| 摘要 |
PURPOSE:To ensure that the inspection of a luminous amount of a print pattern can be performed correctly if the transfer speed of sheets changed by providing a part for setting two different types of reference level in accordance with the transfer speed of sheets and a comparison part for comparing the two different types of reference level set by the former part with an output signal from a light receiving part. CONSTITUTION:The first comparison part 7a compares an output from a photoelectric conversion part 4 with an output from a reference lower limit level setting part 6a. The second comparison part 7b compares the output from the photoelectric conversion part 4 with a reference upper limit level setting part 6n. An AND circuit 7c receives the output from the first comparison part 7a with that from the second comparison part 7b, and outputs a signal (HIGH level) which indicates 'passed', if the output signal from the photoelectric conversion part 4 is at a level between the reference upper limit level and the reference lower limit level, and a signal which indicates 'failed' (LOW level) is output, if the output signal is at a level between any other levels. Subsequently, it is possible to test the luminous amount of a correct pattern 2 constantly, even if the transfer speed is not fixed. |
