JP6672930B2 - Optical writing device, image forming apparatus, and method of holding rod lens unit - Google Patents

Description

  The present invention relates to an optical writing device, an image forming apparatus including the optical writing device, and a method of holding a rod lens unit. In particular, the present invention relates to an optical writing device that focuses light emitted from a light emitting element on an image carrier. The present invention relates to a technology for holding a device.

2. Description of the Related Art Conventionally, as an optical writing device, an optical writing device using a gradient index rod lens array as a rod lens unit for condensing light emitted from a plurality of light emitting elements on an image carrier is known.
The rod lens array is held by a holder and incorporated into an optical writing device. Specifically, the elongated rod lens array was inserted into the through hole of the holder having the elongated through hole so that the elongated direction of the rod lens array was along the elongated direction of the through hole. It is held in the holder in the state. Further, in the through hole, a light source substrate on which a plurality of light emitting elements are arranged is held by a holder in a state where the light source substrate is inserted so as to face the rod lens array in the depth direction of the through hole. Light emitted from the element is received by the rod lens array.

As a technique for holding a rod lens array in a holder, for example, in Patent Document 1, the width (width in the lateral direction) of a central portion in the longitudinal direction of a through hole is made narrower than a region other than the central portion, and both sides of the central portion are provided. A technique is disclosed in which the rod lens array is held by a holder (housing) in a state in which the central portion (central portion in the longitudinal direction) of the rod lens array is sandwiched between the walls.
This makes it difficult for the optical axis direction of the rod lens array to be inclined with respect to the reference optical axis direction, thereby preventing image quality deterioration due to the inclined optical axis direction of the rod lens array.

JP 2014-94472 A

  However, in the above prior art, since the area other than the central part of the rod lens array is bonded to the holder with an adhesive, the adhesive is hardened when the adhesive is cured due to uneven application of the adhesive or a difference in the curing speed of the adhesive. Variations occur in the degree of accumulation of the stress accumulated in the layers, which may cause variations in the bonding position of the rod lens array. For example, as shown in FIG. 17, the rod lens array 2002 adhered by the adhesive 2000 and held by the holder 2001 rotates in the width direction (the direction indicated by the arrow P in FIG. 17). After holding the light emitting element and the light source substrate in the holder, the relative position between the light emitting element and the rod lens array is shifted, which causes a problem that image quality is deteriorated.

  The present invention has been made in view of the above-described problem, and after the rod lens unit is held in the holder, the rod lens unit is rotated in the width direction, so that the distance between the light emitting element and the rod lens unit is reduced. An object of the present invention is to provide an optical writing device capable of preventing a relative position from being shifted, an image forming apparatus including the optical writing device, and a method of holding a rod lens unit.

In order to achieve the above object, an optical writing device according to the present invention includes a plurality of light-emitting elements, a light rod emitted from each light-emitting element on an image carrier, a long rod lens unit, The rod lens unit is held in a state where the rod lens unit is inserted into the through hole so that the longitudinal direction of the rod lens unit extends along the longitudinal direction of the through hole. And a holder, wherein the rod lens unit is in contact with both walls in the short direction of the through hole at the both ends or in the vicinity of both ends in the long direction, and on both walls in contact with the rod lens unit. In a state where the rod lens unit is pressed down, the holder is elastically deformable and is in a state before the rod lens unit is inserted into the through hole. In the above, the through-hole is a spindle-shaped long shape, and the holding is such that the rod lens unit further has a center portion in the long direction and the walls on both sides in the short direction of the through-hole and the holder are elastic. It is in a state where it abuts in a deformed state and is pressed against both abutting walls, and the through hole is formed in a state where the rod lens unit is not inserted, and both ends in the longitudinal direction are The width in the short direction is the same as or smaller than the width in the short direction of the rod lens unit, and the holding is such that the width in the short direction at the center of the spindle-shaped through hole in the long direction is the holder. In a state where the rod lens unit is narrowed by the elastic deformation of the rod lens unit, both ends in the long direction of the rod lens unit and both ends in the long direction are formed on both sides in the short direction of the through hole, respectively. Contact, characterized by a state of being made is押止in contact with both side walls.

Furthermore, a plurality of light emitting elements, a long rod lens unit for condensing light emitted from each light emitting element on the image carrier, and a long through hole, A holder for holding the rod lens unit in a state where the rod lens unit is inserted into the through-hole such that the long direction of the rod lens unit extends along the length direction of the rod lens unit. In a state where the lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. The holder is elastically deformable and abuts on the rod lens unit in a state before the rod lens unit is inserted into the through hole. The distance between the walls on both sides of the through-hole is smaller than the width of the rod lens unit in the short direction, and the holder is elastically deformed when the rod lens unit is inserted into the through-hole. Then, in a state where the distance between the walls is expanded, the holder is brought into contact with the walls on both sides, and the holder is pressed against the walls on both sides in contact with an elastic reaction force generated by elastically deforming the holder. In which the rod lens unit abuts on both sides of the through-hole, and protrudes inward of the through-hole. The thickness of the wall at the end portion in the long direction may be smaller than the thickness of the wall at the center portion in the long direction of the through hole than the protruding portion.

A plurality of light emitting elements, a long rod lens unit for condensing light emitted from each light emitting element on the image carrier, and a long through hole; A holder for holding the rod lens unit in a state where the rod lens unit is inserted into the through-hole such that the long direction of the rod lens unit extends along the length direction of the rod lens unit. In a state where the lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. The holder is elastically deformable and should abut on the rod lens unit in a state before the rod lens unit is inserted into the through hole. The distance between the walls on both sides of the through hole is smaller than the width of the rod lens unit in the short direction, and the holder is elastically deformed when the rod lens unit is inserted into the through hole. In a state in which the distance between the walls is widened, the holder abuts against the walls on both sides, and is pressed against the walls on the abutted sides by an elastic reaction force generated by elastic deformation of the holder. In this state, the walls on both sides in the short direction of the through-hole have different thicknesses, and the portions in contact with the rod lens unit protrude inward of the through-hole on the walls on both sides, and the wall having the thicker The longitudinal width of the through hole of the projecting portion projecting from the wall is wider than the longitudinal width of the through hole of the projecting portion projecting from the thinner wall. It can be.
Further, the walls on both sides projecting inward are formed such that the width in the short direction between the walls on both sides decreases as the depth of the through hole increases in the direction in which the rod lens unit is inserted. It may have a ramp that slopes inward of the hole.

  Further, the plurality of light emitting elements are arranged on an elongated substrate unit, and the substrate unit is configured such that the elongated direction of the substrate unit extends along the elongated direction of the through hole. The holder is inserted into the through-hole from a side opposite to the insertion direction in the depth direction, and the holder holds the substrate unit, and the side on which the plurality of light emitting elements of the substrate unit are arranged and the rod lens unit are connected to the through-hole. Holding the substrate unit in the holder in the depth direction and holding the substrate unit in the holder at the end or near the end on both sides in the long direction, with the walls on both sides in the short direction of the through hole. It can be made to be pressed against the walls on both sides in contact with each other.

