JP4998539B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning device and an image forming apparatus.

  2. Description of the Related Art Conventionally, image forming apparatuses such as laser printers have been provided with an optical scanning device that exposes a photoreceptor surface by causing light from a light source to enter a polygon mirror (rotating polygon mirror) and scanning the reflected light. .

  In this optical scanning device, a light source made of a semiconductor laser and a coupling lens for converting diffused light from the light source into a light beam are held in one holding member (Patent Document 1). ). The holding member is screwed to the optical scanning device main body via a screw or the like. As a result, the light source and the coupling lens are positioned with respect to the optical system of the optical scanning device main body.

JP 2005-338545 A

  However, the following problems have occurred in the above optical scanning device. That is, in the conventional method in which the holding member and the optical scanning device main body are screwed together using a screw, the holding member is sandwiched between the optical scanning device main body and the screw when screwed with the screw. At this time, a sudden rotational force due to the rotation of the screw is applied to the holding member, and the entire holding member is easily rotated. Therefore, when the holding member is completely screwed with the screw, the optical axis of the light from the light source is inclined in the screw rotation direction at the time of screwing, and as a result, the optical axis may be displaced from the correct position. .

  In view of the above problems, an object of the present invention is to provide an optical scanning device and an image forming apparatus capable of accurately positioning the optical axis of light.

  In order to solve the above problems, an optical scanning device and an image forming apparatus including the optical scanning device according to the present invention integrally hold a light source and an optical element that converts light emitted from the light source into a light beam. A housing having a holding member, a screwing portion for screwing the holding member with a screwing member, and a deflecting unit for deflecting light converted into a light beam, the holding member including the light source A first opening that has a main body portion that holds the optical element and a pair of extending portions that extend from the main body portion, and the threaded portion can be inserted into the pair of extending portions. A portion is formed, and at least one of each of the extending portions and the housing is in a state where the screwing portion is inserted through the first opening when the holding member is held in the housing. In order to form a predetermined gap between the extension part and the casing, the screwing part is sandwiched in the optical axis direction of light. And the holding member is formed by the gap forming portion when the extension portion is screwed to the housing by the screwing member via the screwing portion. The air gap is supported by the casing so as to bend and narrow.

  In the invention according to claim 2, the holding member is formed with a second opening portion that is opened along the optical axis direction of light between the extension portion and the main body portion. Features.

  According to a third aspect of the present invention, a third opening disposed so as to sandwich the first opening is formed in one of the housing and the extension, and the other is formed in the other A pair of protrusions that are inserted into the third opening for positioning the holding member, and one of the third openings has light from the inner peripheral surface thereof in the extension portion. A pressing portion that presses the protruding portion toward the end in the optical axis direction.

  According to a fourth aspect of the present invention, the extending portion has a protruding portion that protrudes along a peripheral edge portion of the first opening, and the protruding portion includes the first screwing portion. In the state of being inserted through the opening, the projection protrudes in the insertion direction of the threaded portion from the tip of the threaded portion.

  According to a sixth aspect of the present invention, the casing and the holding member are made of resin, and the holding member has a higher elastic coefficient than the casing.

  According to the optical scanning device and the image forming apparatus according to the present invention, the optical scanning device includes the gap forming portion so as to form a predetermined gap between the extending portion and the housing. And a holding member is screwed together with a housing | casing through the 1st opening part formed in the holding member by the screwing member.

  In this configuration, when the pressure due to the screwing of the screwing member is applied to the extension part, a gap is formed between the extension part and the housing. The gap is bent so as to be narrowed without being sandwiched between the joint member and the casing. And a holding member can improve the adhesiveness of the part which is contacting the housing | casing using the spring property when an extension part bends.

  As a result, when the holding member is screwed into the housing, the holding member is not applied with a rapid rotational force by the screwing member on the extension portion. Therefore, rotation of the holding member at the time of screwing is prevented, and the operator can accurately position the optical axis of the light from the light source.

  According to the second aspect of the present invention, since the second opening is formed, the extending portion is easily bent when the holding member is screwed into the housing. Therefore, the holding member can be easily brought into close contact with the housing during screwing.

  According to the invention described in claim 3, the pressing portion provided on the holding member presses one side of the pair of protruding portions provided on the housing for positioning. The holding member is moved toward the protruding portion on the other side in the optical axis direction end portion of the light in the extending portion by the reaction force of the pressing. As a result, when the holding member is assembled to the housing with the protruding portion on the other side as a positioning reference, rattling that occurs in the optical axis direction is reduced, so the holding member is assembled to the housing with high accuracy. It is done.

  According to the fourth aspect of the present invention, the projecting portion is formed on the extending portion so as to project along the peripheral edge portion of the first opening. The convex part protrudes from the front end surface of the screwing part. Therefore, when it is screwed by the screwing member, the extending portion can be bent by the amount of the protrusion.

