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6324344 |
Light measuring device and camera
A light measuring device includes an integration-type light measuring sensor having a plurality of pixels and arranged to logarithmically compress a signal of light received by each pixel and to...
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5708880 |
CMOS-analog IC for controlling camera and camera system using the same
In a camera controller using a CMOS-analog-IC, a microcomputer, logarithmic compression type distance measuring and photometric circuits, each constituted by a CMOS device having a parasitic...
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5602615 |
Photometric device to determine a correct photometric value of a spot photometric region
A photometric device, used in an optical apparatus such as a camera, which includes photometric elements to measure photometric values according to plural regions of a subject field, and corrects...
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5548398 |
Illuminant discriminator providing detection of high efficiency illumination
An illuminant discriminator distinguishes a range of separate illuminants, including high efficiency fluorescent lighting, by modifying the frequency response of a signal output from a...
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5291238 |
Photometering circuit
A photometering circuit comprises a photo-diode, an operational amplifier, a feedback diode and a latch releasing transistor. In a circuit utilizing a PNP transistor, for example, a cathode of the...
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4802107 |
Offset drift correction method in color film inspection apparatus
An offset drift correction method for use in in a color film inspection apparatus includes the steps of; measuring the changes of various amounts of light at intervals of a predetermined amount of...
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4711546 |
Photometric circuit
A photometric circuit which has an operational amplifier and produces a result of light measurement with a logarithmic compression element arranged between the input and output terminals of the...
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4647175 |
Circuit arrangement for an electronic exposure meter
In a switching circuit for an electronic exposure meter in optical devices with a photoelectric converter at the input of an amplifier which logarithmizes the output current from said converter,...
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4498753 |
Photometric apparatus for cameras
A photometric apparatus for a camera comprises a reference voltage circuit; an operational amplifier including a photoelectromotive element for photometry, an output terminal of said reference...
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4492858 |
Photometric circuit having a plurality of photoelectric transducer elements capable of being selectively enabled for photometry
A photometric circuit comprises an operational amplifier including a plurality of differential amplifiers, a constant current bias circuit for supplying a constant current bias to the differential...
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4477161 |
Compensator system for diaphragm control in a single-lens reflex camera of interchangeable lens type
A compensator system for diaphragm control in a single-lens reflex camera of interchangeable type having an exposure control circuit responsive to the position of a lever that is operatively...
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4473744 |
Photometric apparatus for camera
A photometric apparatus for a camera includes a diode for logarithmic compression and a semiconductor analog switch in series connection between an output terminal of a first operational amplifier...
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4462670 |
Light measuring apparatus for camera
A light measuring apparatus for camera is disclosed. It is known that some type of light measuring apparatus for camera involves the problem of so-called "latch" which is caused by opposite charge...
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4391488 |
Mount device of an interchangeable lens
In an interchangeable lens having a mount mountable on a camera incuding an electric circuit associated with exposure control and a displaceable actuating member for correcting the electric circuit...
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4390258 |
Photomeric circuit for camera
A photometric circuit includes a differentiator arranged in cascade connection with an integrating circuit including an integrating capacitor which directly integrates a photocurrent produced by a...
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4367932 |
Exposure control system
An exposure control system includes a device for measuring an intensity of the ambient light, three controllers for controlling three factors of exposure time, aperture size and amount of flash...
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4367022 |
Exposure control circuit for camera of TTL reflective photometry type
An exposure control circuit for camera of TTL reflective photometry type includes a shutter blind of a lower reflectivity than that of a film. The circuit is arranged such that until a given...
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4353631 |
Exposure information input circuit for electric shutter
In an electric shutter having a photoelectric element, a time constant circuit for use in controlling exposure and a low brightness sensor circuit for use in connecting said photoelectric element...
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4325615 |
Exposure control system for single lens reflex cameras
A through-the-lens type automatic exposure control system controls exposure time in accordance with an object light representative signal stored in a storage device prior to a shutter actuation,...
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4306807 |
Light measuring system
In the disclosed system, a light measuring circuit having a logarithmical amplifier, is constructed to produce pulses at a frequency corresponding to the output of the light measuring circuit....
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4302780 |
Photometric system
A photometric system for use in an image pick-up device is disclosed. The photometric system comprises the steps of forming an image focussed by a camera lens system on a light receiver consisting...
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4269490 |
Programmed shutter gamma switching circuit
A gamma switching circuit of a programmed shutter having a voltage conversion circuit which subjects to logarithmic compression an optical current which varies with γ=1 with respect to brightness...
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4258993 |
Light discrimination apparatus
A control apparatus is disclosed for discriminating between light emitted from sources having respectively different flicker ratios (the ratio of the brightest and the dimmest intensities during a...
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4247186 |
Photometric circuit for camera
A photometric circuit for a camera including a first operational amplifier with a photo-electric element connected between its inverted and non-inverted input terminals and, a logarithmic...
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4188551 |
Amplifier circuit having photoelectric converter
A photometric amplifier circuit, having a photocurrent converting element connected between a pair of inverting and noninverting input terminals of a differential amplifier, for amplifying an...
