Method and apparatus for optical recording and image forming capable of correcting a magnification error in scanning

An optical recording apparatus for use in a color image forming apparatus, comprising:

• a light source which sequentially emits a plurality of light beams corresponding to basic color elements of a full color image;
• a scanning mechanism configured to independently reform the plurality of light beams emitted by the light source into respective cyclic scanning light beams to sequentially scan in a main scanning direction a photosensitive surface moving in a sub-scanning direction;
• and
• a phase shift controlling mechanism configured to perform an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one, and the pixel clock signals being used for a control of the light source to turn on and off each of the cyclic scanning light beams in accordance with each of the basic color elements of the full color image.

An image forming apparatus, comprising:

• a photosensitive member having a photosensitive surface movable in a sub-scanning direction;
• an optical recorder which comprises:
• a light source which emits a light beam;
• a scanner configured to reform the light beam emitted by the light source into a cyclic scanning light beam which scans in a main scanning direction the photosensitive surface moving in the sub-scanning direction;
• and
• a phase shift controller configured to perform an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one, and the pixel clock signals being used for a control of the light source to turn the light beam on and off in accordance with image data, and
• an image forming controller configured to determine the positions, at which the phase change is performed by the phase shift controller, randomly or evenly within an effective image area.

An image forming apparatus, comprising:

• a photosensitive member having a photosensitive surface movable in a sub-scanning direction;
• an optical recorder which comprises:
• a light source which sequentially emits a plurality of light beams corresponding to basic color elements of a full color image;
• a scanner configured to independently reform the plurality of light beams emitted by the light source into respective cyclic scanning light beams to sequentially scan in a main scanning direction the photosensitive surface moving in the sub-scanning direction;
• a phase shift controller configured to perform an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one, and the pixel clock signals being used for a control of the light source to turn on and off each of the cyclic scanning light beams in accordance with each of the basic color elements of the full color image, and
• an image forming controller configured to determine the positions, at which the phase change is performed by the phase shift controller, randomly or evenly within an effective image area.

An optical recording method, comprising the steps of:

• generating a pixel clock signal;
• emitting a light beam in accordance with image data in steps of pixel clock signal;
• reforming the light beam into a cyclic scanning light beam which scans in a main scanning direction a photosensitive surface moving in a sub-scanning direction;
• and
• performing an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one.

An optical recording method for use in a color image forming apparatus, comprising the steps of:

• generating a pixel clock signal;
• emitting sequentially a plurality of light beams with a scanning mechanism in accordance with basic color elements of a full color image in steps of the pixel clock signal;
• reforming the plurality of light beams independently into respective cyclic scanning light beams to sequentially scan in a main scanning direction a photosensitive surface of the image forming apparatus moving in a sub-scanning direction;
• and
• performing an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one.

An image forming method, comprising the steps of:

• providing a photosensitive member having a photosensitive surface movable in a sub-scanning direction;
• generating a pixel clock signal;
• emitting sequentially a plurality of light beams in accordance with basic color elements of a full color image in steps of the pixel clock signal;
• reforming independently the plurality of light beams into respective cyclic scanning light beams to sequentially scan in a main scanning direction the photosensitive surface moving in the sub-scanning direction;
• performing an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one;
• and
• determining the positions, at which the phase change is performed by the performing step, randomly or evenly within an effective image area.

An optical recording apparatus, comprising:

• generating means for generating a light beam;
• reforming means for reforming the light beam generated by the generating means into a cyclic scanning light beam which scans in a main scanning direction a photosensitive surface moving in a sub-scanning direction;
• and
• correcting means for performing an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one, and the pixel clock signals being used for a control of the generating means to turn the light beam on and off in accordance with image data.

An optical recording apparatus for use in a color image forming apparatus, comprising:

• generating means for sequentially generating a plurality of light beams corresponding to basic color elements of a full color image;
• reforming means for independently reforming the plurality of light beams emitted by the generating means into respective cyclic scanning light beams to sequentially scan in a main scanning direction a photosensitive surface moving in a sub-scanning direction;
• and
• correcting means for performing an image magnification correction by a phase change for changing a phase of pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, n being an integer greater than one, and the pixel clock signals being used for a control of the generating means to turn on and off each of the cyclic scanning light beams in accordance with each of the basic color elements of the full color image.