Image forming method, image forming apparatus, optical scan device, and image forming apparatus using the same

An image forming apparatus configured to scan a plurality of media, comprising:

• a plurality of light beam source parts configured to emit light beams modulated by image data and pixel clock data from corresponding pixel clocks, the emitted light beams corresponding in number to the plurality of media to be scanned;
• a deflector configured to be driven by a rotating motor, the deflector having a plurality of separate scanning portions less in number than the number of the plurality of media, the separate scanning portions being configured to cause each emitted light beam received from the plurality of light beam source parts to be deflected so as to form separate scanning light beams, each separate scanning light beam being used to scan a corresponding different one of the plurality of media;
• a plurality of scan optical systems corresponding in number to the plurality of media, each one of the scan optical systems being configured to receive each separate scanning light beam from the plurality of separate scanning portions and to project each separate scanning light beam onto the corresponding different one of the plurality of media to form a scanned image thereon;
• a plurality of temperature detectors configured to detect temperature information indicating temperatures of the plurality of scan optical systems;
• and
• a plurality of scanning light beam detectors, each scanning light beam detector being configured to detect a corresponding separate scanning light beam at a predetermined position with respect to a corresponding one of the plurality of media being scanned and to output a corresponding detection signal,
• wherein the image forming apparatus is configured to:
• scan each different one of the plurality of media with a predetermined timing based on the corresponding detection signal so as to form the scanned image on each different one of the plurality of media,
• correct a displacement of scan positions of each of the scanned images on each of the plurality of media being scanned by adjusting a phase of the corresponding pixel clock based on the temperature information detected by the plurality of temperature detectors, and
• form a superposed image by superposing the scanned images formed on each different one of the plurality of media.

An image forming method using an image forming apparatus configured to scan a plurality of media, the image forming apparatus comprising:

• a plurality of light beam source parts configured to emit light beams modulated by image data and pixel clock data from corresponding pixel clocks, the emitted light beams corresponding in number to the plurality of media to be scanned, the light beam source parts each including a semiconductor laser as a light beam source;
• a deflector configured to be driven by a rotating motor, the deflector having a plurality of separate scanning portions less in number than the number of the plurality of media, the separate scanning portions being configured to cause each emitted light beam received from the plurality of light beam source parts to be deflected so as to form separate scanning light beams, each separate scanning light beam being used to scan a corresponding different one of the plurality of media;
• a plurality of scan optical systems corresponding in number to the plurality of media, each one of the scan optical systems being configured to receive each separate scanning light beam from the plurality of separate scanning portions and to project each separate scanning light beam onto the corresponding different one of the plurality of media to form a scanned image thereon;
• a plurality of temperature detectors configured to detect temperatures close to each of the light beam source parts;
• and
• a plurality of scanning light beam detectors, each scanning light beam detector being configured to detect a corresponding separate scanning light beam at a predetermined position with respect to a corresponding one of the plurality of media being scanned and to output a corresponding detection signal,
• the image forming method comprising the steps of:
• scanning each different one of the plurality of media using the image forming apparatus with a predetermined timing based on the corresponding detection signal so as to form the scanned image on each different one of the plurality of media;
• correcting a displacement of scan positions of each of the scanned images on each of the plurality of media being scanned by adjusting a phase of the corresponding pixel clock based on the temperature information detected by the plurality of temperature detectors;
• and
• forming a superposed image by superposing the scanned images formed on each different one of the plurality of media.

An image forming apparatus, comprising:

• a plurality of light beam source parts configured to emit light beams modulated by image data and pixel clock data from corresponding pixel clocks, the emitted light beams corresponding in number to the plurality of media to be scanned, the light beam source parts each including a semiconductor laser as a light beam source;
• a deflector configured to be driven by a rotating motor, the deflector having a plurality of separate scanning portions less in number than the number of the plurality of media, the separate scanning portions being configured to cause each emitted light beam received from the plurality of light beam source parts to be deflected so as to form separate scanning light beams, each separate scanning light beam being used to scan a corresponding different one of the plurality of media;
• a plurality of scan optical systems corresponding in number to the plurality of media, each one of the scan optical systems being configured to receive each separate scanning light beam from the plurality of separate scanning portions and to project each separate scanning light beam onto the corresponding different one of the plurality of media to form a scanned image thereon;
• a plurality of temperature detectors configured to detect temperatures close to each of the light beam source parts;
• and
• a plurality of scanning light beam detectors, each scanning light beam detector being configured to detect a corresponding separate scanning light beam at a predetermined position with respect to a corresponding one of the plurality of media being scanned and to output a corresponding detection signal,
• wherein the image forming apparatus is configured to:
• scan each different one of the plurality of media with a predetermined timing based on the corresponding detection signal so as to form the scanned image on each different one of the plurality of media,
• correct a displacement of scan positions of each of the scanned images on each of the plurality of media being scanned by adjusting a phase of the corresponding pixel clock based on the temperature information detected by the plurality of temperature detectors, and
• form a superposed image by superposing the scanned images formed on each different one of the plurality of media.

