JP4617979B2 - Optical unit, image forming apparatus and holder manufacturing method - Google Patents

Description

  The present invention is provided for deflecting an incident light beam while being moved with a predetermined scanning width and guiding it onto an image carrier, and is relatively long in the scanning direction and short in a direction perpendicular to the scanning direction. An optical unit having a thin and elongated optical member and supporting both ends in the longitudinal direction of the optical member to hold the optical member, an image forming apparatus on which the optical unit is mounted, and an optical member. The present invention relates to a method for manufacturing a holder to be held.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method, a photosensitive drum as an image carrier is centered so as to face a peripheral surface of the photosensitive drum. A charging unit, an optical scanning unit, a developing unit, a transfer unit, and the like are arranged.

  That is, the surface of the photosensitive drum is uniformly charged by applying a predetermined voltage to the charging unit, an electrostatic latent image is formed by the light beam from the optical scanning unit, and toner is supplied to the developing unit for development. Then, for example, after the toner image is transferred to an intermediate transfer member or the like in the transfer unit, the image is transferred to a sheet.

  The sheet onto which the image has been transferred is subjected to a fixing process in the fixing unit while being conveyed to the discharge port.

  By the way, the optical scanning unit includes an LD (laser diode) which is a light source for emitting a light beam, a polygon mirror for scanning (main scanning) light emitted from the LD on the photosensitive drum, and an output from the polygon mirror. A plurality of optical members for deflecting the scanning light by reflecting or transmitting it in order to guide the incident light to the photosensitive drum.

  As the optical member, a thin and long mirror that is relatively long in the scanning direction and short in the direction orthogonal to the scanning direction (sub-scanning direction) is often used.

  In such a mirror, both end portions in the longitudinal direction are held around a pair of side plates parallel to each other.

  A holder is interposed between the side plate and the mirror. More specifically, the holder is attached to the side plate in a state in which both end portions in the longitudinal direction of the mirror are accommodated in accommodation grooves formed in the holder.

  The holder is provided with an adjustment mechanism that adjusts the relative position with the side plate, and it is possible to adjust the positional deviation in the sub-scanning direction by deflecting the reflection angle of the mirror and to adjust the magnification by changing the optical path length. (See Patent Document 1).

In addition, as a related technique, a technique as described in Patent Document 2 and Patent Document 3 is proposed as a holder structure capable of holding an elongated mirror and adjusting the magnification and the like as described above. .
JP 2002-40348 A JP 2001-356259 A Japanese Patent No. 3379544

  However, in the holding structure of Patent Document 1, when it is necessary to adjust the adjustment directions of both ends of the mirror in opposite directions (for example, the inclination of the scanning line), there is a possibility that the mirror is deformed by applying the stress.

  In addition, when the holder is made of synthetic resin, the mirror is supported along the mold release gradient because the mold release direction is the opening end direction of the receiving groove, and before the holder is attached to the side plate. For example, the mirror does not bend due to the displacement of the holder. However, when the holder is fixed to the side plate, stress is applied to the mirror as much as the holder is corrected, and bending may occur.

  In Patent Document 2, since the entire mirror is covered with a cover, it can be said that the cover can avoid bending of the mirror, but a space for covering the entire mirror is required. In particular, in the case of a full-color image forming apparatus, it is necessary to route four light beams in an extremely narrow space, and a structure in which the entire mirror is covered with a cover is contrary to compactness.

  Further, in Patent Document 3, since the mirror is biased and held by an elastic member such as a leaf spring, the number of parts that can be absorbed by the leaf spring is large, and assembly workability is increased. Is bad. In Patent Document 3, since only the adjustment of the rotation direction of the mirror is possible, the shift of the scanning line in the sub-scanning direction cannot be corrected.

  In consideration of the above-mentioned facts, the present invention holds the optical member with a simple structure, and includes a light beam deflection adjustment and magnification adjustment mechanism, and prevents transmission of stress generated by the adjustment to the optical member. It is an object to obtain an optical unit, an image forming apparatus, and a method for manufacturing a holder that can be used.

