JP4687705B2 - Optical scanning device - Google Patents

Description

  The present invention relates to an optical scanning device used in an electrophotographic apparatus such as a laser printer or a digital copying machine which records an image by scanning and exposing a light beam on a scanning object based on image information.

  An optical scanning device used in a conventional laser printer or electrophotographic apparatus will be described with reference to FIG.

  The optical scanning device 300 includes a light source 302 that emits a light beam L based on image information, a polygon mirror 304 that deflects the light beam L emitted from the light source 302 in a predetermined direction, an imaging lens system 306, A reflection mirror 310 that guides the light beam L to the scanned body 308 is provided, and each component is disposed in a housing 312 that is closed by a cover (not shown). The housing 312 is fixed to the frame 314 with screws 316 and incorporated in the electrophotographic apparatus.

  In the electrophotographic apparatus in which the optical scanning device 300 is disposed, a known charging unit, developing unit, and transfer unit are disposed on the frame 314 around the scanned body 308 and formed on the scanned body 308. The formed toner image is transferred onto a recording sheet, and the toner image is fixed by a fixing unit, whereby an image is formed on the recording sheet.

  As described above, in the optical scanning device 300 arranged in the electrophotographic apparatus, the vibration of the polygon mirror 304, the drive motor of the scanned object 308, and the sheet conveying means in the electrophotographic apparatus are transmitted to the housing 312. As a result, as shown in the schematic diagram of FIG. 22, the reflection mirror 310 disposed in the housing 312 generates a flexural vibration that oscillates between the positions of the broken line with respect to the normal solid line position, and the light changes due to the fluctuation of the reflection surface 310A. There is a problem that the optical path of the beam L is deviated from the normal position and the scanning line is shifted on the scanned body 308, resulting in poor image quality.

  As a means for solving this problem, for example, in the optical scanning device disclosed in Japanese Patent Laid-Open No. 11-187224 (hereinafter referred to as Conventional Example 1), it is formed in the housing as shown in FIGS. The reflection mirror 324 is inserted into the holes 322A and 322B of the pair of supports 320A and 320B, and the projection 326A formed to protrude from the reflection surface 324A side of the reflection mirror 324 into the hole 322A and the hole 322B. While being supported by the formed projections 326B and 326C, the surface 324B opposite to the reflecting surface 324A of the reflecting mirror 324 (hereinafter referred to as the back surface) 324B is pressed by the leaf springs 328A and 328B inserted into the holes 322A and 322B. To do. Furthermore, support portions 330A and 330B that protrude with a predetermined clearance X (see FIG. 23B) with respect to the reflection surface 324A are provided in the hole 322A of the support 320A, and the support portions 330A and 330B and the reflection surface 324A are provided. The adhesive 332 is applied between the two.

  Conventionally, as shown in FIG. 24A, since the reflecting surface 324A is supported only by the protrusions 326A to 326C, the reflecting mirror 324 (reflecting surface 324A) is brought into contact with the protrusion 326A by transmission of vibration. Although it swings in the direction of arrow B as the center (see FIG. 24B), in this configuration, it is fixed by the support portions 330A and 330B and the adhesive 332, so that the swing can be prevented.

  Another example disclosed in Japanese Patent Laid-Open No. 9-120039 (hereinafter referred to as Conventional Example 2) is shown in FIGS. In this optical scanning device, a weight 344 is attached to the back surface 342B side of the reflective mirror 342, and the resonance frequency of the reflective mirror 342 is changed to avoid the input frequency of the electrophotographic device and the drive motor of the polygon mirror to approximately 20 Hz. So we are trying to improve the image quality.

  Another example disclosed in JP-A-2-253274 (hereinafter referred to as Conventional Example 3) will be described with reference to FIG.

  In this optical scanning device, a cushioning member such as rubber or foamed polyurethane is placed between a housing 356 and a lower surface 354C which is placed on a pair of support members 350 and is fixed by a leaf spring 352 and orthogonal to the reflecting surface 354A of the reflecting mirror 354. 358 is provided to suppress flexural vibration of the reflection mirror 354.

  Next, Japanese Patent Laid-Open No. 2000-241735 (hereinafter referred to as Conventional Example 4) will be described with reference to FIGS. In this optical scanning device, as shown in FIG. 27A, the reflecting surface 362A of the reflecting mirror 362 is composed of one point on the outer side of the light beam scanning region S of the reflecting surface 362A and two points on the other end side. A pair of supporting members 364A and 364B to be supported and both ends of the reflection mirror 362A on the outside thereof are supported by the supporting members 366A and 366B. As shown in FIG. 27B, the back surface 362B of the reflection mirror 362 is supported at both ends by leaf springs 368A and 368B. The leaf spring 368A has contact portions 370 and 372 branched into two, and presses the reflection mirror 362 against the support members 364A and 364B, respectively. The same applies to the leaf spring 368B.

  By adopting such a configuration, the maximum amplitude W1 (refer to FIG. 27C) of the scanning region S of the reflection mirror, which has been conventionally supported at both ends by the supporting members 364A and 364B and the corresponding elastic members, is obtained. The support members 366A and 366B are disposed outside the support member 364A and the support member 364B, and the maximum amplitude W2 is suppressed by being pressed from the back surface 362B side by the contact portions 372 of the leaf springs 368A and 368B. (See FIG. 27D). In addition, the leaf springs 368A and 368B are provided with contact portions 370 and 372 in an integrated manner so as to reduce the cost.

  Furthermore, another example disclosed in Japanese Patent Laid-Open No. 6-324253 (referred to as Conventional Example 5) will be described with reference to FIGS. As shown in FIG. 28 (B), this mirror support mechanism 380 inserts and fixes a V-shaped elastic body 388 when the reflecting mirror 382 is inserted into the hole 386 of the wall surface 384 and fixed. is there.

  As shown in FIG. 28 (A), the V-shaped elastic body 388 is provided with a locking portion 390 partially folded downward on one surface folded back into a V-shape and the other surface. Two large and small protrusions 392 and 394 are provided (hereinafter also referred to as contact surfaces). Further, a folded portion 396 is provided at the tip of the contact surface.

  As shown in FIG. 28C, the mirror support mechanism 380 thus configured has an elastic body 388 in the hole 386 (below the reflection mirror 382) after the reflection mirror 382 is inserted into the hole 386. By inserting and locking to the wall surface 384 by the locking portion 390, the large protrusion 392 on the contact surface supports the reflection mirror 382 and presses against the wall surface 384. Further, the folded portion 396 of the elastic body 382 supports the end face of the reflection mirror 382. In this state, when the reflecting mirror 382 vibrates (the end surface moves from the two-dot chain line position to the solid line position), the elastic body 388 is deformed by the folded portion 396 being pressed, and the two-dot chain line with the large protrusion 392 as a fulcrum. Rotates from position to solid line position. As a result, the small protrusion 394 increases the pressure contact force with respect to the reflection mirror 382 and restrains the displacement of the reflection mirror 382, whereby the vibration (amplitude) of the reflection mirror 382 can be suppressed.

  Each of the above conventional examples has the following disadvantages.

  In the embodiment of the conventional example 1, since the reflecting surface 324A in the vicinity of the scanning area of the reflecting mirror 324 is adhered, it is necessary to prevent the adhesive from being applied to the scanning area by mistake, and the application work is difficult. .

  Further, in the optical scanning device of Conventional Example 2, since the weight 344 is attached to the back surface 342B of the reflection mirror 342, the reflection surface 342A of the reflection mirror 342 is distorted to deteriorate the light beam characteristics on the scanned object 308. There was a case.

  Further, in the optical scanning device of the conventional example 4, the reflection mirror 362 has to be elongated in order to support the outside of the conventional support members 364A, 364B by the support members 366A, 366B, and the housing (optical scanning device) is required. There was an inconvenience of increasing the size.

