JP2008009000A - Laser scanner and image forming apparatus furnished with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser scanner which is made compact while having an adjustment function of holding angle of a reflection mirror, and to provide an image forming apparatus furnished with the laser scanner. <P>SOLUTION: A groove part 380 is formed on a bottom cover member 374 of a housing, and the reflection mirror 350 is held on the housing by using a holding member 400. In this case, one end part (groove engagement part 440) of the holding member 400 is freely turnably engaged in the groove part 380, the other end part (main end part or upper supporting part 420) of the holding member 400 is abutted to an adjustment screw 500. Further, an elastic member 360 energizes the reflection mirror 350 toward the adjustment screw 500 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser scanning device and an image forming apparatus including the same.

  In recent years, there are electrophotographic image forming apparatuses (for example, facsimile machines, copiers, printers, multifunction machines, etc.) that form an electrostatic latent image on a photosensitive drum using a laser scanning device. The laser scanning device includes, for example, a semiconductor laser unit, a polygon motor unit that deflects laser light output from the semiconductor laser unit, and laser light deflected by the polygon motor unit on an object (photosensitive drum). And a reflection mirror for bending the optical axis of the deflected laser light and guiding the laser light to the object. By providing the reflection mirror, the laser scanning device can be installed at a predetermined position in the image forming apparatus.

  Since the reflection mirror is held in contact with the convex portion formed on the housing of the laser scanning device, the holding angle of the reflection mirror is determined by the shape and position of the convex portion. For this reason, if the holding angle of the reflection mirror is deviated, the laser beam is not irradiated to a predetermined position of the photosensitive drum, which adversely affects the image. Therefore, in general, a structure for adjusting the holding angle of the reflection mirror is provided in the housing of the laser scanning device.

  As a conventional reflection mirror holding angle adjustment structure (hereinafter simply referred to as “holding angle adjustment structure”), for example, the structure shown in FIG. 13 is known (see Patent Document 1). In this structure, an adjustment screw 5 is provided in the housing 3 to which the reflection mirror 1 is attached so as to penetrate the housing 3, and one end of the adjustment screw 5 protrudes toward the bottom surface 7 of the housing 3. The other end of the adjustment screw 5 is exposed to the outside from the back surface 9 of the housing 3, and a hexagon wrench used to rotate the adjustment screw 5 is turned to the other end of the adjustment screw 5. An engaging portion 5a for engaging is formed.

  In such a conventional holding angle adjusting structure, the holding position of the reflecting mirror 1 is at both ends in the longitudinal direction (laser beam scanning direction) of the reflecting mirror 1, and an adjusting screw 5 is disposed at one end thereof. At this time, the head 5b of the adjusting screw 5 is disposed near the upper edge of the reflecting mirror 1 in the short direction (laser beam width direction), and near the lower edge of the housing 3 that supports the reflecting mirror 1. The convex part 11 formed in is provided.

Such a holding angle adjusting structure of the reflection mirror 1 exists outside the laser beam scanning range, that is, in a region where the laser beam does not pass, and therefore does not interfere with the laser beam during image formation.
Japanese Utility Model Publication No. 5-45621

However, in the conventional holding angle adjusting structure, since the laser beam is bent toward the object using the reflection mirror 1, the reflection mirror 1 is disposed in a state inclined at a predetermined angle with respect to the laser beam. become. Moreover, for reasons to be described later, in order to shorten the length in the lateral direction of L ₁ of the reflecting mirror 1 has the structure constant of limitation. On the other hand, when the short transverse direction of the length L ₁ of the reflecting mirror 1, since the angle just turned the adjustment screw 5 slightly changes greatly, not only difficult to adjust the retention angle, adjustment vibration The angle change is large, for example, when the screw 5 is slightly rotated. Therefore, in practice, the lateral direction of the length L ₁ of the reflecting mirror 1 is forced to not give become relatively long, the inside of the laser beam scanning range disposing a reflection mirror 1 so as not to interfere with the laser beam, the laser There is a problem that the scanning device is enlarged. In the figure, the symbol “L ₂ ” is the distance between the fulcrums between the convex portion 11 serving as a reference for adjusting the reflection mirror holding angle and the head 5 b of the adjustment screw 5.

To avoid an increase in the size of the laser scanning device, as laser light do not interfere with the reflection mirror, the reflecting mirror to shorten the length L ₁ in the lateral direction or a non-reflective surface that does not reflect the laser beam It is necessary to use a reflection mirror with chamfered edges in the short direction. In fact, when chamfering the short edge of the reflecting mirror, it would be costly to chamfer a part along the longitudinal direction of the reflecting mirror. Is often applied.

However, in the conventional holding angle adjustment structure, the adjustment screw 5 is installed at the upper end portion in the short direction of the reflection mirror 1, and the lower end portion of the reflection mirror 1 is formed on the housing 3 that supports the reflection mirror 1. Since the convex portion 11 is arranged, when the lower end portion of the reflection mirror 1 is chamfered, the convex portion 11 is arranged on the chamfered portion 13 of the reflection mirror 1, and the reflection mirror 1 is held in a stable posture. It cannot be held (see FIG. 14A). Further, if the convex portion 11 of the housing 3 is disposed on the surface (that is, the non-reflecting surface) 1b parallel to the reflecting surface 1a near the adjusting screw 5 while avoiding the chamfered portion 13 of the reflecting mirror 1, the distance between the fulcrums is shortened. (If the distance between the fulcrums at this time is L ₃ , L ₃ <L ₂ ), the reflection mirror 1 cannot be held in a stable posture (see FIG. 14B). This is also the case of using the short-side direction of the reflection mirror to shorten the length 1 (in the lateral direction of the length of the reflecting mirror 1 at this time is _{L 4, L 4 <L 1} ) ( (See FIG. 14C). Therefore, in the conventional holding angle adjustment structure, in order to reduce the size of the laser scanning apparatus, using a reflective mirror chamfered in the widthwise direction of the length L ₁ of the shortened reflection mirror or lateral direction edge It is structurally difficult to do. Note that the above-described inconvenience when the lower end portion of the reflection mirror 1 is chamfered is that the laser beam is reflected to avoid interference at the corner when the reflection surface 1a of the reflection mirror 1 is on the side opposite to the holding side. This is a case where chamfering is performed on the ridge in the short direction on the non-reflecting surface 1b side. When the reflecting surface 1a of the reflecting mirror 1 is on the same side as the holding side, even if the corner of the non-reflecting surface 1b is chamfered, the holding is not affected.

