摘要:
A high speed light measuring circuit utilizing a photodiode is combined with a high speed exposure terminating circuit utilizing two polarized filters and a liquid or ferroelectric crystal placed between the polarized filters to constitute an exposure control circuit operative without modification for both daylight and flash exposure.
摘要:
A single operating switch replaces the main switch connecting the diaphragm control means to the battery and the release switch activating the film transport. All camera circuits are directly connected to the battery when the main operating switch is closed. An electronic switch is connected in series with the film transport motor and is closed only upon receipt of a control signal. In a first embodiment the control signal is furnished by a timing circuit after a predetermined time interval following the activation of the main operating switch. In a second embodiment the control signal is furnished by a NAND-gate which has a first input which receives a "1" signal while the diaphragm is being adjusted and a second input which receives a "1" signal while the electronic switch is open. The NAND-gate thus furnishes a "1" signal to the electronic switch causing it to be conductive at all times except when the initial adjustment of the diaphragm takes place.
摘要:
Pulses are furnished which each indicate transport of a frame. The pulses are counted on a BCD counter. Selected outputs of the counter are connected to the inputs of coupling stages, each including a JK flip-flop. Each flip-flop changes state for a predetermined count on the counter. When each flip-flop changes state, a corresponding indicator lights up, thereby furnishing an indication to the photographer of how many frames have been transported.
摘要:
Diapositives are copied on negative photosensitive paper in an apparatus wherein the positive is electronically scanned, line-by-line, and the thus obtained density signals are electronically inverted prior to influencing the beam of a CRT or laser which is used to reproduce the image of the positive on paper, either line-by-line or point-by-point. The inversion of signals renders it possible to scan the high-transmissivity portions of the positives with a narrow beam, i.e., with a high degree of resolution.
摘要:
A color filtering device for a charge-coupled photoelectric converting device including a series of uniformly configured photoelectric converting elements which are sensitized by the filtering arrangement in the order of green, blue, green and red. The filtering arrangement includes a transparent filter carrier supporting a series of green, blue, green, red, blue, green, and so on, filtering elements. The active surface of each blue filtering element is equal to the active surface of the assigned photoelectric converting element. The green and red filtering elements are reduced in size in inverse proportion to the spectral sensitivity of the assigned photoelectric converting element. The resulting spacings between the elements are covered by an opaque masking layer, preferably of chromium.
摘要:
Apparatus for stepwise transport of exposed and developed photographic films through a copying machine so as to place selected film frames, namely those film frames which are to be imaged onto photographic paper and are designated by holes or other types of indices, into register with the copying station has two photoelectronic detectors the first of which transmits signals to the forward input and the second of which transmits signals to the reverse input of a forward and reverse counter in a circuit which regulates the speed of the film transporting motor. The second detector is located downstream of the first detector and both detectors transmit signals on detection of indices denoting the film frames to be copied. The circuit decelerates the motor, either stepwise or abruptly, in response to detection of indices by the first detector, arrests the motor for a given interval of time in response to detection of indices by the second detector, and ensures that the motor is driven at a maximum speed in the absence of indices between the first and second detectors. The speed of the motor can be increased from zero to maximum speed in a single stage, in several stages, or continuously. This can be accomplished by connecting the operational amplifier for the motor in circuit with a voltage divider wherein one or more resistors are connected in parallel with switching transistors which are energizable with appropriate delays by a timer receiving impulses from the second detector.
摘要:
An electric motor which can drive the objective of a slide projector or which can adjust the blade or blades of a diaphragm receives signals from the output of an operational amplifier which receives first and second signals from a photosensitive transducer and a differentiating capacitor. The (second) signals from the capacitor are modified (first) signals from the transducer, and the combined intensity of first and second signals is such that the signals at the output of the amplifier reach a value which they would normally reach only when the component has already assumed a predetermined position before the motor can complete the movement of the component to such position. This allows for idling of the motor during the last stage of movement of the component to its predetermined position and/or for braking of the motor during such stage to ensure that the motor can rapidly advance the component during the major part of movement to the predetermined position and the component does not overshoot such position during the last stage of its movement.
摘要:
A semiconductor switch connected in the motor current path is controlled by a clocked flip-flop having a switch-ON and a switch-OFF state, capable of changing states only in response to a clock pulse. RPM is selected by establishing the initial count on a downwards counter having a carryover output at which a carryover signal appears when zero count is reached. A first higher-frequency pulse train is counted by the counter. A second lower-frequency train of set pulses has a repetition frequency dependent upon motor speed. The leading end of each set pulse starts the counter counting. An unclocked flip-flop responds to the carryover signal by assuming a motor-speed-too-low state. The clocked flip-flop when clocked responds to the state of the unclocked flip-flop. The trailing flank of the set pulse clocks the clocked flip-flop so that the latter can respond to the state of the unclocked flip-flop and slightly thereafter sets the unclocked flip-flop to the motor-speed-too-high state. Thus, at the time when the clocked flip-flop responds to state of the unclocked flip-flop, the latter is in the speed-too-low state only if the carryover signal was produced before the trailing end of the set pulse.
摘要:
A shutter mechanism alternates between an exposure phase and a reflex phase. In the reflex phase it reflects incident scene light onto a light-sensitive stage which generates a light-indicating signal. A first control pulse is generated at the start of the reflex phase, and a second control pulse at the end of the reflex phase. An integrating circuit receives the first pulse and during the reflex phase generates an integral signal dependent upon the time integral of the light-indicating signal. A signal-transmission switch is operative in response to the second pulse for transmitting the integral signal to a signal-storing stage. The signal from the signal-storing stage is used as the feedback signal to a negative-feedback control arrangement for the camera diaphragm. This feedback signal is dependent not only upon scene light but also the duration of the reflex phase. Accordingly, if the scene light remains constant but the speed of the motor driving the shutter is below or above rated speed, that is automatically compensated by a change in the feedback signal, so that the diaphragm setting takes into account the longer or shorter exposure times resulting from the shutter-motor speed deviation.
摘要:
The pulse repetition rate of a pulse generator furnishing pulses to a stepmotor which opens and closes the aperture in response to signals indicating that the quantity of light falling on the film is too little or too much respectively, is varied so that the aperture size is changed more rapidly when the difference between the desired and the actual quantity of light falling on the film is great, and is changed more slowly as the quantity of light falling on the film approaches the desired light quantity.