Image forming apparatus and main scanning scale correcting method therefor

An image forming apparatus comprising:

• a pixel division modulating device that performs pixel-division modulation on an input image signal and outputs the pixel-division-modulated image signal in synchronism with an image clock of a fixed frequency;
• a laser light source;
• a driving device that drives said laser light source based on the image signal outputted from said pixel division modulating device to modulate laser light emitted from said laser light source;
• a latent image carrier;
• and
• a scanning device that scans said latent image carrier using the laser light emitted from said laser light source to form a latent image on said latent image carrier;
• wherein said pixel division modulating device comprises a correction device that, for each of at least one correction point on one of lines along which scanning is carried out on said latent image carrier by laser light, adds leading bit data of pixel-division-modulated pixel data of a pixel preceding the correction point to pixel-division-modulated pixel data of a pixel located at the correction point as leading bit data thereof, and sequentially shifts predetermined bit data of pixel-division-modulated pixel data of each of pixels subsequent to the correction point to a next pixel to generate pixel data of at least one new pixel added for the one line, and an output device that outputs the pixel data of the generated at least one new pixel in synchronism with the image clock of the fixed frequency.

A main scanning scale correcting method for an image forming apparatus comprising a pixel division modulating device that performs pixel-division modulation on an input image signal and outputs the pixel-division-modulated image signal in synchronism with an image clock of a fixed frequency, a laser light source, a driving device that drives the laser light source based on the image signal outputted from the pixel division modulating device to modulate laser light emitted from the laser light source, a latent image carrier, and a scanning device that scans the latent image carrier using the laser light emitted from the laser light source to form a latent image on the latent image carrier, the method comprising the steps of:

• adding, for each of at least one correction point on one of lines along which scanning is carried out on said latent image carrier by laser light, final bit data of pixel-division-modulated pixel data of a pixel preceding the correction point to pixel-division-modulated pixel data of a pixel located at the correction point as leading bit data thereof, and sequentially shifting predetermined bit data of pixel-division-modulated pixel data of each of pixels subsequent to the correction point to a next pixel to generate pixel data of at least one new pixel added for the one line;
• and
• outputting the pixel data of the generated at least one new pixel in synchronism with the image clock of the fixed frequency.

A main scanning scale correcting method for an image forming apparatus comprising a pixel division modulating device that performs pixel-division modulation on an input image signal and outputs the pixel-division-modulated image signal in synchronism with an image clock of a fixed frequency, a laser light source, a driving device that drives the laser light source based on the image signal outputted from the pixel division modulating device to modulate laser light emitted from the laser light source, a latent image carrier, and a scanning device that scans the latent image carrier using the laser light emitted from the laser light source to form a latent image on the latent image carrier, the method comprising the steps of:

• adding, for each of at least one correction point on one of lines along which scanning is carried out on said latent image carrier by laser light, leading bit data of pixel-division-modulated pixel data of a pixel preceding the correction point to pixel-division-modulated pixel data of a pixel located at the correction point as leading bit data thereof, and sequentially shifting predetermined bit data of pixel-division-modulated pixel data of each of pixels subsequent to the correction point to a next pixel to generate pixel data of at least one new pixel added for the one line;
• and
• outputting the pixel data of the generated at least one new pixel in synchronism with the image clock of the fixed frequency.