| 摘要 |
<p>PURPOSE:To attain the automatic adjustment of convergence with high accuracy by providing a screen-protecting panel in the front of the the translucent screen of a rear projection type television, and arraying photoelectric transducers on the said panel to detect signal locations. CONSTITUTION:On the screen-protecting panel 32, the photoelectric transducers 33 are provided. When an adjusting point A is specified to a write address control part 8, only the cross hatch signals close to the sad point A are outputted from a cross hatch generator 7, and the location of green cross hatch signal is detected by the transducers 33 provided on the panel 32. During a second field scanning time, a red cross hatch signal shown by the broken line is outputted. Clock pulses are counted by using these signals to set a reference signal location counter 27 and a comparison signal location counter 35. A comparator 37 compares the contents of the both counters, and operates a data variable counter 11 until the said contents coincide with each other. The red cross hatch signal location is moved from point B to point C by changing the correction data in a one frame memory 10.</p> |
