| 摘要 |
<p>PURPOSE:To form an enlarged recorded letter having a good image by expanding the focal point of the electron beam of a CRT in accordance with the increase in the magnification thereby to increase the roundness of the letter shape. CONSTITUTION:In case a code of twofold magnification is accommodated in a buffer memory 5, the operations of a CRT 1 and an auxiliary scanning drive system 13 are at the same speed as that of the operation of the same size but have the pulse frequencies C, S and l reduced to 1/2. The printing signals of one bit of a letter pattern memory are rcorded over two picture elements of the horizontal scanning of the CRT 1 to have a towofold magnification in length and width. According to this magnification, the focal point of the electron beam is enlarged in an intermediate manner so that the reduction in brightness is compensated by the fact that the input analog signals to a video amplifier 9 are raised to an intermediate level. As a result, a roundness apperars in the intrinsic discontinuous points of the recorded letter shape so that the envelope of the recorded picture element becomes gentle to form a letter shape having a good image and so that the printing density is maintained constant irrespective of the magnification.</p> |
