WO2004063790A1 - 光走査装置およびカラー画像形成装置 - Google Patents
光走査装置およびカラー画像形成装置 Download PDFInfo
- Publication number
- WO2004063790A1 WO2004063790A1 PCT/JP2003/015688 JP0315688W WO2004063790A1 WO 2004063790 A1 WO2004063790 A1 WO 2004063790A1 JP 0315688 W JP0315688 W JP 0315688W WO 2004063790 A1 WO2004063790 A1 WO 2004063790A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- optical
- curved
- light beam
- light
- mirror
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
- G02B26/12—Scanning systems using multifaceted mirrors
- G02B26/125—Details of the optical system between the polygonal mirror and the image plane
- G02B26/126—Details of the optical system between the polygonal mirror and the image plane including curved mirrors
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
- G02B26/12—Scanning systems using multifaceted mirrors
- G02B26/123—Multibeam scanners, e.g. using multiple light sources or beam splitters
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/12—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers
- G06K15/1238—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point
- G06K15/1257—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on more than one main scanning line
- G06K15/1261—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on more than one main scanning line using an array of light sources
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/113—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using oscillating or rotating mirrors
- H04N1/1135—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using oscillating or rotating mirrors for the main-scan only
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/12—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using the sheet-feed movement or the medium-advance or the drum-rotation movement as the slow scanning component, e.g. arrangements for the main-scanning
- H04N1/121—Feeding arrangements
- H04N1/1215—Feeding using one or more cylindrical platens or rollers in the immediate vicinity of the main scanning line
Definitions
- the present invention relates to a color image forming apparatus typified by a laser beam printer, a laser facsimile, a digital copier, and the like, and an optical scanning device used for these.
- Background art a laser beam printer, a laser facsimile, a digital copier, and the like, and an optical scanning device used for these.
- a plurality of image forming units are arranged in order on a paper transport path along a horizontal direction, and a sheet moving along the paper transport path from each of the image forming units.
- tandem type in which toner images are sequentially transferred to form a blank image on paper.
- an optical scanning device used in a tandem-type color image forming apparatus one using only four optical scanning devices that scan a single light beam (see Japanese Patent Application Laid-Open No. 2000-1417 ⁇ ) and a single optical deflection device
- An apparatus using a lens and four lens systems see JP-A-2001-133717
- an apparatus using four sets of curved mirrors and lenses see JP-A-10-148777) are known.
- each of the optical scanning devices proposed above has a problem that the number of components is large, the cost is high, and it is difficult to make the performance of each scanning line uniform. Disclosure of the invention
- the present invention has been made in view of the above problems, and has a low cost and excellent optical performance.
- An object of the present invention is to provide an undemand type color image forming apparatus and an optical scanning apparatus suitably used for the apparatus.
- an optical scanning device includes: a plurality of light sources; a single light deflector that scans each light beam emitted from the plurality of light sources; and the plurality of light sources and the light.
- a first imaging optical system that is arranged between the light deflector and forms a line image of each light beam on the same deflection surface of the light deflector; and a plurality of scan surfaces corresponding to the plurality of light sources;
- a second imaging optical system that is disposed between the optical deflector and has a plurality of curved mirrors corresponding to the plurality of scanning surfaces and one-to-one, and each light flux from the first imaging optical system.
- main scanning plane that includes a normal line at the center of the deflecting plane of the optical deflector and is parallel to the main scanning direction;
- Each of the luminous fluxes from the plurality of curved mirrors includes a normal line at each vertex of the plurality of curved mirrors and is parallel to the main scanning direction.
- the plurality of light sources, the optical deflector, and the second imaging optical system are arranged at different positions in the sub-scanning direction so that the light enters the curved mirror obliquely.
- the mirrors are arranged on the same side with respect to the main scanning plane, and the plurality of curved mirrors have different curved shapes.
- the color image forming apparatus of the present invention is the same as the above optical scanning apparatus of the present invention.
- FIG. 1 is an optical unit which is an optical scanning device according to Embodiment 1 of the present invention.
- FIG. 1 is an optical unit which is an optical scanning device according to Embodiment 1 of the present invention.
- FIG. 2 is a front view of a curved mirror used in the optical scanning device according to Embodiment 1 of the present invention.
- FIG. 3 is a cross-sectional view taken along the XZ plane of a curved mirror used in the optical scanning device according to Embodiment 2 of the present invention.
- FIG. 4 is a front view of a curved mirror used in the optical scanning device according to Embodiment 2 of the present invention.
- FIG. 5 is a schematic configuration diagram of a first imaging optical system according to Embodiment 3 of the present invention.
- FIG. 6 is a schematic configuration diagram of an optical unit that is an optical scanning device according to Embodiment 4 of the present invention.
- FIG. 7 is a schematic configuration diagram of an optical unit which is an optical scanning device according to Embodiment 5 of the present invention.
- FIG. 8 is a schematic configuration diagram of an optical unit that is an optical scanning device according to Embodiment 6 of the present invention.
