Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
Claim 1. In a cathode ray tube (CRT) display (22) compensation system (20, Figs. 1 and 5) for correction of uniformity including storage apparatus (86) for storing correction signals as a function of primary color and as a function of location on a screen of display; said system characterized by a combiner (98) for combining the correction signals with video signals employed in driving electron guns (38) of said display; and altering circuit (96, 100, 102) coupled between said storage apparatus and said combiner for altering the values of said correction signals inversely to the magnitudes of the video signals.
Claim 2
Dependent Claim
33 words
Claim 2. A system according to claim 1 wherein said altering circuit includes a logarithmic subtractor (100) for subtracting a video signal from a brightness reference signal and for scaling the correction signal.
Claim 3
Dependent Claim
16 words
Claim 3. A system according to claim 2 wherein said combiner comprises a summing circuit (98).
Claim 4
Dependent Claim
47 words
Claim 4. A system according to claim 3 wherein the correction signal (Figure 4, 86) for any one color has a magnitude equal to the ratio between said one color at full brightness and a color reference signal, said ratio being dependent on location on said screen.
Claim 5
Dependent Claim
23 words
Claim 5. A system according to claim 4 wherein said color reference signal (Figure 3, 68) is obtained by photographing a reference subject.
Claim 6
Dependent Claim
72 words
Claim 6. A system (Figure 4) according to claim 5 wherein said one color at full brightness has a dependency on location on said screen which dependency is attained by photographing (48) said screen (32), said system further comprising logarithmic circuitry (66) for subtraction of logarithmic values of the intensity of said color reference signal from logarithmic values of the intensity of said one color at full brightness to attain said ratio.
Claim 7
Dependent Claim
125 words
Claim 7. A system for correction of uniformity of color and brightness in a CRT display according to claim 1 wherein said correction signals are obtained by photographing (48) said display (32) under separate illuminations of said primary colors; and wherein said altering circuit comprises a scaler (77) responsive to a reference signal of predetermined value and to a set of video signals used in exciting said display for scaling the magnitudes of said correction signals in accordance with a difference between each of said video signals and said reference signal to provide a set of scaled correction signals, there being one scaled correction signal for each primary color, the value of the individual correction signal varying with location on a face of the display.
Claim 8
Dependent Claim
33 words
Claim 8. A system according to claim 7 further comprising a normalizing circuit (64, 68, 88) for normalizing said correction signals to compensate for any nonuniformities in a camera utilized in said photographing.
Claim 9
Dependent Claim
53 words
Claim 9. A system according to claim 8 wherein said scaler includes a subtractor (80) for subtracting a video signal from said reference signal, said subtractor and said combiner means cooperating to provide an inverse relationship between the magnitudes of said video signals and the amounts of correction signals applied to said display.