means for setting other photographing informations than the information of the brightness of the object to be photographed, is connected to the other input terminal of the above mentioned operation amplifier. This is done in such a manner that proper exposure conditions can be obtained by means of the output of the exposure control circuit connected to the output of the above mentioned operation amplifier. Each input signal to the operational amplifier is adjusted by a bias signal which is controlled in accordance with ambient temperature conditions.

Abstract: In the photographic apparatus disclosed a long-exposure adapter is attached to a camera to lengthen the camera's shutter operating times. When the camera's light sensing system responds to a low illumination by setting the shutter time to B (infinite time), an operator shifts to the long exposure range. The adapter then responds to a high sensitivity sensor and a long exposure timing device in the adapter is adjusted for the low illumination. The adapter then operates the shutter release of the camera, which has been set to B to obtain long exposures.

Abstract: An optical system for a television camera provided with a device for emitting bias-light which is directed to the image pickup tube. Rays of light coming from a light source and entering a light guide plate at a side edge thereof are guided through the interior of the plate toward the opposite side edge after a number of successive total internal reflections from the two boundary surfaces of the plate. The surface of the plate near to the image pickup tube is provided with a diffraction grating formed therein to diffract a fraction of the light rays entering the plate, and to direct it toward the image pickup tube, thereby the image pickup tube is illuminated by the diffracted rays of light.