| 摘要 |
PURPOSE:To enhance the stability by eliminating the possibility of error in memory information by providing a constant current source which injects the current of a fixed value and a means of reducing the current of a value determined from an injected current by means of input control signals. CONSTITUTION:Only a current I1 of the constant current 201 is injected to the titled laser 200 at all times, and either one of amounts of emitted light of P0 or P1 is held to the laser 200. The laser 200 is set by giving an incidence light Pin having a light amount of Pt or more, and the amount of emitted light P1 is held even on removal of the light Pin. When a voltage V is applied to a control signal input terminal 203, a transistor 300 turns on, and most of the current I1 flows into the collector of the transistor 300. The laser 200 is reset and helds the amount of emitted light P0 even when the control input voltage becomes 0. The factor of memory information error becomes only the variation in current I1 of a constant amount source 201, and stable action can be performed. |