  According to the invention described in claim 5, since the rib is formed between the main body portion and the extension portion of the housing, the load when the extension portion is pressed by the screwing member is reduced. Some are distributed towards the ribs. Therefore, it can prevent that the load at the time of screwing concentrates between a main-body part and an extension part, and an extension part is damaged.

  According to the sixth aspect of the invention, since the elastic modulus of the holding member is higher than that of the casing, the casing side is not easily deformed during screwing.

It is explanatory drawing which represents roughly the structure of a laser printer. It is the top view which looked at the inside of a scanner unit from the upper part. It is the perspective view which showed a part of scanner unit, Comprising: The light source device supported by the housing | casing is shown. The optical axis direction of the laser beam is the Z-axis direction, the direction when the light source device is attached to the scanner unit is the Y-axis direction, and the direction extending in the direction perpendicular to the X-axis and the Z-axis is the X-axis. The Y-axis direction is the vertical direction. It is a disassembled perspective view of a housing | casing and a light source device. It is a disassembled perspective view of a housing | casing and a light source device, Comprising: It has shown from the angle different from FIG. It is a sectional side view of the light source device supported by the housing. (A) is the figure which simplified the sectional side view of the light source device supported by the housing | casing, Comprising: The holding member has shown the state which is not screwed together by the housing | casing with the screw | thread. (B) is a side sectional view similar to (A), showing a state in which the holding member is screwed into the housing by a screw and the extension portion is bent.

[Overall configuration of laser printer]
Next, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the laser printer 1 includes a pair of transport rollers 2 that transport paper P supplied one by one from a paper feed tray (not shown).

  The sheet P transported by the transport roller 2 passes between the photosensitive drum 3 and the transfer roller 4, and further passes between the heating roller 5 and the pressure roller 6, so that the upper surface of the laser printer 1. The paper is discharged to a paper discharge tray (not shown) provided in the printer.

  In addition to the transfer roller 4, a charger 9, a laser scanner unit 100 as an example of an optical scanning device to which the present invention is applied, and a developing unit are provided on the outer periphery of the photosensitive drum 3 from the upstream side in the rotation direction. 20 is arranged.

  The charger 9 is a positively charged scorotron charger that generates corona discharge from a charging wire, and is configured to uniformly charge the surface of the photosensitive drum 3 to a positive polarity. The laser scanner unit 100 scans and exposes the photosensitive drum 3 with laser light L by a mechanism described later. The developing unit 20 supplies positively charged toner (not shown) via the developing roller 21 to the surface of the photosensitive drum 3.

  For this reason, the surface of the photosensitive drum 3 is first uniformly charged positively by the charger 9 as the photosensitive drum 3 rotates, and then is scanned by the laser beam L from the laser scanner unit 100 at a high speed. It is exposed to form an electrostatic latent image corresponding to the print data.

  Next, when positively charged toner is supplied from the developing unit 20 to the photosensitive drum 3, the toner is an electrostatic latent image formed on the surface of the photosensitive drum 3, that is, uniformly positive. The surface of the charged photosensitive drum 3 is supplied to the exposed portion exposed to the laser beam L and the potential is lowered, and is selectively attached to be visualized, thereby forming a toner image. Is done.

The transfer roller 4 is configured to be applied with a transfer bias (transfer forward bias) from a transfer bias application power source (not shown) during transfer. Therefore, the toner adhered on the surface of the photosensitive drum 3 is transferred to the paper P while the paper P passes between the photosensitive drum 3 and the transfer roller 4. The sheet P after the toner transfer is sandwiched between the heating roller 5 and the pressure roller 6 so that the toner is heat-fixed and then discharged onto the discharge tray.
[Configuration of scanner unit]
Next, a specific configuration of the scanner unit 100 will be described. As shown in FIG. 2, the scanner unit 100 includes a semiconductor laser and a coupling lens (described later), a light source device 160 that emits a laser beam, and cylindrical lenses 170A and 170B that converge the laser beam from the light source device 160. A polygon mirror 180, an fθ lens 190, a reflecting mirror 195, etc. are provided as an example of the deflecting means of the present invention, and these are fixed to a resin casing 150. The configuration of the housing 150 for fixing the light source device 160 will be described in detail later.

  The polygon mirror 180 is provided with a mirror surface on each side of a regular polygon (regular hexagon in this embodiment), and is rotated by a polygon motor 185 so that the laser beam emitted from the light source device 160 is emitted. Reflected and deflected and scanned in the main scanning direction.

