Image forming system employing effective optical scan-line control device

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, said beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate,
• wherein a beam deflection amount of the beam deflecting deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled,
• at least one resinous image-formation optical device is disposed in the optical scanning system,
• the beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction, and
• the beam deflection control device has liquid crystal deflection areas separated in a subscanning direction for respective laser beams corresponding to a plurality of colors, and the liquid crystal deflection areas are configured by a single laser beam transmitting member.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, wherein a beam deflection amount of the beam deflecting deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled;
• a beam separating device separating a part of the beam before it is incident on the scanning surface, wherein said beam separating device directs the thus-separated beam part toward a detection surface which is optically equivalent to the scanning surface, and then, a scan line bending state on said detection surface, which is equivalent to the scan line bending occurring on the scanning surface, is detected;
• a scanning position detection device which detects the position of scanning line on said detection surface, wherein said scanning position detection device comprises a number of optical sensors, which number is the same as the number of the beam deflection control units included in said beam deflection control device, said number of optical sensors being disposed at positions corresponding to the positions of the respective beam deflection control units and detecting the subscanning-directional positions of the optical spots, wherein
• a supporting member supporting the number of optical sensors is made of a material having a thermal expansion coefficient of not more than 1.0×10−5/° C.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface,
• wherein a beam deflection amount of the beam deflecting deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled,
• a plurality of light sources are provided, and scanning optical systems defining light paths from the respective light sources toward the respective scanning surfaces are mutually equivalent;
• one of the scanning optical systems is regarded as a reference, and, the beam deflection control device is provided on the light path in each of the other scanning optical systems, is used for correcting the scanning characteristic of each of the other scanning
• optical systems for the scanning characteristic of the reference scanning optical system, and
• a transparent member is provided on the light path of the reference scanning optical system for the purpose of correcting the difference in light path length caused by the existence of the beam deflection control device provided on the light path of each of the other scanning optical systems.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, said beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate, wherein
• a beam deflection amount of the beam deflecting device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled,
• a plurality of light sources are provided, and scanning optical systems defining light paths from the respective light sources toward the respective scanning surfaces are mutually equivalent;
• one of the scanning optical systems is regarded as a reference, and, the beam deflection control device is provided on the light path in each of the other scanning optical systems, is used for correcting the scanning characteristic of each of the other scanning optical systems for the scanning characteristic of the reference scanning optical system, and
• each of the scanning optical systems comprises a lens system, and the lens system of the reference scanning optical system is made of a material having a thermal expansion coefficient of not more than 1.0×10−5/° C.

An optical scanning device in which a plurality of beams for respective color components for forming a color image in combination are deflected, are converged by a scanning and image-formation optical system, are directed to respective scanning surfaces individually and thus performing optical scanning of the scanning surfaces respectively, so as to write images of respective color components, comprising:

• a scan line correcting device which corrects a scan line bending, wherein:
• a scan line bending on the beam of one color component is regarded as a reference scan line bending;
• the scan line correcting device electronically corrects a scan line bending of the beam of each of the other color components for the reference scan line bending;
• at least one resinous image-formation optical device is disposed in the optical scanning system;
• the scan line correcting device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction,
• laser beams corresponding to a plurality of colors have at least a single scanning image-formation device to pass through;
• and
• the control of a scanning characteristic of the optical scanning is carried out individually for each of a plurality of ranges divided in the main scanning direction.

An optical scanning control method applied to an optical scanning system in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said method comprising the steps:

• a) disposing a beam deflection control device on the light path of the beam before it is incident on the scanning surface, said beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• b) controlling a beam deflection amount of the beam deflecting control device provided to an incident beam so as to control a scanning characteristic of the optical scanning:
• and
• c) causing the incident beam to pass through the beam deflection control device without application of any beam deflection thereon when no correction of the current scanning characteristic is needed, wherein
• at least one resinous image-formation optical device is disposed in the optical scanning system;
• the beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction;
• laser beams corresponding to a plurality of colors have at least a single scanning image-formation device to pass through;
• and
• the control of the scanning characteristic of the optical scanning is carried out individually for each of a plurality of ranges divided in the main scanning direction.

A beam deflection apparatus, comprising:

• a beam deflection control device configured for use in an optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, wherein:
• said beam deflection control device is disposed on the light path of the beam before it is incident on the scanning surface, said beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• a beam deflection amount of the beam deflecting device provided to an incident beam is controlled if necessary so that a scanning characteristic of the optical scanning is controlled;
• at least one resinous image-formation optical device is disposed in the optical scanning system;
• the beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction;
• laser beams corresponding to a plurality of colors have at least a single scanning image-formation device to pass through;
• and
• the control of the scanning characteristic of the optical scanning is carried out individually for each of a plurality of ranges divided in the main scanning direction.

A beam deflection control device, comprising:

• a beam deflection device configured for use in an optical scanning device in which a plurality of beams for respective color components for forming a color image in combination are deflected, are converged by a scanning and image-formation optical system, are directed to respective scanning surfaces individually and thus performing optical scanning of the scanning surfaces respectively, so as to write images of respective color components, wherein:
• said beam deflection control device acts as a scan line correcting device which corrects a scan line bending;
• a scan line bending on the beam of one color, component is regarded as a reference scan line bending;
• the scan line correcting device electronically corrects a scan line bending of the beam of each of the other color components for the reference scan line bending;
• at least one resinous image-formation optical device is disposed in the optical scanning system;
• the beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction;
• laser beams corresponding to a plurality of colors have at least a single scanning image-formation device to pass through;
• and
• the control of a scanning characteristic of the optical scanning is carried out individually for each of a plurality of ranges divided in the main scanning direction.