  Further, the holder is elastically deformable, and in a state before the substrate unit is inserted into the opposite side through hole, the shape of the opposite side through hole is a spindle-shaped elongate shape, and The holding of the unit is further performed in such a manner that, at the central portion of the substrate unit in the longitudinal direction, the walls on both sides in the short direction of the through hole on the opposite side abut on the holder in an elastically deformed state, and the walls on both sides abutted. It can be said that it has been held down.

Furthermore, a plurality of light emitting elements, a long rod lens unit for condensing light emitted from each light emitting element on the image carrier, and a long through hole, A holder for holding the rod lens unit in a state where the rod lens unit is inserted into the through-hole such that the long direction of the rod lens unit extends along the length direction of the rod lens unit. In a state where the lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. The plurality of light emitting elements are arranged on a long-sized substrate unit, and the substrate unit has a long direction in the long direction of the through-hole. As described above, the rod lens unit is inserted into the through hole from the side opposite to the insertion side of the rod lens unit in the depth direction, and the holder connects the substrate unit to the side on which the plurality of light emitting elements of the substrate unit are arranged. A rod lens unit is held in the through-hole so as to face in the depth direction, and the holding of the substrate unit in the holder is performed such that the substrate unit is inserted into the through-hole at the end or near the end on both sides in the longitudinal direction. The holder is in contact with the walls on both sides in the short direction of the hole, and is pressed against the walls on both sides in contact with each other. The holder is elastically deformable, and before the substrate unit is inserted into the through hole on the opposite side. In the state described above, the shape of the through hole on the opposite side is a spindle-shaped elongate shape, and the holding of the substrate unit is further performed at the center of the elongate direction at the center of the elongate direction. Short opposite sides of the wall and the holder on the opposite side of the through-hole abuts in a state of elastic deformation, have been made are押止by contact with both side walls, said opposite side of the through hole, the longitudinal direction The width in the short direction of both ends is the same as or smaller than the width in the short direction of the substrate unit, and the holding of the substrate unit is performed at the center in the long direction of the through hole on the opposite side of the spindle shape. In a state where the width in the short direction of the portion is narrowed by the elastic deformation of the holder, the long center portion and the long end portions of the substrate unit abut against the short side walls of the through hole, respectively. It can be made to be pressed against the walls on both sides in contact.

Further, the substrate unit has a light source substrate including the plurality of light emitting elements, and a fixing plate for mounting and fixing the entire light source substrate, and the substrate unit is provided in the short direction of the through hole by the light source substrate. The fixing plate may be in contact with both side walls, and may be exposed to the outside of the holder.
Furthermore, a plurality of light emitting elements, a long rod lens unit for condensing light emitted from each light emitting element on the image carrier, and a long through hole, A holder for holding the rod lens unit in a state where the rod lens unit is inserted into the through-hole such that the long direction of the rod lens unit extends along the length direction of the rod lens unit. In a state where the lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. The plurality of light emitting elements are arranged on a long-sized substrate unit, and the substrate unit has a long direction in the long direction of the through-hole. As described above, the rod lens unit is inserted into the through hole from the side opposite to the insertion side of the rod lens unit in the depth direction, and the holder connects the substrate unit to the side on which the plurality of light emitting elements of the substrate unit are arranged. A rod lens unit is held in the through-hole so as to face in the depth direction, and the holding of the substrate unit in the holder is performed such that the substrate unit is inserted into the through-hole at the end or near the end on both sides in the longitudinal direction. The hole is in contact with the walls on both sides in the short direction of the hole, and is pressed against the walls on both sides in contact with each other. The board unit mounts and fixes the light source board including the plurality of light emitting elements and the entire light source board. It includes a fixing plate, wherein the substrate unit, a light source substrate, the through-hole short opposite sides of the wall and in contact with the said fixed plate is exposed to the outside of the holder, The holder is elastically deformable, and in a state before the substrate unit is inserted into the opposite side through hole, the shape of the opposite side through hole is a spindle-shaped long shape, and the light source substrate is The fixing plate has a wiring portion on a side surface in the short direction, and the fixing plate extends upward so as to face each of the side surfaces on both sides in the short direction of the center in the long direction of the light source substrate in a non-contact manner . A restricting member for restricting the side walls on both sides in the short direction and the side surface on which the wiring portion of the light source substrate is disposed from abutting , the holding further includes: The opposite side walls of the through hole in the short direction may be brought into contact with the regulating member in a state where the holder is elastically deformed.

  Further, the both side walls with which the substrate unit abuts may protrude inside the through hole. The rod lens unit is composed of an elongated rod lens array and a protection member. The rod lens unit is configured such that the through-hole is formed in a state where both short sides of the rod lens array are sandwiched by the protection members. The through-hole may be inserted into the through hole and abut on the walls on both sides in the short direction of the through hole via the protection member.

A plurality of light emitting elements, a long rod lens unit for condensing light emitted from each light emitting element on the image carrier, and a long through hole; A holder for holding the rod lens unit in a state where the rod lens unit is inserted into the through-hole such that the long direction of the rod lens unit extends along the length direction of the rod lens unit. In a state where the lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. The holder is elastically deformable, and in a state before the rod lens unit is inserted into the through hole, the through hole has a spindle-shaped long shape. In the holding, the rod lens unit further abuts on both sides of the through-hole in the short direction of the through-hole and the holder in an elastically deformed state at a central portion in the long direction, and on both sides of the abutted wall. It is in a state where it is pressed down, and it is possible that the wall on both sides in the short direction of the through-hole which abuts on the long center of the rod lens unit in the long direction is pressed by a pressing tool. Further, an image forming apparatus according to the present invention can include the optical writing device .

Further, in the method for holding a rod lens unit according to the present invention, the rod lens unit has a long rod lens unit for condensing light emitted from each of a plurality of light emitting elements on an image carrier. A holding method in which the rod lens unit is held by a resiliently deformable holder having a spindle-shaped elongated through hole in a previous state, wherein the rod lens unit extends in a longitudinal direction of the through hole. In a state where the rod lens unit is inserted into the hole, a force is applied to both outer sides in the short direction at the central portion in the long direction of the holder to elastically deform the holder, so that the rod lens unit is elongated. At both ends or in the vicinity of both ends in the direction, the two walls in contact with the walls on both sides in the short direction of the through hole. So that the walls in a state in which the rod lens unit is押止, holds the rod lens unit, the rod lens unit further, in the central portion in the longitudinal direction, in the short direction of the through hole The walls on both sides are in contact with the holder in an elastically deformed state, are held by being pressed by the walls on both sides in contact with each other, and the through-hole is in a state where the rod lens unit is not inserted. The width in the short direction of both ends in the long direction is the same as or shorter than the width in the short direction of the rod lens unit, and the short direction of the center in the long direction of the spindle-shaped through-hole. When the width of the rod lens unit is narrowed by the elastic deformation of the holder, the central portion of the rod lens unit in the longitudinal direction and both ends in the longitudinal direction are respectively formed with the through holes Contacts the both side walls in the short direction, it is preferred to held in a state that is adapted to be 押止 in contact with both side walls.

