JP2007292913A - Light source unit and optical scanner provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source unit in which optical elements which are adjusted in position are fixed without being dislocated and which is easily disassembled and reassembled when the readjustment of the positions of the optical elements is necessary. <P>SOLUTION: Holes 17 to 20 penetrating from the diagonal face of a sliding groove 16 to the bottom face of a barrel supporting part 14b for applying adhesive are made on the barrel supporting part 14b in a state that the open part is located at the part at which the outer peripheral face of the barrel 13 and the diagonal face of the sliding groove 16 are made to contact each other, the position of the barrel 13 is adjusted, an adhesive 21 is injected and applied from the open parts of the holes 17 to 20 for applying adhesive on the bottom face side of the barrel supporting part 14b, thus the barrel 13 is bonded and fixed on the barrel supporting part 14b by hardening the adhesive 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light source device used as a writing optical system in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an optical scanning device including the light source device.

  In general, in an optical scanning device used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, a laser beam emitted from a light source device having a laser light emitting unit (hereinafter referred to as LD) is used as a cylinder lens, a polygon mirror, and an fθ lens. A scanning optical system composed of, etc. is used to form an image as a beam spot on the scanned surface and rotate the polygon mirror to scan the scanned surface at a constant speed in the main scanning direction. ing.

  In order to obtain an image of good quality using such an optical scanning device, exposure scanning with a laser beam is performed at a predetermined position on a photosensitive drum as a scanning surface, and a beam for exposure scanning is used. The spot image needs to be formed in a predetermined state. Therefore, at the manufacturing stage of the image forming apparatus, for example, the lens barrel holding the collimator lens is temporarily fixed to the base on the light source device, and the laser beam is actually emitted from the LD, and the photoconductor Finely adjust the position of the lens barrel until the beam spot image on the drum is properly formed at the predetermined position. When the fine adjustment is completed, the lens barrel is adhered and fixed to the base with an adhesive. I have to.

  However, since the adhesive used for fixing the lens barrel shrinks when it hardens and changes in volume, as shown in FIG. 5A, the adhesive 102 is applied to the base 101 in advance. After that, when the lens barrel 100 is placed, there is a layer of the adhesive 102 between the base 101 and the lens barrel 100. Therefore, when the adhesive 102 is cured and contracted, the lens barrel 100 is removed from the adjustment position. The amount of contraction of 102 is shifted to the base 101 side.

  Further, as shown in FIG. 5B, after the lens barrel 100 is finely adjusted in a state where the lens barrel 100 is pressed against the base 101 with a jig or an elastic member and temporarily fixed, the lens barrel 100 is then adjusted. When the adhesive 102 is applied only from the upper side to the contact portion between the base 101 and the base 101, a tensile force that pulls the lens barrel 100 upward is generated when the adhesive 102 is cured and contracted. Here, since the pressing force by the jig or the like is set to be weak so that the position of the lens barrel 100 can be adjusted, the lens barrel 100 is displaced upward against the pressing force by the tensile force of the adhesive 102. Will end up.

  As described above, when the position of the collimator lens deviates from the adjustment position, the convergence state of the laser light changes, the beam spot image is blurred when performing exposure scanning on the photosensitive drum, or the laser beam exposure is performed. The scanning position deviates from a predetermined position, so that an electrostatic latent image faithful to the original image cannot be formed, and the image quality is deteriorated.

Therefore, a method for suppressing the position variation of the optical element such as a collimator lens as much as possible has been proposed, and in Patent Document 1, after adjusting the optical position of the LD as the light emitting element and the collimator lens as the optical element, By fixing the lens barrel holding the collimator lens to the base of the light source device by laser welding, the position variation of the optical element caused by shrinkage of a large amount of adhesive applied to fix the lens barrel is prevented. A light source device is disclosed.
JP 2001-111155 A

  However, in the light source device described in Patent Document 1, the lens barrel holding the collimator lens is fixed to the base of the light source device by laser welding, and the light source device cannot be disassembled. It is impossible to readjust the optical position between the optical element and the optical element. Therefore, if an assembly failure occurs during the manufacture of the light source device, the base of the light source device, the light emitting element, and the optical element must be discarded. Extra costs will be incurred.