- FIG. 9 is a schematic configuration diagram of an optical unit that is an optical scanning device according to Embodiment 7 of the present invention.
- FIG. 10 is a cross-sectional view of the curved mirror used in the optical scanning device according to Embodiment 7 of the present invention, taken along the XZ plane.
- FIG. 11 is a cross-sectional view of the curved mirror used in the optical scanning device according to Embodiment 7 of the present invention, taken along the YZ plane.
- FIG. 12 is a schematic configuration diagram of an optical unit that is an optical scanning device according to Embodiment 8 of the present invention.
- FIG. 13 is a schematic configuration diagram of a color image forming apparatus according to Embodiment 9 of the present invention.
- FIG. 14 shows a case where the color image forming apparatus according to Embodiment 9 of the present invention is used.
- FIG. 1 is a cross-sectional view of an image forming unit according to an embodiment of the present invention.
- the optical scanning device of the present invention includes a plurality of light sources, a single optical deflector that scans each light beam emitted from the plurality of light sources, the plurality of light sources and the optical deflector.
- a first imaging optical system that forms a linear image of each of the light beams on the same deflection surface of the optical deflector; a plurality of scanned surfaces corresponding to the plurality of light sources; and the optical deflector.
- a second imaging optical system having a plurality of curved mirrors corresponding to the plurality of scanned surfaces on a one-to-one basis.
- Each light beam from the first imaging optical system enters the deflecting surface obliquely with respect to a plane (main scanning surface) parallel to the main scanning direction and including a normal at the center of the deflecting surface of the optical deflector.
- the plurality of light sources such that each light beam from the optical deflector enters the curved mirror at an angle to a plane parallel to the main scanning direction and including a normal line at each vertex of the plurality of curved mirrors.
- the light deflector and the second imaging optical system are arranged at different positions in the sub-scanning direction. Further, the plurality of curved mirrors are arranged on the same side with respect to the main scanning plane. Further, the curved surface shapes of the plurality of curved mirrors are different from each other.
- the “normal at the center of the deflecting surface of the optical deflector” means that the deflecting surface on which the light beam enters is an XZ surface (the rotation axis of the optical deflector and the vertexes of the plurality of curved mirrors). Means the normal when moving in the direction included in
- the optical scanning device of the present invention although the optical scanning device has different optical paths from the light source to the photosensitive member, the number of components is small, the optical scanning device has good optical performance, and each scanning line has An optical scanning device having a small relative difference in performance can be realized.
- the width of the plurality of curved mirrors in the sub-scanning direction increases as the distance from the curved mirror near the optical deflector to the curved mirror increases.
- the light is incident on the optical deflector on a plane including a rotation axis of the optical deflector and vertexes of the plurality of curved mirrors (hereinafter referred to as “XZ plane”).
- XZ plane a plane including a rotation axis of the optical deflector and vertexes of the plurality of curved mirrors
- none of the two is parallel to each other.
- the light beam incident on the scanned surface farthest from the optical deflector among the plurality of scanned surfaces, and the scanned surface closest to the optical deflector is 20 degrees or less.
- the plurality of curved mirrors are integrally formed.
- the positions of the vertices in the sub-scanning direction of the plurality of curved mirrors are different from each other.
- the positions of the vertices in the sub-scanning direction of the plurality of curved mirrors are such that the curved surface is closer to the curved mirror farther from the curved mirror closer to the optical deflector. It is preferable that the distance from the central portion in the sub scanning direction of the mirror be increased.
- the first imaging optical system includes a single cylindrical lens on which the plurality of light beams enter.
- the optical scanning device further includes: emitting light from the plurality of light sources.
- a single aperture having a plurality of apertures for adjusting the shape of the light beam to be formed is provided, and the aperture is preferably arranged immediately before the cylindrical lens.
- any two of the plurality of light beams emitted from the plurality of light sources are not parallel to each other.
- the main scanning plane is selected from a plurality of curved mirrors.
- the distance between the vertex of the first curved mirror closest to the main surface and the vertex of the Nth (N is an integer of 2 or more) furthest from the main scanning surface is Lm.
- the intersection of the first scanned surface corresponding to the first curved mirror and the optical axis of the light beam incident thereon, and the Nth scanned surface corresponding to the Nth curved mirror and incident on this The distance between the intersection of the light beam and the optical axis is L i, the distance between the vertex of the N-th curved mirror and the deflection surface is D 1, and the vertex of the N-th curved mirror is; Assuming that the distance between the N-th surface to be scanned and the intersection of the optical axis of the light beam incident thereon is D 2,
- the optical scanning device of the present invention in a plane (XZ plane) including a rotation axis of the optical deflector and vertices of the plurality of curved mirrors, of the plurality of luminous fluxes directed to the plurality of scanned surfaces,
- the angle formed by the optical axis of the first light beam closest to the optical deflector and the optical axis of the Nth light beam (N is an integer of 2 or more) farthest from the optical deflector is ⁇ r;
- the main scanning plane is selected from the plurality of curved mirrors.