  By the way, as a recent optical scanning device, as represented by Japanese Patent Application No. 2000-345698 shown in FIG. 30, an optical scanning device having a complicated optical path of a light beam has been proposed. The optical scanning device 402 of the electrophotographic apparatus 400 includes four light beams LY, LM, LC, and LK (hereinafter referred to as LY to LK) corresponding to yellow, magenta, cyan, and black with one polygon mirror 403. The same is applied to the scanning bodies 404Y to 404K, and a color image is formed by multiple transfer from the scanning bodies 404Y to 404K to the transfer belt 406. The optical paths of the respective light beams LY to LK are below the reflecting mirrors 408Y to 408K disposed in the optical scanning device 402, and a cover 412 that closes the housing 410 is located above. Even in the optical scanning apparatus having such a configuration, it is necessary to suppress the vibration of the reflection mirrors 408Y to 408K in order to form a good color image. However, since the optical path of the light beam is complicated, the conventional method is difficult.

  For example, if the method of Conventional Example 3 (installation of a buffer member) is to be applied, there are optical paths of the respective light beams LY, LM, LC, and LK below the reflecting mirrors 408Y to 408K of the optical scanning device 402. It is difficult to secure the installation space for the members. Further, there is a cover 412 that closes the housing 410 on the upper side of the reflection mirrors 408Y to 408K. However, since the cover 412 is a member that closes the open surface of the housing, it is difficult to increase the rigidity. Even if a buffer member is interposed between 408Y to 408K, it is difficult to achieve the above buffering action.

  Further, the mirror support mechanism 380 of the conventional example 5 is applicable to the reflection mirrors 408Y to 408K because it is not necessary to dispose a member at a position in the vertical direction (direction orthogonal to the scanning direction) of the reflection mirror. As shown, the small protrusion 394 restricts the displacement of the reflecting mirror 382 and suppresses the vibration of the reflecting mirror 382 with respect to the downward (−y) direction displacement (see FIGS. 29A to 29B). However, with respect to displacement in the upward (y) direction, the vibration directions of the small protrusion 394 and the reflection mirror 382 are the same (both upward), and the vibration of the reflection mirror 382 cannot be suppressed (FIG. 29A → (See (C)).

  In the method of the conventional example 2, as described above, the thickness of the reflection mirror 342 is increased by attaching the weight 344 to the back surface 342B of the reflection mirror 342, so that the optical path is below or above the reflection mirror. If present, it may interfere with the optical path.

  In order to solve the above problems, an object of the present invention is to provide an optical scanning device that suppresses vibration of a reflecting member without interposing a vibration suppressing member in a scanning region (reflecting surface, back surface, reflecting surface orthogonal surface) of the reflecting member. It is to provide.

In order to achieve the object, the optical scanning device according to claim 1, a light beam emitted from a light source is deflected by a polygon mirror, reflected by a reflecting member via an imaging lens system, and scanned to a scanned object. In the optical scanning device, a housing for housing each optical component, and one end side in the longitudinal direction outside the light beam scanning region of the reflecting member provided in the housing and arranged with the longitudinal direction set as the light beam scanning direction First reflecting means for supporting the reflecting surface of the reflecting surface or the back surface of the reflecting surface at one point, and the reflecting surface on the other end side in the longitudinal direction of the reflecting member that is provided in the housing and is outside the light beam scanning region or the reflecting surface. A second supporting means for supporting the back surface of the surface at two points in the short direction of the reflecting member; and the reflecting surface or the back surface of the reflecting member supported by the first supporting means and the second supporting means. And a pressing means for pressing the opposite surface to the first supporting means and the second supporting means side, and a wall surface of the housing that protrudes from the wall surface of the housing and contacts the end surface of the longitudinal end of the reflecting member on the first supporting means side. A regulating member that contacts and regulates vibration of the reflecting member, and a contact portion between the regulating member and the end surface of the reflecting member, and a support portion of the first support means in the longitudinal direction of the reflecting member When projected, the projected abutting portions are present on both sides of the reflecting member in the short direction across the projected support portion .

  The operation of the optical scanning device according to claim 1 will be described.

  In this optical scanning device, each optical component is arranged inside the housing, and the light beam emitted from the light source is deflected by a polygon mirror and reflected by a reflecting member through an imaging lens system, thereby scanning the light beam. Scan over the body.

In this apparatus, the reflecting member is disposed with the longitudinal direction set as the light beam scanning direction. On one end side in the longitudinal direction outside the light beam scanning region of the reflecting member, the reflecting surface or the back surface of the reflecting surface is supported by the first support means provided in the housing. Further, on the other end side in the longitudinal direction outside the light beam scanning region, the reflection surface or the back surface of the reflection surface is supported by the second support means provided in the housing. And it positions by pressing to a 1st support means and a 2nd support means side with a press means from the opposite surface side.

Moreover, since such an end face of the end portion of the reflecting member in the first support means side for restricting the vibration is brought into contact with the regulation member that protrudes from the wall surface of the housing, without or thickening the reflecting member, also, The natural frequency of the reflection mirror can be moved to a high range without interposing a member in the vicinity of the scanning region of the reflection mirror.

The reason is that focusing on the support portion of the conventional reflecting member, as shown in FIG. 3A, when the reflecting member vibrates, the end portion in the scanning direction of the reflecting member moves as shown in FIG. The natural frequency (Hz) of the reflecting member at this time is
f (Hz) = λ ² / 2πL ² × (EI / ρA) ^1/2
Here, L: length of tension,
E: Elastic modulus of elasticity
I: Section moment of inertia,
ρ: density,
A: sectional area,
Since λ is considered to be supported by both ends, λ is the first order λ: π, λ is the second order λ: 2π, and the third order λ is 3π.
On the other hand, in the configuration of the present invention (see FIG. 3C), λ approaches the one-sided support and one-sided fixed state, so the one-sided supported and one-sided fixed λ is the primary λ: 3.927 Second-order λ: 7.069 and third-order λ: 10.210. Therefore, for example, when compared with the first order, the natural frequency of the configuration of the present invention is higher. That is, since the natural frequency of the reflecting member can be increased with a simpler configuration than before, the cost of the optical scanning device can be reduced.

Furthermore, in the longitudinal direction of the reflecting member, the end portion on the first supporting means side that supports the reflecting surface or the back surface at one point is restrained by the regulating member. At this time, when the contact portion between the regulating member and the end surface of the reflection member and the support portion of the first support means are projected in the longitudinal direction of the reflection member, the light is reflected across the projected support portion of the first support means. Since there are contact portions between the projected regulating member and the end face of the reflecting member on both sides in the short direction of the member, it is possible to suppress the rotational vibration generated on the one-point support side in addition to the bending vibration of the reflecting member, Furthermore, it is possible to obtain a better image quality.
An optical scanning device according to a second aspect of the invention is an optical scanning device in which a light beam emitted from a light source is deflected by a polygon mirror, reflected by a reflecting member through an imaging lens system, and scanned by a scanning object. A housing for storing optical components, and a reflecting surface on one end side in the longitudinal direction outside the light beam scanning region of the reflecting member provided in the housing and arranged with the longitudinal direction set to the light beam scanning direction, or of the reflecting surface A first support means for supporting the back surface at one point; and a reflective surface on the other end side in the longitudinal direction of the reflective member that is provided in the housing and is outside the light beam scanning region, or the back surface of the reflective surface of the reflective member. Second supporting means for supporting at two points in the short direction, the first supporting means, and the reflecting surface of the reflecting member supported by the second supporting means or the opposite surface of the back surface to the first supporting hand. A pressing means that presses against the second supporting means side, and protrudes from the wall surface of the housing, and abuts against an end face of the reflecting member in the longitudinal direction on the first supporting means side to restrict vibration of the reflecting member. A support member projected onto the longitudinal direction of the reflection member, and a contact portion between the restriction member and the end surface of the reflection member, and a support portion of the first support means. the when the reference, the abutment portion projected, characterized in that over the other side from the one side in the lateral direction of the reflecting member with respect to the reference.
The operation of the optical scanning device according to claim 2 will be described.
When the contact portion between the restriction member and the end surface of the reflection member and the support portion of the first support means are projected in the longitudinal direction of the reflection member and the projected support portion is used as a reference, the projected restriction member and reflection are projected. contact portion between the end face of the member, because it is over the other side from the one side in the lateral direction of the reflecting member with respect to the reference, controls the rotational vibration generated in 1-point support side in addition to flexural vibration of the reflecting member And good image quality can be obtained.
The optical scanning device according to claim 3 is the optical scanning device according to claim 2, wherein the restriction member is in contact with the end surface of the reflecting member between the one side and the reference, The length in contact with the end face of the reflecting member is equal between the other side and the reference.
The operation of the optical scanning device according to claim 3 will be described.
Since the length of the regulating member in contact with the end surface of the reflecting member from one side to the reference is equal to the length in contact with the end surface of the reflecting member from the other side to the reference, In addition to bending vibration, rotational vibration generated on the one-point support side can be suppressed, and good image quality can be obtained.

