| 摘要 |
PURPOSE:To attain both horizontal and vertical address corrections and to eliminate a malfunction due to noises by indicating a CRT reference point in an initial state with a light pen to read an address and calculating an error the read- out address and the reference point address to perform a correction. CONSTITUTION:The reference points (x0, y0) glow on a CRT display screen, and a light pen is applied to the screen to detect light pen addresses (x1, y1). Some error is produced between both addresses through a waveform processing circuit 9 by the difference of the signal transmitting system. An arithmetic is given to said error from an address correction value calculating circuit 11 to obtain correction addresses X and Y. These addresses are led to a light pen controller 8 via an address correcting circuit 12 and then used to give corrections to adresses xn and yn which are obtained hereafter by the light pen. In this case, the correction equations are used as Xn=xn-X and Yn=yn-Y.
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