| 摘要 |
<p>PURPOSE:To prevent a cut field angle by providing a distortion correction means correcting distortion of an image by an optical system of video data and an adjustment means avoiding deviation of a video image after the correction from a prescribed screen region to the processor. CONSTITUTION:On the occurrence of pincushion distortion, a corner point A at the upper left portion of a picture area is moved to a point B by optical distortion correction and a video image corresponding to video image data is deviated from a prescribed picture region and a cut field angle is caused. A pitch of, e.g. 0.9 is set as a zoom magnification setting pitch set to an H address pitch generating circuit and a V address pitch generating circuit. A microcomputer receiving an f-value at this point of time calculates the correction quantity for distortion correction based on the f-value and outputs an H address pitch and a V address pitch for an electron beam accordingly. Thus, deviation of the video image after the correction from processing area of a video image is avoided and a cut field angle is prevented.</p> |
