| 摘要 |
<p>PURPOSE:To accurately adjust the light emitting intensity of a light emitting element so that the output value of a light receiving element is the proper value by providing a signal level rising means to input the analog signal of a digital/analog converting means and rise the level to a constant quantity. CONSTITUTION:The title switch provides a control means 7 to output a digital signal to adjust the light emitting intensity of the light emitting element so that the light receiving intensity of a light receiving element is the proper value, a digital analog converting means 14 to input the digital signal of a control means and convert and output to an analog signal, a signal level rising means 15 to input the analog signal of a digital/analog converting means and rise the constant quantity of the level and a voltage/current converting means 19 to input the output signal of the signal level rising means and convert the voltage, which is the signal contents, to the impressing current for the light emitting element. Consequently, between the minimum set value and the maximum set value of the digital/analog converting means, for the portion in which the voltage level due to the signal level rising means is risen, the impressed current range of the light emitting element becomes narrow, and the minimum variation of the light emitting element also becomes small. Thus, the light emitting intensity of the light emitting element can be accurately adjusted.</p> |