  With the above-described configuration, the rod lens unit is pressed against the walls on both sides in contact with the walls on both sides in the short direction of the through hole at the ends or near the ends on both sides in the long direction, and is pressed by the holder. Since the rod lens unit is held by the holder, the rod lens unit is rotated in the width direction (short direction) of the through hole, and the relative position between the light emitting element and the rod lens array is shifted, thereby deteriorating the image quality. Can be prevented.

FIG. 2 is a diagram illustrating a main configuration of the image forming apparatus. FIG. 2 shows an exploded perspective view of the optical writing device 100. The perspective view of the holder 203 seen from the 2nd housing | casing part 203B side is shown. FIG. 2 is a schematic diagram illustrating a state in which an optical writing device performs optical writing on a photosensitive drum. It is a top view and a sectional view showing a holding process of rod lens array 202 to holder 203. It is a top view and a sectional view showing a holding process of light source board 201 to holder 203. It is a top view showing the 1st modification of a holding process of rod lens array 202 to holder 203. The perspective view of the light source board unit 201A is shown. It is a top view and a sectional view showing a holding process of light source board unit 201A to 2nd housing part 203B. It is a top view showing the 2nd modification of a holding process of rod lens array 202 to holder 203. It is a top view showing the 3rd modification of a holding process of rod lens array 202 to holder 203. It is a top view showing the 4th modification of a holding process of rod lens array 202 to holder 203. A sectional view in the depth direction of the protruding wall 203AA3 is shown. FIG. 9 is a plan view showing a state where the rod lens array 202 is held by a first housing portion 203A while being sandwiched between protective members 2021. It is the top view and sectional drawing which show the state where the rod lens array 202 was hold | maintained by the 1st housing | casing part 203A using the press tool. FIG. 4 is a cross-sectional view in the depth direction showing a state in which the light source substrate 201 is held in a thin layer by being adhered in a holder. It is a top view showing the state where rod lens array 2002 was held by holder 2001 by conventional technology.

Hereinafter, embodiments of an optical writing device, an image forming apparatus, and a method of holding a rod lens unit according to the present invention will be described with reference to the drawings.
[1] Configuration of Image Forming Apparatus First, the configuration of an image forming apparatus according to an embodiment of the present invention will be described.
FIG. 1 is a diagram illustrating a main configuration of the image forming apparatus according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 is a so-called tandem type color printer. The image forming units 101Y to 101K included in the image forming apparatus 1 form toner images of respective colors of Y (yellow), M (magenta), C (cyan), and K (black) under the control of the control unit 102.

  For example, in the image forming unit 101Y, the charging device 111 uniformly charges the outer peripheral surface of the photosensitive drum 110. The optical writing device 100 includes a light emitting element (organic EL element; OLED: Organic Light Emitting Diode) arranged in a line in the main scanning direction as described later, and according to a digital luminance signal generated by the control unit 102. Each OLED is caused to emit light. As a result, optical writing is performed on the outer peripheral surface of the photosensitive drum 110, and an electrostatic latent image is formed.

The developing device 112 supplies toner to the outer peripheral surface of the photoconductor drum 110 to develop (visualize) the electrostatic latent image. The primary transfer roller 113 electrostatically transfers (primary transfer) the toner image from the photosensitive drum 110 to the intermediate transfer belt 103.
Similarly, the M, C, and K toner images formed by the image forming units 101M to 101K are primarily transferred onto the intermediate transfer belt 103 so as to overlap each other, and become a color toner image. At the same time that the color toner image is conveyed to the secondary transfer roller pair 104 by the intermediate transfer belt 103, the recording sheet S supplied from the paper supply cassette 105 is also conveyed to the secondary transfer roller pair 104.

The secondary transfer roller pair 104 electrostatically transfers (secondarily transfers) the toner image on the intermediate transfer belt 103 onto the recording sheet S. The recording sheet S to which the toner image has been transferred is discharged outside the apparatus after the toner image is thermally fixed by the fixing device 106.
[2] Configuration of Optical Writing Device 100 Next, the configuration of the optical writing device 100 will be described. FIG. 2 is an exploded perspective view of the optical writing device 100. As shown in the figure, the optical writing device 100 includes a light source substrate 201 on which a plurality of OLEDs 2011 and a driving circuit for emitting the OLEDs 2011 are mounted, and a rod lens array (SELFOC Lens Array. SELFOC is a registered trademark of Nippon Sheet Glass Co., Ltd.). ) 202, and a holder 203 for holding the light source substrate 201 and the rod lens array 202.

On the light source substrate 201, a number of OLEDs 2011 are arranged in a line along the main scanning direction (the direction of the dotted arrow A in FIG. 3). These OLEDs may be arranged in a line or in a staggered arrangement.
The rod lens array 202 is a long rod lens unit configured by arranging a plurality of rod lenses 2020 in a plurality of rows. The rod lens array 202 is held by the holder 203 so as to be substantially parallel to the OLED arrangement direction (A direction). Each rod lens 2020 is configured such that the refractive index at the central axis (optical axis) is low, and the refractive index increases as the distance from the central axis increases.

  The holder 203 includes a first housing 203A that holds the rod lens array 202 and a second housing 203B that holds the light source substrate 201. Both the housings are arranged in the depth direction (the direction of the dotted arrow B). It has a long through-hole 2031 penetrating through it. The holder 203 is made of an elastically deformable resin material (for example, a liquid crystal polymer), and the through-hole 2031 is formed as shown in FIGS. 2 and 3 (a perspective view of the holder 203 viewed from the second housing 203B). The shape of both ends in the depth direction is such that the center part is bulged outward in the short direction (sub-scanning direction) perpendicular to the long direction, and the end part in the long direction is inwardly converged. It has a long shape.

  The rod lens array 202 is inserted into the through-hole 2031 from one end in the depth direction of the through-hole 2031 (the end on the first casing 203A side) as shown by the dotted arrow C, and the light source substrate 201 Is, as indicated by the dotted arrow D, from the other end of the through hole 2031 in the depth direction (the end opposite to the insertion side of the rod lens array 202 and the depth direction) (the end on the second housing portion 203B side). It is inserted into the through hole 2031 and is held by the holder 203 by a holding method described later (see FIGS. 5 and 6 described later). The planar shape of the end portion of the through hole 2031 on the first housing portion 203A side is larger than the planar shape size of the rod lens array 202 in the insertion direction, and the end of the through hole 2031 on the second housing portion 203B side. The size of the planar shape of the portion is larger than the size of the planar shape in the insertion direction of the light source substrate 201, and the rod lens array 202 and the light source substrate 201 are configured so as not to contact the holder 203 at the time of insertion.

