Abstract: Because the prior art liquid crystal driving control circuit needs shift registers, latch circuits and selectors in a number corresponding to the number of cells in the liquid crystal shutter array, the structure of the circuit inevitably becomes complicated and involves a large number of components to thereby push up the production cost. Since this invention method controls a liquid crystal shutter array with pulse width modulation, image data can be serially converted into the data necessary for switching ON/OFF the driving voltage, and the conversion circuit can be structured with only one system. As this invention method controls opening/closing of the cells with binary pulse width signals in a number corresponding to the number of liquid crystal cells, the structure of the circuit can be simplified and yet efficiency of recording in controlled gradation can be enhanced.

Abstract: Because the prior art liquid crystal driving control circuit needs shift registers, latch circuits and selectors in a number corresponding to the number of cells in the liquid crystal shutter array, the structure of the circuit inevitably becomes complicated and involves a large number of components to thereby push up the production cost. Since this invention method controls a liquid crystal shutter array with pulse width modulation, image data can be serially converted into the data necessary for switching ON/OFF the driving voltage, and the conversion circuit can be structured with only one system. As this invention method controls opening/closing of the cells with binary pulse width signals in a number corresponding to the number of liquid crystal cells, the structure of the circuit can be simplified and yet efficiency of recording in controlled gradation can be enhanced.

Abstract: Multiple light-emitting diodes in an array are supplied with a constant amount of electric current and the duration of time for which that current is supplied to the individual light-emitting diodes is changed according to the specific level of contrast to be produced. The amount of light received by a light-sensitive material can thus be controlled so that a halftone image is formed. The duration of time for which the electric current is applied to the individual light-emitting diodes consists of a predetermined constant portion and a variable portion to be added thereto. The variable portion is compensated for in accordance with the difference between the relative intensities of light emission from the individual light-emitting diodes when they are supplied with the constant electric current.

Abstract: An image forming method and apparatus characterized in that current supply periods of time to light-emitting diodes constituting a light-emitting diode arrays are controlled corresponding to gradation levels while a constant current is being supplied to the light-emitting diodes, and in that the current supply period of time is adjusted at every gradation level corresponding to the variations in light intensity of the light-emitting diodes when the constant current is supplied to thereby correct for the variations in output light intensities of the light-emitting diodes.