A beam deflection control device used in an optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam,

• wherein:
• said beam deflection control device is used for adjusting the optical spot formed on the scanning surface:
• said beam deflection control device comprises a plurality of beam deflection control units each individually controllable of a deflection amount provided to an incident beam, arranged along a main scanning direction, each beam deflection control unit configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• the deflection amount of each beam deflection control unit is controlled according to the optical scanning;
• at least one resinous image-formation optical device is disposed in the optical scanning system;
• the beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction;
• laser beams corresponding to a plurality of colors have at least a single scanning image-formation device to pass through;
• and
• the control of a scanning characteristic of the optical scanning is carried out individually for each of a plurality of ranges divided in the main scanning direction.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, comprising:

• a liquid crystal beam deflection control device adjusting the optical spot formed on the scanning surface;
• and
• a ghost light removal device blocking a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, wherein
• said liquid crystal beam deflection control device is disposed between an optical deflection scanning device which performs the optical scanning of the scanning surface and the scanning surface, and
• said ghost light blocking device comprises a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, comprising:

• a liquid crystal beam deflection control device adjusting the optical spot formed on the scanning surface;
• and
• a ghost light removal device blocking a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, wherein
• said ghost light blocking device comprising a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, comprising:

• a liquid crystal beam deflection control device adjusting the optical spot formed on the scanning surface;
• and
• a ghost light removal device blocking a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, wherein
• said ghost light blocking device comprises a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed, and
• the following requirements by satisfied:
• L>(½)(b+Δ)/tan Θ
• where:
• ‘b’ denotes a width in a subscanning direction of each beam deflected by the liquid crystal beam deflection control device;
• ‘Δ’ denotes a width in the subscanning direction of the slit opening of the ghost light removal device;
• ‘L’ denotes a distance between the liquid crystal beam deflection control device and the slit opening of the ghost light removal device;
• and
• ‘Θ’ denotes an angle formed in the subscanning direction between the regular optical scanning beam obtained from the liquid crystal beam deflection control device and the ghost light which is nearest to said regular optical scanning beam with respect to the chief rays thereof.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, comprising:

• a liquid crystal beam deflection control device adjusting the optical spot formed on the scanning surface;
• and
• a ghost light removal device blocking a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, wherein
• said ghost light blocking device comprises a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed, and
• said ghost light removal device is provided in such a manner that it is integrally combined with any one of the optical devices disposed between the optical deflection scanning device and the scanning surface.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a liquid crystal beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, said liquid crystal beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• and
• a ghost light removal device configured to block a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, and including a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed, wherein
• a beam deflection amount of the liquid crystal beam deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled to adjust the optical spot formed on the scanning surface,
• at least one resinous image-formation optical device is disposed in the optical scanning system,
• the liquid crystal beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction, and
• the liquid crystal beam deflection control device includes liquid crystal deflection areas separated in a subscanning direction for respective laser beams corresponding to a plurality of colors, and the liquid crystal deflection areas are configured by a single laser beam transmitting member.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a liquid crystal beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, said liquid crystal beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• and
• a ghost light removal device configured to block a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, and including a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed, wherein
• a beam deflection amount of the liquid crystal beam deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled to adjust the optical spot formed on the scanning surface,
• at least one resinous image-formation optical device is disposed in the optical scanning system,
• the liquid crystal beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction,
• the liquid crystal beam deflection control device includes liquid crystal deflection areas separated in a subscanning direction for respective laser beams corresponding to a plurality of colors, and the liquid crystal deflection areas are configured by a single laser beam transmitting member, and
• the following conditions are satisfied:
• L>(½)(b+Δ)/tan Θ
• where:
• ‘b’ denotes a width in a subscanning direction of each beam deflected by the liquid crystal beam deflection control device;
• ‘Δ’ denotes a width in the subscanning direction of the slit opening of the ghost light removal device;
• ‘L’ denotes a distance between the liquid crystal beam deflection control device and the slit opening of the ghost light removal device;
• and
• ‘Θ’ denotes an angle formed in the subscanning direction between the regular optical scanning beam obtained from the liquid crystal beam deflection control device and the ghost light which is nearest to said regular optical scanning beam with respect to the chief rays thereof.

An optical scanning device in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam, said device comprising:

• a liquid crystal beam deflection control device disposed on the light path of the beam before it is incident on the scanning surface, said liquid crystal beam deflection control device configured to cause an electric field distribution in a liquid crystal by applying electricity to an electrode formed on a side of a glass substrate;
• and
• a ghost light removal device configured to block a diffracted beam occurring through said liquid crystal beam deflection control device which acts as a ghost light from reaching the scanning surface, and including a slit opening long along a main scanning direction through which only a regular optical scanning beam is passed, wherein
• a beam deflection amount of the liquid crystal beam deflection control device provided to an incident beam is controlled so that a scanning characteristic of the optical scanning is controlled to adjust the optical spot formed on the scanning surface,
• at least one resinous image-formation optical device is disposed in the optical scanning system,
• the liquid crystal beam deflection control device comprises deflection areas configured by a series of a plurality of deflection devices defined in a main scanning direction,
• the liquid crystal beam deflection control device includes liquid crystal deflection areas separated in a subscanning direction for respective laser beams corresponding to a plurality of colors, and the liquid crystal deflection areas are configured by a single laser beam transmitting member, and
• the ghost light removal device is integrally combined with any one of the optical devices disposed between the optical deflection scanning device and the scanning surface.