| 摘要 |
<p>PURPOSE:To obtain stable feedback signal by inverting polarity of a second electrical signal output from an amplifier with a polarity inverter, inputting such second electrical signal to an integrator with the reference signal and then integrating difference between the inverted signal and reference signal. CONSTITUTION:When a pulse input signal 1 is input, a pulse control signal 2 allows a light emitting diode 3 to generate light 4, which is admitted to a photo diode 5 and converted to a first electrical signal 6. The amplifier 7 amplifies the first electrical signal 6 and outputs a second electrical signal 8 which is proportional to the electrical signal 6, and a polarity inverter 13 inverts the polarity and outputs an inverted signal 14. Meanwhile, a reference voltage generator 9 generates a reference signal 10 and it is then input to an integrator 15 with the inverted signal. Since the integrator 15 integrates the input signal by means of charging function of a capacitor C1, it produces a feedback signal 12 which is slow to respond when sharply-changing inverted signals are supplied. Thereby, stable light 4 can be obtained without oscillation of control system.</p> |
