Multi-mode tdi/raster-scan television camera system

Abstract

Mode selection switches (76, 96, 98) selectively interconnect a sensor line shift timing generator (76) with one of three signal sources - (1) a conventional raster scan timing signal from a raster scan sync generator (70), (2) variable speed external timing signals from a tachometer (32), and (3) fixed speed timing signals developed from the horizontal timing signals of the raster scan sync generator. In a time delay and integration mode, the sensor line shift timing generator causes the CCD arrays of an image section (22) and storage section (24) to shift pixel values down the CCD arrays at a rate commensurate with the external timing signal. As a spot of light emanating from a portion of an object moving through an examination region moves along the CCD array, a corresponding pixel charge is shifted through the CCD array at the same speed such that the same pixel charge integrates light from the same spot as it moves the entire length of the CCD array. An output register timing generator (80) generates timing signals for output registers (26 ) such that an output signal is produced that is compatible with EIA-170 television signal standard. In the conventional raster scan mode, the camera works as a conventional video camera. When connected to the variable frequency timing signal, the video picture scrolls down the TV monitor clocked by the tachometer in proportion to the speed of the conveyor. In the calibration mode, the image scrolls down the video screen at a fixed rate.