Structure is disclosed for a charge-coupled device for generating reference signals indicative of black and white optical conditions and for generating an end-of-scan indicator signal. The black reference signal is generated by electrically and optically isolating one or more photosites of the CCD. A white reference signal is generated by injecting a controlled amount of charge into one or more elements of a shift register of a charge-coupled device. The end-of-scan indicator signal is generated by injecting a signal into at least one element of a shift register which does not have photosites associated with it. The black and white reference signals allow the utilization of the full dynamic range of the device under a wide range of operation conditions, while the end-of-scan indicator eliminates the need for external counting or reset circuits associated with conventional charge-coupled devices.
This application is a continuation of U.S. patent application Ser. No. 621,140, filed 6/15/84, now abandoned, which was a continuation of U.S. patent application Ser. No. 419,097, filed 9/16/82, now abandoned, which was a continuation of U.S. patent application Ser. No. 130,676, filed 3/17/80, now abandoned, which was a continuation of U.S. patent application Ser. No. 875,711, filed 2/06/78, now abandoned.
An optical shaft angle encoder has a plurality of active photodiodes in an array on a semiconductor chip. A rotary code wheel has alternating areas for alternately illuminating or not illuminating the active photodiodes in response to the rotation of the wheel. Errors in the duty cycle involving the end active photodiodes in the array are largely avoided by having a plurality of inactive photodiodes at each end of the array with width and electrical properties effectively the same as the active photodiodes so that leakage current to each end active photodiode of the array is substantially equal to the leakage current to active photodiodes remote from the end of the array. Similarly, leakage current may affect the duty cycle of individual photodiodes may be minimized by surrounding the individual photodiodes with a reverse biased photodiode junction.
A solid state image pickup apparatus includes a solid state image pickup device for receiving an optical image of an object and generating an electrical image signal representing the optical image of the object in synchronism with a driving pulse from a driving circuit. A sampling circuit generates a sampled image signal by sampling the electrical image signal read out of the solid state image pickup device with a first sampling pulse from a first pulse circuit synchronized with the driving pulse. An analog-to-digital convertor converts the sampled image signal to a digital image signal with a second sampling pulse from a second pulse circuit. A test signal generator generates a test signal which is synchronized with the driving pulse and alternately changes in level between consecutive pixels. A controller controls the phase of the first sampling pulse and the phase of the second sampling pulse relative to each other by processing the test signal.
A one-dimensional time-delay integration solid-state imager includes a plurality of light-to-electricity conversion parts which store signal charges generated in response to incident light, a vertical CCD corresponding to a series of the light-to-electricity conversion parts for transferring stored signal charges, and a gate for controlling transfer of signal charges stored at the light-to-electricity conversion parts to the vertical CCD. The signal charges corresponding to the same observed image moving on the plurality of light-to-electricity conversion parts are added to enhance the signal-to-noise ratio, and a background signal charge removing region for removing background signal charges is provided at the vertical CCD for removing background charges during the transfer of signal charges.
A circuit includes a programmable delay circuit to provide a sequence of delayed pulses, an A/D circuit to convert a sequence of values into digital values sampled at times defined by the sequence of delayed pulses, and a jitter correction circuit to adjust the programmable delay circuit based on a sequence of digital values from the A/D circuit sampled at times defined by the sequence of delayed pulses.
An optical shaft angle encoder has a plurality of active photodiodes in an array on a semiconductor chip. A rotating code wheel has alternating areas for alternately illuminating or not illuminating the active photodiodes in response to the rotation of the wheel. Errors in the duty cycle involving the end active photodiodes in the array are largely avoided by having a plurality of inactive photodiodes at each end of the array with width and electrical properties effectively the same as the active photodiodes so that leakage current to each end active photodiode of the array is substantially equal to the leakage current to active photodiodes remote from the end of the array. Similarly, leakage current which may affect the duty cycle of individual photodiodes may be minimized by surrounding the individual photodiodes with a reverse biased photodiode junction.
