Claims
- 1. A circuit for convergence setting in a projection television display, having a display screen with a photosensor for detecting illumination by a marker contained in a projected picture, said photosensor generating an output signal having a specific time characteristic, said circuit comprising; an integrating element coupled to receive said output signal from said sensor when illuminated by a blue marker, said integrating element being dimensioned in such a way that said time characteristic of said output signal of said sensor when illuminated by said blue marker is approximately equal to said time characteristic of output signals from said sensor when illuminated by a red or green marker.
- 2. The circuit according to claim 1, further comprising, coupling means receiving said output signal for suppressing a DC voltage component of said output signal.
- 3. The circuit according to claim 1, wherein only an AC voltage component of said output signal is evaluated in a circuit for evaluating said output signal of said sensor.
- 4. The circuit according to claim 1, wherein said output signal of said sensor is coupled to trigger a monostable multivibrator having a period greater than a frame duration.
- 5. The circuit according to claim 4, wherein an output signal of said monostable multivibrator is sampled repeatedly during said frame duration and a manipulated variable is generated only when said output signal of said monostable multivibrator has a value “1” for a duration of two or more frames.
- 6. The circuit according to claim 1, further comprising, a plurality sensors connected in parallel and positioned adjacent to edges of said display screen.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 02 452.7 |
Feb 1997 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation in part of application Ser. No. 09/007,986 filed Jan. 16, 1998.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09007986 |
Jan 1998 |
US |
Child |
09731492 |
Dec 2000 |
US |