Multi-mode TDI/raster-scan television camera system

A camera system comprising:

• a conveying means for conveying at least one item to be examined through an examination region;
• a speed-dependent timing signal means for generating a speed-dependent timing signal that varies in accordance with a speed of the conveying means through the examination region;
• a lens which focuses photons from the examination region on at least a portion of an image sensor array, which array is defined by lines and columns of photosensitive elements;
• a timing generator means for controlling timing of integrating photons received at photosensitive elements of each column, the timing means being operatively connected with the speed-dependent timing signal means such that the timing means variably controls a time duration between integrations of photons along the columns in accordance with the speed-dependent timing signal such that as a given point on the conveying means moves through the examination region, the photons emanating therefrom and impinging sequentially on the photosensitive elements of the column are integrated.

A multimode CCD camera comprising:

• a CCD array having a plurality of lines of light sensitive elements for accumulating lines of pixel values each indicative of an accumulated amount of light received;
• a lens means for focusing light from a region of interest on the CCD array;
• a serializing means for serializing each line of pixel values from the CCD array into an output video signal;
• a line shift means for shifting the lines of pixel values along the CCD array to the serializing means at a rate controlled by received timing signals;
• a raster scan sync generating means for generating conventional raster scan timing signals including horizontal timing signals of a preselected frequency and vertical flyback timing signals;
• a timing signal conditioning means for conditioning an externally generated timing signal of adjustable frequency for compatibility with the line shift timing means;
• and,
• a switching means for selectively switching one of (1) the raster scan sync generating means into electrical communication with the line shift means for providing horizontal and vertical flyback timing signals thereto such that the lines, of pixel data are read from the CCD array in a conventional raster scan mode, (2) the signal conditioning means into electrical communication with an external source of adjustable frequency timing signals such that the lines of pixel data are shifted along the CCD array at a rate in accordance with the external timing signal, and (3) the signal conditioning means into electrical communication with raster scan sync generating means for receiving the horizontal timing signals therefrom such that the lines of pixel data are shifted along the CCD array at a rate fixed by the raster scan sync generating means.

A method of generating video signals, the method comprising:

• fixedly disposing a test chart in an examination region, the test chart having a plurality of parallel stripes;
• while the test chart is in the examination region;
• clocking an image sensing array at a fixed rate such that lines of pixel data are shifted therealong and integrated at the fixed rate,
• serially reading the lines of data from the array, converting the lines into a video calibration signal,
• adjusting at least one of focus, alignment, and calibration in accordance with the video calibration signal;
• removing the test chart and moving a conveying means through the examination region in a direction parallel to the test chart stripes;
• monitoring a speed of movement of the conveying means through the examination region and clocking the image sensing array in accordance therewith;
• and,
• reading out the lines of data from the array and converting the lines of data into a video signal.

A camera inspection system comprising:

• a web conveyor for substantially continuously conveying a web through an examination region;
• a speed monitor for monitoring a conveying a speed at which the web is conveyed through the examination region;
• a time delay and integration camera including:
• an image sensor having an array of light sensitive elements,
• a lens for focusing light from the examination region on the image sensor, the light from the examination region altering charge values on the photosensitive elements of the image sensor,
• a timing generator for controlling shifting of the charge values along the image sensor such that the charge values represent an integration of light received at a plurality of locations as the charge values shifts along the image sensor, the timing generator being connected with the a speed monitor such that the charge values are shifted along the image sensor in accordance with movement of the web such that each charge value comes to represent an integration of light from a corresponding portion of the web as such corresponding portion of the web moves through the examination
• region.

A method of video inspection of a web moving through an examination region at a non-constant conveying speed, the method comprising:

• monitoring a conveying speed of the web;
• receiving light from at least a preselected portion of the examination region with a video camera operated in a time delay and integration mode;
• controlling operation of the video camera such that light from an incremental element of the web is integrated as it moves across the
• preselected portion of the examination region.