- the angle formed by a line connecting the intersection of the light flux with the optical axis with the optical axis is ⁇ ⁇ ⁇ / 3, and the Nth incident on the Nth curved mirror from the deflection surface and the normal at the vertex of the Nth curved mirror
- the angle between the optical axis of the luminous flux of the N-th curved mirror and the distance between the vertex of the N-th curved mirror and the deflecting surface is D 1. If the distance between the vertex of the N-th curved surface mirror and the intersection of the N-th scanned surface and the optical axis of the light beam incident thereon is D2,
- a plane (XZ plane) including a rotation axis of the optical deflector and vertices of the plurality of curved mirrors, of the plurality of luminous fluxes directed to the plurality of scanned surfaces An angle formed by the optical axis of the first light beam closest to the optical deflector and the optical axis of the Nth light beam (N is an integer of 2 or more) farthest from the optical deflector is / 3r.
- orthogonal to the XZ plane The plane including the normal line at each vertex of the curved mirror is defined as the YZ plane of each curved mirror.
- the radius of curvature of the first curved mirror in the XZ section at the vertex of one curved mirror is RxL
- the radius of curvature in the YZ section is Ry.
- the radius of curvature of the Nth curved mirror at the vertex of the Nth curved mirror farthest from the main scanning plane in the XZ section is RxH
- the radius of curvature in the YZ section is RyH.
- a plane including a rotation axis of the optical deflector and vertexes of the plurality of curved mirrors, among the plurality of curved mirrors
- the line connecting the intersection of the N-th scanned surface corresponding to the curved mirror of the above and the optical axis of the light beam incident thereon and the optical axis of the N-th light beam incident on the N-th scanned surface are If the angle formed is / 3 id (degree),
- the color image forming apparatus of the present invention corresponds to the optical scanning device of the present invention described above, a plurality of photoconductors arranged on the plurality of scanned surfaces, and a plurality of photoconductors, respectively.
- a plurality of developing units for developing toner images of different colors on each other a transfer unit for transferring the toner image on the photoconductor to a transfer material, and a toner image transferred to the transfer material
- a fixing device for fixing the toner.
- a small and good image can be formed.
- a low-cost color image forming apparatus that can be formed can be realized.
- FIGS. 1 to 14 showing specific embodiments.
- FIG. 1 is a schematic configuration diagram of an optical unit 40 that is an optical scanning device according to the first embodiment of the present invention.
- the suffixes a to d attached to the element symbols indicate that they correspond to the four colors (yellow, magenta, cyan, and black) for forming a color image. If it is not necessary to omit the subscript, omit the subscript.
- reference numerals 42a to 42d denote collimating lenses, which convert each light beam emitted from a plurality of semiconductor lasers 41a to 41d, which are light sources, into parallel light.
- 4 3a to 4 3d are cylindrical lenses that have a refractive power only in the direction perpendicular to the optical axis (sub-scanning direction) in the XZ plane and that collimate lenses 4 2a to 4 2d A linear image is formed on the reflecting surface 46, which is one of the deflecting surfaces.
- Numeral 47 denotes a polygon monitor which rotates the polygon mirror 44 at a constant speed to scan a light beam incident on the reflection surface 46.
- the polygon mirror 44 and the polygon mirror 47 constitute an optical deflector.
- the collimating lenses 42a to 42d and the cylindrical lenses 43a to 43d constitute a first imaging optical system.
- L1d is reflected obliquely with respect to the plane parallel to the main scanning direction (the main scanning plane) including the normal to the reflecting surface 46.
- the light enters the surface 46, and according to the respective incident angles, the light flux is emitted as 2 & to 2 (1.
- the light flux 2a to L2d is reflected by the respective reflecting surfaces of the curved mirrors 45a to 45d.
- the curved mirrors 45a to 45d are arranged on the same side (upper side in the figure) with respect to a plane (main scanning plane) including the normal of the reflecting surface 46 and parallel to the main scanning direction.
- the light beams 1 a to L 1 d, the light beams L 2 a to L 2 d and the light beams 3 a to L 3 d are not parallel to each other in the XZ plane.
- the non-arc shape of the cross section in the main scanning direction and the radius of curvature in the sub-scanning direction corresponding to each image height are determined so as to correct the main and sub field curvatures and the f0 error.
- the amount of surface torsion at a position corresponding to each image height is determined to correct the scanning line curvature, and as a result, they are different from each other.
- a curved mirror or the like disclosed in Japanese Patent Application Laid-Open No. H11-153,764 and Japanese Patent Application Laid-Open No. 201,100,130 can be used.
- the lengths of the light beams L3a to L3d are almost the same, and are fan-shaped so as to move away from the curved mirrors 45a to 45d toward the photoconductors 4a to 4d. Emit.
- the distance between the optical axes between the adjacent photoconductors 4a to 4d is 25 mm.
- the light beam 3a and the light beam L3d are incident on the photoconductors 4a and 4d at an angle of about 8 ° in the vertical direction with respect to the horizontal direction. That is, the angle between the light beam L 3 d farthest from the polygon mirror 44 and the light beam L 3 a closest to it on the XZ plane is 16 °.