  In the conventional holding angle adjusting structure, the adjusting screw 5 is in contact with the end surface of the reflecting mirror 1 near the upper edge in the short direction, and therefore the adjusting screw 5 is used to change the protruding amount of the adjusting screw 5. If it rotates, there exists a problem that the upper end surface of the transversal direction of the reflective mirror 1 may be damaged by the contact with the adjusting screw 5.

  Furthermore, in the conventional holding angle adjusting structure, when the adjusting screw 5 is rotated from the head 5b of the adjusting screw 5 using a tool (driver or the like) that rotates the adjusting screw 5, The end of the upper edge in the short direction (including both the end face in the short direction and the end face in the thickness direction) comes into contact with the tool, or the end of the upper edge in the short direction of the reflecting mirror 1 There is also a problem that a tool is accidentally applied to the upper end of the reflecting mirror 1 and the upper edge of the reflecting mirror 1 may be damaged.

  The present invention has been made in view of the above points, and provides a laser scanning device capable of reducing the size of the device while having a function of adjusting the holding angle of the reflecting mirror, and an image forming apparatus including the laser scanning device. For the purpose.

  The laser scanning device of the present invention includes a laser light source, deflecting means for deflecting laser light output from the laser light source and scanning the object, and reflecting the laser light deflected by the deflecting means to the object. A reflection mirror for guiding the light source, the laser light source, the deflecting means, and a housing for housing the reflection mirror, an adjustment screw attached to the housing for adjusting a holding angle of the reflection mirror, and the reflection mirror for the adjustment screw And a biasing member biased to the side, wherein the groove formed in the housing and the reflection mirror are held, and one end is rotatably engaged with the groove, and the other end And a holding member that abuts the adjustment screw.

  ADVANTAGE OF THE INVENTION According to this invention, size reduction of an apparatus can be achieved, providing the holding angle adjustment function of a reflective mirror.

  The laser scanning device according to the first aspect of the present invention includes a laser light source, deflection means for deflecting the laser light output from the laser light source to scan an object, and laser light deflected by the deflection means. A reflection mirror that reflects and leads to the object; a housing that houses the laser light source, the deflection means, and the reflection mirror; an adjustment member that is attached to the housing and adjusts a holding angle of the reflection mirror; And a biasing member that biases the reflecting mirror toward the adjusting member. The laser scanning device includes a groove formed in the housing, holds the reflecting mirror, and has one end pivotable to the groove. A holding member that engages and has the other end abutting against the adjustment member.

  According to this configuration, in order to hold the reflecting mirror using the holding member, the reflecting mirror whose length in the short direction is shortened, or the reflecting mirror whose chamfer is applied to the ridge in the short direction on the non-reflecting surface side. Even if it is used, the distance between the fulcrum between the groove and the adjustment member, which is the reference for adjusting the holding angle of the reflecting mirror, can be secured only for the dimensions necessary for stable holding. Regardless of the presence or absence, the dimensions required for stable holding can be made (the two ends in the longitudinal direction of the reflecting mirror need not be considered interference with the laser beam, so the distance between the supporting points for holding is increased. The reflecting mirror can be held in a stable posture. In addition, since the distance between the fulcrums between the groove and the adjustment member is ensured in this way, the angle changes greatly (ie, it is difficult to adjust the holding angle) just by moving the adjustment member a little, and vibrations, etc. There is no inconvenience that the angle changes greatly even when the adjustment member moves slightly. For this reason, actually, it is possible to use a reflecting mirror with a shorter length in the short direction or a reflecting mirror with a chamfered ridge in the short direction on the non-reflecting surface side. Can be planned. On the other hand, since the holding member is pivotally engaged with a groove portion whose one end is a reference for holding angle adjustment, an adjustment member (adjustment screw) is used when adjusting the inclination angle of the holding member (and thus the reflection mirror). By changing the position (protrusion amount) of, it can be freely rotated around one end. For this reason, the holding | maintenance angle of a reflective mirror can be adjusted so that a laser beam may be irradiated to the predetermined position of a target object. That is, according to this configuration, it is possible to reduce the size of the apparatus while having the function of adjusting the holding angle of the reflecting mirror.

  In the laser scanning device according to the second aspect of the present invention, in the laser scanning device configured as described above, the holding member has a groove engaging portion that is rotatably engaged with the groove portion at one end, and the groove The engaging portion adopts a configuration that is formed in a shape that facilitates movement with respect to the groove portion.

  According to this configuration, since the groove engaging portion of the holding member is formed in a shape that makes the movement relative to the groove portion smooth, when changing the position (projection amount) of the adjustment member (adjustment screw), The movement (turning) of the joint becomes smooth, and the holding angle of the reflecting mirror can be easily adjusted.

  The laser scanning device according to the third aspect of the present invention employs a configuration in which the groove engaging portion is formed in a substantially cylindrical shape or a columnar shape in the laser scanning device having the above-described configuration.

  According to this configuration, since the shape of the groove engaging portion is substantially cylindrical or columnar, the movement (rotation) of the groove engaging portion with respect to the groove portion is performed in a state where the groove engaging portion and the groove portion are engaged. It can be smooth.

