Patent ID: 6222580
Filing Date: 2001-04-24
Classification: G02B,G06K,H04N

Abstract:
An electrophotographic image forming method, in which (a) when a laser beam emitted from laser emitting means in response to a driving current supplied from current supply means is deflected and scanned by beam deflection means in a main scanning direction, and exposes and scans latent image carrier means which moves in a sub-scanning direction, (i) the driving current is pulse-width-modulated by current modulation means in correspondence with externally input image data, (ii) a latent image formed on said latent image carrier means is developed by toner and is transferred onto a recording medium, and (iii) pulse width modulation of the driving current is started a predetermined period of time after beam detection by beam detection means which is located at a position which leads said latent image carrier means in the main scanning direction, (b) when said beam detection means detects the deflectively scanned laser beam, said laser emitting means is controlled to continuously emit a laser beam and laser monitor means detects a light amount of the laser beam, and (c) the driving current of said current supply means is adjusted in correspondence with the detected light amount, comprising the steps of:generating predetermined adjustment data by adjustment supply means, and supplying the adjustment data to said current modulation means in the same manner as image data;detecting the laser beam, which is pulse-width-modulated by said current modulation means on the basis of the supplied adjustment data, and is emitted from said laser emitting means, by said laser monitor means under the control of monitor control means; andstarting supply of the adjustment data by said adjustment supply means and detection control by said monitor control means a predetermined period of time after beam detection of said beam detection means, when a pulse width of said current modulation means is adjusted in correspondence with the light amount detected by said laser monitor means.