Optical scanning apparatus according to claim 4, in the optical scanning apparatus of any one Kouki placement of claims 1 to 3, inside the housing, the light beam up and down at least one of the light beam scanning area of the reflecting member The optical path is formed.

The operation of the optical scanning device according to claim 4 will be described.

By adopting a configuration in which the longitudinal end of the reflecting member is regulated by the regulating member, vibration of the reflecting member can be suppressed without interposing a member in the vicinity of the light beam scanning region of the reflecting member. The degree of freedom in designing the light beam optical path in the vertical direction of the scanning region (direction orthogonal to the scanning direction) is increased. That is, when viewed from the cross section of the optical scanning device, there are no inclusions in the vertical vertical direction of the reflecting surface, so that an optical path can be provided on at least one of the reflecting members, and the optical scanning device can be miniaturized. .

In the optical scanning apparatus according to claim 5 optical scanning apparatus according to any one of claims 1-4, wherein the reflecting member and reaches the light beam inside the housing is ultimately reflected in the scanning target final It is a reflecting member.

The operation of the optical scanning device according to claim 5 will be described.

The reflecting member is a final reflecting member that finally reflects the light beam inside the housing to reach the body to be scanned. Since the optical scanning device scans the light beam with a polygon mirror, the scanning width increases as it approaches the object to be scanned. Therefore, the light beam scanning region (member length) of the final reflecting member is a reflecting member in the optical scanning device. The longest of all. That is, since the length of the final reflecting member is the longest, it is difficult to suppress vibration. Therefore, conventionally, or increase the thickness of the final reflecting member, while the back side of the final reflecting member to increase the weight of the final reflecting member had to put a metal member, by the configuration of claim 1 or 2 Further, it is not necessary to increase the thickness of the reflecting member, and the metal member can be eliminated, so that the reflecting member (optical scanning device) can be reduced in weight. The reduction in the weight of the reflecting member leads to a reduction in the pressing force of the pressing means, and the pressing means can be reduced in size. Therefore, the cost of the optical scanning device can be reduced. In addition, as the dimension of the reflecting member in the thickness direction is reduced, it contributes to miniaturization of the optical scanning device.

The optical scanning apparatus according to claim 6, wherein, in the optical scanning apparatus of any one of claims 1-5, wherein the pressing means in the longitudinal direction of the reflecting member, the first support means, said second support The means is characterized by pressing at two positions offset by a predetermined distance on both sides with respect to the position supporting the reflecting member.

The operation of the optical scanning device according to claim 6 will be described.

In the beam scanning direction of the reflecting member, the pressing means presses at two positions offset by a predetermined distance on both sides of the positions supported by the first support means and the second support means. As shown in the figure, the pair of pressing means (46A, 46B) suppress the vibration in both directions of the reflecting member which is about to be bent about the support position (28, 30, 34). As a result, the vibration of the reflecting member can be suppressed, and the natural frequency can be moved to a high range.

The optical scanning apparatus according to claim 7, in the optical scanning apparatus of any one of claims 1 to 6, wherein the pressing means includes a mounting portion fixed in contact with the said housing, the said reflective member A pressing portion that presses the reflective surface or the back surface with two abutting portions, and is disposed between the attachment portion and the pressing portion, and is elastically deformed to integrally displace the pressing portion in a predetermined direction. And an elastic portion, wherein the predetermined direction is disposed in the housing so as to be orthogonal to the reflecting surface of the reflecting member.

The operation of the optical scanning device according to claim 7 will be described.

  In the longitudinal direction of the reflecting member, the pressing means can press two positions offset on both sides with respect to the support position of the supporting means with respect to the reflecting member with the two contact portions of the pressing portion. In addition, when different forces act on the two contact portions due to the vibration of the reflecting member (there is a twisting action between the two contact portions), the displacement direction of the pressing portion due to the elastic deformation of the elastic portion is changed. Since the direction is orthogonal to the reflecting surface, the torsional action that acts between the two abutting portions is restricted by the integrally displaced pressing portion, and the flexural vibration of the reflecting member is further suppressed.

The optical scanning apparatus according to claim 8, wherein, in the optical scanning apparatus of any one of claims 1-7, bonding the longitudinal end portion of at least one said reflective member of the regulating member or the pressing member It is characterized by that.

The operation of the optical scanning device according to claim 8 will be described.

By adhering at least one of the regulating member or the pressing member and the end of the reflecting member in the longitudinal direction, the end of the reflecting member in the longitudinal direction is fixed. As a result, the natural frequency of the reflecting member can be moved to a higher range, and in particular, the position of the reflecting member can be kept stable even against an abnormal external impact during transportation. In addition, since the adhesive is applied not at the position of the support means but at the end in the longitudinal direction away from the light beam scanning area of the reflecting member, when applying the adhesive, the adhesive is erroneously applied to the light beam scanning area of the reflecting member. There is no risk of doing so. Therefore, the working time can be shortened and the manufacturing cost of the optical scanning device can be reduced.

As described above, according to the first and second aspects of the present invention, the natural frequency of the reflecting member is not increased without increasing the thickness of the reflecting member and without interposing a vibration suppressing member in the vicinity of the scanning region of the reflecting member. Can move. Therefore, since the natural frequency of the reflecting member can be moved to a high range with a simpler structure than before, the manufacturing cost of the optical scanning device can be reduced.

Further, since the rotational vibration is suppressed in addition to the bending vibration of the reflecting member, a better image quality can be obtained.
According to the invention described in claim 3, since the rotational vibration is further suppressed, a good image quality can be obtained.

According to the fourth aspect of the present invention, the natural frequency of the reflecting member can be moved to a high frequency with a simpler configuration than before, so that the manufacturing cost of the optical scanning device can be reduced. Further, it is possible to suppress the vibration of the reflecting member without interposing any member in the vicinity of the scanning region of the reflecting member, and the vertical space portion of the reflecting member can be used effectively. That is, when considered in the cross section of the optical scanning device, there are no inclusions in the vertical direction of the reflecting surface, so that the optical scanning device can be miniaturized by bending the optical path in a complicated manner.

According to the fifth aspect of the present invention, it is possible to reduce the thickness of the reflecting member and to eliminate the need for attaching a metal member, and thus it is possible to reduce the weight of the optical scanning device. The reduction in weight of the reflecting member leads to a reduction in the pressing force of the pressing means used for support, and the pressing means can be reduced in size. Therefore, the cost of the optical scanning device can be reduced. Further, the optical scanning device can be miniaturized as the thickness of the reflecting member decreases in the plate thickness direction.

According to the sixth aspect of the present invention, the natural frequency of the reflecting member can be further moved to a high range.

According to the seventh aspect of the invention, it is possible to more reliably suppress the vibration of the reflecting member.

According to the eighth aspect of the present invention, the movement of the end portion of the reflecting member is fixed. Therefore, the natural frequency of the reflecting member can be further moved to a higher range, and in particular, the position of the reflecting member can be stably maintained against an abnormal external impact during transportation. When applying the adhesive, there is no risk of applying the adhesive by mistake to the scanning region of the reflecting member. Therefore, the working time can be shortened, and the cost of the optical scanning device can be reduced.

