JP2008051841A - Laser scanner unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser scanner unit in which the position of a collimator lens unit is adjusted and fixed by a simple work. <P>SOLUTION: The laser scanner unit 2 incrudes a pressing member 5 which is extended astride the collimator lens unit 4 and the both end parts 52 are fixed on a housing 2A, thus the collimator lens unit 4 is pressurized on a guide groove 25. The pressing member 5 has a curved portion 51 which is protruded to the opposite side of the collimator lens unit 4 and the inner side face pressurizes the collimator lens unit 4, and the pressing member 5 is composed of a magnetostriction material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser scanner unit.

  2. Description of the Related Art Conventionally, a laser scanner unit that is incorporated in an image forming apparatus and forms an electrostatic image on a photosensitive drum by irradiating laser light is known. In this laser scanner unit, a collimator lens unit, a polygon mirror, an fθ lens, and the like are accommodated in a housing in which a semiconductor laser as a light source is mounted.

  The collimator lens unit is a collimator lens that converts laser light emitted from a light source into a parallel light beam, a lens barrel in which the collimator lens is provided, and a laser beam that is attached to the lens tube and converted into a parallel light beam. (For example, refer to Patent Document 1).

  Such a collimator lens unit is fixed to the housing after its position is adjusted in the optical axis direction.

  Generally, the housing is provided with a guide groove that supports the collimator lens unit so as to be movable in the optical axis direction. The position of the collimator lens unit is adjusted by moving the collimator lens unit along the guide groove.

Further, for fixing the collimator lens unit, for example, a pressing member (leaf spring) as described in Patent Document 2 is used. This holding member is fixed by pressing the collimator lens into the guide groove by fixing both ends of the collimator lens to the housing with screws in a state of being disposed across the collimator lens.
JP 2004-170854 A JP 2004-34608 A

  However, in order to fix the collimator lens unit with the holding member, first, adjust the position of the collimator lens unit with the screws that fix both ends lightly tightened, and then tighten the screws further to fix both ends of the leaf spring. It is necessary to firmly fix the part, and the work becomes complicated.

  Here, it is conceivable to fix the collimator lens unit with an adhesive. However, when an adhesive is used, it is difficult to adjust the position of the collimator lens unit again.

  In view of such circumstances, it is an object of the present invention to provide a laser scanner unit capable of adjusting and fixing the position of a collimator lens unit with a simple operation.

  The invention of claim 1 has a collimator lens unit in which a collimator lens is provided in the lens barrel and an aperture is mounted on the lens barrel, and a guide groove that supports the collimator lens unit so as to be movable in the optical axis direction. A housing that houses the collimator lens unit, and a pressing member that extends across the collimator lens unit and that fixes both ends of the collimator lens unit to the housing by fixing the collimator lens unit to the guide groove, The presser member has a curved portion that is convex on the opposite side to the collimator lens unit and presses the collimator lens unit on the inner surface, and the presser member is made of a magnetostrictive material. This is a featured laser scanner unit.

  According to a second aspect of the present invention, in the laser scanner unit according to the first aspect, a substantially hemispherical protrusion is provided on the inner surface of the curved portion, and the collimator lens unit is pressed by the protrusion. It is characterized by.

  According to a third aspect of the invention, in the laser scanner unit according to the first or second aspect, the curved portion is provided with a plurality of windows.

  According to the first aspect of the present invention, the presser member having a curved portion that is convex on the opposite side of the collimator lens unit and presses the collimator lens unit on the inner surface is made of a magnetostrictive material. The pressing member is deformed so that the curved portion is further convex. As a result, the force with which the bending portion presses the collimator lens unit becomes weak, so that the position can be adjusted by moving the collimator lens unit along the guide groove. Then, after the position adjustment is completed, if the magnetic field is removed, the pressing member returns to its original shape, so that the collimator lens unit can be pressed with a strong force. That is, the position of the collimator lens unit can be adjusted or the collimator lens unit can be fixed by a simple operation of adding or removing the magnetic field.

  According to the invention of claim 2, since the collimator lens unit is pressed by the protrusion provided on the inner surface of the bending portion, the collimator lens unit can be pressed at one point. For this reason, when the magnetic field is removed from the presser member, the direction in which the presser member presses the collimator lens unit is always constant, and the collimator lens unit can be prevented from tilting.

  According to the invention of claim 3, since the plurality of windows are provided in the bending portion, the bending portion is easily bent when a magnetic field is applied to the pressing member.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a printer 10 that is an image forming apparatus according to an embodiment of the present invention. The present invention is not limited to a printer but can be applied to other image forming apparatuses such as a copying machine, a facsimile machine, and a multifunction machine.

  The printer 10 forms an image on a sheet based on image data sent from a terminal or the like in the middle of conveying the sheet along the conveyance path L. A photoconductor is provided inside the box-shaped apparatus main body 1. An image forming unit 13 that forms a toner image on the surface of the drum 131 and then transfers the toner image to a sheet, a paper feeding unit 12 that supplies the sheet to the image forming unit 13, and a fixing unit 14 that fixes the toner image on the sheet. And.

