Patent ID: 7292258
Filing Date: 2007-11-06
Classification: H01Q

Abstract:
1. A multibeam scanning optical apparatus for forming an image on a photosensitive member by irradiating the photosensitive member with beams at predetermined intervals in a secondary scanning direction, the beams being emitted from a plurality of beam generating elements spaced at predetermined intervals in a direction, the apparatus comprising: a plurality of memory portions each for storing image data for a respective one of the beam generating elements line by line; a determiner for checking the light emission state as to whether each of the beam generating elements operates normally or suffers a failure and for specifying the beam generating elements operating normally and arranged in a continuous row which are the largest in number of beam generating elements when at least one of the beam generating elements suffers a failure; a memory controller for controlling writing and reading of image data with respect to the memory portions, the memory controller causing the image data to be written in and read out successively line by line only with respect to the memory portions corresponding to the specified beam generating elements specified by the determiner; a driver for controlling the light emission of the beam generating elements, the driver performing the light emission control only with respect to the specified beam generating elements specified by the determiner; a deflector controller for controlling the number of revolutions of a deflector for deflecting and scanning a plurality of beams, the deflector controller being capable of changing the number of revolutions of the deflector depending on the number of the specified beam generating elements specified by the determiner; and a pixel clock controller for controlling a pixel clock frequency, the pixel clock controller being capable of changing the pixel clock frequency depending on the number of the specified beam generating elements specified by the determiner.