| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of a quality testing device. SOLUTION: This device is provided with an analog comparator means 9 and a switch means 11. The comparator means 9 receives a digital signal by one input, and receives a signal in one level of plural prescribed levels switched by the switch means 11 to the comparator means 9 by the other input. The switch means 11 operates switching among the plural prescribed levels according to a logical level presumed to be received by one input, and the output of the comparator means 9 gives the indication of the quality of the logical level of the digital signal. |
