| 摘要 |
PURPOSE: To print highly definite images such as thin lines and halftones clearly by cutting off laser light bias current when image information is not outputted for more than a prescribed period, using a laser light output varying means. CONSTITUTION: A light output varying means is composed of a memory 7, integration circuits 8, 9, transistors 11, 12, a thermistor 4, and a voltage comparator 5 around a CPU 6. The CPU 6 detects a voltage level for light emission by the thermistor 4 which is fitted near a laser diode element 3 and whose resistance changes in accordance with temperature and a partial pressure resistor R1 as atmospheric temperature of the laser diode element 3 through an A/DP1. The CPU6 refers a laser emission threshold current value at which the laser diode body 1 begins to emits light to L.U.T(Look Up Table) stored in the memory 7 on the basis of temperature information thus obtained. |