(First embodiment)
The optical scanning device according to the first embodiment of the present invention will be described in detail with reference to FIGS. Here, FIG. 1 is an explanatory view of an optical scanning apparatus to which the present invention is applied, and FIG. 2 is an enlarged view of a main part of FIG.

  The optical scanning device 10 includes a light source 12 that emits a light beam L based on image information, a polygon mirror 14 that deflects the light beam L emitted from the light source 12 in a predetermined direction, an imaging lens system 16, and a target. The reflection mirror 20 guides the light beam L to the scanning body 18 and a housing 22 that houses and installs these optical components and is closed by a cover (not shown). The housing 22 is fixed to the frame 26 of the electrophotographic apparatus with screws 24. The optical scanning device 10 is incorporated in an electrophotographic apparatus, and a scanning beam 18 is main-scanned based on image information, thereby forming an electrostatic latent image on the scanning member 18.

  The electrophotographic apparatus includes known means, that is, a charging unit that uniformly charges the scanning target 18, a developing unit that forms a toner image on the scanning target 18 on which the electrostatic latent image is formed, and a toner image. A sheet conveying unit that conveys the recording paper at a timing capable of transferring the image, a transfer unit that transfers the toner image on the scanned body onto the recording sheet, and a fixing unit that fixes the transferred toner image onto the recording sheet. Has been.

  The reflection surface 20A of the reflection mirror 20 is adjusted by the first support 28 at one end (outer end of the scanning region) in the longitudinal (light beam scanning) direction, and the second support 30 and the reflection mirror angle adjusting mechanism 32 at the other end in the longitudinal direction. Supported by a screw 34. Here, the first support 28 and the second support 30 are integrally formed with the housing 22. On the other hand, the back surface 20B of the reflecting mirror 20 is pressed by plate springs 36A and 36B at positions facing the supports 28 and 30 at both ends in the longitudinal direction. Therefore, the light beam L is scanned at a desired position of the scanning target 18 by adjusting the screwing amount of the adjusting screw 34 with the reflection mirror 20 pressed by the support members 28 and 30 and the adjusting screw 34 by the plate springs 36A and 36B. Can be adjusted.

  On the other hand, as shown in FIG. 2, the housing 22 is formed with a regulating member 38 that protrudes from the wall surface in contact with the end face 20 </ b> C that is the longitudinal end face of the reflection mirror 20. The reflection mirror angle is adjusted in a state where the regulating member 38 and the end face 20C are not in contact with each other and the clearance C is secured as shown in FIG. After adjusting the angle with the adjusting screw 34, as shown in FIG. 4B, the reflecting mirror 20 is slid in the longitudinal direction (regulating member 38 side) to bring the regulating member 38 into contact with the end face 20C. As a result, the movement of the end face 20 </ b> C of the reflection mirror 20 is restricted by the restriction member 38. When the reflection mirror 20 is slid, the back surface 20B of the reflection mirror 20 is pressed by the leaf springs 36A and 36B, and the reflection surface 20A is supported by three points of the first support 28, the second support 30 and the adjusting screw 34. Therefore, the adjustment (reflection) angle of the reflection mirror 20 does not go wrong. Further, by appropriately setting the pressing force of the leaf springs 36A and 36B, it is possible to prevent the end face 20C of the reflecting mirror from being separated from the regulating member 38 due to an unnecessary impact during transportation.

  The operation of the thus configured optical scanning device 10 (suppression of vibration of the reflection mirror 20) will be described.

  First, as in the comparative example shown in FIG. 3A, the both ends of the reflection mirror 20 are supported only by the first support 28, the second support 30 and the adjusting screw 34, as shown in FIG. 3A. In the case of the comparative example shown in the figure, the vibration of the polygon mirror 14, the sheet conveying means in the electrophotographic apparatus, or the drive motor that drives the scanned object 18 is transmitted to the housing 22, and the reflection mirror 20 is flexed. As a result, the optical path of the light beam L reflected toward the scanned object 18 by the reflecting mirror 20 is shifted, causing a scanning line shift on the scanned object 18 and degrading the image quality. At this time, the end face 20C of the reflection mirror 20 freely vibrates due to flexural vibration as indicated by a two-dot chain line in FIG.

  On the other hand, in the optical scanning device 10 of the present embodiment, as shown in FIG. 3C, the end surface 20C of the reflecting mirror 20 is in contact with the regulating member 38, so that the movement of the end surface 20C is regulated. . Therefore, the reflection mirror 20 does not vibrate from the end face 20C to the support position of the first support 28 as shown by a two-dot chain line in FIG. 3D, and only the second support 30 side from the first support 28 is provided. It becomes a vibration. That is, when the reflecting mirror 20 is viewed as a beam, the restraint state of the portion where the end face 20C and the regulating member 38 are in contact approaches the fixed state. That is, since the restraint state of the end face 20C is fixed from the support, the natural frequency of the reflection mirror 20 can be moved to a high range, and the flexural vibration of the reflection mirror 20 can be suppressed.

  In addition, since a good image quality can be obtained with a simpler structure than the conventional bending vibration preventing method, the cost of the optical scanning device can be reduced.

  Further, the reflecting mirror 20, the positions where the supports 28 and 30 support the reflecting surface 20A of the reflecting mirror 20, and the light beam scanning direction end surfaces 20C and 20D of the reflecting mirror 20 (on the side opposite to the light beam scanning direction end surface 20C). The positional relationship with the end face is set as shown in FIG. That is, when the distance from one end face 20C (regulating member 38 side) of the reflection mirror 20 to the first support 28 is α and the distance from the other end face 20D to the second support 30 is β, β <α Therefore, the end face 20C can be brought closer to a fixed state when the longer distance is pressed with the same force. That is, it is possible to move closer to the fixed state and move the natural frequency of the reflection mirror 20 to a higher range.

  As described above, the natural frequency of the reflecting mirror 20 is increased by constraining the end face 20C of the reflecting mirror 20 with the regulating member 38, and therefore the thickness of the reflecting mirror 20 is increased in order to suppress the vibration of the reflecting mirror 20. In order to increase the mass of the reflection mirror 20, there is no need to attach a metal member to the back side of the reflection mirror 20. Therefore, the optical scanning device 10 can be reduced in weight. In particular, in this respect, it is more desirable to apply to a final reflecting mirror that finally reflects the light beam to the scanned object 18 inside the housing. This is because the light beam L is deflected by the polygon mirror 14, so that the light beam scanning region is the longest in the final reflection mirror. Therefore, the mirror length of the final reflecting mirror is the longest and vibration is most difficult to suppress, but if this configuration is applied, vibration can be easily suppressed without increasing the weight of the mirror.

  Further, by reducing the weight of the reflecting mirror 20, the pressing force of the leaf spring 36 that supports the reflecting mirror 20 can be reduced, and the dimensions (width, plate thickness) of the leaf springs 36A and 36B can be reduced. Therefore, the cost of the optical scanning device 10 can be reduced. Furthermore, since it is not necessary to increase the thickness direction dimension of the reflection mirror 20, the optical scanning device 10 can be reduced in size.

Furthermore, the reflection mirror 20 is supported at two points on one side (second support body 30, adjustment screw 34) and at the other point (first support body 28), and supports the regulating member 38 at one point (first support body 28). Since it is installed on the side, in addition to the bending vibration of the reflection mirror 20, rotation vibration (see arrow B in FIG. 24) due to torsion of the reflection mirror 20 can be suppressed, and better image quality can be obtained. The rotational vibration is particularly effective when a cylindrical reflecting mirror is applied to the present invention. In the case where the rotational vibration due to the torsion of the reflection mirror 20 is not particularly concerned, the two-point support (first support 30, adjustment screw 34) side may be regulated by the regulating member 38.
(Second Embodiment)
Next, an optical scanning device according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same referential mark is attached | subjected to the component similar to 1st Embodiment, and the detailed description is abbreviate | omitted. Moreover, only a different part from 1st Embodiment is demonstrated and description of another part is abbreviate | omitted.

