Patent ID: 6693659
Filing Date: 2004-02-17
Classification: G06K,H04N

Abstract:
An electrophotographic image forming apparatus which includes an LED print head having a multiplicity of LEDs disposed in an array for exposure of a photoreceptor surface, t e image forming apparatus comprising:lighting period setting means which predefines a relationship between an image density and a lighting period; and LED driving means which reads a lighting period according to a tone level of inputted image data from the lighting period setting means, and lights an LED of the LED print head for the read lighting period, wherein the light ng period setting means predefines the relationship between the image density and the lighting period by a lighting reference clock signal which has a cycle period variable depending on an image tone level on the basis of a &ggr;-characteristic of the image forming apparatus, wherein the LED driving means comprises a tone data counter which outputs a count number according to the tone level of the inputted image data, and a frequency division counter which divides a frequency of the lighting reference clock signal read out of the lighting period setting means to output pulses which are equal in number to the count number, and provides the pulses outputted from the frequency division counter as the lighting period.