  A laser scanning device according to a fourth aspect of the present invention employs a configuration in which, in the laser scanning device configured as described above, the groove has a V-shaped or U-shaped cross section.

  According to this configuration, since the groove portion of the housing has a V-shaped or U-shaped cross section, the groove with respect to the groove portion is supported in cooperation with the shape of the groove engaging portion of the holding member while supporting the holding member. The movement (turning) of the engaging portion can be made smooth.

  In the laser scanning device according to the fifth aspect of the present invention, in the laser scanning device having the above-described configuration, the holding member includes a first support portion that surrounds and supports one end portion in the short direction of the reflection mirror at one end. And an end including the first support portion is in contact with the adjustment member.

  According to this configuration, the first support portion is formed on the holding member so as to surround one end portion in the short direction of the reflection mirror, and the holding member is disposed so as to contact the adjustment member. The member does not come into contact, and the adjusting member (adjusting screw) can be moved (turned) without damaging one end of the reflecting mirror in the short direction. Also, when moving (turning) the adjustment member (adjustment screw) using a tool (driver or the like) from the head of the adjustment member, the one end of the reflecting mirror in the short direction and the tool come into contact with each other, Alternatively, the adjustment member (adjustment screw) can be moved (turned) without damaging the short end of the reflection mirror without damaging the short end of the reflection mirror. Can be made.

  The laser scanning device according to a sixth aspect of the present invention is the laser scanning device having the above-described configuration, wherein the holding member has the other end in the short-side direction of the reflection mirror facing the first support portion. The structure which has the 2nd support part which pinches | interposes and supports a part is taken.

  According to this configuration, since the reflection mirror is sandwiched between the first support portion and the second support portion, the holding member can be easily attached to the reflection mirror, and the reflection mirror can be held without being detached from the holding member. The angle can be adjusted. In addition, it is possible to attach the reflection mirror to the housing in a state where the holding member is attached to the reflection mirror, and the assembling property of the laser scanning device can be improved.

  A laser scanning device according to a seventh aspect of the present invention employs a configuration in which, in the laser scanning device having the above-described configuration, the holding member is formed of a metal material.

  According to this configuration, since the holding member is formed of a metal material, in particular, the second support portion facing the first support portion can be formed into a shape having an elastic action so that the reflection mirror can be removed. The holding member can be attached to the reflection mirror in advance and easily.

  An image forming apparatus according to an eighth aspect of the present invention employs a configuration including the laser scanning device having each configuration described above.

  According to this configuration, since the downsized laser scanning device is provided, the size of the image forming apparatus can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 1 is a schematic configuration diagram showing a color image forming apparatus to which a laser scanning apparatus according to an embodiment of the present invention is applied.

  A color image forming apparatus (hereinafter simply referred to as “image forming apparatus”) 100 shown in FIG. 1 includes an image forming unit 200 that forms a color image on a recording sheet 110 through processes of charging, exposure, development, transfer, and fixing. Have. The recording sheet 110 accommodated in the paper feed cassette of the paper feed unit 120 is sequentially fed into the image forming unit 200 via a paper feed path A from the paper feed unit 120 toward the image forming unit 200. The recording paper 110 on which a required image has been formed by the image forming unit 200 is discharged to the paper discharge unit 130 through a paper discharge path B from the image forming unit 200 to the outside of the apparatus.

  The image forming unit 200 includes a plurality (four in this case) of process units 210a, 210b, and 210c that form toner images of color components of yellow (Y), magenta (M), cyan (C), and black (K). 210d. Each of the process units 210a to 210d includes a photosensitive drum 212a, 212b, 212c, 212d, a charger 214a, 214b, 214c, 214d, a developing device 216a, 216b, 216c, 216d, a primary transfer roller 218a, 218b, 218c and 218d.

  Further, the image forming unit 200 includes a laser scanning device 300 that scans an image forming surface of the photosensitive drums 212a to 212d in the process units 210a to 210d with an exposure light beam (laser light), and each process unit 210a. The intermediate transfer belt (intermediate transfer member) 220 is formed by sequentially transferring and synthesizing the toner images of the respective colors formed on the photosensitive drums 212a to 212d in -210d. The image forming unit 200 has a tandem structure in which photosensitive drums 212 a to 212 d for each color are arranged along the intermediate transfer belt 220.

  In each of the process units 210a to 210d, an exposure light beam (laser light) is scanned from the laser scanning device 300 on the image forming surfaces of the photosensitive drums 212a to 212d uniformly charged by the chargers 214a to 214d. As a result, an electrostatic latent image is formed. The electrostatic latent images on the photosensitive drums 212a to 212d are developed with toners of the respective colors supplied from the developing devices 216a to 216d. As a result, single color toner images of the respective color components are formed on the image forming surfaces of the respective photosensitive drums 212a to 212d.

  The intermediate transfer belt 220 is supported by being wound around a driving roller 230 and a driven roller 240. Inside the intermediate transfer belt 220, primary transfer rollers 218a to 218d for each color are arranged. Each of the primary transfer rollers 218 a to 218 d presses the intermediate transfer belt 220 to transfer the toner images on the corresponding photosensitive drums 212 a to 212 d to the intermediate transfer belt 220. A secondary transfer roller 250 that transfers the toner image on the intermediate transfer belt 220 to the recording paper 110 is disposed on the side of the end of the intermediate transfer belt 220.

  The recording paper 110 onto which the toner image has been transferred by the secondary transfer roller 250 is conveyed to the fixing device 260. In the fixing device 260, processing for fixing the toner image on the recording paper 110 by heat and pressure is performed. Thereafter, the recording paper 110 passes through the paper discharge path B and is discharged onto the paper discharge unit 130 by the paper discharge roller 140.