- the curved mirrors 45a to 45d are integrally formed by means such as resin molding, and constitute an integral mirror 51.
- FIG. 2 is a front view of the curved mirrors 45a to 45d.
- 52 a to 52 d indicate the trajectories of the central positions of the light beams L 2 a to L 2 d scanned on the curved mirrors 45 a to 45 d.
- Luminous flux L la ⁇ : L id is the reflection surface 46 oblique to the plane (main scanning surface) parallel to the main scanning direction, including the normal to the reflection surface 46. Therefore, the trajectories 52 a to 52 d on the curved mirror 45 a to 45 d are curved as shown in FIG.
- the curvature increases as the angle of incidence of the light beams L1a to L1d on the reflection surface 46 in the XZ plane increases, and the width D1 in the sub-scanning direction of the curved mirrors 45a to 45d correspondingly increases.
- a to D 1 d have a relationship of D la ⁇ D lb ⁇ D lc ⁇ D ld.
- the light beams from the semiconductor lasers 41 a to 41 d are collimated lenses, respectively.
- Parallel light is formed by 42a to 42d. Then, the light is converged only in the sub-scanning direction by the cylindrical lenses 43a to 43d, and is formed as a line image on the reflection surface 46 of the polygon mirror 44.
- the light beams L1a to L1d are scanned by rotating the polygon mirror 44 about the rotation optical axis, and are incident on the curved mirrors 45a to 45d as light beams 2a to L2d.
- the light beams L2a to L2d are reflected by the curved mirrors 45a to 45d, respectively, and are favorably imaged on the photoconductors 4a to 4d as light beams L3a to L3d.
- the shapes of the curved mirrors 45a to 45d are the non-arc shape of the cross section in the main scanning direction and the sub scanning direction corresponding to each image height so as to correct the main and sub field curvature and the f0 error.
- the radius of curvature is determined, and the amount of surface torsion at a position corresponding to each image height is also determined in order to correct the scanning line curvature. Therefore, the relative difference in the performance between each scanning line is reduced.
- the light beam that scans the photoconductors 4a to 4d is a curved mirror 45a to 4d.
- an image is formed on a photodiode (not shown) arranged at the end in the scanning direction.
- a control device (not shown) using the detection signal from the photodiode as a synchronization signal controls the semiconductor lasers 41a to 41d.
- the curved mirrors 45 a to 45 d have different curved shapes. Accordingly, even if the optical scanning devices have different optical paths from the light sources 41 a to 41 d to the photoconductors 4 a to 4 d, light having good optical performance and a small relative difference in performance of each scanning line can be obtained. A running device can be realized. In addition, no folded mirror is required between the curved mirrors 45a to 45d and the photoconductors 4a to 4d, and the number of parts can be reduced.
- the furthest distance from polygon mirror 44 is Of the light beam L 3 d toward the photosensitive member 4 d and the light beam L 3 a toward the photosensitive member 4 a closest to the polygon mirror 44 in the XZ plane (that is, an angle j3 r described later (FIG. 7). , See Fig. 9)) is less than 20 degrees.
- each photoconductor has an eccentric component and rotates while swinging around the rotation axis.
- Each light beam is generally incident on the photoreceptor surface at an angle of incidence oblique to the normal direction at the incident position in order to suppress the effect of stray light due to the reflected light on the surface of each photoreceptor. Therefore, if the photosensitive member oscillates, the incident position of the light beam fluctuates, and a color shift occurs in the paper transport direction. However, with the above configuration, this color shift amount can be suppressed to a level that does not substantially cause a problem.
- the curved mirrors 45 a to 45 d are configured as a body mirror 51. This makes it possible to reduce the number of parts, suppress variations in the characteristics of the curved mirror when manufacturing by resin molding or the like, and obtain a good image without color shift and color unevenness.
- FIG. 3 is a cross-sectional view of the curved mirrors 55a to 55d in the XZ plane according to the second embodiment
- FIG. 4 is a front view thereof.
- Configurations not particularly described are the same as those in the first embodiment. 3 and 4, the curved mirrors 55a to 55d are independent and have the same width in the sub-scanning direction.
- Reference numerals 56a to 56d denote the trajectories of the central positions of the light beams L2a to L2d scanned on the curved mirrors 55a to 55d.
- Light beams L1a to L1d are incident on the reflecting surface 46 obliquely with respect to a surface (main scanning surface) parallel to the main scanning direction, including the normal to the reflecting surface 46.
- Trajectories 56 a to 56 d on the curved mirror 55 a to 55 d are curved as shown in FIG.
- the curvature increases as the angle of incidence in the XZ plane with respect to the reflection surface 46 of the light beams L1a to L1d increases.
- the curvature of the trajectories 56a to 56d gradually increases from the trajectory 56a to 56d.
- 57 a to 57 d are vertices of the surface mirror 55 a to 55 d.
