| 摘要 |
PURPOSE:To quicken the reading speed by driving a common TR switch always once in reading switch information belonging to one line of matrix form. CONSTITUTION:In reading the switch information of switches S11, S12, S13,...S1m belonging to the 1st line, a signal is fed to the base of a transistor (TR)1 to turn on it and read amplifiers SA1, SA2, SA3,-,SAm are operated in such a state. The output of the amplifiers SA1-SA8 is read via a selector SEL. The output of the SA9-SA12 sets respectively only flip-flops F9-F12, then the selector SEL is activated at the next step, the information of the flip- flops F9-F12 is read and inputted to a microprocessor. Since the information of the flip-flops F9-F12 in the 2nd step is read in high speed, the time required for reading the switch information of the switches S11, S12, S13...S1m belonging to the 1st line is reduced remarkably in comparison with a conventional system even if (m) is larger than 8. |