  A first invention is provided for deflecting an incident light beam while moving with a predetermined scanning width and guiding it onto an image carrier, and is relatively long in the scanning direction and perpendicular to the scanning direction. An optical unit having a short, thin and elongated optical member and supporting both ends in the longitudinal direction of the optical member, and holding the optical member, corresponding to both ends of the optical member. A base assembly provided with a pair of side plates over which the respective end portions of the optical member are provided, and the end portions of the optical member are accommodated and held by a biasing force in the thickness direction of the optical member. A holder provided with an accommodation groove, provided with at least one adjustment mechanism for adjusting the deflection and magnification of the light beam with respect to the side plate, and formed in the accommodation groove of the holder; Support A positioning part for positioning the optical member along a direction orthogonal to the longitudinal direction of the optical member or a line of an allowable range thereof when used as a reference for positioning, when viewed from the thickness direction of the optical member The optical member and the holder absorb the displacement applied to the holder by relatively rotating around a line contact line with the positioning portion.

  According to the first invention, when the holder is attached to, for example, both ends of the optical member, since the force that restricts the relative position between the optical member and the holder is not applied, the optical member is bent. There is no.

  However, when this holder is fixed to the side plate, the holder is displaced and fixed in a specific state due to displacement of the side plate itself or relative displacement between the pair of side plates. At this time, since the optical member is stretched between the pair of side plates, stress is applied from the holder, and deformation such as bending occurs.

  Therefore, in accordance with this stress, the optical member and the holder are relatively rotated around the line contact line with the positioning portion. Thereby, stress is absorbed and an optical member does not change.

  1st invention WHEREIN: The line contact part of the said positioning part has a predetermined width dimension according to the vertical and horizontal dimension of the said optical member, It is characterized by the above-mentioned.

  In the first invention, the positioning portion is a datum protruding from the receiving groove and intermittently provided on the line contact line.

  Furthermore, the first invention is characterized in that the positioning part is composed of an assembly of a plurality of intermittent columnar protrusions.

  The second invention is provided for deflecting an incident light beam while being moved with a predetermined scanning width and guiding it to the image carrier, and is relatively long in the scanning direction and perpendicular to the scanning direction. An optical unit having a short, thin and elongated optical member and supporting both ends in the longitudinal direction of the optical member, and holding the optical member, corresponding to both ends of the optical member. A base assembly provided with a pair of side plates over which the respective end portions of the optical member are stretched, and the optical member are accommodated with the end portions and held by a biasing force in the thickness direction of the optical member. At least one adjustment mechanism for adjusting the deflection of the light beam and adjusting the magnification with respect to the housing groove and the side plate is provided. A holder made of synthetic resin and a small amount of the optical member in the housing groove of the holder are provided. A positioning portion that is formed so as to face at least one surface in the thickness direction and serves as a reference for supporting the optical member, and the positioning portion is in a range of 0 ° to 45 ° with respect to the longitudinal direction of the optical member. It is characterized by protruding in a shape that can avoid die cutting from the direction along the inside.

  According to the second aspect of the present invention, when the positioning portion is formed so as to protrude without the holder receiving groove, die cutting is essential. When this die cutting is in the longitudinal direction of the optical member, that is, the opening end direction from the back side of the housing groove, an inclined surface is generated along this die cutting.

  That is, since the positioning portion serving as a reference is inclined, when the holder is fixed to the side plate, the optical member bends following the inclined surface.

  Therefore, when the positioning portion is formed so as to project, the positioning portion is formed into a shape that can avoid die cutting from the direction along the range of 0 ° to 45 ° with respect to the longitudinal direction of the optical member. Even if this occurs, the optical member does not coincide with the bending direction. Thereby, the fluctuation | variation of the relative position of a holder and an optical member is accept | permitted, and the stress added from a holder can be absorbed.

  In the second aspect of the invention, a deflection or magnification adjustment mechanism by the holder is provided only at one end of the optical member.

  In the second invention, the holder is provided only at one end of the optical member.

  A third invention is an image forming apparatus on which the optical unit according to any one of the first to seventh aspects is mounted.

  When forming an image, a two-dimensional image is formed by repeating the main scanning while moving the image carrier in a direction orthogonal to the scanning (main scanning) direction. At this time, if the scanning line is inclined, curved, or the magnification fluctuates, the image quality is greatly affected.

  Therefore, positioning the optical member that guides the scanned light beam to the image carrier in an appropriate state leads to an improvement in image quality.