  The fθ lens 190 forms an image on the photosensitive drum 3 and converts the laser beam scanned at a constant angular velocity by the polygon mirror 180 into a constant velocity scan. The reflecting mirror 195 returns the laser beam that has passed through the fθ lens 190 and reflects it to the cylindrical lens 170B side. The cylindrical lens 170B has a converging force in the sub-scanning direction in order to re-image the laser beam focused in the sub-scanning direction on the polygon mirror 180 on the surface of the photosensitive drum 3.

  With such a configuration, the laser beam emitted from the light source device 160 is converged in the sub-scanning direction by the cylindrical lens 170A and imaged on the rotating polygon mirror 180.

The laser beam is deflected and scanned in the main scanning direction by the rotation of the polygon mirror 180, passes through the fθ lens 190 and another cylindrical lens 170 </ b> B, and is irradiated onto the surface of the photosensitive drum 3.
[Configuration of light source device]
Next, the configuration of the light source device 160 fixed to the housing 150 will be described. As shown in FIGS. 3, 4, and 5, the light source device 160 is mainly composed of a resin-molded holding member 110 and a laser light emitting unit as an example of the light source of the present invention integrally held by the holding member 110. 120 and a coupling lens 125 as an example of the optical element of the present invention.

  The coupling lens 125 is a substantially symmetrical lens that is held on the opposite side of the light emitting unit 120 with respect to the holding member 110, and converts the laser beam that has passed through the lens surface into a parallel light beam. The coupling lens 125 is held by the holding member 110 via the adhesive 126 so that the center thereof coincides with the optical axis O (Z axis). The adhesive 126 is a known UV curable resin that cures when irradiated with UV light.

  As shown in FIG. 3, the laser light emitting unit 120 includes a light emitting element 121 made of a laser diode (LD) and a flat circuit board 122 attached to the light emitting element 121. The circuit board 122 is connected to a cable 127 extending from a circuit (not shown) on the housing 150 side. As shown in FIG. 4, the circuit board 122 has an insertion hole 123 of the screw 50 formed so as to be screwed to the holding member 110 with a screw 50 as an example of the screwing member of the present invention. is doing.

  The light emitting element 121 is controlled based on an electrical signal sent from the circuit board 122 and emits a laser beam.

  The light source device 160 provided with these is fixed to the housing 150 by being screwed together by screws 50.

  As shown in FIGS. 3 and 4, the holding member 110 includes a box-shaped main body 130 and a pair of extensions extending in a wing shape from both lower ends in the Y direction of the main body 130 toward the X-axis direction. 140A, 140B, and ribs 155A, 155B extending between the extended portion 140A and the main body 130 and between the extended portion 140B and the main body 130. The holding member 110 is made of resin, and the elastic coefficient of the resin forming the holding member 110 is higher than that of the housing 150.

  The main body 130 is formed by a top surface 131 formed from a plane perpendicular to the Y axis, and extends vertically downward (−Y side) from both edges of the top surface 131 in the X axis direction. The laser light emitting portion 120 is held by extending vertically downward from both edges of the side surface portions 132A and 132B facing each other and the top surface portion 131 in the Z axis direction, and fitting the laser light emitting portion 120 in the Z axis direction. A lens holding portion 137 for holding the fitting portion 133 and the coupling lens 125 is formed. The main body portion 130 is surrounded by the top surface portion 131 and the side surface portions 132A and 132B, the fitting portion 133, and the lens holding portion 137, and has a space opened downward (−Y side) therein.

  The fitting part 133 is screwed together with the fitting hole 134 for fitting the light emitting element 121 of the laser light emitting part 120, the two abutting projections 135 abutted against the circuit board 122, the clamping part 136, and the circuit board 122 with the screw 50. A second screw hole 128 or the like.

  The fitting hole 134 has a cylindrical shape and communicates with the space in the main body 130 in the Z-axis direction. Further, a recess is formed at the edge of the fitting hole 134, and the recess is filled with an adhesive.

  The two abutting projections 135 are arranged at a predetermined interval in the Y-axis direction, and project from the surface of the fitting portion 133 in the Z-axis direction. A flat surface is formed on the top surface of the abutting protrusion 135.

  The sandwiching part 136 is disposed so as to face the two butting protrusions 135 from the Y-axis direction. Like the two abutting protrusions 135, the clamping part 136 protrudes from the surface of the fitting part 133 in the Z-axis direction, and the amount of protrusion is larger than that of the two abutting protrusions 135.

  The laser light emitting unit 120 is held with respect to the fitting unit 133 configured as described above. Specifically, the light emitting element 121 is fitted into the fitting hole 134. At that time, the light emitting element 121 is bonded to the fitting hole 134 with an adhesive filled in a recess in the edge of the fitting hole 134. Further, the laser light emitting unit 120 is positioned in the + Z direction at the fitting unit 133 by abutting the top surfaces of the two abutting projections 135 facing the flat plate portion of the circuit board 122. At this time, the circuit board 122 is clamped by the clamping unit 136, so that movement in the Y-axis direction and rotation about the rotation axis in the Z-axis direction are restricted.

