| 摘要 |
PURPOSE:To provide a light-emitting element driving circuit for supplying a stable driving current for a light-emitting element without receiving influences caused by scattering of a pinch-off voltage and a temperature change of each element. CONSTITUTION:This embodiment comprises a FET2 for supplying a driving signal for a light-emitting element and a current power source circuit 7 to which is inputted the same signal as a pulse signal which is so supplied as to set an operating point of the FET2. The current power source circuit 7 is connected to a source of the FET2 and supplies a current in proportion to a mark ratio of a pulse signal to be inputted for the FET2, whereby an amplitude of a drain current of the FET2 is made constant irrespective of the mark ratio of the pulse signal to be inputted to a gate of the FET2. |