  In the present invention, in view of the above-described circumstances, an optical device that is capable of adjusting a beam spot image when performing exposure scanning on a photosensitive drum so as to form an image in a predetermined state. Provided is a light source device that can be accurately fixed to a predetermined position and can be easily disassembled and reassembled when the position of an optical element needs to be readjusted, and an optical scanning device including the same. The purpose is to do.

  To achieve the above object, the present invention provides a light emitting element that emits a light beam, an optical element that controls the light beam emitted from the light emitting element, a lens barrel that holds the optical element, and the light emitting element. A light source device comprising: a light emitting element holding unit for holding; and a base including a lens barrel holding unit for holding the lens barrel; wherein the lens barrel holding unit includes the lens barrel on the surface side from the light emitting element. A slide groove is provided for slidably holding in the optical axis direction of the emitted light beam, and an injection hole for injecting and applying an adhesive for fixing the lens barrel is formed on the rear surface of the lens barrel holding portion. It is characterized by being drilled so as to penetrate to the position where the lens barrel contacts the inner surface of the moving groove.

  According to the present invention, in the light source device configured as described above, the adhesive for fixing the lens barrel is an ultraviolet curable adhesive.

  The present invention also provides an optical scanning device comprising the light source device having the above-described configuration.

  According to the first configuration of the present invention, the optical element is pressed against the lens barrel holding portion with a jig or the like, and is applied to the lens barrel holding portion in a state where the optical element is brought into contact with the sliding groove and temporarily fixed. Since the adhesive can be injected and applied from the hole, the adhesive layer is not formed between the lens barrel and the lens barrel holder, and the position of the lens barrel is shifted due to curing shrinkage of the adhesive. Absent. In addition, a tensile force that pulls the lens barrel toward the lens barrel holding portion is generated by curing shrinkage of the adhesive, but the lens barrel is in contact with the sliding groove, so that the position does not shift.

  Further, according to the second configuration of the present invention, in the light source device of the first configuration, the curing of the adhesive is accelerated by using an ultraviolet curable adhesive as an adhesive for fixing the lens barrel. The assembly efficiency of the optical device can be improved.

  According to the third configuration of the present invention, in the light source device having the above first or second configuration, for example, the light source device of the optical scanning device for exposing and scanning the photosensitive drum in the image forming apparatus such as a printer. In this case, it is possible to prevent the beam spot image from blurring on the photosensitive drum and the exposure scanning position of the laser beam from deviating from a predetermined position, thereby improving the image quality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an optical scanning device provided with a light source device according to the present invention. For convenience of explanation, FIG. 1 does not show the lid member that closes the casing of the optical scanning device.

  As shown in FIG. 1, the optical scanning device 1 includes a light source device 10, a cylindrical lens 3, a polygon mirror 4 and its driving motor, a scanning lens 5, and a folding mirror 6 disposed on the inner side surface or inner bottom surface of the housing 2. , A mirror 7 and a beam detection sensor 8. In addition, a photosensitive drum (not shown) that is an image carrier is disposed outside the housing 2, and laser light is guided to the bottom surface of the housing 2 from the housing 2 toward the photosensitive drum. The window portion 9 is provided.

  In the optical scanning device 1 configured as described above, the laser light emitted from the LD 11 (see FIG. 2) provided in the light source device 10 is condensed into a linear light beam by the cylindrical lens 3 and is then reflected by the polygon mirror 4. Deflection scanning is performed in a predetermined scanning direction, and an image is formed on the photosensitive drum through the scanning lens 5 and the folding mirror 6. The imaged light beam forms an electrostatic latent image on the surface of the photosensitive drum by scanning the photosensitive drum in the main scanning direction by the rotation of the polygon mirror 4 and in the sub-scanning direction by the rotation of the photosensitive drum. It will be.