  FIG. 4 is a schematic diagram showing how the optical writing device 100 performs optical writing on the photosensitive drum 110. As shown in the figure, the optical writing device 100 holds a light source substrate 201 and a rod lens array 202 in a holder 203, and the light beam L emitted from the OLED 2011 arranged on the light source substrate 201 is transmitted to the rod lens array 202. As a result, the light is focused on the outer peripheral surface of the photosensitive drum 110.

  5A, 5B, and 5D are plan views showing a process of holding the rod lens array 202 on the holder 203. FIG. 5C is a cross-sectional view taken along line AA of FIG. 5B. As shown in FIG. 5A, the rod lens array 202 is inserted into the through hole 2031 from the first housing portion 203A side such that the long direction of the rod lens array 202 extends along the long direction of the through hole 2031. It is inserted into the through hole 2031 until the insertion depth into the through hole 2031 reaches a predetermined depth, and is fixed with a jig (not shown). Further, the width (c) in the short direction of both ends in the long direction of the through hole 2031 is equal to or less than the width (d) in the short direction of the rod lens array 202 (c ≦ d).

  Next, the walls on both sides of the first housing portion 203A facing the central portion in the long direction of the rod lens array 202 in the short direction are directed inward in the short direction (directions indicated by arrows A1 and A2 in FIG. 5A). 5 (b), and in a state where the walls on both sides are brought into contact with the center of the rod lens array 202 in the longitudinal direction as shown in FIG. 5 (b), an adhesive (for example, , UV-curable adhesive) 204 is applied so as to straddle the upper surface of the walls on both sides and both side surfaces of the exposed portion at the central portion in the longitudinal direction, and adheres the upper surface to the exposed portion, and The parts are pressed against the walls on both sides. The central portion in the longitudinal direction is pressed by the walls on both sides, so that the walls on both sides of the first housing portion 203A opposed in the longitudinal direction with the rod lens array 202 interposed therebetween are inward of the through holes 2031. The rod lens array 202 is pushed to the side and comes into contact with both ends in the long direction of the rod lens array 202, and both ends in the long direction are pressed by the walls on both sides.

  Next, as shown in FIG. 5D, the adhesive 204 is applied to the upper surfaces of the walls on both sides of the first housing 203 </ b> A, which oppose the vicinity of both ends in the longitudinal direction of the rod lens array 202 in the longitudinal direction. It is applied so as to straddle both sides of the exposed portion in the vicinity and adheres the exposed portion in the vicinity to the upper surfaces of the walls on both sides to increase the holding force of the rod lens array 202 on the first housing portion 203A. Reinforce. Although the holding force is weaker than in the case of FIG. 5D, the rod lens array 202 is not bonded to the exposed portion and the upper surfaces of the side walls in the state shown in FIG. 5B. It may be held in the first housing 203A.

  As shown in FIGS. 6A to 6D, the light source substrate 201 is held by the holder 203 (the second housing portion 203B) in the same manner as the method of holding the rod lens array 202 as shown in FIGS. . FIGS. 6A, 6B, and 6D are plan views showing a process of holding the light source substrate 201 on the holder 203. FIG. FIG. 6C is a cross-sectional view taken along the line BB of FIG. 6B.

  The light source substrate 201 has an appropriate distance in the depth direction of the through-hole 2031 from the second housing part 203B side to the rod lens array 202 held in the holder 203 (based on a reference determined in advance by the manufacturer). After being inserted into the through-hole 2031 so as to have a predetermined distance and being fixed by a jig (not shown) (see FIG. 6A, both ends in the longitudinal direction of the through-hole 2031 on the second housing portion 203B side) Is less than or equal to the width dd of the light source substrate 201 in the short direction (cc ≦ dd).) Of the second housing portion 203B facing the center of the light source substrate 201 in the long direction in the short direction. The walls on both sides are pushed inward in the short direction (directions indicated by arrows B1 and B2 in FIG. 6A), and the central part and both ends in the long direction of the light source substrate 201 are opposed to them in the short direction. In contact with the walls on both sides of the housing 203B, In the 押止 (FIG. 6 (b), the reference (c)).

As shown in FIG. 6C, the bonding of the adhesive 204 to the side walls of the two side walls of the second casing 203 </ b> B in the longitudinal direction of the light source substrate 201 is performed with the side surfaces of the both side walls. This is performed by coating so as to straddle a lower surface (a surface on which the OLED 2011 is not arranged) facing the outside of the central portion.
Then, as shown in FIG. 6D, the side surfaces of the walls on both sides of the second housing portion 203 </ b> B opposed to the both ends in the long direction of the light source substrate 201 in the short direction and face the outside of the nearby portions. By applying so as to straddle the lower surface, the walls on both sides and the lower surface facing outward of the adjacent portion are adhered, and the holding force of the light source substrate 201 on the second housing portion 203B is reinforced. Note that, similarly to the case of holding the rod lens array 202, the light source substrate 201 may be held in the second housing 203B in the state illustrated in FIG. 6B without performing the bonding illustrated in FIG. Good.

  As described above, the light source substrate 201 and the rod lens array 202 are held by the holder 203, so that both ends in the long direction of the light source substrate 201 and the rod lens array 202 are in contact with the walls on both sides of the through hole 2031 facing the short direction. Since the light source substrate 201 and the rod lens array 202 are held by the holder 203, they are rotated in the width direction (short direction) of the through hole 2031 to rotate the light emitting element (OLED 2011) and the rod lens array. It is possible to prevent the relative position between the image data 202 and the image data 202 from being deviated and the image quality from deteriorating.

[3] Modifications While the present invention has been described based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments, and the following modifications can be made. .
(1) In the above-described embodiment, the wall forming the through hole 2031 is a flat wall, but the wall of the portion in contact with the rod lens array 202 and the light source substrate 201 projects inward in the short direction of the through hole 2031. It is good also as a structure provided.

  FIGS. 7A and 7B are plan views showing a modification of the step of holding the rod lens array 202 on the holder 203. FIG. FIG. 7C is a cross-sectional view taken along line CC of FIG. 7B. The rod lens array 202 is inserted into the through hole 2031 until the insertion depth of the rod lens array 202 into the through hole 2031 reaches a predetermined depth in the same manner as in FIG. Fix it.