  FIG. 2 is a development view showing a schematic configuration of the laser scanning device 300 shown in FIG.

  As shown in FIG. 2, the laser scanning device 300 includes a laser light emitting section 310, a polygon motor unit 320, an fθ lens 330, synchronization sensors 340a and 340b, and synchronization sensor reflection mirrors 342a and 342b.

  The laser light emitting unit 310 generates and outputs laser light. The laser emission unit 310 corresponds to each color component of yellow (Y), magenta (M), cyan (C), and black (K), and a plurality of sets (here, 4 sets) of semiconductor laser units 312a, 312b, 312c and 312d and cylindrical lens units 316a, 316b, 316c and 316d.

  Each of the semiconductor laser units 312a to 312d is provided with laser packages 313a, 313b, 313c, and 313d, and collimator lenses 314a, 314b, 314c, and 314d that use the laser beams output from the laser packages 313a to 313d as parallel light beams. ing. Laser light output from each of the semiconductor laser units 312a to 312d is incident on the cylindrical lens units 316a to 316d.

  Each of the cylindrical lens units 316a to 316d is provided with cylindrical lenses 317a, 317b, 317c, and 317d for condensing laser light, and diaphragms 318a, 318b, 318c, and 318d. The laser light of each color component that has passed through the cylindrical lens units 316 a to 316 d is condensed on the polygon motor unit 320.

  The polygon motor unit 320 includes a polygon mirror 322 and a drive motor 324 that holds and rotates the polygon mirror 322. In the polygon motor unit 320, for example, the laser light of the yellow (Y) and magenta (M) color components and the laser light of the cyan (C) and black (K) color components are opposed to the polygon mirror 322. Each surface is condensed. As a result, the laser light of the yellow (Y) and magenta (M) color components and the laser light of the cyan (C) and black (K) color components are deflected in opposite directions, respectively. The polarized laser light of each color component passes through the fθ lens 330.

The fθ lens 330 can focus the polarized laser light on the image forming surfaces of the photosensitive drums 212a to 212d and scan it at a constant speed. The fθ lens 330 includes two sets of first fθ lenses 332a and 332b and second fθ lenses 334a and 334b. Laser beams of yellow (Y) and magenta (M) color components deflected by the polygon motor unit 320 and passed through the first fθ lens 332a and the second fθ lens 334a are optical path ranges P _{1 to} P required for image formation, respectively. ₂ and is condensed on the image forming surfaces of the corresponding photosensitive drums 212a and 212b. Further, the laser beams of cyan (C) and black (K) color components deflected by the polygon motor unit 320 and passed through the first fθ lens 332b and the second fθ lens 334b are within the optical path ranges P3 to P4 necessary for image formation. And is condensed on the image forming surfaces of the corresponding photosensitive drums 212c and 212d.

  The synchronization sensors 340 a and 340 b detect the timing at which an image signal is given to the image forming apparatus 100. Laser light of yellow (Y) and black (K) color components is used for the synchronization sensors 340a and 340b, respectively. The reflection mirrors 342a and 342b are reflection mirrors for synchronization sensors for reflecting the laser light toward the corresponding synchronization sensors 340a and 340b. The yellow (Y) and black (K) color component laser beams are deflected by the polygon motor unit 320 and pass through the first fθ lenses 332a and 332b and the second fθ lenses 334a and 334b, respectively. The light passes through the optical paths 344a and 344b, is reflected by the reflection mirrors 342a and 342b for the synchronization sensor, and enters the synchronization sensors 340a and 340b. The synchronization sensors 340 a and 340 b provide image signals to the image forming apparatus 100 when the laser beams of the yellow (Y) and black (K) color components are respectively incident.

  FIG. 3 is a schematic cross-sectional view of the laser scanning device 300 shown in FIG.

As shown in FIG. 3, fθ lenses 330, specifically, a pair of first fθ lenses 332 a and 332 b and second fθ lenses 334 a and 334 b are arranged near both sides of the polygon motor unit 320. In the laser scanning device 300, four sets of reflecting mirror groups, specifically four sets of first reflecting mirrors 352a, corresponding to the laser beams LB _{1 to} LB ₄ that have passed through the fθ lens 330, 352b, 352c, 352d, cylindrical mirrors 354a, 354b, 354c, 354d, and second reflecting mirrors 356a, 356b, 356c, 356d are arranged. The laser beams LB _{1 to} LB ₄ that have passed through the fθ lens 330 are reflected by the corresponding reflecting mirror groups 352a to 352d, 354a to 354d, and 356a to 356d, and finally the corresponding photosensitive drums 212a to 212d. Focused on the image forming surface.

Each of the reflecting mirrors, that is, the first reflecting mirrors 352a to 352d, the cylindrical mirrors 354a to 354d, and the second reflecting mirrors 356a to 356d have an elongated shape in the main scanning direction of the laser light (see FIG. 6 described later). And both ends of the reflection mirror in the longitudinal direction are outside the laser beam scanning range through which the laser beams LB _{1 to} LB ₄ do not pass, and are elastic members 362a to 362d, 364a to 364d, 366a to 366d, It is held in pressure contact with a convex portion (reflection mirror mounting portion) formed on a housing 370 (particularly, a bottom cover member described later) of the laser scanning device 300. In the present embodiment, in particular, for example, for the second reflection mirrors 356a to 356d, the reflection mirror is held at one end of the second reflection mirrors 356a to 356d in order to adjust the final image formation position on the photosensitive drums 212a to 212d. And the structure for adjusting the holding | maintenance angle is provided. For other reflection mirrors, that is, the first reflection mirrors 352a to 352d and the cylindrical mirrors 354a to 354d, angles (positions) are determined by component dimensions. The reflection mirror holding angle adjustment structure will be described in detail later.