  The leaf spring 36A that presses the back surface 20B of the reflecting mirror 20 has a shape obtained by folding the plate body into a V shape as shown in FIGS. 22, a support portion 42 that supports the reflection mirror 20 on the other end side, and an elastic portion (folded portion) 44 that elastically connects the attachment portion 40 and the support portion 42 to each other. It consists of. On the support portion 42, protrusions 46 </ b> A and 46 </ b> B that are in contact with the back surface 20 </ b> B of the reflection mirror 20 are formed along the elastic portion 44 and separated by a predetermined distance.

  The leaf spring 36A is fixed to the housing 22 so that the elastic portion 44 of the leaf spring 36A is parallel to the longitudinal direction of the reflection mirror 20. As a result, as shown in FIGS. 5B and 5C, the protrusions 46A and 46B of the leaf spring 36A are also in the longitudinal direction of the reflection mirror 20 from the position where the first support 28 supports the reflection surface 20A. The back surface 20B of the reflection mirror 20 is pressed at a position separated (offset) by a distance x on both sides in the longitudinal direction.

  As shown in FIGS. 5B and 5C, the elastic member 36B has the same configuration.

  The operation of the thus configured optical scanning device will be described.

  As shown in FIG. 5D, conventionally, the leaf springs 36A and 36B have pressed the positions facing the supports 28 and 30 at both ends in the longitudinal direction of the reflection mirror 20, so that the two-dot chain line indicates The amplitude of the reflection mirror 20 was large. On the other hand, in the present embodiment, the back surface of the reflection mirror 20 is projected by the projections 46A and 46B at a position offset by a distance x on both sides in the longitudinal direction across the position where the support surfaces 28 and 30 support the reflection surface 20A. 20B is pressed (see FIGS. 5B and 5C). By pressing the back surface 20B in this way, vibrations in both directions (± y directions) can be reliably suppressed. That is, as shown in FIG. 5D, the displacement in the y direction of the reflection mirror 20 is suppressed by the protrusion 46A, and the displacement in the −y direction is suppressed by the protrusion 46B. As a result, it is possible to suppress the bending vibration that has been pressed at a position (one point) facing the support bodies 28 and 30 and vibrated like a two-dot chain line as indicated by a broken line. Further, the natural frequency of the reflection mirror 20 can be moved to a high range.

  In the conventional example shown in FIG. 27B, the leaf springs 368A and 368B are shifted to the center in the longitudinal direction of the reflection mirror 362, respectively, and the contact positions of the contact portions 370 and 372 with respect to the back surface 362B of the reflection mirror 362 are obtained. If the support members 364A and 364B are sandwiched between the support positions, the configuration is similar to that of the present embodiment. However, since the contact portions 370 and 372 move independently of the deflection of the reflection mirror 362, the above-described buffering is performed. The effect cannot be fully exerted.

On the other hand, in this embodiment, since the protrusions 46A and 46B are formed on the single support portion 42, when the reflection mirror 20 tries to bend, the support portions 42 of the leaf springs 36A and 36B tend to twist. However, since the elastic portion 44 arranged in parallel with the reflecting surface 20A prevents torsion, vibration can be effectively suppressed.
(Third embodiment)
Subsequently, an optical scanning device according to a third embodiment of the present invention will be described with reference to FIG. In addition, the same referential mark is attached | subjected to the component similar to 1st Embodiment, and the detailed description is abbreviate | omitted. Moreover, only a different part from 1st Embodiment is demonstrated and description of another part is abbreviate | omitted.

In the present embodiment, the shape of the regulating member 38A is different from that of the first embodiment. That is, as shown in FIG. 6A, protrusions (hereinafter referred to as sharp portions) 50A and 50B extending in the longitudinal direction in a triangular cross section are formed on the surface of the regulating member 38A that abuts on the end surface 20C of the reflecting mirror 20. ing.

  Therefore, as shown in FIGS. 4A and 4B, when the reflecting mirror 20 is slid in the longitudinal direction and pressed against the regulating member 38A, a corner (ridge line) formed by the end surface 20C of the reflecting mirror 20 and the reflecting surface 20A is formed. 52, and a corner (ridgeline) 54 formed by the end surface 20C and the back surface 20B destroys and bites a part of the sharp portions 50A and 50B of the regulating member 38A (the broken and bited position is referred to as a biting portion 56A). The broken sharp portions 50A and 50B are removed by cleaning with air.

  In the optical scanning device of the present embodiment, since one end in the longitudinal direction (end surface 20C) of the reflection mirror 20 is fixed to the regulating member 38A in this way, not only the vibration of each part of the electrophotographic apparatus, The position of the reflecting mirror 20 can be kept stable even with an abnormal external impact during transportation.

  A modification is shown in FIG. This is suitable when the depth of the housing 22 is deep and a draft is required at the sharp part.

  The regulating member 38B has a triangular pyramid shape, and is formed so that the sharp portion 50B, which is the apex of the cross-sectional triangle, has a draft toward the upper side. The restricting member 30C arranged in parallel with the restricting member 38B has a triangular pyramid shape, but is formed so that the sharp portion 50C which is the apex of the cross-sectional triangle has a draft toward the lower side. In addition, a die punching hole (not shown) is formed on the lower housing surface of the sharp portion 50C.

By sliding the reflecting mirror 20 in the longitudinal direction against the regulating members 38B and 38C configured in this way and pressing the end face 20C, as shown in FIGS. The portion 52 is pressed against the sharp portion 50C of the regulating member 38C, and the corner portion 54 is pressed against the sharp portion 50B. As a result, as shown in FIG. 7D, the corner portion 52 can bite into the sharp portion 50C, and the corner portion 54 can bite into the sharp portion 50B. Also in this case, the movement of the end face 20C of the reflection mirror 20, that is, one end in the longitudinal direction can be fixed.
(Fourth embodiment)
Subsequently, an optical scanning device according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same referential mark is attached | subjected to the component similar to 1st Embodiment, and the detailed description is abbreviate | omitted. Moreover, only a different part from 1st Embodiment is demonstrated and description of another part is abbreviate | omitted.

  In the present embodiment, as shown in FIG. 8, the pressing protrusion 62 formed on the upright surface 61 of the pressing member 60 fixed to the housing 22 on the end surface 20D opposite to the regulating member in the longitudinal direction of the reflecting mirror 20 The reflecting mirror 20 is disposed so as to be in contact with and press the reflecting mirror 20 toward the regulating member 38 (the other end).

  Further, as a configuration different from that of the first embodiment, the mirror angle adjustment mechanism is omitted, and the support portions 64 and 66 of the first support 30B are formed at two positions separated by a predetermined distance in the short direction of the reflection mirror 20. . The angle of the reflection mirror 20 is determined by supporting the reflection surface 20A on the support portions 64 and 66.

  Thus, the present invention is also effective in the reflection mirror 20 that does not have an angle adjustment mechanism. Further, by pressing the end face 20D of the reflecting mirror 20 with the pressing protrusion 62 of the pressing member 60 (by applying the pressing force P1), as shown by the change from the solid line to the broken line in FIG. Although the cross section is subtle, it can be changed (thickness t → t1). As a result, the cross-sectional area of the reflecting mirror 20 increases and the cross-sectional secondary moment increases. Therefore, the natural frequency of the reflection mirror 20 can be moved to a higher range, and in particular, the position of the reflection mirror 20 can be stably held against an abnormal external impact during transportation.

The pressing member 60 only needs to be able to absorb the dimensional tolerance in the length direction of the reflection mirror 20 during mounting and to achieve the above-described action. For example, the pressing member 60 can be an elastic body, a sheet metal bracket, or the shape of the pressing member 60B shown in FIG. It may be made of plastic.
(Fifth embodiment)
Subsequently, an optical scanning device according to a fifth embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the component similar to 4th Embodiment, and the detailed description is abbreviate | omitted. Moreover, only a different part from 4th Embodiment is demonstrated and description of another part is abbreviate | omitted.