  The conveyance path L has a horizontal portion L1 extending substantially horizontally from the front to the rear (from the right side to the left side in FIG. 1), and a vertical portion L2 rising substantially vertically from the rear end portion of the horizontal portion L1. It is substantially L-shaped.

  The paper feed unit 12 includes a paper feed cassette 121 disposed below the horizontal portion L1 of the transport path L. The paper stored in the paper feed cassette 121 is taken out by a pickup roller 12a and the paper is Are fed one by one to the horizontal portion L1 of the conveyance path L by the paper feed rollers 12b to 12e, and the sheet fed to the conveyance path L is temporarily waited by the registration rollers 12f and supplied to the image forming unit 13 at a predetermined timing. It is supposed to be.

  The paper feed unit 12 also has a manual feed unit 122 disposed in the opening 11 provided on the front surface of the apparatus main body 1. The paper placed on the manual feed unit 122 is fed to the pickup roller 12 g and the paper supply unit 12. The paper rollers 12c and 12e can be sent to the horizontal portion L1 of the transport path L. The opening 11 can be opened and closed by a lid member 11a attached to the apparatus main body 1 so as to be swingable.

  The image forming unit 13 includes a photosensitive drum 131 disposed substantially at the center in the front-rear direction of the horizontal portion L1 of the conveyance path L, a charging unit 132 disposed above the photosensitive drum 131, and a photosensitive drum. A developing unit 133 disposed in front of 131, a transfer unit 134 disposed below the photosensitive drum 131, a cleaning unit 135 disposed behind the photosensitive drum 131, a charging unit 132, and a cleaning unit. And a laser scanner unit (LSU) 2 disposed above the fixing unit 14.

  The photosensitive drum 131 rotates clockwise in FIG. 1, and the surface of the photosensitive drum 131 is based on image data by the laser scanner unit 2 after the surface is uniformly charged by the charging unit 132. An electrostatic latent image is formed by irradiating laser light from between the charging unit 132 and the developing unit 133, and toner is supplied from the developing unit 133 to the surface on which the electrostatic latent image is formed. A toner image is formed.

  The paper supplied from the paper supply unit 12 is conveyed while being pressed against the photoconductive drum 131 by the transfer roller 134a of the transfer unit 134, so that the surface of the photoconductive drum 131 is transferred to the surface (transfer surface). The toner image formed on the toner image is transferred and then sent to the fixing unit 14.

  Note that the toner and residual charges remaining on the surface of the photosensitive drum 131 after transfer are removed by the cleaning unit 135.

  The fixing unit 14 includes a heat roller 14a and a pressure roller 14b. The toner image is fixed to the sheet with heat and pressure by sandwiching the sheet onto which the toner image has been transferred by the rollers 14a and 14b. It is supposed to let you.

  The sheet on which the toner image is fixed is discharged by a discharge roller 18 to a discharge unit 19 formed on the upper surface of the apparatus main body 1.

  In the printer 10 of the present embodiment, a switchback unit 15 is provided between the horizontal portion L1 of the transport path L and the paper feed cassette 121 so that images can be formed on both sides of the paper. .

  Specifically, as shown in FIG. 2, the laser scanner unit 2 has a container shape having a peripheral wall 28 and a bottom wall 29 and opened upward, and a collimator lens unit 4 and a polygon mirror 6 are attached. A housing 2A for housing the polygon motor 7, two fθ lenses 8A, 8B, and the like, and a lid 2B (see FIG. 1) for closing the opening of the housing 2A are provided. A semiconductor laser 3 as a light source is attached to the peripheral wall 28 of the housing 2A, and the collimator lens unit 4 is disposed on the optical axis of laser light emitted from the semiconductor laser 3 toward the polygon mirror 6. Has been. In the present specification, the optical axis direction of the laser light emitted from the semiconductor laser 3 is referred to as the X direction.

  As shown in FIG. 3, the collimator lens unit 4 is provided with a circular cylindrical barrel 41 extending in the X direction, and the laser beam emitted from the semiconductor laser 3 is converted into a parallel light beam. It has a collimator lens (not shown) and an aperture 42 that is attached to the lens barrel 41 and shapes the laser light that has been converted into a parallel light beam. The collimator lens unit 4 is fixed to the housing 2A by a pressing member 5.

  A guide groove 25 extending in the X direction with a substantially V-shaped cross-sectional shape is provided at a corner portion formed by the portion of the peripheral wall 28 to which the semiconductor laser 3 is attached and the bottom wall 29. The lens barrel 41 of the collimator lens unit 4 can be fitted in the guide groove 25, so that the collimator lens unit 4 is supported by the guide groove 25 so as to be movable in the X direction. .

  Further, the bottom surface of the guide groove 25 is provided with a concave groove 25a that is further depressed by one step, while the lower end portion of the lens barrel 41 is provided with a convex portion 41a that can be fitted into the concave groove 25a. By fitting the convex portion 41a into the concave groove 25a, the collimator lens unit 4 is prevented from rotating around the optical axis of the laser beam.