The housing 370 of the laser scanning device 300 includes a top cover member 372 and a bottom cover member 374. The top cover member 372 and the bottom cover member 374 are divided along a plane parallel to the bottom surface of the polygon mirror 322 in the polygon motor unit 320 and perpendicular to the laser light reflecting surface. The top cover member 372 is formed with light emission windows 376a to 376d for emitting the laser beams LB _{1 to} LB ₄ of the respective color components toward the corresponding photosensitive drums 212a to 212d. The top cover member 372 is provided with dust-proof glasses 378a to 378d in the light emission windows 376a to 376d of the laser beams LB _{1 to} LB ₄ of the respective color components in order to prevent dust from entering the laser scanning device 300. It has been.

The laser beams LB _{1 to} LB ₄ of each color component output from the laser light emitting unit 310 are polarized by the polygon motor unit 320 and pass through the first fθ lenses 332a and 332b and the second fθ lenses 334a and 334b. The laser beams LB _{1 to} LB ₄ of the respective color components that have passed through the second fθ lenses 334a and 334b are reflected by the first reflecting mirrors 352a to 352d toward the cylindrical mirrors 354a to 354d. Cylindrical mirror 354a~354d a laser _LB 1 _{~LB 4} reflected by the first reflecting mirror 352A～352d, it is reflected toward the second reflecting mirror 356A～356d. The second reflecting mirror 356a~356d a laser beam _LB 1 _{~LB 4} reflected by the cylindrical mirror 354A～354d, is reflected toward the imaging surface of the corresponding photosensitive drum 212 a ~ 212 d.

  In the present embodiment, for the second reflecting mirrors 356a to 356d, the holding member having a special configuration is used to reduce the size of the laser scanning device 300 while ensuring the function of adjusting the holding angle. The two reflecting mirrors 356a to 356d are attached to the housing 370.

  In the following description, for the sake of convenience, an arbitrary reflection mirror for the first reflection mirrors 352a to 352d, the cylindrical mirrors 354a to 354d, and the second reflection mirrors 356a to 356d is denoted by reference numeral “350”, and this arbitrary reflection mirror A holding angle adjustment structure is provided for 350. An arbitrary elastic member for the plurality of elastic members 362a to 362d, 364a to 364d, and 366a to 366d will be represented by reference numeral “360”.

  FIG. 4 is a perspective view showing the configuration of the reflection mirror holding member in the present embodiment.

  The holding member 400 shown in FIG. 4 has a planar main body 410, an upper support 420, a lower support 430, and a groove engaging portion 440.

  For example, the non-reflecting surface 350 b of the reflecting mirror 350 is brought into contact with the main body 410. Depending on the direction in which the laser light is bent, the reflecting surface 350a of the reflecting mirror 350 may come into contact. In this case, a reflecting mirror having a shorter length in the short direction is used.

  The upper support part 420 is formed on the upper part of the main body part 410 and surrounds and supports the end part of the upper edge of the reflecting mirror 350 (including both the end face in the short direction and the end face in the thickness direction). This has a function of protecting the end portion.

  The lower support portion 430 is formed at the lower portion of the main body portion 410 so as to face the upper support portion 420, and has an end portion at the lower edge of the reflecting mirror 350 (both the end surface in the short direction and the end surface in the thickness direction). And the like). The lower support part 430 has a shape having an elastic action so that the reflection mirror 350 can be removed. In the example shown in FIG. 4, the lower support portion 430 includes a pair of claw portions 430a and 430b. Further, by providing the lower support portion 430 in addition to the upper support portion 420 in this manner, the reflection mirror 350 can be attached to the housing 370 while the holding member 400 is attached to the reflection mirror 350, and laser scanning is performed. The effect that the assemblability of the apparatus 300 is improved is also obtained.

  The groove engaging portion 440 is rotatably engaged with a groove portion (see FIG. 5 to be described later) formed in the housing 370 (bottom cover member 374), and is reflected to the housing 370 via the holding member 400. 350 has a function of supporting. The groove engaging portion 440 has a shape that makes the movement (rotation) of the housing 370 relative to the groove portion smooth when the holding angle of the reflection mirror 350 is adjusted. In the example shown in FIG. 4, the groove engaging portion 440 has a substantially cylindrical shape. In addition, the shape of the groove engaging part 440 is not limited to a substantially cylindrical shape. Variations in the shape of the groove engaging portion 440 will be described later.

  The holding member 400 is made of a metal material, for example, stainless steel (SUS301-CSP). By forming the holding member 400 from a metal material, in particular, the lower support part 430 facing the upper support part 420 can be formed into a shape having an elastic action so that the reflection mirror 350 can be removed.

  The holding member 400 is manufactured, for example, by subjecting a metal plate of a predetermined size to a predetermined bending process to form the upper support part 420, the lower support part 430, and the groove engaging part 440. Specifically, for example, the upper support portion 420 is formed by bending the upper end portion in the longitudinal direction of the metal plate into an L shape (L-shaped bending), and the lower support portion 430 is the lower end in the longitudinal direction of the metal plate. The groove engaging portion is formed by bending both ends of the portion in the short side direction to the same side as the upper support portion 420 (that is, so as to face the upper support portion 420) in an L shape (L shape bending). 440 is formed by bending a portion of the metal plate sandwiched between the lower support portions 430 into a substantially cylindrical shape on the side opposite to the upper support portions 420 and the lower support portions 430.

  FIG. 5 is a cross-sectional view of an essential part showing a reflection mirror holding angle adjustment structure using the holding member 400 shown in FIG. Note that the reflecting mirror 350 illustrated in FIG. 5 includes a chamfered portion 351 on the non-reflecting surface 350b side, for example. The chamfered portion 351 is formed by chamfering the entire edge from end to end along the longitudinal direction at the edge of one end in the short direction on the non-reflecting surface 350b side of the reflecting mirror 350.