  9A, the screw hole 68 is formed in the upright surface 61 of the pressing member 60A, and the adjustment screw 70 that presses the end surface 20D of the reflecting mirror 20 is formed in the screw hole 68. It is screwed.

  Since it comprised in this way, the pressing force P2 (refer FIG.9 (B)) with respect to the reflective mirror 20 is changed by adjusting the screwing amount with respect to the screw hole 68 of the adjusting screw 70, and the cross-sectional area (thickness) of the reflective mirror 20 is changed. t2) Finely adjust the secondary moment of section. That is, the natural frequency of the reflection mirror 20 can be finely adjusted. Further, the tolerance in the longitudinal direction of the reflecting mirror 20 can be absorbed by adjusting the screwing amount of the adjusting screw 70.

  FIG. 10 shows a modification of FIG. The upright surface 61 of the pressing member 60B is configured to directly contact the end surface 20D of the reflecting mirror 20. A long hole 74 is formed in the base portion 72 of the pressing member 60B, and the screw 76 is inserted into the long hole 74. Is screwed into a screw hole (not shown) of the housing 22 so that the pressing member 60B can be fixed to the housing 22. That is, the pressing member 60 </ b> B is configured to be movable along the long hole 74.

The shape of the pressing member 60B is not particularly limited, and is made of plastic. In particular, a contact portion with respect to the end surface 20D of the reflecting mirror 20 may be formed as a pressing protrusion 62 shown in FIG. You may make it the shape of the member 38 (refer FIG. 2), 38A (refer FIG. 6), 38B, 38C (refer FIG. 7).
(Sixth embodiment)
Subsequently, an optical scanning device according to a sixth embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the component similar to 5th Embodiment, and the detailed description is abbreviate | omitted. Further, only the parts different from the fifth embodiment will be described, and description of other parts will be omitted.

  11A and 11B, the pressing member 60C is configured by an adjusting screw 70A screwed into a screw hole 80 formed on the wall surface of the housing 22. As shown in FIGS. Yes. An adjustment dial 82 is formed at one end of the adjustment screw 70 </ b> A located outside the housing 22 so that the operator can adjust the pressing force from the outside. In addition, a scale 84 is formed around the adjustment dial 82 on the wall surface of the housing 22 as a guide for the adjustment amount.

  Therefore, the operator can easily and accurately adjust the pressing force applied to the reflecting mirror 20 by the adjusting screw 70A by rotating the adjusting dial 82 according to the scale 84 without opening a cover (not shown) of the housing 22.

By the way, if adjustment is possible as in the fifth embodiment and the present embodiment, the reflection mirror 20 may be distorted in the normal direction of the scanning line, and the light beam on the scanning target may be bent (BOW). . However, in the case of the fifth embodiment, adjustment may be made within the BOW specification range at the time of adjustment of the optical scanning device, and in the case of this embodiment, the adjustment range of the adjustment dial 82 may be determined. For example, the adjustment screw 70A is shipped in contact with the end face 20D when adjusting the optical scanning device. If it is incorporated in the electrophotographic apparatus and the natural frequency of the reflecting mirror 20 is to be moved, the adjustment range may be determined by the number of scales 84 of the housing. Since the pressing member 60C can be adjusted from the outside of the optical scanning device in this way, fine adjustment of the natural frequency of the reflection mirror 20, especially adjustment corresponding to individual variations of the excitation source of the electrophotographic apparatus is performed. be able to. Therefore, since the manufacturing requirement standard of the excitation source of the electrophotographic apparatus can be relaxed, the cost of the excitation source can be reduced.
(Seventh embodiment)
Furthermore, an optical scanning device according to a seventh embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the component similar to 1st-6th embodiment, and the detailed description is abbreviate | omitted.

  As shown in FIG. 12, the electrophotographic apparatus 90 includes light beams LK, LC, LM, and LY (hereinafter referred to as LK to LY; other reference numbers) of black, cyan, magenta, and yellow recording colors from the optical scanning apparatus 92. (Similarly) is emitted to the scanned bodies 96K to 96Y. On the scanned bodies 96K to 96Y, electrostatic latent images are formed by the light beams LK to LY, and toner images of colors corresponding to the respective image signals are formed on the portions exposed by the light beams LK to LY. Each toner image formed on each of the scanned bodies 96K to 96Y is superimposed and transferred on the intermediate transfer belt 98 conveyed at a constant speed in the direction of arrow A, and then transferred onto the conveyed paper 100. Is done. The paper 100 onto which the toner image has been transferred is fixed on the toner image by a fixing device (not shown) and discharged to a paper discharge tray (not shown). An optical scanning device 92 used in the electrophotographic apparatus 90 will be described with reference to FIG. FIG. 13 is a perspective view of the optical scanning device with the cover 102 removed. The optical scanning device 92 is configured by arranging optical components inside the housing 22A shielded from the outside by the cover 102 in order to scan and expose the light beams LK to LY to the scanned objects 96K to 96Y. That is, the optical scanning device 92 applies the light beams LK to LY to the polygon mirror 14 in accordance with each recording information signal of black (K) cyan (C) magenta (M) yellow (Y) output from an image processing unit (not shown). The optical components are arranged in the housing 22A so that the scanning objects 96K to 96Y can be exposed from an opening (not shown). Details of the configuration will be described along the optical path of the light beam LM. As shown in FIG. 12, the light beam LM emitted from the light source 104M is transmitted through the collimator lens 106M to be loosely divergent light, is transmitted through the cylinder lens 108M, and is reflected by the small mirror 110YM, and is transmitted in the sub-scanning direction. It is narrowed down and enters the polygon mirror 14. The light beam LM reflected by the polygon mirror 14 passes through the fθ lens 112YM as an imaging optical system, reflects from the middle mirror 114M, passes below the large mirror 118M, reflects by the cylinder mirror 116M, and then reflects to the large mirror 118M. And the object to be scanned 96M is exposed. The reflecting surface of the cylinder mirror 116M forms an R surface in the sub-scanning direction, and functions to prevent a scanning line shift in the sub-scanning direction even when the polygon mirror 14 is tilted. Note that another small mirror 109Y is inserted between the cylinder lens 108Y and the small mirror 110YM on the optical path of the light beam LY. A similar arrangement is made on the optical path of the light beam LK.

  In addition, as shown in FIGS. 14A and 14B, an optical scanning device 92 having a tandem configuration that forms a color image by superimposing such toner images has SKEW correction, BOW correction (image position of a two-dot chain line). Is corrected to a solid line image position). SKEW correction is performed by a cam mechanism (not shown) in the skew correction mechanisms 120K to 120Y with reference to the end of the cylinder mirrors 116K to 116Y opposite to the skew correction mechanism side in the skew correction mechanisms 120K to 120Y shown in FIG. For example, the skew correction is performed by moving the two-dot chain line position of the cylinder mirror 116Y of FIG. 12 to the solid line position by adjustment by the skew correction mechanism 120Y.

  Next, the large mirrors 118K to 118Y (large mirror 118M, representative of the four) provided with the BOW adjusting mechanism will be described with reference to FIGS. FIG. 15 is a partially cutaway view taken along the arrow A in FIG. FIG. 16 is a diagram in which the regulating member shown in FIG.

  As shown in FIG. 15, the large mirror 118M has one end of the reflecting surface 122M as two support portions 126 and 128 of the first support 124M, and the other end as one support of the second support 130M. The back surface 134M is pressed to the support portions 126, 128, and 132 by the leaf springs 36A and 36B. The angle of the large mirror 118M (reflective surface 122M) is defined by supporting the reflective surface 122M on the three support portions 126, 128, and 132 in this way. A BOW adjusting mechanism is provided on the first support 124M side, and an angle member 136M is disposed substantially parallel to the inclined surface 135M formed on the housing 22A. As shown in FIG. 16, a hemispherical convex portion 140M is formed on the inclined surface 138M of the angle member 136M, and the convex portion 140M supports the back surface 134M of the large mirror 118M. The inclined surface 138M of the angle member 136M is formed with a screw portion 142M. By rotating the adjusting screw 144M, the distance between the inclined surface 138M and the inclined surface 135M of the angle member 136M is adjusted, and the first support body 124M. The pressing amount of the convex portion 140M against the back surface 134M of the large mirror 118M supported at two points can be increased or decreased. Therefore, the amount of bending of the large mirror 118M supported at two points on the first support 124M is changed to correct the BOW from the two-dot chain line position to the solid line position as shown in FIG. 14B.