  A fourth aspect of the invention is provided to deflect an incident light beam while moving with a predetermined scanning width and guide it onto the image carrier, and is relatively long in the scanning direction and perpendicular to the scanning direction. Holding the optical member in a short, thin and long shape, supporting the end in the longitudinal direction where the bending of the optical member is likely to occur, and absorbing the stress from the fixing destination after fixing to a predetermined position, A holder manufacturing method for generating a holder for avoiding stress transmission to the optical member as a synthetic resin molded product, wherein a housing groove for housing an end of the optical member is formed, The optical member is supported by point contact or line contact, a datum serving as a reference for positioning the optical member is formed, and at least the mold drawing direction for forming the datum is different from the accommodation direction of the optical member in the accommodation groove. Direction and The surface opposite to the surface of the optical member supported by the datum is pressed by an urging force of its own elastic deformation so that the optical member is always in contact with the datum. It is said.

  According to the fourth aspect of the invention, when manufacturing the holder that holds the optical member and hangs it on the side plate and allows the position of the optical member to be adjusted, first, a receiving groove for receiving the end of the optical member is formed. To do.

  Next, the optical member is supported by point contact or line contact in the receiving groove, and a datum serving as a reference for positioning the optical member is formed.

  At the time of forming the datum, at least the direction in which the datum is formed is different from the direction in which the optical member is received in the receiving groove.

  In addition, the surface opposite to the surface of the optical member supported by the datum is pressed by a biasing force due to its own elastic deformation so that the optical member is always in contact with the datum.

  According to the holder manufactured as described above, the relative position between the holder and the optical member can be held at a predetermined position, and the holder and the optical member can be moved relative to the stress from the outside such as the side plate, The stress can be absorbed, and the holding state of the optical member at an appropriate position can be maintained.

  In addition, stress similar to that described above may be applied during adjustment, but even in such a case, there is no deformation such as bending of the optical member, and proper adjustment is possible.

  As described above, according to the present invention, the optical member is held with a simple structure, and also includes a light beam deflection adjustment and a magnification adjustment mechanism, and prevents transmission of stress generated by the adjustment to the optical member. It has an excellent effect of being able to.

  FIG. 1 shows an image forming apparatus 10 according to the present exemplary embodiment. This image forming apparatus has a tandem full-color printer structure.

  The main body 10 of the full-color printer includes a spray paint type optical scanning device 12 (ROS (Raster Output Scanner)) and a print head device 14 (Print Head Device) that is an image forming unit that performs full-color image formation. Yes.

  The print head device 14 includes four photosensitive drums 16, 18, 20, and 22 as image carriers.

  The optical scanning device 12 is configured so that the peripheral surfaces of the four photosensitive drums 16, 18, 20, and 22 are uniformly charged by the charging rolls 16A, 18A, 20A, and 22A, and the optical scanning device 12 is charged. Exposure processing is performed by scanning light beams emitted from the image data of each color (yellow (Y), magenta (M), cyan (C), and black (K)). The four photosensitive drums 16, 18, 20, and 22 are provided with developing devices 23C, 23M, 23Y, and 23K for each color, and toner is applied to the electrostatic latent image corresponding to the scanning of each color of the light beam. It comes to supply.

  A primary transfer member 36A corresponds to the photosensitive drums 16 and 18, and Y and M toner images are superimposed and transferred. On the other hand, the primary transfer member 36B corresponds to the photosensitive drums 20 and 22, and the toner images of C color and K color are superimposed and transferred.

  The primary transfer members 36A and 36B are in contact with the secondary transfer member 36C, and the toner images of the respective colors (four colors) are superimposed and transferred on the secondary transfer member 36C.

  The main body 10 of the full-color printer is provided with a paper feed cassette 25 below the print head device 14, and the recording paper P is transferred from the paper feed cassette 25 to the secondary transfer body 36 </ b> C, the transfer roller 37, and the like. (Transfer section).

  In response to the supply of the recording paper P, the transfer unit transfers the toner image from the secondary transfer body 36C to the recording paper P, and performs a fixing process on the recording paper P on which the toner image has been transferred by the fixing device 27. The recording medium on which is formed is discharged onto a discharge tray.

