| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laser diode luminescent circuit capable of limiting excessive light by DC driving of a laser diode and suppressing excessive current to achieve stable operation when a photodiode detection signal ceases. <P>SOLUTION: The laser diode luminescent circuit consists of: a driving circuit unit comprising a first NPN transistor connected to a laser diode, a first operational amplifier for driving the transistor, a first reference voltage, a current detecting resistor, and two resistance dividing circuits disposed between output of the first operational amplifier and input of the first NPN transistor; a photodiode signal amplifying circuit unit; a first comparison deciding unit comprising a second operational amplifier for determining a comparison between output of the amplifying circuit unit and a second reference voltage in response to out of the amplifying circuit; and a second comparison deciding unit comprising a third operational amplifier for configuring an integrator. <P>COPYRIGHT: (C)2008,JPO&INPIT |