  On the other hand, as shown in FIG. 17, the housing 22A is integrally provided with a regulating member 38 that comes into contact with the end face 146M at one end in the longitudinal direction of the large mirror 118M. When performing BOW correction (rotating the adjusting screw 144M), as shown in FIG. 4A, the regulating member 38 and the reflecting mirror end surface 146 are separated (clearance C). After adjustment with the adjustment screw 144, as shown in FIG. 4B, the large mirror 118M is slid in the longitudinal direction (regulating member 38 side), and the regulating member 38 and the end surface 146M of the large mirror 118M are brought into contact with each other. Since the reflecting surface 122M of the large mirror 118M is supported at three points, the scanning position on the scanning target 18 is not shifted from the desired position by the adjusted slide.

  By configuring in this way, as in the first embodiment, the regulating member 38 regulates and fixes the movement of the end surface 146M of the large mirror 118M, so that flexural vibration can be suppressed and the formed image quality can be improved. Can do.

  Similarly to the first embodiment, in the longitudinal direction of the large mirror 118M, the distance from the support position of the reflection surface 122M of the support portions 126 and 128 to the end surface 146M is α, and the support position of the reflection surface 122M of the support portion 130M. When the distance from the end surface 148M on the opposite side of the large mirror 118M to the end surface 148M of the large mirror 118M is β, the relationship is β <α. As a result, the natural frequency of the large mirror 118M can be moved to a higher range.

  In particular, by applying to the large mirror 118M, which is the final reflection mirror, the optical path of the light beam is formed in a direction orthogonal to the scanning direction of the scanning region of the large mirror 118M (hereinafter sometimes referred to as the vertical direction). The optical path in the optical scanning device can be made compact. Moreover, even when the scanning region (mirror length) is the longest as in the case of the large mirror 118M, vibration can be suppressed without increasing the thickness of the mirror or increasing the mass, so that the weight (weight) of the large mirror 118M can be reduced. Prevention).

  FIG. 18 shows the measurement result of the natural frequency of the large mirror 118M configured as described above. The large mirror 118M has a length of 310 mm, a width of 16 mm, a thickness of 8 mm, and a corner in the scanning direction of the back surface 134M is C3 chamfered over a length of 310 mm. Α = 30 mm and β = 5 mm in FIG. is there. FIG. 18 (A) is the state of FIG. 4 (A), and the clearance C is 0.5 mm. In the state of FIG. 4 (A), as shown in FIG. 18 (A), the natural frequency of the large mirror 118M is 276.9 Hz, but in the case of the configuration of this embodiment, it is shown in FIG. 18 (B). As described above, it was confirmed that the natural frequency of the large mirror 118M was 315.9 Hz, and the natural frequency of the large mirror 118M was moved to a high frequency by about 40 Hz by this configuration.

In this example, the support for supporting the large mirror 118M is composed of two points (first support 124M) on one side and the other point (second support 130M). However, the first support 124M and the second support are provided. The body 130M may be reversed. When the one-point support side is set to the regulating member side, in addition to the flexural vibration of the reflecting member, the rotational vibration due to the torsion of the reflecting mirror is suppressed, so that even better image quality can be obtained. This rotational vibration is particularly effective when a cylindrical reflecting mirror is applied to the present invention. Moreover, you may apply to the leaf | plate springs 36A and 36B what has a pair of protrusion 46A, 46B shown in 2nd Embodiment (FIG. 5 (A)-(C)).
(Eighth embodiment)
Furthermore, an optical scanning device according to an eighth embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the component similar to 7th Embodiment, and the detailed description is abbreviate | omitted.

  In the present embodiment, the regulating member 38A described in the third embodiment is used instead of the regulating member 38 in the seventh embodiment. That is, as shown in FIG. 19, sharp portions 50A and 50B are provided on the regulating member 38A that regulates the movement of the end surface 146M of the large mirror 118M. Therefore, when the large mirror 118M is slid in the longitudinal direction in accordance with FIGS. 4 (A) → (B), the corners (ridge lines) 150 between the sharp portions 50A and 50B, the end surface 146M of the large mirror 118M, and the reflecting surface 122M and Corner portions (ridge lines) 152 between the end surface 146M and the back surface 134M enter the sharp portions 50A and 50B of the regulating member 38A, destroy part of the sharp portions 50A and 50B, and form biting portions 56B and 56C. The mirror end face 146M is set in a fixed state. Therefore, the position of the large mirror 118M can be stably maintained not only for vibration of each part of the electrophotographic apparatus but also for an abnormal external impact during transportation.

  FIG. 20 shows a modification of FIG. 19 in which the regulating members 38B and 38C shown in FIG. 7 are applied instead of the regulating member 38A.

  As shown in FIGS. 20B to 20D, the corner portion 150M between the reflecting surface 122M and the end surface 146M abuts the sharp portion 50C, and the corner portion 152M between the back surface 134M and the end surface 146M abuts the sharp portion 50B. As a result, the biting portion 56C is formed in the sharp portion 50C with respect to the corner portion 150, and the biting portion 56B is formed in the sharp portion 50B with respect to the corner portion 152. Therefore, the movement of the end face 146M of the reflecting mirror is fixed.

  In addition, the structure which presses the end surface on the opposite side to a control member with the press member shown in 4th Embodiment is applicable to these 7th, 8th embodiment. By pressing the end surface 148M of the large mirror 118M toward the regulating member with the pressing member, it is possible to increase the cross-sectional secondary moment of the large mirror 118M and move the natural frequency to a higher range. Therefore, the position of the reflecting member can be stably maintained even with an abnormal external impact during transportation. The pressing member only needs to have the above-described action under the condition that it has a structure capable of absorbing the dimensional tolerance in the length direction of the reflecting mirror when attached. For example, the pressing member is an elastic body, a bracket made of sheet metal, as shown in FIG. It may be of any shape and made of plastic.

  Further, in the seventh embodiment, FIG. 18C shows the measurement result of the large mirror 118M when the end face 148M of the large mirror 118 is applied with a pressing force of 2 kgf to the regulating member 38 side by the pressing member 60 shown in FIG. Show. In this case, the natural frequency of the large mirror 118M is 324.4 Hz, and it has been confirmed that the natural frequency can be further moved to a higher range than when the large mirror 118M is merely brought into contact with the regulating member (FIG. 18B). .

  Further, in the seventh and eighth embodiments, as in the fifth embodiment (see FIG. 9), an adjustment screw may be provided on the pressing member so that the pressing force can be adjusted. With this configuration, the natural frequency of the large mirror 118M can be finely adjusted. Moreover, the tolerance in the length direction of the reflecting mirror can be absorbed. Similarly, as shown in FIG. 10, the pressing member may be provided with a long hole so that the pressing member itself can be adjusted.

  In addition, the shape of the contact portion of the pressing member with respect to the end surface 148M of the large mirror 118M is made of plastic, in particular, may be the pressing protrusion 62 shown in FIG. 8, or may be the regulating members 38 (see FIG. 17), 38A ( 19B), 38B, and 38C (see FIG. 20).

  The seventh and eighth embodiments may be configured such that the pressing member can be pressed and adjusted from the outside of the housing by an adjustment dial as in the sixth embodiment. Since the pressing member 60d can be adjusted from the outside of the optical scanning device in this way, fine adjustment of the natural frequency of the large mirror 118M, in particular, adjustment for individual variations of the excitation source of the electrophotographic apparatus. Can do. Therefore, since the manufacturing requirement standard of the excitation source of the electrophotographic apparatus can be relaxed, the manufacturing cost of the excitation source can be reduced. In addition, the seventh and eighth embodiments are configured to include a BOW adjustment mechanism, but the effect is also achieved by a reflection mirror having a mirror angle adjustment mechanism or a mirror having no mirror angle adjustment mechanism as in the first embodiment. Play.