  The optical scanning device 12 includes a laser light source (not shown) formed of a semiconductor laser or the like that emits four light beams each including image information of each color of YMCK inside the housing 24. The light beam emitted from the laser light source passes through a collimator lens and a cylindrical lens (both not shown), is adjusted to a parallel beam, and enters the polygon mirror 26.

  The light beam reflected and scanned by the polygon mirror 26 passes through the fθ lens 28 and enters the separating polygon mirror 30. The reflecting surface of the separating polygonal mirror 30 is formed by a plane (two orthogonal planes) including two adjacent sides of a substantially square shape. The separation polygon mirror 30 is configured so that four light beams are incident on the optical path at symmetrical positions by two at equal intervals.

  In the reflecting direction of the reflecting surface of the separating polygonal mirror 30, four mirrors 32 are disposed as four optical members that receive and reflect four light beams separately.

  The light beam reflected by each of the four reflecting mirrors 32 is incident on each of the four cylindrical mirrors 34A, 34B, 34C, and 34D, and is reflected in the direction of the photosensitive drums 16, 18, 20, and 22 described above. The

  Here, as shown in FIG. 2, the housing 24 of the optical scanning device 12 has a pair of side plates 100 and 102, and the reflection mirror 32 is stretched over the pair of side plates 100 and 102. Is held by. At this time, holders 104 are attached to both ends of the reflection mirror 32 in the longitudinal direction, and the holders 104 are fixed to the side plates 100 and 102.

  As shown in FIGS. 3 to 5, the holder 104 is a molded product of synthetic resin and has a rectangular shape as a whole of the overall structure.

  The holder 104 is notched on the side facing the end of the reflecting mirror 32 with the vertical wall portion 106, the bottom plate portion 108, and a part of the ceiling portion 110 remaining at right angles. An accommodation groove 112 that can accommodate the end of the reflection mirror 32 is formed.

  The reflecting mirror 32 housed in the housing groove 112 has its end face abutted against the inner wall 114 of the housing groove 112 so that the position in the housing direction is determined. The back wall 114 is formed with a streak-like projection 116 extending in the lateral direction (the short side direction of the reflection mirror 32), and the front end surface of the projection 116 is in contact with the actual reflection mirror 32. It becomes a contact surface.

  In addition, the bottom plate portion 108 of the receiving groove 112 is provided with a rectangular through hole 118 for facilitating die cutting at the time of forming the holder. A datum 120 is formed on the periphery of the through hole 118 along a line parallel to the line of the protrusion 116. The datum 120 is divided at the middle of the line (the region of the through hole 118), and as a result, is intermittently formed along the line.

The width W _D of the datum 120 is approximately 1 mm, stamped from the side facing the vertical wall portion 106 along the line-shaped is adapted to be made. The protruding front end surface of the datum 120 is a support surface that supports the reflection mirror 32 and serves as a positioning reference for the reflection mirror 32. The reflecting mirror 32 is supported by being in line contact with the datum 120 (actually, the surface contact is 1 mm wide, but here it is referred to as line contact).

  In addition, a slit 122 is formed on a part of the ceiling portion 110 following the vertical wall portion 106 on the back wall portion 114 side. For this reason, the ceiling part 110 is held in a so-called cantilever state with respect to the vertical wall part 106. The ceiling portion 110 is provided with a rectangular through hole 124, and is used for die cutting at the time of holder molding.

  Further, the end of the ceiling portion 110 opposite to the cantilever side is bent at a substantially right angle in the direction of the bottom plate portion 108 to form a bent portion 110A.

  The bent portion 110 </ b> A is extended to the extent that it comes into contact with the upper surface when the reflecting mirror 32 is accommodated in the accommodating groove 112, and is thus pushed up by the reflecting mirror 32 accommodated. At this time, the ceiling 110 is elastically deformed because it is in a cantilever state. In other words, due to the elastic force of the ceiling portion 110, a force that the tip of the bent portion 110A pushes down the reflection mirror 32 is generated, and the reflection mirror 32 can be held so as to be pressed against the datum 120 serving as the reference surface. Yes.

  Due to the pressing by the elastic force, the reflection mirror 32 has a relative position with respect to the reference surface of the holder 104 in a steady state, but is supported by line contact as described above. The position can be changed by relative rotation about the arrangement direction (line) of the datum 32.