  Further, the laser light emitting unit 120 fitted to the fitting unit 133 is completely fixed to the holding member 110 by the circuit board 122 being screwed to the holding member 110 and the housing 150 by the screw 50.

  In a state where the light emitting element 121 as described above is fitted to the fitting portion 133, the light emitting element 121 emits a laser beam to a space in the main body portion 130. Here, the laser beam emission direction (optical axis direction O) coincides with the Z-axis direction.

  As shown in FIG. 5, the lens holding portion 137 is formed on the main body portion 130 on the opposite side of the fitting portion 133. In other words, the lens holding portion 137 is formed at a position that intersects the optical axis of the laser beam.

  The lens holding portion 137 has a concave shape in the Z-axis direction (optical axis O direction) with the + Z direction as the outside and the −Z direction as the inside, and further, the top surface portion 131 (+ Y direction) side is open. Specifically, the lens holding portion 137 includes a bottom surface portion 31 that is the innermost side (fitting portion 133 side) of the lens holding portion 137, and a step portion 139 that is formed on both ends of the bottom surface portion 31 in the X-axis direction. The outer portion 32 extends from the step portion 139 to the outside (+ Z direction), and the filling portion 33 for filling the adhesive 126 provided in a part of the step portion 139.

  The bottom surface portion 31 is a flat surface and is open in the Y-axis direction. In addition, the bottom surface portion 31 has a light transmission hole 138 having an opening. The light passage hole 138 is formed concentrically with the fitting hole 134 formed in the fitting portion 133 with the optical axis O as the center. That is, the laser beam emitted from the laser light emitting unit 120 passes through the space in the main body 130 and is emitted outside the main body 130 through the light transmission hole 138.

  The stepped portion 139 is opposed to the lens holding portion 137 so as to sandwich the light passage hole 138 and the optical axis O from the X-axis direction. More specifically, the two step portions 139 are arranged so as to be spaced apart from each other in the X-axis direction. The interval between the stepped portions 139 is the width of the bottom surface portion 31 in the X-axis direction. The length of the width between the stepped portions 139 is substantially constant in the Y-axis direction and is slightly wider than the diameter of the light transmission hole 138.

  The two stepped portions 139 extend from the bottom surface portion 31 in a vertical direction (Z-axis direction) and a planar first surface 34 and perpendicular to the first surface 34, that is, perpendicular to the optical axis O. It consists of a planar second surface 35. The first surfaces 34 face each other with an interval corresponding to the width of the bottom surface portion 31 in the X-axis direction.

  The outer portion 32 extends in the + Z-axis direction so as to surround the edge of the second surface 35. In other words, the outer portion 32 is formed in a U shape when viewed from the optical axis O direction. The outer portions 32 are arranged with a predetermined interval in the X-axis direction as in the step portion 139, but the interval is wider than the interval between the first surfaces 34 of the step portion 139. By forming in this way, the width of the lens holding portion 137 in the X-axis direction becomes narrower from the outside toward the bottom surface portion 31.

  The filling portion 33 is disposed adjacent to the first surface 34 of the two step portions 139 and sandwiching the light passing portion 138 from the X-axis direction. The filling portion 33 has an uneven surface on the end surface in the optical axis O direction, and the uneven surface 36 is at a position lower than the second surface 35 of the stepped portion 139 in the optical axis O direction.

  The coupling lens 125 is held by the lens holding portion 137 configured in this way. First, the above-mentioned adhesive 126 is filled in the uneven surface 36 (see FIG. 3). The adhesive 126 is filled in the filling portion 33 in the form of a gel. However, since the filling portion 33 has an uneven surface, it is difficult for the adhesive 126 to flow down from the filling portion 33.

  Then, the coupling lens 125 is held by the lens holding portion 137 in a state where the center of the coupling lens 125 substantially coincides with the optical axis O of the laser beam. Specifically, the coupling lens 125 is positioned between the two filling parts 33 using a holding tool (not shown). At this time, the filling portion 33 and the coupling lens 125 are not in contact with each other. In this state, the uncured adhesive 126 filled in the filling portion 33 adheres to the periphery of the coupling lens 125. Since the adhesive 126 is in an uncured state, the position of the coupling lens 125 is adjusted (X-axis, Y-axis, and Z-axis directions) using a holding tool. When the position adjustment is completed, the adhesive 126 is cured by irradiation with UV light. As a result, the coupling lens 125 is completely fixed (held) to the lens holding portion 137 in a non-contact state.

