Crt display system with automatic alignment employing personality memory

Abstract

Disclosed are systems and techniques for alignment of CRT-based display systems, particularly those employing a high resolution cathodochromic projection CRT. The disclosed techniques permit all major CRT-related alignment to be performed at a factory or other centralized facility, with automatic precision alignment in the field of the overall display system, including a CRT assembly as one element. A replaceable, standardized CRT subsystem includes a CRT assembly, itself subject to sample variations, and a non-volatile personality memory, such as an EEPROM, having stored parameters specifically applicable to the CRT assembly on an individual basis. The CRT assembly has no field adjustable parts, but does include elements for electron beam control, such as electromagnetic coils for focus and deflection permanently affixed to the CRT. Thus at the factory, a skilled operator having appropriate equipment available performs an electronic alignment procedure with reference to a particular CRT. In the case of a projection display system, the CRT is mounted during alignment within an optical projection system which represents a standardized optical configuration, identical to the optical configuration in which the CRT will be operated in the field. Alignment parameters are digitally recorded as data in the non-volatile 'personality' memory, which then applies specifically to that CRT assembly. When the CRT subsystem including the CRT assembly and the personality memory are later mated with the display electronics subsystem, the display electronic subsystem reads and correctly interprets the data from the personality memory to effect corrections tailored to that particular CRT. When field replacement of a CRT eventually becomes necessary, the replacement CRT is supplied with its own personality memory, which is plugged into the circuit in place of the original one.