  Note that the stress that changes the relative position between the holder 104 and the reflecting mirror 32 occurs when the holder 104 is fixed to the side plates 100 and 102 (see FIG. 2B). In other words, in the assembly of only the holder 104 and the reflection mirror 32, the stress is not generated, and the reflection mirror 32 is not bent. For example, when the holder 104 is fixed to the side plates 100 and 102, The stress may be generated due to finishing accuracy of the side plates 100 and 102, deformation with time, position adjustment of the holder 104 (see FIG. 2C), or the like.

  Here, a cylindrical protrusion 126 is formed on the surface of the holder 104 opposite to the side on which the receiving groove 112 is formed, and a flange 128 protrudes in the lateral direction of FIG. . A substantially semicircular cutout 130 is formed in the flange 128.

  As shown in FIG. 2, the end surface of the holder 104 on which the protrusions 126 are formed is an abutting surface against the side plates 100 and 102, and the protrusions 126 are inserted into the through holes 130 formed in the side plates 100 and 102. It is designed to be inserted.

  A metal adjustment plate 132 is provided on the outer surface of the side plates 100 and 102 so as to face the holder 104. The adjustment plate 132 is fixed to each other by screwing or the like with the holder 32 abutted against the inner side surfaces of the side plates 100 and 102. Thus, the side plates 100 and 102 are sandwiched between the holder 32 and the adjustment plate 132, respectively.

  The adjustment plate 132 has an adjustment screw for adjusting the angle of the reflection mirror 32 (deflection adjustment, registration adjustment), and an adjustment screw for adjusting the direction along the optical path direction of the reflection mirror 32 (magnification adjustment). Both are not shown), and the relative positional relationship between the side plates 100, 102 and the holder 104 can be finely adjusted after being fixed. Adjustment using the adjustment screw is performed by using the notch 130 or the like, slightly loosening the tightened state, rotating or moving the holder 104, and tightening again.

  The operation of this embodiment will be described below.

(Molding of holder 104)
The holder 104 is a synthetic resin and is molded by pouring a material into a mold. After solidification, the die is cut out. However, with respect to the die forming the datum 120, the die from the range of less than ± 45 ° with respect to the longitudinal direction of the reflection mirror 32 and the longitudinal direction as a reference (0 °). Design the mold in consideration of avoiding punching. As a result, even if the upper end surface of the datum 120 is inclined due to die cutting, the longitudinal direction of the reflecting mirror 32 is not achieved, and the reflecting mirror 32 is not encouraged to bend.

  That is, as shown in FIG. 6, in the conventional holder H, since the insertion direction of the reflection mirror M is the die cutting direction of the datum D, the linearity of the reflection mirror M is maintained in the free state. When the holder H is fixed to the side plate G (see FIG. 6A), the reflection mirror M is curved along the inclined surface of the datum D (see FIG. 6B), or the adjustment of the holder H only on one side is performed. The reflection mirror M may meander (a kind of curve) along the inclined surface of the datum D (see FIG. 6C).

(Assembly)
When the reflection mirror 32 is assembled to the side plates 100 and 102 that are a part of the housing 12 of the optical scanning device 12, first, the holders 104 are attached to both ends in the longitudinal direction of the reflection mirror 32.

  That is, the end portion of the reflecting mirror 32 is placed in the receiving groove 112 of the holder 104 and is inserted while sliding along the datum 120, so that the tip surface abuts against the protruding portion 116.

  At this time, since the bent portion 110 </ b> A of the ceiling portion 110 presses the upper surface of the reflection mirror 32 with its own elastic force, the reflection mirror 32 is kept in line contact with the datum 120.

  In the assembly in which the holder 104 is mounted on the reflection mirror 32, the assembly is supported by the datum 120, the protrusion 116, and the bent portion 110 </ b> A of the ceiling portion 110.

  Next, mounting is completed by attaching the holder 104 to the side plates 100 and 102 at predetermined positions and fixing the side plates 100 and 102 so as to sandwich the side plate 100 and 102 with the adjustment plate 132.