  Both side portions 132A and 132B have a rectangular shape when viewed in the X-axis direction. The side surfaces 132A and 132B have long sides in the direction of the optical axis O, and their surfaces form a plane extending substantially parallel to the optical axis O.

  Then, extending portions 140A and 140B extending in the −X direction and the + X direction respectively extend from the lower ends of the side surface portions 132A and 132B. The extending portions 140A and 140B are disposed at positions symmetrical with respect to the optical axis O of the laser beam with the main body portion 130 interposed therebetween. More specifically, the extending portions 140 and 140B extend so as to be parallel to a flat surface portion 159 (described later) of the housing 150 when placed on the housing 150.

  The extending portions 140A and 140B are flat plate portions 141A and 141B, first opening portions 142A and 142B formed in the flat plate portions 141A and 141B, and a pair of positioning holes 143A as an example of the third opening portion of the present invention. , 143B, leg portions 144A, 144B forming a part of the gap forming portion of the present invention, and a convex portion 147. In addition, second openings 145A and 145B are formed between the extended portions 140A and 140B and the side surface portions 132A and 132B of the main body portion 130. Hereinafter, the configuration of the extending portion 140A will be described in detail, and the description of the extending portion 140B having substantially the same shape will be omitted.

  The flat plate portion 141A is formed in a plate shape with the optical axis direction O as a long side and the X-axis direction as a short side, and is integrally formed by extending in the −X direction from the lower end edge of the side surface portion 132A.

  The first opening 142A is formed in a circular shape so as to penetrate the vicinity of the center of the flat plate portion 141A in the Y-axis direction. The diameter of the first opening 142 is formed to be larger than the diameter of the shaft of the screw 50 and smaller than the diameter of the head portion.

  The convex portion 147 protrudes along the peripheral edge of the first opening 142 on the front side (that is, the + Y direction side) of the flat plate portion 141A. The convex portion 147 has a hollow cylindrical shape and protrudes in the + Y direction from the front side of the flat plate portion 141A. The + Y direction end portion of the convex portion 147 is a screw receiving surface 148 that has an annular shape when viewed in the Y-axis direction and is configured by a plane. The screw receiving surface 148 receives the head of the screw 50 inserted through the first opening 142 </ b> A when the holding member 110 is screwed into the housing 150.

  The pair of positioning holes 143A are formed to penetrate the flat plate portion 141A in the Y-axis direction. The pair of positioning holes 143A are arranged so as to sandwich the first opening 142A from the optical axis O direction (that is, the Z-axis direction).

  Of the pair of positioning holes 143A, one on the one side (+ Z side) in the optical axis O direction is formed in a substantially rectangular shape when viewed in the Y-axis direction. On the other hand, the one on the other side (−Z side) in the optical axis O direction is a circular hole.

  The inner peripheral surface of the positioning hole 143A on one side (+ Z side) in the optical axis O direction is opposite to two planes facing in the X axis direction and two facing in the Z axis direction (that is, the optical axis O direction). It is formed by a continuous plane.

  Further, the inner peripheral surface of the positioning hole 143A on one side in the optical axis O direction has a pressing portion 149 that presses the protruding portion 152A of the casing 150 described later by protruding to the other side in the optical axis O direction. Yes. Specifically, the pressing portion 149 protrudes from the plane on the other side in the optical axis O direction toward the plane on the one side in the optical axis O direction. The end surface in the Z-axis direction of the pressing portion 149 is opposed to the inner peripheral surface of the positioning hole 143A.

  The leg portions 144A are provided along the back side (that is, the −Y direction side) of both end edges in the Z-axis direction of the flat plate portion 141A, and each protrudes downward. The pair of leg portions 144A has a flat end surface. The amount of protrusion from the flat plate portion 141A to the end surface of the leg portion 144A is about 0.4 mm.

  The second opening 145A is formed along the optical axis O direction between the side surface portion 132A and the flat plate portion 141A. That is, by forming the second opening 145A, the side surface portion 132A and the flat plate portion 141A are connected at both ends in the direction of the optical axis O and are separated in the vicinity of the center.