  In this modification, since the wall of the holder 203 of the contact portion is provided to protrude inward in the short direction of the through hole 2031, the width c in the short direction of both ends in the long direction of the through hole 2031 is: It is not necessary that the width d in the short direction of the rod lens array 202 be equal to or smaller than d (c ≦ d). Even if c> d, the area near the center in the long direction and both ends of the rod lens array 202 is short of them. It can be configured to be pressed by the protruding walls (2031A, 2032A) on both sides of the second housing portion 203B facing the direction.

  Next, the projecting walls 2031A on both sides of the first housing portion 203A facing the central portion in the long direction of the rod lens array 202 in the short direction are inwardly positioned in the short direction (arrows C1 and C2 in FIG. 7A). 7B) so that the protruding walls 2031A on both sides and the central part of the rod lens array 202 in the longitudinal direction are brought into contact with each other, as shown in FIG. The area in the vicinity of both ends in the length direction is brought into contact with the protruding walls 2032A on both sides of the first casing 203A facing in the short direction. Then, as shown in FIGS. 7B and 7C, the adhesive 204 is exposed to the upper surface of the protruding wall 2031A on both sides of the first housing portion 203A and the central portion in the longitudinal direction of the rod lens array 202. The upper surface and the exposed portion are adhered by being applied so as to straddle both side surfaces of the portion, so that the central portion in the long direction is pressed by the protruding walls 2031A on both sides, and a rod lens array is provided. The region in the vicinity of both ends in the longitudinal direction of 202 is pressed by the protruding walls 2032A on both sides. Here, the region near both ends in the longitudinal direction is a region closer to the end than the intermediate point between the central portion in the longitudinal direction and the end in the longitudinal direction. The same applies to the following.

  Although not shown, the configuration of the second housing portion 203B is the same as the configuration of the first housing portion 203A of the present modification, and the wall of the contact portion is located on the inner side in the short direction of the through hole 2031. As a protruding structure, the second case in which the central portion in the long direction and the regions near both ends of the light source substrate 201 face in the short direction by a holding method similar to the holding method of the rod lens array 202 of the present modification. It may be configured to be pressed by the protruding walls on both sides of the body part 203B.

  Further, in the case where wiring portions such as power supply lines are formed on both side surfaces in the short direction of the light source substrate 201, if both side surfaces come into contact with the wall of the second housing portion 203B, the wiring portion is damaged. In the case where the light source board 201 is held in the second casing 203B, there is a possibility that both sides of the light source board 201 do not come into contact with the walls of the second casing 203B. The light source substrate 201 may be configured so as not to protrude from the central portion in the long direction and the two walls facing the short direction.

  FIG. 8 is a perspective view of a light source board unit 201A of the present modification. As shown in the drawing, a light source substrate unit 201A has a main surface on which OLEDs 2011 are arranged, a light source substrate 201 having wiring portions 2010 on both side surfaces in a short direction, a fixing plate 2012 for fixing the light source substrate 201, and a fixing plate 2012. And a regulating member 2013 extending upward so as to face the non-contact side surfaces of both sides of the light source substrate 201 in the longitudinal direction in the longitudinal direction. The fixing plate 2012 can be made of, for example, a metal plate of aluminum, copper, or the like having high heat dissipation. Thereby, the heat generated when the OLED 2011 of the light source substrate 201 is turned on can be efficiently radiated through the fixing plate 2012.

FIGS. 9A and 9B are plan views showing a process of holding the light source board unit 201A on the second housing 203B. 9A and 9B, the fixing plate 2012 is indicated by a dotted line for convenience of explanation. FIG. 9C is a cross-sectional view taken along line DD in FIG. 9B.
In the case of the above configuration, as shown in FIG. 9A, the walls on both sides of the second housing portion 203 </ b> B facing the central portion in the long direction of the light source substrate 201 in the short direction are inward in the short direction (arrows). D1 and D2), as shown in FIGS. 9B and 9C, the pushed-in walls and the regulating members 2013 come into contact with each other, and the regulating members 2013 contact the light source and the light source. It is regulated so that the side surface of the substrate 201 on which the wiring section 2010 is arranged does not abut.

  Then, in a state where the walls on both sides that are pushed in and the regulating member 2013 are in contact with each other, as shown in FIGS. 9B and 9C, the fixing plate 2012 and the second housing portion 203B are bonded with the adhesive 204. By bonding, the vicinity of both ends in the longitudinal direction of the light source substrate 201 is formed by the two walls 2031B and 2032B protruding in a state of being in contact with the protruding walls 2031B and 2032B on both sides of the second housing 203B. It is stopped.

Accordingly, when the wiring portions 2010 such as power supply lines are formed on both side surfaces in the short direction of the light source substrate 201, the side walls on which the wiring portions 2010 of the light source substrate 201 are arranged by the regulating members 2013 Are restricted so as not to come into contact with each other, so that the wiring portion can be prevented from being damaged.
(2) FIGS. 10A and 10B are plan views showing another modification of the step of holding the rod lens array 202 on the holder 203. FIG. In this modification, as shown in FIG. 10A, the thickness of the first housing portion 203A on both sides in the short direction of the through hole 2031 is different, and one wall (the upper wall 203A1 in FIG. 10A) is different. ) Is smaller (e1 <e2) than the thickness (e2) of the other wall (the lower wall 203A2 in FIG. 10A). The wall 203A1 has an arcuate shape that bulges outward from both ends in the elongate direction toward the center in the elongate direction, and the wall 203A2 extends substantially linearly in the elongate direction.

Also, the width of the through hole 2031 in the short direction is such that the central portion in the long direction swells and narrows from the central portion in the long direction toward the end in the long direction. In the vicinity of the region where both ends of the rod lens array 202 in the long direction are inserted, the width (d) of the rod lens array 202 in the short direction is smaller.
The insertion depth of the rod lens array 202 into the through hole 2031 from the first housing part 203A side is set to a predetermined depth such that the long direction of the rod lens array 202 extends along the long direction of the through hole 2031. When the rod lens array 202 is inserted into the through hole 2031 so as to be pushed to the right, the distance between the two opposite walls (203A1 and 203A2) in the short direction across the rod lens array 202 at both ends in the long direction of the rod lens array 202 is reduced. In a state of being expanded by elastic deformation (here, mainly by elastic deformation of the wall 203A1 having a small thickness and low rigidity), both ends of the rod lens array 202 in the long direction and the walls 203A1 and 203A2 on both sides are formed. Are pressed against each other by the elastic reaction force generated by the elastic deformation (see FIG. 10B).

