Abstract: A circuit and method for converting signals from a photoelectric image sensor into digital signals containing information as to a characteristic of the sensor signals. The photoelectric image sensor provides output pulses having characteristic determined by the manner in which light is incident thereon and this, in turn, is determined by a light influencing medium in an optical path between a light source and the image sensor. In particular, the peak amplitude of each signal from the sensor is determined and then converted into a digital signal containing information as to the peak amplitude. This is accomplished by detecting the rise of each sensor signal to a peak amplitude and then holding a signal level corresponding to the peak level of the sensor signal as the sensor signal falls in amplitude for a time at least equal to the time for acquiring or converting into the digital signal.

Abstract: An automatic refractometer comprising a photosensitive device having a relatively narrow dynamic range in the form of a linear scanned array including a plurality of photoelectric elements each providing an output pulse during a scan and the amplitude of each pulse being determined by the amount of illumination of the corresponding element by incident light, an optical system for directing light onto the array in a manner such that the particular photoelectric elements of the array which are illuminated by the light are determined by the index of refraction of a light transmitting substance placed in operative association with the optical system, a circuit for converting signals from the array into digital signals containing information as to the amplitudes of the signals from the array, a digital processing circuit for storing respective signals from reference and sample substances placed in operative association with the optical system and for computing the index of refraction of the sample substance by mea

Abstract: A current to frequency converter comprising a current source, for example a photocell, a voltage to frequency converter, an integrator in the feedback loop of the converter, the current source being connected to the summing junction of the converter and integrator such that the frequency of output pulses from the converter is directly proportional to the magnitude of current injected from the converter to the summing junction, and a controlled circuit for attenuating the current injected from the converter to the summing junction to increase the frequency of output pulses. The controlled attenuating circuit includes a transistor switching arrangement for introducing increased resistance in the path for current injected from the converter to the summing junction in response to the presence of a control signal.

Abstract: An exposure and camera control system comprising a keyboard for providing input information relating to film parameters and camera type, a light to frequency converter for providing signals having a frequency proportional to the intensity of light to be used in exposing the film, and a control operatively connected to the information providing keyboard and to the light to frequency converter for determining the film exposure time and for providing signals for controlling film exposure to light and signals for controlling film transport when the exposure is complete. The control includes a microprocessor, programmable memory, and input/output interface components. A display operatively connected to the control provides visual display of information inputs to the control and of calculated quantitites such as exposure time. A printer operatively connected to the control provides a hard copy record of the displayed information.