| 摘要 |
PURPOSE:To obtain a high picture quality picture in which no uneven density is caused onto a gradation recording material with excellent color balance without any deterioration in picture quality and fluctuation in the gradation characteristic by providing a specific picture element clock generating circuit, a specific integration device, a specific comparator and a specific temperature control means to the exposure respectively. CONSTITUTION:A temperature controller 62 is used to keep the temperature of circuit components susceptible to the effect of temperature fluctuation such as those for at least a picture element clock generating circuit (frequency divider) 52, an integration device 56 and a transfer circuit (driver) 54 for various signals, especially for those of a transfer circuit 64 most susceptible to temperature fluctuation among circuit components of a modulation means 32 modulating a light beam at a prescribed narrow band wavelength into the exposure intensity in response to a digital picture signal in picture element synchronization a constant temperature. Thus, the temperature fluctuation of the circuit components is eliminated, a modulation signal in response to a picture signal accurately is stably outputted without causing deformation or deviation in various pulse signals, picture element clock pulses, triangle waves and modulation signals in the modulation means 32. |