The rib 155A is plate-shaped and extends between one side of the side surface portion 132A in the optical axis O direction and one side of the flat plate portion 141A in the optical axis O direction. The edge of the rib 155A extends from the top surface portion 131 side of the side surface portion 132A to the other end portion in the X-axis direction of the flat plate portion 141A. That is, the rib 155A has a substantially right triangle shape when viewed in the optical axis O direction. The rib 155A is provided only on one side of the optical axis O direction, while the rib 155B is provided on both ends of the flat plate portion 141B in the optical axis O direction.
[Case side configuration]
Next, a configuration for screwing the holding member 110 in the housing 150 will be described. As shown in FIGS. 5 and 6, the housing 150 has a configuration for positioning and screwing the holding member 110 so that the polygon mirror can be irradiated with the laser beam. Specifically, the housing 150 is configured to be paired in the X-axis direction as a configuration for positioning and screwing the extended portions 140A and 140B of the holding member 110 with respect to the flat surface portion 159. Pedestal portions 151A and 151B as part of the gap forming portion, projecting portions 152A and 152B provided for positioning the holding member 110, and screwing portions 153A and 153B are provided. The pedestal portions 151A and 151B, the projecting portions 152A and 152B, and the screwing portions 153A and 153B project from the flat surface portion 159 upward in the Y-axis direction, and are aligned in the Z-axis direction. Hereinafter, only one side will be described, and description of the other side having the same configuration will be omitted.

  The pedestal portion 151 </ b> A extends from the flat surface portion 159 of the housing 150 in order to support the leg portion 144 </ b> A of the holding member 110. The pedestal portion 151A is disposed on one side (−Z side) and the other side (+ Z side) of the housing 150, and the projecting portion 152A and the screwing portion 153A are sandwiched therebetween.

  The pedestal portion 151A has a long side in the X-axis direction and a short side in the Z-axis direction. The top surface of the pedestal portion 151 </ b> A is configured as a flat surface so as to receive the back surface side of the leg portion 144 </ b> A of the holding member 110.

  The projecting portion 152A is disposed so as to be sandwiched between the pair of pedestal portions 151A in the Z-axis direction. Each of the pair of projecting portions 152A projects from the flat portion 159 of the housing 150 toward the upper side in the Y-axis direction, and the one on the other side in the Z-axis direction has a cylindrical shape. On the other hand, the one on the one side in the Z-axis direction is formed in a substantially quadrangular prism shape. When positioning the holding member 110, one of the pair of projecting portions 152A on the one side in the Z-axis direction is a substantially square shape positioning hole 143A formed on one side in the Z-axis direction of the flat plate portion 141A of the holding member 110. And is further pressed by the pressing portion 149. The other protrusion 152A is inserted through a circular positioning hole 143A formed on the other side in the Z-axis direction.

The threaded portion 153A has a cylindrical shape and protrudes from the housing 150 so as to penetrate the flat surface portion 159 of the housing 150 in the Y-axis direction as shown in FIG. The threaded portion 153A has a hole extending in the Y-axis direction, and a thread groove through which the screw 50 can be inserted in the Y-axis direction (insertion direction) is formed on the inner peripheral surface thereof. A portion of the threaded portion 153A that protrudes toward the + Y-axis direction is formed in a slightly tapered shape so as to become thinner toward the tip. This front end portion (+ Y direction end surface) has a front end surface 156A formed in an annular shape when viewed in the Y-axis direction. The outer diameter of the threaded portion 153A is smaller than the inner diameter of the convex portion 147 formed on the extending portion 140A of the holding member 110. Therefore, the screwing portion 153A can be inserted into the convex portion 147.
[Supporting state of holding member to housing]
Next, a state where the holding member 110 is instructed with respect to the housing 150 (supported state) will be described. As shown in FIG. 6, the holding member 110 is supported by the housing 150 by being screwed onto the housing 150 by screws 50.

  First, a process until the holding member 110 is supported with respect to the housing 150 will be described. The holding member 110 inserts the positioning holes 143A and 143B and the first openings 142A and 142B into the protrusions 152A and 152B and the screwing portions 153A and 153B formed in the housing 150, respectively. The leg portions 144A and 144B are placed on the pedestal portions 151A and 151B.

  In this state, the holding member 110 is brought closer to the other side (−Z direction) of the housing 150 in the optical axis O direction. Specifically, when the protrusions 152A and 152B on one side of the housing 150 are inserted into the positioning holes 143A and 143B on one side (+ Z direction side) in the optical axis O direction, as shown in FIG. The pressing portion 149 formed on the inner peripheral surface of the positioning holes 143A and 143B on one side in the O direction presses the protruding portions 152A and 152B on the one side in the optical axis O direction toward the one side in the optical axis O direction in the extending portion 140A. To do.

  Then, the pressing portion 149 receives a reaction force from the protruding portions 152A and 152B on one side in the optical axis O direction. Accordingly, the holding member 110 is brought closer to the other side in the optical axis O direction and comes into contact with the projecting portions 152A and 152B inserted through the positioning holes 143A and 143B on the other side in the optical axis O direction. The other protrusions 152A and 152B are positioned with reference to the optical axis O direction (Z-axis direction).

