Total raster error correction apparatus and method for the automatic set up of television cameras and the like

An automatic correction system for correcting all raster related errors in image pickup devices of a camera head system which generates a video signal corresponding to a video picture, comprising the combination of;

• optical test pattern means of alternate black and white horizontal and vertical areas corresponding to a selected pattern frequency, with selected gray areas therebetween;
• error measurement means for receiving the video signal and for generating horizontal and vertical spatial error data corresponding to errors in the scans of the image pickup devices, at selected sample points within selected box areas of the video picture, and for generating black and white shading error data corresponding to errors in the video signal with relation to selected black and white video voltage levels taken from the test pattern means;
• A/D convertor means coupled to the error measurement means for digitizing the resulting error data;
• and
• error correction means including digital memory/retrieval means disposed in the camera head system to receive the digitized error data for storage therein, for subsequently selectively retrieving the digital error data during camera head system operation, and for applying analog spatial error correction signals to the image pickup device scans, and black and white shading errors to the video signal, respectively.

A method for selectively and automatically correcting;

• raster related spatial errors in and between the green, red and blue scans of respective image pickup devices in a television camera head system which generates a video signal commensurate with a video picture;
• black and white video signal levels;
• and gamma errors in the image pickup devices, comprising the steps of;
• comparing the positions of the scans at selected points within specified boxes of a box array corresponding to the video picture of an optical test pattern, against an electronic test pattern signal of given black and white D.C. voltage levels related in turn to the video picture;
• generating spatial error data corresponding to the horizontal and vertical positional errors at selected sample points within each box, and during selected lines within the box;
• digitally storing the spatial error data in the camera head system;
• retrieving the digitally stored spatial error data during real time camera head operation with selected timing relative to the positions of the errors within the box array when the errors were detected during the error measurement process;
• and
• applying analog error correction signals corresponding to the retrieved digital spatial error data to the image pickup devices, respectively, to correct any detected spatial errors.