An image forming method using an image forming apparatus configured to scan a plurality of media, the image forming apparatus comprising:

• a plurality of light beam source parts configured to emit light beams modulated by image data and pixel clock data from corresponding pixel clocks, the emitted light beams corresponding in number to the plurality of media to be scanned;
• a deflector configured to be driven by a rotating motor, the deflector having a plurality of separate scanning portions less in number than the number of the plurality of media, the separate scanning portions being configured to cause each emitted light beam received from the plurality of light beam source parts to be deflected so as to form separate scanning light beams, each separate scanning light beam being used to scan a corresponding different one of the plurality of media;
• a plurality of scan optical systems corresponding in number to the plurality of media, each one of the scan optical systems being configured to receive each separate scanning light beam from the plurality of separate scanning portions and to project each separate scanning light beam onto the corresponding different one of the plurality of media to form a scanned image thereon;
• a temperature detector configured to detect temperature close to the rotating motor of the deflector;
• and
• a plurality of scanning light beam detectors, each scanning light beam detector being configured to detect a corresponding separate scanning at a predetermined position with respect to a corresponding one of the plurality of media being scanned and to output a corresponding detection signal,
• the image forming method comprising the steps of:
• scanning each different one of the plurality of media using the image forming apparatus with a predetermined timing based on the corresponding detection signal so as to form the scanned image on each different one of the plurality of media;
• correcting a displacement of scan positions of each of the scanned images on each of the plurality of media being scanned by adjusting a phase of the corresponding pixel clock based on the temperature information detected by the temperature detector;
• and
• forming a superposed image by superposing the scanned images formed on each different one of the plurality of media.

An image forming apparatus, comprising:

• a plurality of light beam source parts configured to emit light beams modulated by image data and pixel clock data from corresponding pixel clocks, the emitted light beams corresponding in number to the plurality of media to be scanned;
• a deflector configured to be driven by a rotating motor, the deflector having a plurality of separate scanning portions less in number than the number of the plurality of media, the separate scanning portions being configured to cause each emitted light beam received from the plurality of light beam source parts to be deflected so as to form separate scanning light beams, each separate scanning light beam being used to scan a corresponding different one of the plurality of media;
• a plurality of scan optical systems corresponding in number to the plurality of media, each one of the scan optical systems being configured to receive each separate scanning light beam from the plurality of separate scanning portions and to project each separate scanning light beam onto the corresponding different one of the plurality of media to form a scanned image thereon;
• a temperature detector configured to detect temperature close to the rotating motor of the deflector;
• and
• a plurality of scanning light beam detectors, each scanning light beam detector being configured to detect a corresponding separate scanning light beam at a predetermined position with respect to a corresponding one of the plurality of media being scanned and to output a corresponding detection signal,
• wherein the image forming apparatus is configured to:
• scan each different one of the plurality of media with a predetermined timing based on the corresponding detection signal so as to form the scanned image on each different one of the plurality of media,
• correct a displacement of scan positions of each of the scanned images on each of the plurality of media being scanned by adjusting a phase of the corresponding pixel clock based on the temperature information detected by the temperature detector, and
• form a superposed image by superposing the scanned images on each different one of the plurality of media.

An optical scan device having an optical deflector configured to deflect a light beam from a light beam source and having a surface scanned by the deflected light beam from the deflector so as to write information on the surface, the optical scan device comprising:

• optical detectors arranged at least at a start side of writing location and an end side of writing location, the start side of writing location and the end side of writing location being outside of an effective writing area;
• a measuring part configured to measure a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors at the start side of writing location and the end side of writing location;
• an estimation part configured to estimate offset of a dot position based on a relationship between a characteristic value and the scan time measured by the measuring part;
• and
• a correcting part configured to shift the dot position of image data in the effective writing area to an arbitrary position based on the offset estimate of the estimation part.

An optical scan device having an optical deflector configured to deflect a light beam from a light beam source and having a surface scanned by the deflected light beam from the deflector so as to write information on the surface, the optical scan device comprising:

• optical detectors arranged at least at a start side of writing location and an end side of writing location, the start side of writing location and the end side of writing location being outside of an effective writing area;
• a measuring part configured to measure a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors at the start side of writing location and the end side of writing location;
• a look-up table configured to record in advance a relationship between the scan time in the area between the optical detectors and a correction amount for shifting the dot position to an arbitrary position;
• and
• a correction part configured to shift each dot position of image data in the effective writing area to the arbitrary position based on the look-up table,
• wherein a phase shift amount for obtaining the arbitrary position is set based on a measured result of the scan time.

An optical scan device having an optical deflector deflecting a light beam from a light beam source so as to deflect the light beam and having a surface to be scanned on which information is written such that the light beam deflected by the deflector scans the surface, the optical scan device comprising:

• a temperature sensor;
• a look-up table configured to record in advance a relationship between a temperature change detected by the temperature sensor and a corresponding phase shift to be applied to a pixel clock;
• and
• a correcting part configured to shift each dot position of image data in an effective writing area to an arbitrary position based on the temperature change and the corresponding phase shift being applied to the pixel clock.

An image forming apparatus, comprising:

• an optical deflector configured to deflect a light beam from a light beam source;
• a surface scanned by the deflected light beam from the deflector so as to write information on the surface;
• optical detectors arranged at least at a start side of writing location and an end side of writing location, the start side of writing location and the end side of writing location being outside of an effective writing area;
• a measuring part configured to measure a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors at the start side of writing location and the end side of writing location;
• an estimation part configured to estimate offset of a dot position based on a relationship between a characteristic value and the scan time measured by the measuring part;
• and
• a correcting part configured to shift the dot position of image data in the effective writing area to an arbitrary position based on the offset estimate of the estimate part.

An image forming apparatus, comprising:

• an optical deflector configured to deflect a light beam from a light beam source;
• a surface scanned by the deflected light beam from the optical deflector so as to write information on the surface;
• a temperature sensor;
• a look-up table configured to record in advance a relationship between a temperature change detected by the temperature sensor and a corresponding phase shift to be applied to a pixel clock;
• and
• a correcting part configured to shift each dot position of image data included in said information in an effective writing area to an arbitrary position based on the temperature change and the corresponding phase shift being applied to the pixel clock,
• wherein an electrostatic latent image is formed on the surface being scanned as said information, the image forming apparatus being further configured to develop and transfer the electrostatic latent image onto a sheet of transfer paper.