发明名称 Semiconductor laser driving device and image forming apparatus having the semiconductor laser driving device
摘要 A semiconductor laser driving device that drives a semiconductor laser with a driving current output from a driving current output terminal is disclosed. The semiconductor laser driving device includes a driving current monitoring terminal configured to output a driving current monitoring current having a value of 1/α of the driving current; a current-voltage conversion resistor connected to the driving current monitoring terminal and configured to convert the driving current monitoring current having the value of 1/α of the driving current into a corresponding driving current monitoring voltage; and a detector configured to generate a reference voltage and detect whether the corresponding driving current monitoring voltage has reached the reference voltage.
申请公布号 US8804784(B2) 申请公布日期 2014.08.12
申请号 US201013386463 申请日期 2010.07.14
申请人 Ricoh Company, Ltd. 发明人 Kamatani Tomohiko
分类号 H01S3/00 主分类号 H01S3/00
代理机构 Cooper & Dunham LLP 代理人 Cooper & Dunham LLP
主权项 1. A semiconductor laser driving device driving a semiconductor laser, the semiconductor laser driving device comprising: a driving current output terminal configured to output a driving current; a driving current monitoring terminal configured to output a driving current monitoring current having a value of 1/α, α≧1, of the driving current, the driving current monitoring terminal being connected in parallel with a line of the driving current output terminal and a power supply voltage; a detector configured to detect whether the driving current monitoring terminal has reached a reference voltage, wherein the driving current monitoring terminal is connectable to a current-voltage conversion resistor outside the semiconductor laser driving device, and the current-voltage conversion resistor is configured to convert the driving current monitoring current having the value of 1/α of the driving current into a corresponding driving current monitoring voltage; and a resistor disconnection detector configured to detect a disconnection of the current-voltage conversion resistor from the driving current monitoring terminal, wherein the detector for detecting whether the driving current monitoring terminal has reached the reference voltage is switched into a standby mode when the resistor disconnection detector detects the disconnection of the current-voltage conversion resistor from the driving current monitoring terminal and outputs a corresponding signal to the detector.
地址 Tokyo JP