  In the reflection mirror holding angle adjusting structure shown in FIG. 5, the holding member 400 has a groove engaging portion 440 formed at one end of the holding member 400 outside the laser beam scanning range through which laser light does not pass. The groove 380 formed in the cover member 374 (here, for example, a V-shaped groove having a V-shaped cross section) is engaged, and the other end (the main body 410 and / or the upper support 420) is an adjustment screw. It is arranged so as to abut on 500 heads 502. In addition, the shape of the groove part 380 is not limited to V shape. As will be described later, the groove 380 may be U-shaped.

  At this time, the reflecting mirror 350 has one end portion in the longitudinal direction on the non-reflecting surface 350b side sandwiched between the holding members 400, that is, the body portion 410 in a state sandwiched between the upper support portion 420 and the lower support portion 430. It is supported in contact with.

  Further, an elastic member 360 (here, for example, a leaf spring) fixed to the bottom cover member 374 of the housing 370 is in pressure contact with the reflection surface 350a of the reflection mirror 350. By the elastic member 360, the reflection mirror 350 (and the holding member 400) is urged toward the adjustment screw 500 around the groove portion 380 and pressed against the bottom cover member 374 of the housing 370.

  In this reflection mirror holding angle adjustment structure, the holding angle of the reflection mirror 350 is adjusted by engaging a tool (driver or the like) 510 that rotates the adjustment screw 500 with an engaging portion 504 formed on the head 502 of the adjustment screw 500. And the adjustment screw 500 is rotated by using the tool 510, and the protrusion amount of the head 502 of the adjustment screw 500 protruding from the bottom cover member 374 of the housing 370 is appropriately adjusted.

  6 is a perspective view showing a reflection mirror holding structure including the reflection mirror holding angle adjusting structure shown in FIG. FIG. 7 is an exploded perspective view of the reflecting mirror holding structure shown in FIG.

  As shown in FIGS. 6 and 7, both end portions of the reflection mirror 350 in the longitudinal direction are attached to a pair of convex portions (reflection mirror attachment portions) 374 a and 374 b formed on the bottom cover member 374 of the housing 370, respectively. The reflection mirror holding angle adjustment structure shown in FIG. 5 described above is provided on the side of one convex portion 374a. That is, a structure for holding the reflection mirror 350 and adjusting the holding angle is provided on the convex portion 374a side. On the other hand, only the structure for holding the reflection mirror 350 is provided on the other convex portion 374b side.

  An adjustment screw attachment portion 382 having a screw hole for attaching the adjustment screw 500 and a groove portion (V-shaped groove) 380 that engages with the holding member 400 are formed on the convex portion 374a. Further, a boss 384a for positioning the elastic member (plate spring) 360a and a screw hole 388a for attaching a fixing screw 386a for fixing the elastic member (plate spring) 360a are formed in the convex portion 374a. Has been.

  Further, a boss 384b for positioning the elastic member (plate spring) 360b and a screw hole 388b for attaching a fixing screw 386b for fixing the elastic member (plate spring) 360b are formed in the convex portion 374b. Has been. Further, a support portion 390 for supporting the reflection mirror 350 is formed on the convex portion 374b.

  Thus, although the reflection mirror 350 is held at both ends in the longitudinal direction, only one side has a holding angle adjustment function. The side without the holding angle adjustment function is supported by the central portion in the short direction of the reflection mirror 350 (the support portion 390 of the housing 370 is applied to the central portion of the holding side surface, The plate spring 360b is urged in the same manner as on the adjustment side), and the holding angle adjustment by the adjustment screw 500 provided on the opposite side follows the rigidity of the reflection mirror 350.

  Therefore, when the reflection mirror 350 is attached to the housing 370 (bottom cover member 374), as shown in FIG. 6, one end portion of the reflection mirror 350 in the longitudinal direction is disposed on the convex portion 374a and the holding member 400 is attached. In this state, it is supported by the groove 380 and the adjusting screw 500 and is pressed against the housing 370 (bottom cover member 374) by the elastic member 360a. The other end of the reflection mirror 350 in the longitudinal direction is disposed on the convex portion 374b, supported by the support portion 390, and pressed against the housing 370 (bottom cover member 374) by the elastic member 360b. Thereby, the reflection mirror 350 is held by the housing 370 (bottom cover member 374). The holding angle of the reflection mirror 350 is adjusted by adjusting the protruding amount of the adjusting screw 500 using a tool (driver) 510. In FIG. 6, the symbol “S” indicates the scanning range of the laser beam.

As described above, according to the present embodiment, the holding mirror 400 is used to hold the reflection mirror 350. Therefore, when the laser scanning device 300 is downsized, the length in the short direction is set so that the laser beam is not blocked. The conventional structure shown in FIG. 13 (the structure in which the reflecting mirror is directly held in the housing) can be used even when a reflecting mirror having a shorter length or a reflecting mirror having a chamfered ridge in the short direction on the non-reflecting surface side is used. In comparison, the distance between the fulcrums between the groove 380 serving as a reference for adjusting the holding angle of the reflecting mirror and the adjusting screw 500 can be secured only for the dimensions necessary for stable holding, that is, the dimensions and chamfering of the reflecting mirror itself. Regardless of the presence or absence, it is possible to make the dimensions necessary for stable holding, and the reflecting mirror can be held in a stable posture. Specifically, in the case of the reflection mirror to shorten the length of the lateral direction, larger than the distance between supporting points L ₂ a in the lateral direction of the reflecting mirror length L ₁ between the grooves 380 and the adjusting screw 500 (L ₂ > L ₁ ). Further, in the case of a reflecting mirror having a chamfered ridge in the short direction on the non-reflecting surface side, the dimension of the fulcrum distance L ₂ between the groove 380 and the adjusting screw 500 can be maintained. Moreover, in this way for distance between supporting points L ₂ between the groove portion 380 and the adjusting screw 500 is secured, an angle just by turning the adjustment screw 500 little or greatly changed (i.e., difficult to adjust the holding angle ), There is no inconvenience that the angle changes greatly even when the adjusting screw 500 is slightly rotated due to vibration or the like. For this reason, actually, it is possible to use a reflecting mirror with a shorter length in the short direction or a reflecting mirror with a chamfered ridge in the short direction on the non-reflecting surface side. You can plan.

