| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving circuit provided with a protecting function for preventing a semiconductor optical scanning device from being broken caused by the abnormality of a driving signal waveform. SOLUTION: A sampling pulse (b) is generated from a sampling pulse generating circuit 12 by each half period of a driving signal (a), so that a delay signal (c) having the phase delay of 180 deg. is generated from a delay memory circuit 13 to the signal (a). By the output (d) of an exclusive OR circuit 14 obtained when the levels of the signal (a) and (c) coincide, the output (e) of a logical value 0 is generated from a monostable circuit 15 for a specified time, the signal (a) is shielded so as not to be inputted to a driving circuit 17 by an AND gate 16, and the supply of a driving current to the optical scanning device 18 is stopped. |