Further, by setting the thickness of the wall 203A2 having the higher rigidity to an appropriate thickness that hardly causes elastic deformation, as shown in FIG. 10B, the entire portion of the rod lens array 202 facing the wall 203A2 is formed. It can be brought into contact with the wall 203A2.
Although not shown, the configuration of the second housing 203B is the same as the configuration of the first housing 203A of the present modification, and the same as the method of holding the rod lens array 202 of the present modification. By the holding method, the light source substrate 201 is brought into contact with the opposite side walls having different thicknesses in the short direction with the light source substrate 201 interposed therebetween at both ends in the long direction. It may be configured to be pressed by the walls on both sides by the force. Also in this case, as in the case of the rod lens array 202, the entire portion of the light source substrate 201 facing the thicker wall can be brought into contact with the wall.

Thus, the rod lens array 202 and the light source substrate 201 can be easily held by the holder 203 without using an adhesive. Further, since the contact area with the holder 203 can be increased, the rod lens array 202 and the light source substrate 201 can be held by the holder 203 in a stable state.
(3) In the modified example of (2), the wall of the portion in contact with the rod lens array 202 and the light source substrate 201 may be configured to protrude inward in the short direction of the through hole 2031. FIGS. 11A and 11B are plan views showing another modification of the step of holding the rod lens array 202 on the holder 203. FIG. FIG. 11C is a cross-sectional view taken along the line EE of FIG. 11B. As shown in FIGS. 11A and 11B, the walls 203A3 and 203A4 on both sides of the first housing portion 203A, which are in contact with the rod lens array 202, in the region near both ends in the longitudinal direction of the rod lens array 202. It is protruding. The short distance (a1) between the protruding walls 203A3 and 203A4 in the short direction is smaller than the short width (d) of the rod lens array 202 (a1 <d).

  In addition, as shown in FIG. 11C, the protruding portion of the wall is configured such that the length of the wall 203A4 in the depth direction (B direction) is longer than the length of the wall 203A3 in the depth direction. Can be configured such that the stop positions in the depth direction substantially coincide with each other. By doing so, the rod lens array 202 can be stably held by the holder 203 so that the rod lens array 202 does not rotate around the direction perpendicular to the paper surface as a central axis.

  The insertion depth of the rod lens array 202 into the through hole 2031 from the first housing part 203A side is set to a predetermined depth such that the long direction of the rod lens array 202 extends along the long direction of the through hole 2031. When the rod lens array 202 is inserted into the through hole 2031 so as to be pushed to the right, the protruding walls (203A3, 203A3, 203A4) is expanded by elastic deformation (here, mainly by the elastic deformation of the wall 203A1 having a small thickness and low rigidity) in a state where the rod lens array 202 is in the vicinity of both ends in the longitudinal direction. The protruding walls 203A3 and 203A4 on both sides come into contact with each other, and the region near both ends in the longitudinal direction is caused by an elastic reaction force generated by the elastic deformation. Is 押止 above both sides of the projecting walls 203A3,203A4 (see FIG. 11 (b)).

  Although not shown, the configuration of the second housing 203B is the same as the configuration of the first housing 203A of the present modification, and the same as the method of holding the rod lens array 202 of the present modification. By the holding method, the light source substrate 201 is brought into contact with the protruding walls on both sides facing in the short direction with the light source substrate 201 interposed therebetween in the vicinity of both ends in the long direction, and near the both ends in the long direction of the light source substrate 201. The area may be configured to be pressed by the projecting walls on both sides by the elastic reaction force.

  (4) FIGS. 12A and 12B are plan views showing another modification of the step of holding the rod lens array 202 on the holder 203. FIG. In the present modified example, as shown in both figures, the wall of the first housing portion 203A at the portion in contact with the rod lens array 202 is protruded inward in the short direction of the through hole 2031. The thickness (e3) of the wall 203AA1 at the end in the long direction is smaller than the thickness (e4) of the wall 203AA2 at the center in the long direction from the protruding portion (e3 <e4). The short distance (a2) between these protruding walls 203AA3 is smaller than the short width (d) of the rod lens array 202 (a2 <d).

  The insertion depth of the rod lens array 202 into the through hole 2031 from the first housing part 203A side is set to a predetermined depth such that the long direction of the rod lens array 202 extends along the long direction of the through hole 2031. When the rod lens array 202 is inserted so as to be pushed into the through hole 2031 until the end thereof, the protruding walls (203AA3) on both sides of the rod lens array 202 which are opposed in the short direction across the rod lens array 202 in a region near both ends in the long direction. In a state where the distance between them is expanded by elastic deformation (here, mainly by the elastic deformation of the wall 203AA1 having a small thickness and low rigidity), the area near both ends in the longitudinal direction of the rod lens array 202 and the both sides Abuts against the wall 203AA3 provided with the protrusion, and the region near both ends in the long direction is formed by the elastic reaction force generated by the elastic deformation. Is 押止 walls 203AA3 that (see FIG. 12 (b)).

Further, as shown in FIG. 13, as the depth of the through hole 2031 increases in the direction in which the rod lens array 202 is inserted (in the direction of the dotted arrow C), the walls on both sides protrude from the walls 203AA3 provided on both sides. An inclined portion 203AA30 that is inclined inward of the through hole 2031 may be provided so that the width in the short direction between the 203AA3 becomes narrow.
Accordingly, in the holding step, the rod lens array 202 can be easily guided to the contact portion via the inclined portion 203AA30 and held by the holder 203.

The inclined portion may be provided also on the protruding wall of the first housing portion 203A and the second housing portion 203B of the modified example (3).
Although not shown, the configuration of the second housing 203B is the same as the configuration of the first housing 203A of the present modification, and the same as the method of holding the rod lens array 202 of the present modification. By the holding method, the light source substrate 201 is brought into contact with the protruding walls on both sides facing in the short direction with the light source substrate 201 interposed therebetween in the vicinity of both ends in the long direction, and near the both ends in the long direction of the light source substrate 201. The area may be configured to be pressed by the projecting walls on both sides by the elastic reaction force. Similarly, the inclined portions may be provided on the projecting walls on both sides.

  (5) In the above embodiment, the rod lens array 202 is held in the holder 203 by directly abutting the walls on both sides of the first housing 203A. The rod lens unit may be held by the holder 203 (first housing 203A) in a state where the rod lens unit 202 is sandwiched by the protective member. More specifically, as shown in FIG. 14, the rod lens array 202 may be configured such that the side surfaces on both sides in the short direction are held by the first housing portion 203A while being sandwiched by the protective member 2021. Good.

Accordingly, the rod lens array 202 can be held by the holder 203 so as not to directly contact the wall of the first housing portion 203A, and the rod lens array 202 can be protected and hardly damaged.
Similarly, in the modified examples (1) to (4), the both sides of the rod lens array 202 in the short direction are held by the first housing portion 203A while being sandwiched by the protective member 2021. It may be configured.

