Abstract: In a through-the-lens, single lens reflex camera wherein light reflected from an object to be photographed is intercepted when a quick-release mirror jumps up in response to the depression of a shutter button to one of a plurality of positions, a system for generating and supplying a voltage signal corresponding to the intensity of the reflected light for use in a circuit for opening and closing the camera shutter or a circuit for opening or closing the camera diaphragm. An input pulse generator generates an input pulse signal having a first frequency related to the intensity of the light reflected from the object to be photographed and a reference pulse generator generates a reference pulse signal having a second frequency.

Abstract: This invention provides for automatically adjusting the diaphragm opening in a camera having a shutter operated in an automatic manner for controlling exposure time, so as to counteract such problems as the exposure time being adjusted to the point within its adjustability range at which slight hand movements result in a blurred photograph. A camera embodying the invention includes diaphragm driving circuitry responsive to a drive control signal, such as a sequence of drive pulses, supplied thereto, and a digital circuit arrangement for selectively applying the drive control signal to cause the diaphragm opening to be adjusted from a manual presetting thereof to a setting that, under prevailing lighting conditions, is consistent with an acceptable range of exposure times.

Abstract: In an automatic focusing system having an objective spaced an adjustable distance from an image plane, two variable frequency oscillators, each controlled by a separate photoconductor element, produce two variable-frequency signals that have substantially the same frequency when light passing through the objective is brought into focus at the image plane. The two variable-frequency signals are compared, and, upon detecting a difference in frequency between them, the spacing between the objective and the image plane is adjusted to a relative position at which the frequencies thereof are substantially the same.

Abstract: This invention provides apparatus for producing a command signal used to control the closing of a camera shutter. Before the shutter opens, a photo-responsive portion of the apparatus generates a number of serially occurring data pulses. After the shutter opens, a timing pulse generator portion produces a number of serially occurring timing pulses. A memory portion, including a plurality of registers, accumulates a decimal count of the serially occurring data pulses with each register storing a respective one of unit and higher decimal place portions of the decimal count. The memory forms part of a comparison circuit arrangement which responds to the data pulses and the timing pulses to produce the command signal.

Abstract: An electronic flash apparatus to be used for photographing purposes and controlled by a digital memory system. A flash structure provides flash illumination while an oscillator circuit produces pulses the frequency of which is determined according to a factor such as the light intensity or the distance of the object from the flash apparatus, and these pulses are counted by a memory device which is set to terminate the counting of the pulses according to one or more parameters such as the film speed, the diaphragm aperture, or the like. The flash illumination is terminated by a flash control structure actuated either according to the number of pulses counted or according to the time interval required to count a given number of pulses.

Abstract: A camera is provided with a photo-responsive pulse generator for generating pulses the number of which is determined by the logarithmically converted light intensity at an object which is to be photographed. A reference pulse generator is also provided for generating a series of reference pulses at intervals from one reference pulse to the next which become progressively greater. A shutter-operating plunger is available to the operator to be depressed for tripping the shutter, and this plunger is operatively connected to the photo-responsive pulse generator for activating the latter just prior to opening of the shutter and to the reference pulse generator for activating the latter simultaneously with opening of the shutter.

Abstract: Focusing apparatus for use in optical systems, such as photographing cameras, is disclosed. The focusing apparatus of the invention comprises an electronic system for developing, through either a single or two separate channels, pulse trains, the number of pulses contained in the pulse trains being related to the brightness of the image forming light received by the optical system as focused on photoconductive elements. The electronic system further includes a comparing subsystem for comparing the number of pulses included in the two pulse trains and, in accordance therewith, generating an information output signal related to the focus state of the optical system. Alternatively, the output signal may control a drive system adapted to move the imaging lens portion of the optical system toward focus.

Abstract: A method and device for use in detecting a precise focussing point, which comprises the steps of: placing a photoelectric element on an optical path or optical axis of a lens of a camera; converting the information of the precise focussing point for a photographic object into a frequency variation of an A. C. signal; feeding said signal having varying frequency to a highly sensitive frequency detector such as a resonance circuit, a tuned amplifier, or frequency-amplitude convertor having acute frequency characteristics; and detecting the precise focussing point with high sensitivity by means of the output thus obtained; whereby the aforesaid functions may be satisfactorily performed, irrespective of the variation in the luminance of the object and whereby the focus of the lens may be brought into precise conformity to the predetermined plane (i.e., the position corresponding to a film).

Abstract: A camera having a digitally operating structure for determining exposure time according to a digital value corresponding to the light intensity. The camera also has an adjustable diaphragm. The latter is adjusted in accordance with the difference between the digital value used for determining the exposure time and the actual value of the light intensity where the latter does not coincide with the digital value for the exposure time, so as to increase the precision of the exposure.

Abstract: A system for detecting the brightness of an area which is to be photographed. A plurality of series circuits respectively include a plurality of photosensitive devices for respectively receiving light from different parts of the area while remaining substantially static with respect thereto so that when the area is illuminated unevenly a pair of the photosensitive devices will respectively receive light of maximum and minimum brightness. The plurality of series circuits respectively include also a plurality of series-connected elements respectively connected in series with the plurality of photosensitive devices for respectively providing therewith a plurality of photo-responsive divided voltages. The plurality of series circuits are connected in parallel with each other and with a power source.

Abstract: A system for responding to non-uniform scene brightness. The system includes a plurality of photosensitive devices which are capable of receiving light from different parts of a scene while remaining static with respect thereto. Through an electrical connecting structure these photosensitive devices are all electrically connected with an output structure which will provide an output determined by at least one of a pair of the photosensitive devices which are respectively exposed to light of maximum and minimum brightness from the scene. The plurality of photosensitive devices provide inputs which vary according to a geometric progression in accordance with the variation in light brightness.

Abstract: A camera which has the capability of automatically determining exposure of film. A light-responsive structure of the camera produces a number of pulses which is inversely proportional to light brightness while a reference pulse generating structure is capable of producing a series of reference pulses. A binary counter is connected through a switch structure to both the light-responsive structure and the reference pulse generating structure, with the switch structure first connecting the light-responsive structure to the binary counter so that the latter counts the number of pulses which is inversely proportional to light brightness. Thereafter an inverting structure which is connected to the binary counter inverts the number of pulses counted thereby, and then the switch structure disconnects the light-responsive structure from the binary counter and instead connects the reference pulse generating structure thereto so that the binary counter then counts reference pulses.

Abstract: A light-responsive system which includes a plurality of photosensitive elements respectively directed to different parts of a scene for respectively providing electrical inputs according to the brightness of the light at the different parts of the scene. The several inputs are supplied to a plurality of electrical circuits which in turn are connected with an output unit, these circuits operating in such a way that the output unit will be actuated only by that one of the inputs which corresponds to that part of the scene which has the maximum brightness or the minimum brightness. In this way it is possible to provide an output corresponding either to the maximum brightness of the scene or the minimum brightness of the scene without requiring scanning of the scene.