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4181413 |
Electronic shutter control circuit
An electronic shutter control circuit in a camera has an operational amplifier, a light receiving element connected between the input terminals of the operational amplifier and a logarithmic...
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4174160 |
Programmed automatic exposure control circuitry
In a photographic camera capable of programmed automatic exposure control, circuitry is provided for also enabling exposure time-preferred automatic diaphragm control and diaphragm-preferred...
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4170411 |
Control circuit for a memory type electric shutter
In the system disclosed, a feedback circuit connects the output of the last of a plurality of cascaded amplifier stages to the input of the first stage. A photoelectric transducer is connected to...
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4166679 |
Exposure information setting circuit
The present invention is an exposure information setting circuit for use in photographic cameras which calculates the required exposure time in response to input signals indicative of APEX indices...
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4166696 |
Photometer
A photometer for providing a measurement of shutter speed or aperture setting corresponding to a preselected value of the other comprises a photodiode supplying a voltage proportional to the...
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4132985 |
Automatic control device for cameras
This invention relates to an automatic camera exposure control device comprising a first light measuring circuit including a photoelectric element receiving light through the objective lens of the...
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4129366 |
Photometric device for a camera
A photometric device for a camera, wherein there are provided a photometric circuit having a photo-electric conversion element of quick photo-responsive characteristic so as to convert light from...
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4124855 |
Automatic exposure control apparatus and a camera having the same
An automatic exposure control apparatus of electric type for a photographic camera having an exposure control parameter setting means cooperative with a geometrical progression scale in isometric...
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4112441 |
Exposure control device
An automatic exposure control device for a camera capable of aperture preferred (ES), shutter preferred (EE), and programmed (ES-EE) operation. Transducers and log compression electronic devices...
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4099885 |
Digital display circuit for camera exposure meter
A digital exposure meter display circuit for a camera includes a first oscillator 1 whose output controls the charging of an integrating capacitor 28 from a constant current source 3. When the...
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4099188 |
Automatic exposure control device for single lens reflex camera
An automatic exposure control device for a single lens reflex camera characterized in that a stop determining member which stops down diaphragm blades by rotation thereof at a predetermined speed...
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4085411 |
Light detector system with photo diode and current-mirror amplifier
A light detector system includes a photo-diode being connected to an integrated circuit that includes a current-mirror amplifier. The current-mirror amplifier has a stable gain even down to the...
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4083055 |
Exposure information quantizing circuit utilizing shift register
An exposure information quantizing circuit. A current signal source generates a signal current to be quantized. A controllable bidirectional shift register has a series of bit positions and...
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4076977 |
Light measuring circuit with stray capacitance compensating means
The present invention relates to a light measuring circuit consisting of an operational amplifier, a feed back path connected with said operational amplifier, a photo voltaic cell and a switching...
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4077043 |
Exposure indicating device
An exposure indicating device for use in a photographic camera which includes a light measuring circuit for generating an output representative of scene brightness, a reference voltage circuit for...
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4072962 |
Metering device
A metering device comprises a photoelectric converter circuit for generating a first voltage corresponding to the brightness of a subject to be photographed. The converter circuit includes a...
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4059835 |
Bypass circuits for improving the response of electric shutters
An electric shutter circuit employs a photodiode which forms the collector load of a logarithmic amplifier. The photodiode is shunted with an active device which is caused to conduct during shutter...
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4051490 |
Photographic exposure meter circuit having temperature compensation
An exposure meter circuit includes a photo diode 2 and associated components 1, 3-6 for producing a first logarithmically compressed voltage V 1 proportional to the apex value B v of the sensed...
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4048643 |
Exposure computation system
A diaphragm aperture value which has been set is transformed into corresponding frequency information. A local oscillator starts sweeping upon pushing of the shutter button. The output of the local...
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4045142 |
Metering device for cameras
In a metering device for cameras comprising an operational amplifier, a photodiode connected between the positive and the negative input terminal of the operational amplifier, and a logarithmic...
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4041506 |
Timing circuits for camera shutters
A memory capacitor in an electric shutter circuit has one terminal coupled to a voltage responsive element such as a diode, which operates to effectively reduce the level to which the capacitor is...
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4037234 |
Exposure control system stabilized against temperature variation
An exposure control system for a camera capable of deriving more reliable and accurate exposure values over an extended range of scene luminance despite variation of the ambient temperature of the...
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4032801 |
Electromagnetic radiation intensity comparator apparatus
An electromagnetic radiation intensity comparator is disclosed for providing an indication of differences between electromagnetic radiation intensities occurring at different photodetectors.
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4007466 |
Electrical system having a photoelectric converter to be used in photography
An electrical system to be used for photographic purposes. The electrical system has an input circuit for providing a given input signal as well as an output circuit for utilizing the latter signal...
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4004853 |
Exposure meter circuit
An exposure meter circuit is disclosed in which the photoreceptor may be either a photovoltaic element such as a photodiode or a photoconductive element such as a CdS element. The meter is able to...
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