- Trajectories 56a to 56d are curved lines passing through vertices 57a to 57d.
- rectangles 58a to 58d that include the trajectories 56a to 56d are defined. That is, both ends of the locus 56 a to 56 d are set to both ends of one long side, and the midpoint of the locus 56 a to 56 d (that is, the vertex 57 a to 57 d) is set to the other long side. Define the rectangles 58a-58d as the midpoints. In the present embodiment, the rectangles 58a to 58d are arranged so as to be approximately at the center of the curved mirrors 55a to 55d in the main scanning direction and the sub-scanning direction.
- the positions of the vertices 57 a to 57 d of the curved mirrors 55 a to 55 d in the sub-scanning direction are different from each other among the curved mirrors 55 a to 55 d. (Or from the curved mirror 55a closer to the main scanning plane) to the curved mirror 55d farther from the center in the sub-scanning direction.
- the operation of the optical scanning device configured as described above will be described below with reference to FIG. 3 and FIG.
- Curved surface mirror 5 5 a ⁇ 5 5 d The light beam L 2 a ⁇ L 2 d scans on the trajectory 5 6 a ⁇ 56 d
- the degree of curvature is the reflection surface of the light beam 2 a ⁇ L 2 d 4
- the rectangles 58 a to 58 d are curved surfaces in the main scanning direction and the sub-scanning direction. It is arranged so as to be almost at the center of the Mira 55th to 55d.
- the positions of the vertices 57 a to 57 d of the curved surface mirror 55 a to 55 d in the sub-scanning direction are:
- the distance from the center in the sub-scanning direction increases as one goes to 5d. Therefore, the size of the curved mirror 55a to 55d should be Even if they are equal to each other in the sub-scanning direction, any curved mirror can secure a sufficient effective reflection area and can form good images on the photoconductors 4a to 4d.
- the positions of the vertices 57 a to 57 d of the curved mirrors 55 a to 55 d in the sub-scanning direction are different from each other. Further, as the position of the vertex in the sub-scanning direction moves from the curved mirror 55a closer to the polygon mirror 44 (or the main scanning surface) to the curved mirror 55d farther from the curved mirror 55a, the center of each curved mirror in the sub-scanning direction becomes smaller. From far away.
- the sizes of the curved mirrors 55a to 55d in the main scanning direction and the sub-scanning direction are equal to each other, a sufficient effective reflection area is secured for any curved mirror, and the photoconductors 4a to A good image can be formed on 4d.
- the curved mirrors 55a to 55d are manufactured by resin molding, the sizes of the dies can be made equal, so that molding conditions are easily adjusted, and the curved mirrors 55a to 55d are formed. Variations between them can be reduced.
- FIG. 5 is a schematic configuration diagram showing a preferred embodiment of a first imaging optical system that can be used in Embodiments 1 and 2 described above.
- reference numerals 62a to 62d denote collimating lenses, which convert respective light beams emitted from a plurality of semiconductor lasers 61a to 61d as light sources into parallel light beams.
- 6 3 is a single cylindrical lens having a refractive power only in a direction perpendicular to the optical axis (sub-scanning direction) in the XZ plane, and a polygon mirror that reflects light beams from the collimating lenses 62 a to 62 d.
- a linear image is formed on the reflecting surface 66 which is the deflecting surface.
- Reference numeral 65 denotes an aperture, which has openings 67a to 67d for shaping each light beam from the collimating lenses 62 to 62d into a predetermined shape. Alternatively, it is provided by means such as a press, and is disposed immediately before the cylindrical lens 63.
- a single cylindrical lens 63 is used as the first imaging optical system. As a result, a relative position error due to a change with time does not occur, and the characteristics are stabilized.
- a single aperture 65 in which openings 67 a to 67 d are formed is disposed immediately before the cylindrical lens 63. This not only reduces the number of components, but also reduces the effects of variations in characteristics and aging over time due to mounting errors, as compared to the case where individual apertures are used for each light beam. Neither two of the beams from 1 d are parallel to each other. As a result, the distance between the adjacent semiconductor lasers 61a to 61d can be increased, and the configuration of the light source block is simplified.
- FIG. 6 is a schematic configuration diagram of an optical unit, which is an optical scanning device according to Embodiment 4 of the present invention, viewed from a normal direction of an XZ plane.
- the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
- the first curved mirror 4 closest to a plane (main scanning plane) including a normal line at the center of the reflection plane (deflection plane) 46 and parallel to the main scanning direction. 5a and the vertex of the N-th (N 4 in this embodiment) curved mirror 45 d that is the farthest from the main scanning plane.
- the distance between Lm and the surface of the first photosensitive member 4a corresponding to the first curved mirror 45a among the plurality of photosensitive members (scanned surfaces) 4a to 4d and the light flux L3 incident thereon is L i, the distance between the apex of the Nth curved mirror 45 d and the reflecting surface (deflecting surface) 46 D l, the apex of the Nth curved mirror 45 d and the surface of the Nth photoconductor 4 d If the distance between the point of intersection of the light beam L 3 d with the optical axis of the incident light beam is D 2,
- the optical system described in the first embodiment is described as an example. However, it is preferable that the optical systems according to the second and third embodiments also satisfy the above relationship. It works.