  The scanning light of the polygon mirror 4 is separated below the scanning surface by the mirror 7 at one end in the main scanning direction and introduced into the beam detection sensor 8. The introduced scanning light is converted into a scanning start signal by the beam detection sensor 8 and transmitted to the LD 11 provided in the light source device 10. Then, after receiving the scanning start signal, the LD 11 starts writing modulation.

  Here, the light source device 10 will be further described with reference to FIGS. 2 is a perspective view of the light source device, FIG. 3 is a perspective view showing an application hole provided in the base, and FIG. 4 is a front view of the light source device viewed from the direction of arrow B in FIG. As shown in FIG. 2, the light source device 10 includes an LD 11 that emits laser light, a collimator lens 12 that collimates the laser light, a lens barrel 13 that holds the collimator lens 12, and a base 14 that holds these. Yes.

  The base 14 includes a flat plate-shaped LD holding portion 14a for holding the LD 11 and a lens barrel holding portion 14b for holding the lens barrel 13. The lens barrel holding portion 14b is perpendicular to the lower end edge of the LD holding portion 14a. Thus, it is integrally formed in an L shape. The LD holding portion 14a is provided with a through hole 15, and the LD 11 is fitted into the through hole 15 from the side opposite to the side where the lens barrel holding portion 14b is formed.

  A substantially V-shaped sliding groove is provided on the upper surface of the lens barrel holding portion 14b to slidably hold the lens barrel 13 in the optical axis direction of laser light emitted from the LD 11 (the direction indicated by arrow A in FIG. 2). 16 is provided. The sliding groove 16 is provided so that the lens barrel 13 is held at a position where the laser light emitted from the LD 11 is incident on the collimator lens 12. The distance between the LD 11 and the collimator lens 12 can be adjusted by sliding the lens barrel 13 in the direction of arrow A along the sliding groove 16.

  Further, as shown in FIG. 3, the lens barrel holding portion 14b has coating holes 17, 18, 19 and 20 penetrating from the slope of the sliding groove 16 to the lower surface of the lens barrel holding portion 14b. It is drilled perpendicular to 14b. Here, the cross-sectional shapes and sizes of the application holes 17 to 20 are the same, and the application holes 17 and 18 and 19 and 20 are formed at symmetrical positions with the sliding groove 16 in between. . Further, as shown in FIG. 4, the application holes 17 to 20 are formed at portions where the outer peripheral surface of the lens barrel 13 and the slope of the sliding groove 16 come into contact when the lens barrel 13 is placed in the sliding groove 16. The openings of the application holes 17 to 20 are formed so as to be positioned.

  In such a configuration, at the assembly stage of the light source device 10, first, the lens barrel 13 is pressed against the lens barrel holding portion 14 b by a jig or an elastic member (not shown) and temporarily fixed, and laser light is emitted from the LD 12. The state of the beam spot that is ejected and imaged on a photosensitive drum (not shown) (for example, the size of the diameter and the focus) is confirmed using a known measuring instrument and the like until it reaches a specified state. Then, the optical position of the LD 11 and the collimator lens 12 is adjusted by sliding the lens barrel 13 in the direction of arrow A in minute units.

  Here, the lens barrel 13 may be manually slid and positioned, but positioning can be performed more accurately and easily by using a known feed screw mechanism (not shown) or the like. it can. Then, when the position adjustment of the lens barrel 13 is completed, the ultraviolet curable adhesive 21 is injected from the lower surface side opening of the lens barrel holding portion 14b of the application holes 17 to 20, and the outer peripheral surface of the lens barrel 13 and the sliding groove After the application to the contact portion with the 16 slopes, the adhesive 21 is cured by irradiating ultraviolet rays through the application holes 17 to 20, and the lens barrel 13 is bonded and fixed to the lens barrel holding portion 14 b.

  Note that the adhesive 21 is not limited to the ultraviolet curable type, and for example, an instantaneous adhesive, an epoxy adhesive, a general bond, or the like can be used. Therefore, it is preferable to use an ultraviolet curable type.

