ALIGNER, EXPOSURE METHOD AND PRINTER

摘要

In an aligner in which a photosensitive medium such as a saicolor medium is exposed by a light emitting device such as an LED, the correction of the environmental conditions which vary with temperature, etc. at the time of exposure is performed by changing the value of the current or voltage supplied to the LED dynamically. With this constitution, the exclusive control of the exposure time is available in order to form an image of multigradation level, so that an unnecessarily high resolution for the control of the exposure time is not required and an aligner by which a multigradation image is printed is realized at a low cost. Further, when exposure to one color is executed by a plurality of LEDs, if the gradation levels expressed by the respective LEDs is changed cyclically, the gradation levels of the respective LEDs are controlled with a simple constitution. Moreover, as a plurality of the LEDs can be used with approximately the same duty, difference of individual LEDs does not appear clearly and a drawback of the deterioration of specific LEDs, etc. is avoided.