  Further, as shown in FIG. 7A, the convex portions 147A and 17B formed on the extending portions 141A and 141B allow the threaded portion 153A to be inserted in the + Y direction (that is, inserted through the first openings 142A and 142B). ), More specifically, in a state in which the screwing portion 153A is inserted into the first openings 142A and 142B and the screw 50 is not pressed (ie, before screwing). The screw receiving surface 148 protrudes in the + Y direction from the front end surfaces 156A and 156B of the screwing portion 153A. The protruding amount is about 0.2 mm.

  Further, the leg portions 144A and 144B are placed on the pedestal portions 151A and 151B between the back surfaces of the flat plate portions 141A and 141B of the extending portions 140A and 140B and the flat surface portion 159 of the housing 150, thereby allowing the gap D to be placed. Is formed. The width of the gap D is obtained by adding the length of the pedestal portions 151A and 151B to the length of the leg portions 144A and 144B in the Y-axis direction, and is constant along the optical axis O direction. Further, the gap D is longer than the distance from the front end surfaces 156A, 156B of the housing 150 to the screw receiving surface 148.

  Then, as shown in FIG. 7B, the holding member 110 placed on the housing 150 is screwed with a screw 50. Specifically, by screwing the screw 50 into the screwing portions 153A and 153B, the screw 50 is inserted in the -Y direction (that is, in the insertion direction). At that time, the head of the screw 50 first comes into contact with the screw receiving surface 148 of the holding member 110. When the screw 50 is further screwed, the head of the screw 50 presses the screw receiving surface 148 in the insertion direction.

  The flat plate portions 141A and 141B of the extending portions 140A and 140B bend as shown in FIG. 7B while receiving a force in the rotation direction and insertion direction of the screw 50. Accordingly, the flat plate portions 141A and 141B bend so as to move the screw receiving surface 148 of the convex portion 147 toward the insertion direction. At this time, since the second openings 145A and 145B extend while opening along the optical axis O direction between the side surfaces 132A and 132B and the flat plates 141A and 141B, the flat plates 141A and 141B have the optical axis. The leg portions 144A and 144B that are in close contact with the pedestal portions 151A and 151B on the both ends in the O direction are bent so that the central portion in the optical axis O direction is recessed toward the housing 150 side. That is, the flat plate portions 141A and 141B are bent so as to narrow the width of the gap D.

  During screwing, part of the pressure applied to the flat plate portions 141A and 141B by the screw 50 is transmitted to the ribs 155A and 155B provided at the ends of the flat plate portions 141A and 141B in the optical axis O direction.

  Thus, the screw 50 is screwed into the screwing portions 153A and 153B while bending the flat plate portions 141A and 141B. In addition, when the screws are screwed together, the flat plate portions 141A and 141B are in close contact with each other by pressing the leg portions 144A and 144B against the pedestal portions 151A and 151B with a spring property due to deflection.

  At this time, since the screw receiving surface 148 protrudes from the front end surfaces 156A and 156B of the screwing portions 153A and 153B, the front end surfaces 156A and 156B of the screwing portions 153A and 153B Until the head of the screw 50 comes into contact with the 148 until it reaches the same height, it does not receive the rotational force due to the screwing of the screw 50.

  And the screw 50 is inserted in the state which contact | abutted to front end surface 156A, 156B of screwing part 153A, 153B. As a result, the holding member 110 is screwed into the housing 150.

  As described above, the scanner unit 100 and the laser printer 1 according to the present embodiment form the predetermined gap D between the extended portions 140 </ b> A and 140 </ b> B of the holding member 110 in the light source device 160 and the housing 150. In addition, leg portions 144A and 144B and pedestal portions 151A and 151B are included. And the housing | casing 150 and the holding member 110 are screwed together through 1st opening part 142A, 142B formed in the holding member 110. FIG.

  In this configuration, when the pressure due to the screwing of the screw 50 is applied to the extending parts 140A and 140B, the extending parts 140A and 140B are not sandwiched between the screw 50 and the housing 150 at the time of screwing. It bends as it narrows. At this time, the holding member 110 is in contact with the housing 150 by utilizing the spring property when the extending portions 140A and 140B are bent (that is, the leg portions 144A and 144B and the pedestal portions 151A and 151B). It is possible to improve the adhesion.

  As a result, when the holding member 110 is screwed into the housing 150, the extending portions 140A and 140B are not subjected to a rapid rotational force due to the screwing. Therefore, the rotation of the holding member 110 during screwing is prevented, and the operator can accurately position the optical axis of the laser beam of the light source device 160.

  Further, since the second openings 145A and 145B are formed, the extending portions 140A and 140B are easily bent when the holding member 110 is screwed into the housing 150. Therefore, the holding member 110 can be easily brought into close contact with the housing 150 during screwing.

