Method and device for uniforming luminosity and reducing phosphor degradation of a field emission flat display
Patent 5708451 Issued on January 13, 1998. Estimated Expiration Date: 
July 22, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 22, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesModular display apparatus with means for preventing brightness variations Method of driving a flat type of cathode ray tube to provide uniformity of electron beam emission characteristics for a plurality of beam sources Compensation for field emission display irregularities Passive matrix display having reduced image-degrading crosstalk effects Flat panel convergence circuit Patent #: 5625373 InventorAssigneeApplicationNo. 681099 filed on 07/22/1996US Classes:345/75.2, Field emissive (e.g., FED, Spindt, microtip, etc.)313/391, Storage313/398, Integral or contiguous storage and display element313/422, Flat tube type345/63, Intensity control345/77, Brightness or intensity control345/204, DISPLAY DRIVING CONTROL CIRCUITRY348/687Brightness controlExaminersPrimary: Powell, Mark R.Assistant: Kovalick, Vincent E. Attorney, Agent or FirmForeign Patent References
International ClassG09G 003/36Foreign Application Priority Data1995-07-20 EPAbstractNonuniformities of luminance characteristics in a field emission display (FED) are compensated pixel by pixel by storing a matrix of correction values, determined by testing, and by applying a corrected drive signal through the relative column drive stages. The individual pixel's correction factor that is applied to the corresponding video signal may be stored in digital or analog form in a nonvolatile memory array. Various embodiments are described including the use of a second updatable RAM array wherein pixel's correction factors are calculated and stored at every power-on to provide an opportunity of trimming-up the luminance of the display for compensating long term decline of luminance due to the phosphors ageing process. | |
