Abstract: Disclosed is a color printer which uses a CRT to print on photographic medium. The printer contains a uniformity EEPROM that corrects for brightness of each position on the CRT. If a position cannot be corrected, a blank code is placed in the EEPROM at the position, to blank the CRT at the position. Adjacent positions are intensified, or positions in the same column on other CRT rows are intensified to correct for the defective position. The printer also allows the uniformity information to be field updated by printing an entire page of each primary color, sending these pages back to the factory, scanning them into a computer system using a document scanner, analyzing each page, creating new uniformity data from the analysis, and sending this data back to the printer where it is loaded into the uniformity EEPROM.

Abstract: Disclosed is a system having a memory mapped deflection to control the position of an electron beam within a CRT used to project a color image onto a photographic medium for printing. A horizontal position counter is incremented at a linear rate, and the counter value is translated, using a translation table stored in memory, into a current used to drive the yoke of the CRT. The translation introduces non-linearities into the output voltage which results in a linear forward sweep across the CRT. A sweep direction signal is used as an address bit of the translation table, to allow an optimized retrace motion profile which results in an improved linear beam motion across the face of the CRT during the forward sweep immediately following retrace.