| 摘要 |
PURPOSE:To enable images with the same density to be projected by a method wherein a density determined according to a use mode of a projector for projecting a recorded image on a screen by casting light on a recording medium is preliminarily set, and the use mode is selected by a switching means. CONSTITUTION:A changeover switch 16 is turned ON or OFF selectively according as the recording medium is one for a transmission-type OHP or a reflection- type OHP. A changeover signal from the switch 16 is sent through a controlling part 15 to a power supply controlling part 13. When the changeover signal corresponding to the transmission-type OHP is sent, the power supply controlling part 13 turns OFF a transistor Tr, so that a voltage VTH to be applied to a thermal head part 12 is made to be V - R1I2. When the recording medium for the reflection-type OHP is selected, the transistor Tr is turned ON, so that a current flows also to a resistor R3, and the voltage VTH to be applied to the thermal head part 12 is made to be V - R1(I2 + I3). Thus, the voltage corresponding to the transmission-type OHP is higher, and the density of an image transferred onto the relevant OHP recording medium is higher. It is thereby possible to equalize the apparent projected densities obtained on the two types of OHPs. |
