Multi-beam light source device and multi-beam scanning apparatus using the same

A multi-beam scanning apparatus in which an optical scanning device scans a surface of a photosensitive medium in a main scanning direction by focusing multiple light beams of a multi-beam light source device onto the scanned surface, the multi-beam light source device comprising:

• a light source unit holding light sources and coupling lenses, the coupling lenses coupling light beams emitted by the light sources;
• a base member holding the light source unit such that the light beams from the light source unit held by the base member are rotatable around an axis which passes through a point of intersection of the light beams and is perpendicular to a sub-scanning cross-section in a sub-scanning direction of the optical scanning device;
• and
• an angle adjustment mechanism configured to adjust a mounting angle of the light source unit relative to the base member with respect to the sub-scanning direction, so that respective pitches of beam spots, formed on the scanned surface by the light beams, in the sub-scanning direction are variable in accordance with the mounting angle adjustment.

A multi-beam light source device comprising:

• first light source means for holding first light sources and first coupling lenses, the first coupling lenses coupling light beams emitted by the first light sources;
• second light source means for holding second light sources and second coupling lenses, the second coupling lenses coupling light beams emitted by the second light sources;
• base member means for holding the first light source means and the second light source means such that the light beams from at least one of the first and second light source means held by the base member means are rotatable around an axis which passes through a point of intersection of the light beams and is perpendicular to a sub-scanning cross-section in a sub-scanning direction;
• beam synthesizing means for converting the light beams from the first and second light source means into adjacent light beams that are adjacent to each other and directed to a scanned surface along an emission axis perpendicular to the scanned surface;
• and
• angle adjustment means for adjusting a mounting angle of at least one of the first and second light source means relative to the base member means with respect to the sub-scanning direction, so that respective pitches of beam spots, formed on the scanned surface by the light beams, in the sub-scanning direction are variable in accordance with the mounting angle adjustment.

A multi-beam light source device for use in a multi-beam scanning apparatus in which an optical scanning unit scans a surface of a photosensitive medium in a main scanning direction by focusing multiple light beams of the multi-beam light source device onto the scanned surface, the multi-beam light source device comprising:

• a light source unit supporting light sources and coupling lenses to array the light sources in the main scanning direction, the coupling lenses coupling light beams emitted by the light sources;
• an angle adjustment mechanism which adjusts a mounting angle of the light source unit relative to a base member with respect to a sub-scanning direction;
• and
• an optical path changing unit changing an optical path of part of the light beams of the light source unit such that the light beams from the light source unit and the light beams from the optical path changing unit are converted into adjacent light beams that intersect each other in the main scanning direction in the vicinity of a deflector of the optical scanning unit, the optical path changing unit being provided to vary an intersecting angle of the adjacent light beams.

A multi-beam light source device comprising:

• a light source holder holding a plurality of light sources, the light sources emitting multiple light beams;
• and
• a fastening member supporting the light source holder to maintain a direction of the light source holder relative to an emission axis of the light beams, the fastening member having fastening portions secured to a base member that is fixed to a focusing optical device, wherein the light source holder and the fastening member form a light source unit;
• and
• a mounting member supporting the light source unit on the base member by exerting a pressing force on the light source unit against the base member so as to match a direction of the light source unit relative to the base member with an emission axis perpendicular to a scanned surface of an optical scanning unit.

A multi-beam scanning apparatus in which an optical scanning unit scans a surface of a photosensitive medium in a main scanning direction by focusing multiple light beams of a multi-beam light source device onto the scanned surface, the multi-beam light source device comprising:

• a light source unit supporting light sources and coupling lenses to array the light sources in the main scanning direction, the coupling lenses coupling light beams emitted by the light sources;
• an angle adjustment mechanism which adjusts a mounting angle of the light source unit relative to a base member with respect to a sub-scanning direction;
• and
• an optical path changing unit changing an optical path of part of the light beams of the light source unit such that the light beams from the light source unit and the light beams from the optical path changing unit are converted into adjacent light beams that intersect each other in the main scanning direction in the vicinity of a deflector of the optical scanning unit, the optical path changing unit being provided to vary an intersecting angle of the adjacent light beams.

