Patent ID: 8149192

Claim:
An optical writing image forming device comprising: a positioning section that includes a drive section and a controller, the positioning section positioning an image writing light source head with respect to an optically written display medium, the optically written display medium comprising a pair of electrodes with at least one of which is formed by a group of a plurality of sub-electrodes electrically separated from each other and disposed along one direction, a display layer that changes in reflectance ratio according to voltage applied between the pair of electrodes, and a photoconductor layer capable of voltage modulation by light irradiation, changing the reflectance ratio of the display layer; a display layer initialization section having an initialization light source capable of irradiating initialization light, the display layer initialization section being configured to apply an initialization voltage between the pair of electrodes and initialization light irradiation at the same time over the entire region of the photoconductor layer using the initialization light source, in order to initialize the display layer to give a uniform reflectance ratio; and an optical writing section having the image writing light source head that is capable of scanning movement in a space between the initialization light source and the optically written display medium, the optical writing section being positioned by the positioning section and is configured to carry out light irradiation according to image information, the optical writing section executing the scanning movement of the image writing light source head along an array direction of the sub-electrode group after the display layer has been given the uniform reflectance ratio by the initialization voltage application and the initialization light irradiation using the display layer initialization section; wherein the positioning section identifies which of the sub-electrodes corresponds to the position of the image writing light source head during the scanning movement when a case arises in which it is necessary to stop ongoing light irradiation by the optical writing section according to the image information; and the display layer initialization section, based on information about the position of the image writing light source head identified by the positioning section, erases in a time-series at least writing information in the display layer corresponding to the group of the plurality of sub-electrodes by selecting the sub-electrodes in sequence so that the image writing light source head does not obstruct light emitted from the initialization light source while the image writing head light source is being returned to a standby position.