- FIG. 7 is a schematic configuration diagram of an optical unit, which is an optical scanning device according to Embodiment 5 of the present invention, viewed from the normal direction of the XZ plane.
- the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
- a plurality of light beams L3a to a plurality of photoconductors (scanned surfaces) 4a to 4d Of the L3d, the light axis of the first light beam L3a closest to the polygon mirror 44 and the light beam of the Nth light beam L3d farthest from the polygon mirror 44 (N 4 in this embodiment)
- the angle formed by the axis is 3 r, and among the plurality of photoconductors 4 a to 4 d surfaces, the surface of the first photoconductor 4 a on which the first light flux L 3 a is incident and the first The intersection of the light beam L 3a with the optical axis of the Nth light beam L
- the distance between the surface of the N-th photoconductor 4d on which 3d enters and the intersection of the N-th light beam L3d incident on the surface with the optical axis of L3d is Li, and the N-th photoconductor 4d
- the distance between the apex of the N-th curved mirror 45d and the reflecting surface (deflecting surface) 46 corresponding to D1 the apex of the N-th curved mirror 45d and the surface of the N-th photoconductor 4d
- the distance between the point of intersection with the optical axis of the N-th light beam L 3 d incident thereon is D 2
- the distance of 45 d becomes smaller, and the effective areas where multiple light beams are reflected overlap, making it difficult to separate each light beam.
- the optical system described in the first embodiment is described as an example. However, it is preferable that the optical systems according to the second and third embodiments also satisfy the above relationship. It works.
- FIG. 8 is a schematic configuration diagram of an optical unit, which is an optical scanning device according to Embodiment 6 of the present invention, viewed from the normal direction of the XZ plane.
- the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
- ⁇ ⁇ ⁇ ⁇ 2 -0.2 (D 1 / D 2) is below the lower limit of the above inequality or above the upper limit, field curvature in the main scanning direction occurs by 2.5 mm or more.
- the optical system described in the first embodiment is described as an example. However, it is preferable that the optical systems according to the second and third embodiments also satisfy the above relationship. It works.
- FIG. 9 is a schematic configuration diagram of an optical unit which is an optical scanning device according to Embodiment 7 of the present invention as viewed from a normal direction of an XZ plane.
- FIG. 10 is a cross-sectional view along the XZ plane of a curved mirror used in the optical scanning device according to the seventh embodiment.
- FIG. 11 is a cross-sectional view of each curved mirror on the YZ plane (a plane orthogonal to the XZ plane and including the normal at the vertex of the curved mirror).
- the same components as those in Embodiments 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.
- a plurality of planes including the rotation axis of the polygon mirror (optical deflector) 4 and the vertices of the plurality of curved mirrors 55 a to 55 d are provided.
- the XZ section of the N-th curved mirror 55 d at the vertex 57 d of the N-th curved mirror 55 d farthest from the main scanning plane among the plurality of curved mirrors 55 a to 55 d Let R xH (see Figure 10) be the radius of curvature at, and RyH (see Figure 11) the radius of curvature in the YZ section.
- Embodiment 9 to 11 illustrate the optical system shown in Embodiment 2 as an example, it is preferable that the optical systems of Embodiments 1 and 3 also satisfy the above relationship. Has the same effect as described above.
- FIG. 12 is a schematic configuration diagram of an optical unit, which is an optical scanning device according to Embodiment 8 of the present invention, viewed from the normal direction of the XZ plane.
- the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
- a plurality of planes including the rotation axis of polygon mirror (optical deflector) 44 and the vertices of a plurality of curved mirrors 45 a to 45 d are provided.
- the reflection area of the N-th curved mirror 45 d farthest from the main scanning surface blocks the light beam L 3 c traveling from the adjacent curved mirror 45 c to the photosensitive member 4 c, and This prevents the reflection area of the first curved mirror 45a closest to the light source from blocking the light beam L2b traveling to the adjacent curved mirror 45b. Therefore, good optical performance can be ensured, and the relative performance error of each scanning line can be reduced, so that high resolution can be realized.
- the optical system described in the first embodiment is described as an example. However, it is preferable that the optical systems according to the second and third embodiments also satisfy the above relationship. It works.
- FIG. 13 is a schematic sectional view showing a color image forming apparatus to which any one of the first to eighth embodiments of the optical scanning device is applied.
- reference numerals 2a to 2d denote image forming units corresponding to each of the four colors (yellow, magenta, cyan, and black).
- FIG. 14 is a sectional view of the image forming units 2a to 2d. Since the configuration of each image forming unit is the same, FIG. 14 omits the suffix and shows only one image forming unit.
- Reference numeral 9 denotes a photosensitive drum as a surface to be scanned on which a photoreceptor changes its charge when irradiated with light
- 10 denotes a charging roll for attaching and charging electrostatic ions to the surface of the photoreceptor
- 11 denotes a photosensitive roll.
