| 摘要 |
PURPOSE:To prevent nonuniformity of density from appearing in a page, by a method wherein an impressed voltage set at the top of a page is maintained during recording on the page, and impressed energy is controlled by regulating the width of impressed pulses. CONSTITUTION:Parallel data 47 on the resistance of a thermistor 42 are latched in the first latch circuit 48. The signal is supplied to the second latch circuit 51 and a substrate temperature information calculating circuit 52, a substrate temperature signal 49 is taken in by the circuit 51 in response to a latch clock 53 at the recording- starting position on a page, and is maintained until the recording on the page is finished. A source voltage controlling circuit 64 outputs a voltage-controlling signal to a power source 65 for impressing a voltage, in response to a substrate temperature initial signal 63, and the output voltage VOUT is controlled according to the substrate temperature. On the other hand, the circuit 52 forms a substrate temperature difference information 68 from the signals 49, 63, corrects the current-passing time of the impressed pulse in accordance with current-passing information 71, and outputs current- passing information 72. Accordingly, the impressed voltage is not switched in the same page, and no sharp change occurs in the impressed energy, so that images can be displayed with uniform density and high image quality. |