(6) In the above embodiment and the modified example of (1), the central part of the rod lens array 202 and the light source substrate 201 in the long direction and the holder 203 are adhered with the adhesive 204 so that the central part of the long direction is the holder 203. Although the pressing is performed by the walls on both sides, the pressing may be performed using a pressing tool instead of the adhesive.
FIG. 15A is a plan view showing a state in which the rod lens array 202 is held by the first housing 203A using a pressing tool. FIG. 15B is a cross-sectional view along the line A′-A ′ in FIG. As shown in both figures, the walls on both sides of the first housing portion 203A opposed to the central portion in the long direction of the rod lens array 202 in the short direction are pressed inward by the pressing members 204A and 204B. The central portion in the longitudinal direction of the rod lens array 202 is pressed by the walls on both sides.

As the pressing member 204A, for example, an urging member including a spring or the like can be used. As the pressing member 204B, for example, a set screw can be used.
When the pressing member 204B (set screw) is screwed in the direction of the arrow F, the spring of the pressing member 204A (biasing member) is elastically deformed, and the wall of the first housing portion 203A that comes into contact with the pressing member 204A due to the reaction force. It is urged in the direction of arrow G, whereby the central portion in the long direction of the rod lens array 202 can be pressed against the walls of the first casing 203A on both sides in the short direction.

The pressing member is not limited to the above-described member, and may be another member as long as the rod lens array 202 can be pressed by the both side walls.
Further, the light source substrate 201 may be pressed by using a pressing tool instead of the adhesive in the same manner as described above.

  (7) Also, as in the above embodiment and the modified examples of (1) to (4), instead of holding the light source substrate 201 in contact with and holding the walls on both sides in the short direction of the second housing portion 203B, as in the above embodiment and the modified examples of (1) to (4). As in the modification example of (1), after the light source substrate 201 is fixed to the fixing plate 2012 and the light source substrate 201 is inserted into the through hole 2031 from the second housing portion 203B side, the fixing plate 2012 and the second housing The light source substrate 201 may be held in the holder 203 by thinly bonding the body part 203B with an adhesive.

  In this case, even if the light source substrate 201 does not contact the walls on both sides in the short direction of the second housing portion 203B, the entire main surface of the light source substrate 201 on which the OLEDs 2011 are not arranged is on the fixed plate 2012. , The light source substrate 201 does not rotate in the width direction (short direction) of the through-hole 2031 after holding, and the relative position with respect to the rod lens array 202 does not easily shift.

  As shown in FIG. 16, both ends of the main surface of the light source substrate 201 on the side where the OLEDs 2011 are arranged in the short direction and the stepped portion 203C of the holder 203 are thinly adhered with an adhesive 204 so as to form the inside of the holder 203. Alternatively, the light source substrate 201 may be held. In this case as well, the entire short-side end portions of the light source substrate 201 are bonded to the step portion 203C with a thin layer. Therefore, even if the light source substrate 201 is not brought into contact with both short-side walls of the second housing portion 203B, after holding, There is no possibility that the light source substrate 201 rotates in the width direction (short direction) of the through hole 2031, and the relative position with respect to the rod lens array 202 does not easily shift.

  (8) The present invention may be a method of holding a rod lens unit (rod lens array 202) by using the holder 203 as described above, and in this case, the above-described effects can be obtained. Can play.

  The present invention relates to an optical writing device, an image forming apparatus including the optical writing device, and a method of holding a rod lens unit. In particular, the present invention relates to an optical writing device that focuses light emitted from a light emitting element on an image carrier. It can be used to hold in the device.

1. Image forming apparatus 100 Optical writing apparatus 110 Photoconductor drum 201 Light source substrate 201A Light source substrate unit 202 Rod lens array 203 Holder 203A First housing 203B Second Housing 204: adhesive 2031: through hole

Claims (14)