  Further, since the groove engaging portion 440 is engaged with the groove portion 380 of the bottom cover member 374 serving as a reference for adjusting the holding angle, the holding member 400 adjusts the inclination angle of the holding member 400 (and thus the reflection mirror 350). At this time, by changing the protruding amount of the adjustment screw 500 from the bottom cover member 374, the adjustment screw 500 can be freely rotated around the groove engaging portion 440. Therefore, the holding angle of the reflection mirror 350 can be adjusted so that the laser beam is irradiated to a predetermined position of the photosensitive drum.

  Therefore, it is possible to reduce the size of the apparatus while having the function of adjusting the holding angle of the reflecting mirror.

  Further, according to the present embodiment, the upper support portion 420 is formed on the holding member 400 so as to surround the end of the upper edge of the reflecting mirror 350 in the short direction, and the holding member 400 is applied to the adjustment screw 500. Even if the adjustment screw 500 is rotated to change the protruding amount of the adjustment screw 500, the reflection mirror 350 and the adjustment screw 500 do not come into contact with each other. There is no risk of damage to the top surface. That is, the adjustment screw 500 can be rotated without damaging the upper end surface of the reflecting mirror 350 in the short direction.

  Further, in this way, the upper support portion 420 is formed on the holding member 400, and the adjustment screw 500 is rotated from the head 502 of the adjustment screw 500 in order to arrange the holding member 400 so as to contact the adjustment screw 500. Even if the adjustment screw 500 is rotated using a tool (such as a screwdriver) to be rotated, the upper edge end of the reflecting mirror 350 is in contact with the tool, or the reflecting mirror 350 is short. The tool will not be accidentally applied to the edge of the upper edge. Therefore, the adjustment screw 500 can be rotated without damaging the upper edge of the reflecting mirror 350 in the short direction.

  Further, according to the present embodiment, since the lower support part 430 is formed on the holding member 400 so as to face the upper support part 420, the reflection mirror 350 is simply sandwiched between the upper support part 420 and the lower support part 430. The holding member 400 can be easily attached to the reflection mirror 350. In this attached state, the reflection mirror 350 can adjust the holding angle without being detached from the holding member 400.

  Further, since the lower support portion 430 is formed on the holding member 400 as described above, the reflection mirror 350 can be attached to the housing 370 in a state where the holding member 400 is attached to the reflection mirror 350. For this reason, the holding member 400 can be attached to the reflection mirror 350 in advance and can be easily assembled in the laser scanning device 300, and the assemblability of the laser scanning device 300 can be improved.

  The shape of the holding member 400 is not limited to the above example. Below, the variation of the shape of the holding member 400 (especially groove | channel engaging part 440) is demonstrated using FIGS. 8-12.

  The example shown in FIG. 8 is a case where the holding member is composed of one component. The holding member 400 shown in FIG. 8 is the same as the holding member shown in FIG. That is, as shown in FIG. 8A, the holding member 400 includes a planar main body portion 410 that is in contact with the non-reflecting surface 350b of the reflecting mirror 350, and an end portion of the upper edge of the reflecting mirror 350 in the short direction. The upper support portion 420 that surrounds and supports the lower support portion 430 that sandwiches and supports the end portion of the lower edge of the reflecting mirror 350 and the groove portion 380 of the housing 370 (bottom cover member 374). A substantially cylindrical groove engaging portion 440. At this time, the groove portion of the housing 370 (bottom cover member 374) that engages with the groove engaging portion 440 of the holding member 400 is a V-shaped groove portion 380a as shown in FIG. As shown to (C), the U-shaped groove part 380b may be sufficient.

  The example shown in FIG. 9 is a case where the holding member is composed of two parts. As shown in FIG. 9A, the holding member 450 shown in FIG. 9 includes a main body part 410, an upper support part 420, a lower support part 430, and a substantially cylindrical groove engaging part 460. At this time, the groove portion of the housing 370 (bottom cover member 374) that engages with the groove engaging portion 460 of the holding member 450 may be a V-shaped groove portion 380a as shown in FIG. As shown to (C), the U-shaped groove part 380b may be sufficient.

  FIG. 10 is a diagram illustrating an example of the configuration of the holding member 450 in FIG. 9. A holding member 450a shown in FIG. 10 includes two parts 451 and 453 shown in FIG. One component 451 is formed with a press-fit portion 452. The other component 453 has a cylindrical shape, and a square hole 454 is formed on the side surface thereof. The groove engaging portion 460a of the holding member 450a is configured by press-fitting the press-fit portion 452 of the component 451 into the square hole 454 of the component 453. That is, the holding member 450 a is assembled by press-fitting the press-fitting portion 452 of the component 451 into the square hole 454 of the component 453. FIG. 10B shows a holding member 450a completed by assembling the two parts 451 and 453 of FIG.

  FIG. 11 is a diagram illustrating another example of the configuration of the holding member 450 in FIG. 9. A holding member 450b illustrated in FIG. 11 includes two parts 455 and 457 illustrated in FIG. One part 455 is formed with an insertion portion 456. The other component 457 has a substantially cylindrical shape with a C-shaped cross section, and a C-shaped groove 458 is formed on the side surface thereof. The groove engaging portion 460b of the holding member 450b is configured by inserting the insertion portion 456 of the component 455 into the C-shaped groove 458 of the component 457. That is, the holding member 450 b is assembled by inserting the insertion portion 456 of the component 455 into the C-shaped groove 458 of the component 457. FIG. 11B shows a holding member 450b completed by assembling the two parts 455 and 457 of FIG.