- Dora And a transfer roll 12 for transferring a toner image formed on the photosensitive drum 9 to a transfer material (paper) 30. .
- the image forming unit 2 includes a photosensitive drum 9, a charging roll 10, a developing unit 11, and a transfer roll 12.
- reference numeral 14 denotes a fixing device for fixing the transferred toner to paper
- reference numeral 15 denotes a paper feed cassette.
- 16 is the optical scanning device described in any one of Embodiments 1 to 8
- 17 is a light source block including a semiconductor laser, an axisymmetric lens, and a cylindrical lens
- 18 is a polygon mirror
- 20 a 220 d is a curved mirror.
- FIG. 13 shows an example in which the curved mirrors 20 a to 20 d are integrally formed as in the first embodiment, but a separate type configuration as in the second embodiment is also possible. It is.
- the image forming units 2a to 2d corresponding to each of the four colors are arranged in the vertical direction, and the electrostatic latent units corresponding to the respective colors are arranged on the photosensitive drums 9a to 9d.
- An image is formed, developed by the developing units 11 a to l 1 d, and sequentially developed for each color on the paper conveyed from the paper feed cassette 15 by the transfer ports 12 a to 12 d.
- the toner image is transferred, and the toner image is fixed by the fixing device 14.
- the paper transport path is arranged in the vertical direction, and the image forming units 2 a to 2 d are vertically stacked, so that the vertical dimension of the housing is short.
- the drawback is that the paper cassette 15 protrudes in the horizontal direction, and the installation space is increased by arranging the paper cassette 15 below the image forming units 2a to 2d. Therefore, the size of the apparatus can be easily reduced. That is, four conventional monochromatic optical units are vertically stacked and arranged. According to the present embodiment, a single optical unit is used, and the image forming position of the laser light for each color can be freely adjusted. Even if 2d are arranged in four rows in the vertical direction, the vertical dimension does not increase.
- the curved mirrors 20a to 20d Since the distance d can be made smaller than the distance between the photosensitive drums 9a to 9d, the accuracy of the parts can be ensured. Since the angles of the light beams L la to L 1 d, the light beams L 2 a to L 2 d, and the light beams L 3 a to L 3 d can be set freely, an arrangement suitable for each device can be selected. It is preferable that the distance between the curved mirrors 20a to 20d is reduced as in the embodiment, and the mirrors are integrally formed by resin molding or the like.
- the angle between the light beam L 3 a and the light beam L 3 d in the XZ plane is 16 °, even if the photosensitive drums 9 a to 9 d have an eccentric component of 100 m, this is because The amount of color shift can be suppressed to 30 m or less.
- the smaller the angle between the light beam L3a and the light beam L3d the smaller the amount of color misregistration can be. It is necessary to increase the interval of up to 20 d, which makes it difficult to integrally form the optical scanning device 16 and increases the size of the optical scanning device 16.
- the interval between the adjacent photosensitive drums 9a to 9d is too small, and it is difficult to arrange the developing units 11a to 11d and the charging ports 10a to 10d. Therefore, it is preferable that the length of the light beam L3 is 10 times or less the interval between the positions where the light beams L3 adjacent to each other are incident on the photosensitive drums 9a to 9d.
- the color image forming apparatus was operated continuously for a long time, there was no problem such as image deterioration, and a good image was obtained.
- the second imaging optical system is composed of only the curved mirrors 20a to 20d, it is not affected by a change in the refractive index due to a temperature change unlike the optical system using a lens. Since the curved mirrors 20a to 20d are located farther than the photosensitive drums 9a to 9d and the polygon mirror 18 with respect to the fixing unit 14, the fixing unit 1 which is a heat source is This is due to the fact that it is far from 4 and that deformation due to heat has been reduced.
- the laser beam interval of each color can be freely adjusted by changing the internal configuration of the optical scanning device 16 (for example, changing the normal direction of each curved mirror), and the adjacent image forming units can be adjusted.
- the interval between 2a and 2d can be shortened.
- the interval between the curved mirrors 20a to 20d can be made smaller than the interval between the photosensitive drums 9a to 9d, high mounting accuracy can be maintained.