(Stress absorption)
Here, in FIG. 6, when the holder H is fixed to the side plate G as described above, for example, when the interval dimension of the side plate G is shifted to the minus side (including the allowable dimensional tolerance range), Since a compressive force is applied to the reflecting mirror M, this becomes a stress that curves along the longitudinal direction, and bending occurs (see FIG. 6B).

  Further, in the normal assembly state (without such a deviation), the reflection mirror M will not bend unless the stress is generated (see FIG. 6A), but after the assembly. In some cases, registration adjustment and magnification adjustment are performed. At this time, the same adjustment amount is sufficient for both of the side plates G, but when only one of the adjustments needs to be adjusted, a step in the height direction occurs at both ends in the longitudinal direction of the reflection mirror M, and the reflection mirror M Is deflected (see FIG. 6C).

  In this case, conventionally, since there is no permissible relative movement between the holder H and the reflection mirror M, the stress causing the deflection is directly transmitted to the reflection mirror M, and fine adjustment is rejected to deteriorate the image quality. It was.

  Therefore, in the present embodiment, as shown in FIG. 2, the reflecting mirror 32 and the holder 104 are supported by the datum 120 in line contact along a line in the short side direction of the reflecting mirror 32, and The bent portion 110A itself is held at a predetermined position by the elastic force and positioned.

  With the above structure, when the above-described stress (an external force that bends the reflecting mirror 32) is applied, the holder 104 and the reflecting mirror 32 are relatively rotated around the line contact line (actually, the reflecting mirror 32 is Rotate. Further, the displacement in the thickness direction that can be caused by this relative rotation is absorbed by the elastic deformation of the ceiling portion 110, and the holding force of the holder 104 on the reflection mirror 32 does not drop.

  Further, when the datum 120 is formed, the die cutting direction is the direction along the short side of the reflecting mirror 32, so that the inclined surface caused by die cutting does not coincide with the bending direction of the reflecting mirror 32. Therefore, even if the upper end surface of the datum 120 is substantially supported by a surface (in theory, it is a line contact, but in practice, it has a certain width (about 1 mm in this embodiment)), it is inclined. There is no problem that the reflecting mirror 32 bends along, and linearity can be maintained over the longitudinal direction.

  In the present embodiment, the shape of the datum 120 for positioning the reflecting mirror 32 formed in the receiving groove 112 (see FIG. 3) is changed to an intermittent line-shaped protrusion along the short side direction of the reflecting mirror 32. However, as shown in FIG. 7, it may be one continuous protrusion 120A. In addition, as shown in FIG. 8, two point-like (actually cylindrical) protrusions 120 </ b> B may be arranged in a line along the short side direction of the reflection mirror 32.

  In this embodiment, when the holder 104 is attached to the side plates 100 and 102, the side plates 100 and 102 are sandwiched between the adjustment plate 132 so that registration adjustment and magnification adjustment are possible. The adjustment mechanism may be provided on either one of the side plates 100 and 102. In this case, the reflection mirror 32 may be connected to the side plate (100 or 102) on the side without the adjustment mechanism so as to be movable relative to each other directly or via a holder without the adjustment mechanism (universal joint).

  As described above, in this embodiment, the holder 104 and the reflection mirror 32 are structured to be in line contact with the datum 120 provided on the line along the short side direction of the reflection mirror 32. Even if a force that is deflected by the stress transmitted from the side plates 100 and 102 is applied, it can be absorbed by rotating the datum 120 (line contact line) around the holder 104 to that extent, and the reflecting mirror 32. The linearity of can be maintained.

  Further, when forming the datum 120, the die cutting direction is avoided from a range of less than ± 45 ° with the longitudinal direction of the reflecting mirror 32 as a reference (0 °). Does not promote bending.