  On both sides of the guide groove 25, seat portions 21 having a predetermined height are provided. And the said pressing member 5 is arrange | positioned so that these seat parts 21 may be bridged.

  The pressing member 5 extends in a direction orthogonal to the X direction so as to straddle the collimator lens unit 4 from above, and as shown in FIGS. And a curved portion 51 that protrudes upward between the fixed portions 52. The pressing member 5 is formed by press-molding a thin plate made of a magnetostrictive material that extends in the direction when a magnetic field is applied. Examples of the magnetostrictive material include “ETREMA Terfenol-D” manufactured by ETREMA.

  The fixing portion 52 is provided with an insertion hole 52a through which the screw portion of the fixing screw B is inserted substantially at the center. Further, a substantially hemispherical projection 53 is provided at the center on the inner surface of the curved portion 51 on the collimator lens unit 4 side. Further, the curved portion 51 is provided with a plurality (four in the illustrated example) of windows 51a arranged in the longitudinal direction.

  The height dimension from the lower surface of the fixed portion 52 to the lowest point of the protrusion 53 of the curved portion 51 is smaller than the height dimension from the upper surface of the seat portion 21 to the highest point of the lens barrel 41 of the collimator lens unit 4. Is set. For this reason, the screw B is screwed into the seat portion 21 from the insertion hole 52a of the fixing portion 52 of the presser member 5 with the collimator lens unit 4 placed in the guide groove 25 and the presser member 5 disposed thereon. When both the fixing portions 52 are fixed to the seat portion 21, the lens barrel 41 of the collimator lens unit 4 is pressed against the guide groove 25 by the protrusion 53, and the collimator lens unit 4 is fixed to the guide groove 25.

  Further, since the presser member 5 is made of a magnetostrictive material, a magnetic field is provided on the presser member 5 from the right side to the left side in FIG. 3 or vice versa by, for example, arranging a magnet so as to sandwich the presser member 5. Is added, the presser member 5 tends to extend in the longitudinal direction. However, since the fixing portions 52 at both ends are fixed to the seat portion 21 and cannot be displaced in the longitudinal direction, the presser member 5 is deformed so that the bending portion 51 further protrudes upward. As a result, the force with which the projection 53 of the bending portion 51 presses the collimator lens unit 4 becomes weak, and therefore the position can be adjusted by moving the collimator lens unit 4 along the guide groove 25. After the position adjustment is completed, if the magnetic field is removed, the presser member 5 returns to its original shape, so that the collimator lens unit 4 can be pressed with a strong force.

  As described above, in the laser scanner unit 2 of the present embodiment, since the holding member 5 is made of a magnetostrictive material, it is possible to adjust the position of the collimator lens unit 4 by a simple operation of adding a magnetic field or removing a magnetic field. Or the collimator lens unit 4 can be fixed.

  In addition, since the collimator lens unit 4 is pressed by the protrusion 53 provided on the inner surface of the bending portion 51, the collimator lens unit 4 can be pressed at one point. For this reason, when the magnetic field is removed from the presser member 5, the direction in which the presser member 5 presses the collimator lens unit 4 is always constant, and the collimator lens unit 4 can be prevented from tilting.

  Further, since the bending portion 51 is provided with a plurality of windows 51 a, the bending portion 51 is easily bent when a magnetic field is applied to the pressing member 5.

  In the embodiment, the fixing portion 52 of the pressing member 5 is fixed with the screw B. However, the fixing portion 52 may be fixed to the housing 2A by, for example, a fitting structure.

1 is a schematic configuration diagram of a printer that is an image forming apparatus according to an embodiment of the present disclosure. It is a perspective view of the laser scanner unit which removed the cover. It is the III-III sectional view taken on the line of FIG. It is a figure which shows a pressing member, (a) is the perspective view seen from upper direction, (b) is a front view, (c) is the perspective view seen from the downward direction.

Explanation of symbols

2 Laser scanner unit 2A Housing 25 Guide groove 4 Collimator lens unit 41 Lens barrel 42 Aperture 5 Holding member 51 Curved portion 51a Window 52 Fixed portion (both ends)
53 Projection 10 Printer (image forming apparatus)

Claims (3)

A collimator lens unit in which a collimator lens is provided in the lens barrel and an aperture is attached to the lens barrel, and a guide groove that supports the collimator lens unit so that the collimator lens unit can be moved in the optical axis direction are accommodated. And a holding member that extends so as to straddle the collimator lens unit and that fixes both ends of the collimator lens unit to the guide groove by fixing the collimator lens unit to the guide groove,
The presser member has a curved portion that is convex on the opposite side to the collimator lens unit and presses the collimator lens unit on the inner surface, and the presser member is made of a magnetostrictive material. A featured laser scanner unit.   2. The laser scanner unit according to claim 1, wherein a substantially hemispherical protrusion is provided on an inner surface of the curved portion, and the collimator lens unit is pressed by the protrusion.   The laser scanner unit according to claim 1, wherein the curved portion is provided with a plurality of windows.

Images