- the image forming units 2a to 2d are formed into cartridges so as to include the photosensitive drums 9a to 9d and peripheral components as much as possible in consideration of mounting workability and the like. Is preferred.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Facsimile Scanning Arrangements (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Laser Beam Printer (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/537,420 US7012723B2 (en) | 2003-01-16 | 2003-12-08 | Optical scanning device and color image forming apparatus |
JP2004566287A JPWO2004063790A1 (ja) | 2003-01-16 | 2003-12-08 | 光走査装置およびカラー画像形成装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003-008790 | 2003-01-16 | ||
JP2003008790 | 2003-01-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004063790A1 true WO2004063790A1 (ja) | 2004-07-29 |
Family
ID=32709173
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2003/015688 WO2004063790A1 (ja) | 2003-01-16 | 2003-12-08 | 光走査装置およびカラー画像形成装置 |
Country Status (4)
Country | Link |
---|---|
US (1) | US7012723B2 (ja) |
JP (1) | JPWO2004063790A1 (ja) |
CN (1) | CN1726417A (ja) |
WO (1) | WO2004063790A1 (ja) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4366074B2 (ja) * | 2002-12-24 | 2009-11-18 | キヤノン株式会社 | 走査光学系 |
JP2006184750A (ja) * | 2004-12-28 | 2006-07-13 | Kyocera Mita Corp | 画像形成装置 |
US7993005B2 (en) * | 2006-11-10 | 2011-08-09 | Seiko Epson Corporation | Color laser image generation |
US10578993B1 (en) * | 2019-02-05 | 2020-03-03 | Toshiba Tec Kabushiki Kaisha | Optical uniformization in image forming apparatus |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1217415A2 (en) * | 2000-12-21 | 2002-06-26 | Xerox Corporation | Multiple beam raster output scanning system |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3124741B2 (ja) | 1996-07-22 | 2001-01-15 | 株式会社リコー | 多色画像形成装置の光走査装置 |
JP3646960B2 (ja) | 1997-11-18 | 2005-05-11 | 松下電器産業株式会社 | 光走査装置 |
JP2000141759A (ja) | 1998-11-12 | 2000-05-23 | Canon Inc | カラー画像形成装置 |
JP3349122B2 (ja) | 1999-09-29 | 2002-11-20 | 松下電器産業株式会社 | 光走査装置 |
JP3831560B2 (ja) | 1999-11-01 | 2006-10-11 | ペンタックス株式会社 | 走査光学装置 |
US7173645B2 (en) * | 2001-12-21 | 2007-02-06 | Matsushita Electric Industrial Co., Ltd. | Optical scan apparatus and color image formation apparatus |
-
2003
- 2003-12-08 JP JP2004566287A patent/JPWO2004063790A1/ja not_active Withdrawn
- 2003-12-08 US US10/537,420 patent/US7012723B2/en not_active Expired - Fee Related
- 2003-12-08 WO PCT/JP2003/015688 patent/WO2004063790A1/ja active Application Filing
- 2003-12-08 CN CNA2003801057651A patent/CN1726417A/zh active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1217415A2 (en) * | 2000-12-21 | 2002-06-26 | Xerox Corporation | Multiple beam raster output scanning system |
Also Published As
Publication number | Publication date |
---|---|
CN1726417A (zh) | 2006-01-25 |
JPWO2004063790A1 (ja) | 2006-05-18 |
US20060017995A1 (en) | 2006-01-26 |
US7012723B2 (en) | 2006-03-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4445234B2 (ja) | 光走査装置および画像形成装置 | |
JP3451473B2 (ja) | マルチビーム走査装置および画像形成装置 | |
US7999970B2 (en) | Light source device, optical scanning device, and image forming apparatus | |
US6593951B2 (en) | Optical writing system directed to miniaturization thereof, and image forming apparatus employing it | |
KR102292008B1 (ko) | 광 주사 장치 및 화상 형성 장치 | |
CN108427251B (zh) | 光扫描装置、成像设备和外壳 | |
JP3851469B2 (ja) | マルチビーム光源走査装置 | |
US20060039054A1 (en) | Scanning optical apparatus and image forming apparatus using the same | |
JP2006258918A (ja) | 走査光学装置及びそれを用いたカラー画像形成装置 | |
JP7137401B2 (ja) | 光走査装置及び画像形成装置 | |
JP6786258B2 (ja) | 光走査装置及びそれを備える画像形成装置 | |
EP3125016A2 (en) | Optical scanning device and image forming apparatus including the same | |
US7483193B2 (en) | Light scanning device and image forming device | |
JP5333070B2 (ja) | 光走査装置と画像形成装置 | |
US7843481B2 (en) | Light scanning device capable of producing non-coplanar scanning lines | |
WO2003054611A1 (fr) | Dispositif de balayage optique et dispositif de formation d'images couleur | |
WO2004063790A1 (ja) | 光走査装置およびカラー画像形成装置 | |
JP4715418B2 (ja) | 光走査装置及び画像形成装置 | |
JP4099545B2 (ja) | 光学走査装置の光路構造 | |
JPH1020608A (ja) | カラー画像形成装置 | |
JP4489852B2 (ja) | 露光装置ならびに画像形成装置 | |
JP2006178189A (ja) | 光走査装置および画像形成装置 | |
JP2001350110A (ja) | 光走査装置・画像形成装置 | |
JPH10239626A (ja) | 光学走査装置及び画像形成装置 | |
JP5115351B2 (ja) | タンデム型走査光学系 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 2004566287 Country of ref document: JP |
|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CN JP US |
|
ENP | Entry into the national phase |
Ref document number: 2006017995 Country of ref document: US Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 10537420 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 20038A57651 Country of ref document: CN |
|
WWP | Wipo information: published in national office |
Ref document number: 10537420 Country of ref document: US |