  As described above, in the light source device 10 according to the present invention, the lens barrel 13 is pressed against the lens barrel holding portion 14b with a jig or the like, brought into contact with the inclined surface of the sliding groove 16, and temporarily fixed. Since the adhesive 21 is injected and applied from the application holes 17 to 20 formed in the holding portion 14b, the adhesive 21 is not formed between the lens barrel 13 and the lens barrel holding portion 14b. The position of the lens barrel 13 does not shift due to curing shrinkage of the agent 21. In addition, a tensile force that pulls the lens barrel 13 toward the lens barrel holding portion 14b is generated by curing shrinkage of the adhesive 21, but the lens barrel 13 is in contact with the sliding groove 16, and thus the lens barrel holding portion. The position does not shift to the 14b side.

  Furthermore, since the adhesive 21 is injected from the application holes 17 to 20 formed in the lens barrel holding portion 14b, the lens barrel 13 and the base 14 are formed of a material that does not transmit ultraviolet rays. In addition, the adhesive 21 can be irradiated with ultraviolet rays through the application holes 17 to 20, and the adhesive 21 can be reliably cured. In addition, since the adhesive 21 can be removed by a solvent such as alcohol, it can be easily disassembled and reassembled even when the position of the lens barrel 13 needs to be readjusted.

  The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiment, a lens barrel that holds the collimator lens 12 on the base 14 Although the case of fixing 13 has been described, this can also be applied to the case where an optical element other than the collimator lens 12 is bonded and fixed.

  In the above embodiment, the lens barrel holding portion 14b of the base 14 is integrally formed with the lower end edge of the LD holding portion 14a. However, this is because the lens barrel holding portion 14b is formed at the upper end edge of the LD holding portion 14a. It is also possible to integrally form, and to provide the sliding groove 16 on the lower surface of the lens barrel holding portion 14b, press the lens tube 13 from the lower surface side with a jig or the like, and inject and apply the adhesive 21 from the upper surface side. .

  Further, the sliding groove 16 provided in the lens barrel holding portion 14 b is not limited to the V shape, and is substantially the same as the U-shaped groove having a slightly larger width than the lens barrel 13 and the outer peripheral surface of the lens barrel 13. A semicircular groove having a radius of curvature of Further, the number and shape of the application holes formed in the sliding groove 16 can be appropriately changed according to the required adhesive strength. However, the opening on the sliding groove side of the application hole must be located at a contact portion between the outer peripheral surface of the lens barrel 13 and the sliding groove 16.

  INDUSTRIAL APPLICABILITY The present invention can be used for a light source device used as a writing optical system in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an optical scanning device including the same.

These are the perspective views of the optical scanning device provided with the light source device which concerns on this invention. FIG. 3 is a perspective view of a light source device. FIG. 3 is a perspective view showing an application hole formed in the base. These are the front views which looked at the light source device from the arrow B direction of FIG. These are front views which show the adhesion fixation of the optical element in the conventional light source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical scanner 2 Case 3 Cylindrical lens 4 Polygon mirror 5 Scan lens 6 Folding mirror 7 Mirror 8 Beam detection sensor 9 Window part 10 Light source device 11 LD (light emitting element)
12 Collimator lens (optical element)
13 Lens tube 14 Base 14a LD holder (light emitting element holder)
14b Lens-barrel holding part 15 Through hole 16 Sliding groove 17, 18, 19, 20 Application hole 21 Adhesive

Claims (3)

A light-emitting element that emits a light beam; an optical element that controls the light beam emitted from the light-emitting element; a lens barrel that holds the optical element; a light-emitting element holding unit that holds the light-emitting element; In a light source device comprising a base made up of a lens barrel holding unit for holding,
The lens barrel holding portion is provided with a slide groove on the front surface side thereof for slidably holding the lens barrel in the optical axis direction of the light beam emitted from the light emitting element, and the rear surface of the lens barrel holding portion. The light source device is characterized in that an injection hole for injecting and applying an adhesive for fixing the lens barrel is formed so as to penetrate to a position where the lens barrel contacts the inner surface of the sliding groove.   The light source device according to claim 1, wherein the adhesive for fixing the lens barrel is an ultraviolet curable adhesive.   An optical scanning device comprising the light source device according to claim 1.

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