  FIG. 12 is a diagram illustrating another shape of the groove engaging portion of the holding member. The holding member 470 shown in FIG. 12 has the same basic configuration as that of the holding member 400 shown in FIG. 4 configured by one part, but the shape of the groove engaging portion is different. As shown in FIG. 12 (A), the groove engaging portion 480 of the holding member 470 is such that the portion of the metal plate sandwiched between the lower support portions 430 is positioned below the lower support portion 430. It is formed by being bent into an L shape on the same side as the upper support portion 420 and the lower support portion 430 (L-shaped bending). However, a radius (R) is formed at the bent portion of the groove engaging portion 480. At this time, the groove portion of the housing 370 (bottom cover member 374) engaged with the groove engaging portion 480 of the holding member 470 is, for example, a V-shaped groove portion 380a of about 120 degrees as shown in FIG. is there.

  In the present embodiment, application to a color image forming apparatus has been described as an example. However, the present invention is not limited to this.

  The laser scanning device according to the present invention and the image forming apparatus provided with the laser scanning device have a reflecting mirror or a non-reflecting surface side whose length in the short direction is shortened so that the laser beam is not blocked when the size is reduced. Even if a reflection mirror with chamfered ridges in the short direction is used, such a reflection mirror can be held in a stable posture, and so that laser light can be irradiated to a predetermined position of an object, The effect that the holding angle can be adjusted, that is, the stability of holding the reflecting mirror, the ease of adjusting the holding angle of the reflecting mirror, and the miniaturization of the entire device can all be achieved. And a laser scanning device having a reflection mirror that bends the laser beam toward an object, and an image forming apparatus (printer, digital copying machine, facsimile, etc.) provided with the same.

1 is a schematic configuration diagram showing a color image forming apparatus to which a laser scanning device according to an embodiment of the present invention is applied. 1 is a developed view showing a schematic configuration of the laser scanning device shown in FIG. Schematic sectional view of the laser scanning device shown in FIG. The perspective view which shows the structure of the holding member for reflection mirrors in this Embodiment. Sectional drawing which shows the principal part which shows the reflection mirror holding angle adjustment structure using the holding member shown in FIG. The perspective view which shows the holding structure of a reflective mirror containing the reflective mirror holding angle adjustment structure shown in FIG. 6 is an exploded perspective view of the reflecting mirror holding structure shown in FIG. The figure which shows an example of the variation of the holding member for reflection mirrors in this Embodiment The figure which shows the other example of the variation of the holding member for reflection mirrors in this Embodiment. The figure which shows an example of a structure of the holding member shown in FIG. The figure which shows the other example of a structure of the holding member shown in FIG. The figure which shows the further another example of the variation of the reflection mirror holding member in this Embodiment. The figure which shows an example of the conventional reflective mirror holding | maintenance angle adjustment structure The figure for demonstrating the problem of the reflective mirror holding | maintenance angle adjustment structure shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 200 Image forming part 212a, 212b, 212c, 212d Photosensitive drum 300 Laser scanning device 310 Laser light emission part 312a, 312b, 312c, 312d Semiconductor laser unit 316a, 316b, 316c, 316d Cylindrical lens unit 320 Polygon motor unit 330 fθ lens 340a, 340b Synchronous sensor 342a, 342b Reflective mirror for synchronous sensor 350 Reflective mirror 350a Reflective surface 350b Non-reflective surface 351 Chamfered portions 352a, 352b, 352c, 352d First reflective mirror 354a, 354b, 354c, 354d Cylindrical mirror 356a 356b, 356c, 356d Second reflection mirror 360, 360a, 360b, 362a, 362b, 362c, 36 d, 364a, 364b, 364c, 364d, 366a, 366b, 366c, 366d elastic member 370 housing 372 top cover member 374 bottom cover member 374a, 374b protrusion (reflecting mirror mounting portion)
380 Groove portion 400 Holding member 410 Main body portion 420 Upper support portion 430 Lower support portion 440 Groove engagement portion 500 Adjustment screw 502 Adjustment screw head 510 Tool

Claims (8)

A laser light source;
Deflection means for deflecting the laser beam output from the laser light source and scanning the object;
A reflecting mirror that reflects the laser beam deflected by the deflecting means and guides the laser beam to the object;
A housing for housing the laser light source, the deflecting means, and the reflecting mirror;
An adjustment member attached to the housing and for adjusting a holding angle of the reflection mirror;
A biasing member that biases the reflection mirror toward the adjustment member;
A groove formed in the housing;
A holding member that holds the reflecting mirror, one end of which is rotatably engaged with the groove, and the other end of which is in contact with the adjustment member;
A laser scanning device. The holding member is
At one end, there is a groove engaging portion that is rotatably engaged with the groove portion,
The groove engaging portion is formed in a shape that facilitates movement with respect to the groove portion,
The laser scanning device according to claim 1. The groove engaging portion is
Formed in a substantially cylindrical or columnar shape,
The laser scanning device according to claim 2. The groove is
The cross-section is V-shaped or U-shaped,
The laser scanning device according to claim 3. The holding member is
At one end, it has a first support part that surrounds and supports one end part of the reflecting mirror in the short direction,
An end including the first support portion contacts the adjustment member;
The laser scanning device according to claim 1. The holding member is
On the other end, there is a second support portion that supports the first support portion by sandwiching and supporting the other end portion in the short direction of the reflecting mirror.
The laser scanning device according to claim 5. The holding member is
Formed of metal material,
The laser scanning device according to claim 6. An image forming apparatus comprising the laser scanning device according to claim 1.

Images