  Further, the pressing portion 149 provided on the holding member 110 presses the protrusions 152A and 152B of the housing 150 provided for positioning. The holding member 110 is moved toward the other side in the optical axis O direction of the light in the extending portions 140A and 140B by the reaction force of the pressing. As a result, when the holding member 110 is assembled to the housing 150 with the protruding portion on the other side of the optical axis O direction of light as a positioning reference, rattling that occurs in the optical axis O direction is reduced. Is assembled to the housing 150 with high accuracy.

  In addition, convex portions 147 are formed on the extending portions 140A and 140B so as to protrude along the peripheral edge portions of the first openings 142A and 142B. The convex part 147 protrudes from the front end surfaces 156A and 156B of the screwing parts 153A and 153B. Therefore, when the screws 50 are screwed together, the extending portions 140A and 140B can be bent by the amount of protrusion.

  Moreover, since the rib 155 is formed between the main body part 130 and the extension parts 140A and 140B of the housing 150, a part of the load when the extension parts 140A and 140B are pressed by the screw 50 is formed. Are distributed toward the ribs 155. Therefore, the load at the time of screwing can concentrate between the main-body part 130 and extension part 140A, 140B, and damage to extension part 140A, 140B can be prevented. That is, the strength of the entire holding member 110 can be reinforced by the ribs 155.

  In addition, since the elastic modulus of the holding member 110 is higher than that of the housing 150, the housing 150 side is not easily deformed during screwing.

  Needless to say, the present invention can be modified in various ways. For example, a gap forming portion may be provided in at least one of the extending portions 140A and 140B and the housing 150. That is, the leg portions 144A and 144B may not be provided in the extending portions 140A and 140B, and the gap D may be formed only by the pedestal portions 151A and 151B, or conversely, the leg portions 144A and 144B may be formed only. In any case, the extending portions 140A and 140B can be brought into close contact with the housing 150 using the spring property when bent. Similarly, the protrusions 152A and 152B may be provided on the holding member 110 side, and the positioning holes 143A and 143B may be provided on the housing 150 side.

  Further, the light source device 160 may be mounted on a scanner unit corresponding to a monochrome laser, or may be applied to a color laser printer. Further, the screwing member for screwing the holding member 110 is not limited to a screw, and may be a nut or a small screw.

DESCRIPTION OF SYMBOLS 1 Laser printer 50 Screw 100 Scanner unit 110 Holding member 120 Laser light emission part 121 Light emitting element 130 Main body part 132A, 132B Side surface part 140A, 140B Extension part 141A, 141B Flat plate part 142A, 142B 1st opening part 145A, 145B 2nd 143A, 143B Positioning hole 144A, 144B Leg part 148 Screw receiving surface 149 Pressing part 150 Housing 151A, 151B Base part 152A, 152B Protruding part 153A, 153B Screw part 155A, 155B Rib 156A, 156B Tip surface 160 apparatus

Claims (7)

A holding member that integrally holds a light source and an optical element that converts light emitted from the light source into a luminous flux;
A housing having a screwing portion for screwing the holding member with a screwing member, and deflecting means for deflecting light converted into a light beam;
With
The holding member is
A main body for holding the light source and the optical element;
A pair of extending portions extending from the main body, and a first opening is formed in the pair of extending portions so that the screwing portion can be inserted therein.
At least one of each of the extending portions and the housing includes the extending portion in a state in which the screwing portion is inserted through the first opening when the holding member is held in the housing. In order to form a predetermined gap with the housing, a gap forming portion is provided so as to sandwich the screwing portion in the optical axis direction of light,
The holding member is configured such that when the extension portion is screwed to the housing by the screwing member via the screwing portion, the extension portion is bent so as to narrow the gap formed by the gap forming portion. An optical scanning device characterized by being supported by a housing.   2. The optical scanning according to claim 1, wherein the holding member includes a second opening that is opened along the optical axis direction of light between the extension portion and the main body portion. apparatus. One of the housing and the extension is formed with a third opening disposed so as to sandwich the first opening,
The other has a pair of protrusions that are inserted through the third opening for positioning the holding member,
The one of the third openings includes a pressing portion that presses the protruding portion from an inner peripheral surface thereof toward an end portion in the optical axis direction of light in the extending portion. Or the optical scanning device of 2.   The extending portion has a convex portion protruding along a peripheral edge portion of the first opening portion, and the convex portion has the screw portion in a state where the screwing portion is inserted into the first opening portion. 4. The optical scanning device according to claim 1, wherein the optical scanning device protrudes in the insertion direction of the threaded portion from the tip of the joint portion. 5.   5. The light according to claim 1, wherein the holding member is formed with a rib extending between an end portion in the optical axis direction of the extension portion and the main body portion. Scanning device.   The optical scanning device according to claim 1, wherein the housing and the holding member are made of resin, and the holding member has a higher elastic coefficient than the housing.   An image forming apparatus comprising the optical scanning device according to claim 1.