A multi-beam scanning apparatus comprising:

• light source holder means for holding a plurality of light sources, the light sources emitting multiple light beams;
• fastening member means for supporting the light source holder to maintain a direction of the light source holder means relative to an emission axis of the light beams, the fastening member means having fastening portions secured to a fixed base member, wherein the light source holder means and the fastening member means form a light source unit;
• optical scanning means for focusing the light beams from the light source unit onto a scanned surface;
• mounting member means for supporting the light source unit on the base member by exerting a pressing force onto the base member so as to match a direction of the light source unit relative to the base member with an emission axis perpendicular to the scanned surface of the optical scanning means;
• and
• torsion bar means for connecting the light source holder means to the fastening member means by bringing the fastening member means into contact with a contact portion of the base member by a torsional force of the torsion bar means.

A multi-beam scanning apparatus including a multi-beam light source device, the multi-beam light source device comprising:

• a light source holder holding a plurality of light sources, the light sources emitting multiple light beams;
• and
• a fastening member supporting the light source holder to maintain a direction of the light source holder relative to an emission axis of the light beams, the fastening member having fastening portions secured to a base member that is fixed to a focusing optical device, wherein the light source holder and the fastening member form a light source unit;
• and
• a mounting member supporting the light source unit on the base member by exerting a pressing force onto the base member so as to match a direction of the light source unit relative to the base member with an emission axis perpendicular to a scanned surface of an optical scanning unit.

A multi-beam light source device comprising:

• first light source holder means for holding first light sources and first coupling lenses, the first coupling lenses coupling light beams emitted by the first light sources;
• second light source holder means for holding the second light sources and the second coupling lenses, the second coupling lenses coupling light beams emitted by the second light sources, wherein the first and second light source holder means form a light source unit;
• base member means for integrally supporting the first light source holder means and the second light source holder means by applying pressure of an elastic member to positions that cross over an emission axis of the light source unit, so as to maintain a direction of the light source holder relative to the emission axis,
• wherein each of the first and second light source holder means is mounted on the base member such that an optical path direction of the light sources of the light source unit to the base member is rotatable around a central axis of the light sources.

A multi-beam light source device comprising:

• light source holder means for holding a plurality of light sources, the light sources emitting multiple light beams;
• fastening means for supporting the light source holder means to maintain a direction of the light source holder means relative to an emission axis of the light beams, the fastening means having fastening portions secured to a base member that is fixed to a focusing optical device, wherein the light source holder means is separately provided with and attached to the fastening means to form an integral light source unit, and the light source holder means and the fastening means are of different materials;
• and
• angle adjustment means for adjusting a mounting angle of the light source unit relative to the base member, so that respective pitches of beam spots, formed on a scanned surface by the light beams, in a direction perpendicular to a main scanning direction are variable in accordance with the mounting angle adjustment.

An image forming system including a multi-beam light source device and a multi-beam scanning apparatus, the multi-beam light source device comprising:

• a light source unit holding light sources and coupling lenses, the coupling lenses coupling light beams emitted by the light sources;
• a base member holding the light source unit such that the light beams from the light source unit held by the base member are rotatable around an axis which passes through a point of intersection of the light beams and is perpendicular to a sub-scanning cross-section in a sub-scanning direction of an optical scanning device;
• and
• an angle adjustment mechanism configured to adjust a mounting angle of the light source unit relative to the base member with respect to the sub-scanning direction, so that respective pitches of beam spots, formed on a scanned surface by the light beams, in the sub-scanning direction are variable in accordance with the mounting angle adjustment.

An image forming system including a multi-beam light source device and a multi-beam scanning apparatus, the multi-beam light source device comprising:

• a light source holder holding a plurality of light sources, the light sources emitting multiple light beams;
• and
• a fastening member supporting the light source holder to maintain a direction of the light source holder relative to an emission axis of the light beams, the fastening member having fastening portions secured to a base member that is fixed to a focusing optical device, wherein the light source holder and the fastening member form a light source unit;
• and
• a mounting member supporting the light source unit on the base member by exerting a pressing force on the light source unit against the base member so as to match a direction of the light source unit relative to the base member with an emission axis perpendicular to a scanned surface of an optical scanning unit.