A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The holder is elastically deformable, and in a state before the rod lens unit is inserted into the through hole, the through hole has a spindle-shaped long shape,
In the holding, the rod lens unit further abuts on both sides of the through-hole in the short direction of the through-hole and the holder in an elastically deformed state at a central portion in the long direction, and on both sides of the abutted wall. It is in a state where it is held down,
In the through hole, in a state in which the rod lens unit is not inserted, the width in the short direction of both ends in the long direction is the same as or smaller than the width in the short direction of the rod lens unit. ,
The holding is performed in a state where the width of the spindle-shaped through hole in the longitudinal direction at the central portion in the longitudinal direction is narrowed by elastic deformation of the holder, and the rod lens unit has the longitudinal central portion and both ends in the longitudinal direction. parts, respectively the through hole in contact with both side walls in the short direction of the optical writing device you characterized in that in contact with both sides of the walls is a state of being made is押止. A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The holder is elastically deformable, and in a state before the rod lens unit is inserted into the through hole, the distance between the walls on both sides of the through hole to be brought into contact with the rod lens unit is the rod lens. Narrower than the width of the unit in the short direction, the holding is performed in a state where the rod lens unit is inserted into the through hole, the holder is elastically deformed, and the distance between the walls is expanded, It is in a state in which the holder is in contact with the walls on both sides and is pressed against the walls on the contacted sides by an elastic reaction force generated by the holder being elastically deformed,
The side walls on which the rod lens unit abuts are protruded inside the through hole,
The thickness of the wall on the long side end side of the through hole from the protruding portion is greater than the thickness of the wall on the long side central portion side of the through hole from the protruding portion. thinner optical writing device characterized. A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The holder is elastically deformable, and in a state before the rod lens unit is inserted into the through hole, the distance between the walls on both sides of the through hole to be brought into contact with the rod lens unit is the rod lens. Narrower than the width of the unit in the short direction, the holding is performed in a state where the rod lens unit is inserted into the through hole, the holder is elastically deformed, and the distance between the walls is expanded, It is in a state in which the holder is in contact with the walls on both sides and is pressed against the walls on the contacted sides by an elastic reaction force generated by the holder being elastically deformed,
The walls on both sides in the short direction of the through hole have different thicknesses,
In the walls on both sides, a portion in contact with the rod lens unit is protruded inward of the through hole,
The longitudinal direction width of the through hole of the projecting portion projecting from the thicker wall is the longitudinal direction of the through hole of the projecting portion projecting from the thinner wall. optical writing device characterized wider than the width. The walls on both sides projecting inward are formed such that the width in the short direction between the walls on both sides decreases as the depth of the through hole increases in the direction in which the rod lens unit is inserted. The optical writing device according to claim 2 , further comprising an inwardly inclined portion. The plurality of light emitting elements are arranged on a long-sized substrate unit,
The substrate unit is inserted into the through-hole from the side opposite to the insertion side of the rod lens unit and the depth direction such that the long direction of the substrate unit is along the long direction of the through-hole,
The holder holds the substrate unit such that a side of the substrate unit where the plurality of light emitting elements are arranged and the rod lens unit face each other in the depth direction in the through hole,
The holding of the substrate unit in the holder is such that the substrate unit is in contact with the short-sided walls on both sides in the long direction at the ends or near the ends on the long sides, and is pressed by the walls on both sides in contact. The optical writing device according to any one of claims 1 to 4 , wherein the optical writing device is provided. The holder is elastically deformable, and in a state before the substrate unit is inserted into the opposite side through hole, the shape of the opposite side through hole is a spindle-shaped long shape,
The holding of the substrate unit, further, the substrate unit in the central portion in the elongate direction, the opposite side wall of the through hole on the opposite side and the holder abuts in an elastically deformed state, the both sides of the abutted contact The optical writing device according to claim 5 , wherein the optical writing device is pressed by a wall. A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The plurality of light emitting elements are arranged on a long-sized substrate unit,
The substrate unit is inserted into the through-hole from the side opposite to the insertion side of the rod lens unit and the depth direction such that the long direction of the substrate unit is along the long direction of the through-hole,
The holder holds the substrate unit such that a side of the substrate unit where the plurality of light emitting elements are arranged and the rod lens unit face each other in the depth direction in the through hole,
The holding of the substrate unit in the holder is such that the substrate unit is in contact with the short-sided walls on both sides in the long direction at the ends or near the ends on the long sides, and is pressed by the walls on both sides in contact. It has been done,
The holder is elastically deformable, in a state before the substrate unit is inserted into the opposite side through hole, the shape of the opposite side through hole is a spindle-shaped long shape,
The holding of the substrate unit, further, the substrate unit in the central portion in the elongate direction, the opposite side wall of the through hole on the opposite side and the holder abuts in an elastically deformed state, the both sides of the abutted contact It is made by being stopped by the wall,
In the opposite through-hole, the width in the short direction of both ends in the long direction is the same as or smaller than the width in the short direction of the substrate unit,
The holding of the substrate unit is performed in such a manner that the width of the spindle-shaped through hole on the opposite side in the longitudinal direction is narrowed by the elastic deformation of the holder, and the length of the central part of the substrate unit is reduced. and the longitudinal direction both end portions, each of the through-hole short opposite sides of the wall and in contact with the optical writing device you characterized in that it is made is押止in contact with both side walls. The substrate unit includes a light source substrate including the plurality of light emitting elements, and a fixing plate for mounting and fixing the entire light source substrate,
6. The optical writing according to claim 5 , wherein the substrate unit is in contact with walls on both sides in the short direction of the through hole by the light source substrate, and the fixing plate is exposed outside the holder. 7. apparatus. A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The plurality of light emitting elements are arranged on a long-sized substrate unit,
The substrate unit is inserted into the through-hole from the side opposite to the insertion side of the rod lens unit and the depth direction such that the long direction of the substrate unit is along the long direction of the through-hole,
The holder holds the substrate unit such that a side of the substrate unit where the plurality of light emitting elements are arranged and the rod lens unit face each other in the depth direction in the through hole,
The holding of the substrate unit in the holder is such that the substrate unit is in contact with the short-sided walls on both sides in the long direction at the ends or near the ends on the long sides, and is pressed by the walls on both sides in contact. It has been done,
The substrate unit includes a light source substrate including the plurality of light emitting elements, and a fixing plate for mounting and fixing the entire light source substrate,
The substrate unit is in contact with the walls on both sides in the short direction of the through hole by the light source substrate, and the fixing plate is exposed outside the holder,
The holder is elastically deformable, in a state before the substrate unit is inserted into the opposite side through hole, the shape of the opposite side through hole is a spindle-shaped long shape,
The light source substrate has a wiring portion on a side surface in the short direction,
The fixing plate extends upward so as to face each side of the short side of the light source substrate in the long direction at the center in the long direction in a non-contact manner, and the both sides of the short side of the through hole and the wiring portion of the light source substrate. Has a regulating member that regulates so that the side where the is arranged does not contact ,
The holding is further performed in a state in which the light source substrate is in contact with the wall on both sides in the short direction of the through hole on the opposite side and the regulating member in the long direction central portion in a state where the holder is elastically deformed. optical writing device characterized by being made. The two side walls the substrate unit abuts the optical writing device according to claim 5, 6, 8, 9, characterized in that it is projected inward of the through hole. The rod lens unit has a long shape, a rod lens array, and a protection member,
The rod lens unit is inserted into the through-hole in a state where both short sides of the rod lens array are sandwiched by the protection member, and abuts the short-side walls on both sides of the through hole through the protection member. The optical writing device according to any one of claims 5 to 8 , wherein: A plurality of light emitting elements,
An elongated rod lens unit that condenses light emitted from each light emitting element on the image carrier,
It has an elongated through hole, and holds the rod lens unit in a state where the rod lens unit is inserted into the through hole so that the elongated direction of the rod lens unit extends along the elongated direction of the through hole. And a holder for
The holding by the holder is such that the rod lens unit abuts on both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit presses the both walls in contact with each other. Is in a state of being stopped,
The holder is elastically deformable, and in a state before the rod lens unit is inserted into the through hole, the through hole has a spindle-shaped long shape,
In the holding, the rod lens unit further abuts on both sides of the through-hole in the short direction of the through-hole and the holder in an elastically deformed state at a central portion in the long direction, and on both sides of the abutted wall. It is in a state where it is held down,
Optical writing device short direction both side walls of the through hole into contact with the longitudinal direction center portion of the rod lens unit you characterized by being押止in pressing tool. An image forming apparatus comprising the optical writing device according to any one of claims 1 to 12. A long rod lens unit for condensing light emitted from each of the plurality of light emitting elements on the image carrier, having a spindle-shaped long through hole in a state before holding the rod lens unit. A holding method of holding by an elastically deformable holder,
In a state where the rod lens unit is inserted into the through hole so that the long direction of the rod lens unit is along the long direction of the through hole,
By applying a force to both outer sides in the short direction at the central portion in the long direction of the holder, by elastically deforming the holder,
In a state in which the rod lens unit is in contact with both side walls in the short direction of the through hole at both ends or in the vicinity of both ends in the long direction, and the rod lens unit is pressed against the two walls in contact with each other. So that the rod lens unit is held,
The rod lens unit further abuts against the both side walls in the short direction of the through hole and the holder in an elastically deformed state at a central portion in the long direction, and is pressed by the both side walls in contact. And hold it as it is
In the through hole, in a state in which the rod lens unit is not inserted, the width in the short direction of both ends in the long direction is the same as or smaller than the width in the short direction of the rod lens unit. ,
In a state where the width of the spindle-shaped through-hole in the lengthwise central portion in the lengthwise direction is narrowed by elastic deformation of the holder, the rod lens unit has a lengthwise central portion and both ends in the lengthwise direction, respectively. the through hole on both sides of the wall and in contact with the short direction of the holding method features and to Carlo head lens unit to be held in a state of being made is押止in contact with both side walls.

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