1 is a side view showing an image forming apparatus according to the present embodiment. It is sectional drawing which shows the state by which the reflective mirror was spanned over a pair of side plate which is a part of housing of an optical scanning device. It is a perspective view of the assembly with which the reflective mirror and the holder were assembled | attached. It is a perspective view of a holder simple substance. It is the VV sectional view taken on the line of FIG. It is a front view which shows the concrete application of the stress in the assembly | attachment state of the conventional reflective mirror and a holder. It is a top view of the holder which shows the modification (continuous type) of the shape of a datum. It is a top view of the holder which shows the modification of the shape of a datum (point support type).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Optical scanning device 16, 18, 20, 22
24 Housing (base assembly)
32 Reflecting mirrors 100, 102 Side plate 104 Holder 106 Vertical wall portion 108 Bottom plate portion 110 Ceiling portion 110A Bending portion 112 Accommodating groove 114 Back wall portion 116 Protruding portion 118 Through hole 120 Datum (positioning portion)
122 Slit 124 Through-hole 126 Projection 128 Flange 130 Notch 132 Adjustment plate

Claims (9)

A thin and slender shape provided to deflect an incident light beam while moving at a predetermined scanning width and guide it onto the image carrier, which is relatively long in the scanning direction and short in the direction perpendicular to the scanning direction. An optical unit that holds the optical member by supporting both ends in the longitudinal direction of the optical member,
A base assembly provided with a pair of side plates provided corresponding to both ends of the optical member and over which the respective ends of the optical member are spanned;
The optical member includes an accommodating groove that accommodates an end portion of the optical member and is held by a biasing force in a thickness direction of the optical member, and at least one of adjustment of deflection of the light beam and adjustment of magnification with respect to the side plate A holder provided with an adjustment mechanism;
A direction formed perpendicular to the longitudinal direction of the optical member when viewed from the thickness direction of the optical member, which is formed in the receiving groove of the holder and serves as a reference for supporting and positioning the optical member by line contact. A positioning portion for positioning the optical member along the line of the allowable range,
An optical unit, wherein the optical member and the holder absorb the displacement applied to the holder by relatively rotating around a line contact line with the positioning portion.   The optical unit according to claim 1, wherein the line contact portion of the positioning portion has a predetermined width according to the vertical and horizontal dimensions of the optical member.   The optical unit according to claim 1, wherein the positioning unit is a datum protruding from the receiving groove and intermittently provided on a line contact line.   The optical unit according to claim 1, wherein the positioning portion is configured by an assembly of a plurality of intermittent columnar protrusions. A thin and slender shape provided to deflect an incident light beam while moving at a predetermined scanning width and guide it onto the image carrier, which is relatively long in the scanning direction and short in the direction perpendicular to the scanning direction. An optical unit that holds the optical member by supporting both ends in the longitudinal direction of the optical member,
A base assembly provided with a pair of side plates provided corresponding to both ends of the optical member and over which the respective ends of the optical member are spanned;
An accommodation groove for accommodating the end portion of the optical member and holding the optical member by a biasing force in the thickness direction of the optical member, and at least one of adjustment of deflection of the light beam and adjustment of magnification with respect to the side plate A holder having a mechanism and molded with a synthetic resin;
A positioning portion that is formed to project and face at least one surface in the thickness direction of the optical member in the housing groove of the holder, and serves as a reference for supporting the optical member;
The optical unit is characterized in that the positioning portion protrudes in a shape capable of avoiding die cutting from a direction along a range of 0 ° to 45 ° with respect to the longitudinal direction of the optical member.   The optical unit according to any one of claims 1 to 5, wherein a deflection or magnification adjustment mechanism by the holder is provided only at one end of the optical member.   The optical unit according to claim 1, wherein the holder is provided only at one end of the optical member.   8. An image forming apparatus on which the optical unit according to claim 1 is mounted. A thin and slender shape provided to deflect an incident light beam while moving at a predetermined scanning width and guide it onto the image carrier, which is relatively long in the scanning direction and short in the direction perpendicular to the scanning direction. The optical member is held and supports the end in the longitudinal direction where the optical member is likely to be bent, and after fixing at a predetermined position, the stress from the fixing destination is absorbed, and the stress on the optical member A holder manufacturing method for generating a holder for avoiding transmission as a molded product of synthetic resin,
Forming an accommodation groove for accommodating an end of the optical member;
In the housing groove, the optical member is supported by point contact or line contact, and a datum serving as a reference for positioning the optical member is formed.
At least the direction in which the mold forming the datum is removed is different from the direction in which the optical member is accommodated in the accommodation groove,
Pressing the surface opposite to the surface of the optical member supported by the datum with an urging force of its own elastic deformation so that the optical member is always in contact with the datum.
The manufacturing method of the holder characterized by the above-mentioned.

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