| 摘要 |
PURPOSE:To improve secrecy of scanning line shunt information without increasing the storage capacity of a ROM by providing a latch and constituting a feedback loop to supply the output from the said latch to the input-side of the address table ROM. CONSTITUTION:A line counter 81 generates an orderly array of numbers (0, 1, 2,-). The said signal and the output signal from the latch 84 coming through the ROM 83 (address table) are outputted (feedbacked) to an adder 85. The adder 85 adds up the inputted signals, and inputs the resulting signal to the ROM 83 an address line. In such a case, the latch 84 is controlled by a CLOCK- B signal supplied to its terminal 89. Consequently, the timing of the reading from the ROM 83 is arranged, and at the same time, the feedback operation of the output signal from the ROM 83 to the input-side is cleared when a counter 81 is made count up. That means that by limiting the times of feedbacking of signal, the secrecy of the conversion address information can be improved without increasing the storage capacity of the ROM 83. |