  By the way, in addition to the configurations of the first to eighth embodiments described above, at least one of the regulating member or the pressing member) and at least one of the end surfaces of the reflecting mirror are bonded to fix the movement of at least one of the end surfaces of the reflecting mirror. It can also be considered to be in a state. For example, as shown in FIG. 4C, in a state where the end face of the reflection mirror 20 is offset from the restriction member 38, the adhesive 160 is attached to the contact surface of the restriction member 38 with respect to the reflection mirror 20 to adjust the angle. After the reflection mirror 20 is slid in the longitudinal direction (regulating member side), the end surface 20C of the reflecting mirror 20 is bonded to the contact surface of the regulating member 38 as shown in FIG. Fixed by. As a result, the end face 20C of the reflection mirror 20 is fixed, and the natural frequency of the reflection mirror 20 can be moved to a higher frequency range. In particular, the reflection mirror 20 can be protected against abnormal external shocks during transportation. The position can be kept stable. Moreover, since it adheres not to the support position of the reflection surface as in the conventional example but to the end surface 20D of the reflection mirror 20 away from the light beam scanning region of the reflection surface 20A, when applying the adhesive 160, the scanning of the reflection mirror 20 is performed. There is no risk of applying the adhesive 160 to the area by mistake. Therefore, the working time can be shortened, and the cost of the optical scanning device can be reduced.

  The restricting member in the first to eighth embodiments is integrally formed with the housing. However, on the condition that the natural frequency of the reflecting mirror is moved, for example, an elastic body or a bracket made of sheet metal. 10. A plastic member having a shape as shown in FIG. 10 (the contact portion is the regulating member 38 in FIG. 17, the regulating member 38A in FIG. 19, the regulating member 38C in FIG. 20), or a cover of the optical scanning device. It may be installed and connected and fixed to the housing.

1 is a partially omitted perspective explanatory view of an optical scanning device according to a first embodiment of the present invention. It is a principal part enlarged view of FIG. (A) is explanatory drawing which shows the support state and vibration state of the reflective mirror in a comparative example, (B) is vibration state explanatory drawing in the reflective mirror edge part of a comparative example, (C) is 1st Embodiment. It is explanatory drawing which shows the support state of the reflection mirror which concerns, (D) is a vibration state explanatory drawing in the reflection mirror edge part which concerns on this embodiment. (A), (B) is explanatory drawing which shows the state before contact | abutting of the end surface of a reflective mirror, and a control member, and the state after contact, (C), (D) The end surface of a reflective mirror, and a control member. It is explanatory drawing which shows the state before adhesion | attachment, and the state after adhesion | attachment. (A) is principal part explanatory drawing of the optical scanner which concerns on 2nd Embodiment of this invention, (B) is a front view which shows the support position of the leaf | plate spring in a reflective mirror, (C) is a top view. Yes, (D) is a schematic diagram showing a vibration state. (A) is principal part explanatory drawing of the optical scanner which concerns on 3rd Embodiment of this invention, (B) is the biting state explanatory drawing with respect to the control member of a reflective mirror end surface. FIG. 7 is an explanatory diagram of a main part of an optical scanning device according to a modified example of FIG. 6, and (B) to (D) are explanatory diagrams of biting states with respect to a regulating member on an end face of a reflecting mirror. (A) is principal part explanatory drawing of the optical scanner which concerns on 4th Embodiment of this invention, (B) is a deformation | transformation state explanatory drawing of the reflective mirror at the time of an end surface press. (A) is principal part explanatory drawing of the optical scanner which concerns on 5th Embodiment of this invention, (B) is a deformation | transformation state explanatory drawing of the reflective mirror at the time of an end surface press. It is principal part explanatory drawing of the optical scanning device which concerns on the modification of FIG. (A) is principal part explanatory drawing of the optical scanner which concerns on 6th Embodiment of this invention, (B) is a top view of the said principal part. It is a schematic explanatory drawing of the electrophotographic apparatus which concerns on 7th Embodiment of this invention. It is a perspective explanatory view of an optical scanning device concerning a 7th embodiment of the present invention. (A) is explanatory drawing of SKEW correction | amendment, (B) is explanatory drawing of BOW correction | amendment. FIG. 14 is a partial cutaway view taken along arrow A in FIG. 13. It is the figure which deleted the regulating member of arrow view C in FIG. It is a principal part expansion perspective view of the optical scanning device in 7th Embodiment of this invention. (A) is the configuration of the seventh embodiment, and there is a clearance C between the large mirror and the regulating member, (B) is the case of applying the configuration of the seventh embodiment of the present invention, and (C) is the configuration of the present invention. It is a figure which shows the measurement result of each natural frequency at the time of pressing the end surface on the opposite side to the control member side of a large mirror in the 7th Embodiment to the control member side. (A) is principal part explanatory drawing of the optical scanner which concerns on 8th Embodiment of this invention, (B) is the biting state explanatory drawing with respect to the control member of a reflective mirror end surface. It is principal part explanatory drawing of the optical scanning device which concerns on the modification of FIG. 19, (B)-(D) is a biting state explanatory drawing with respect to the control member of a reflective mirror end surface. It is explanatory drawing of the optical scanner which concerns on a prior art example. It is vibration state explanatory drawing of the reflective mirror in a prior art example. (A) is a principal part explanatory perspective view of the optical scanner which concerns on the prior art example 1, (B) is a principal part front view. (A) is a principal part explanatory perspective view of the optical scanning device concerning a comparative example, and (B) is a principal part front view. (A) is a schematic diagram of an optical scanning device according to Conventional Example 2, and (B) is a perspective view of a reflecting mirror. It is principal part explanatory drawing of the optical scanner which concerns on the prior art example 3. FIG. (A) is the reflective surface side perspective view of the reflective mirror which concerns on the prior art example 4, (B) is a back surface side perspective view, (C) is a vibration state explanatory drawing which concerns on a comparative example, (D) is It is vibration state explanatory drawing which concerns on the prior art example 4. FIG. (A) is a perspective explanatory view of a leaf spring according to Conventional Example 5, (B) is a main part explanatory view of an optical scanning device according to Conventional Example 5, and (C) is a vibration state explanatory diagram. (A) is a reflective mirror support state explanatory drawing which applied the prior art example 5, (B) is a support state explanatory drawing when a reflective mirror is displaced to -y direction, (C) is a reflective mirror y direction. It is explanatory drawing of a support state when it is displaced to. It is explanatory drawing of the electrophotographic apparatus (optical scanning device) which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical scanning device 12 ... Light source 14 ... Polygon mirror 16 ... Imaging lens system 18 ... Scanned body 20 ... Reflection mirror (reflection member)
22, 22A ... Housing 38, 38A, 38B, 38C ... Restriction member

Claims (8)

In an optical scanning device in which a light beam emitted from a light source is deflected by a polygon mirror, reflected by a reflecting member via an imaging lens system, and scanned by a scanning object.
A housing for housing each optical component;
A reflection surface provided at the housing and supporting the reflection surface on one end side in the longitudinal direction outside the light beam scanning region of the reflection member arranged with the longitudinal direction set to the light beam scanning direction or the back surface of the reflection surface at one point. 1 support means;
Second support means provided in the housing and supporting the reflection surface on the other end side in the longitudinal direction of the reflection member outside the light beam scanning region or the back surface of the reflection surface at two points in the short direction of the reflection member. When,
A pressing means for pressing the reflecting surface or the back surface of the reflecting member supported by the first supporting means and the second supporting means toward the first supporting means and the second supporting means;
A regulating member that protrudes from the wall surface of the housing and abuts against an end surface of the reflecting member in the longitudinal direction on the first support means side to regulate vibration of the reflecting member;
With
When the contact portion between the restriction member and the end surface of the reflection member and the support portion of the first support means are projected in the longitudinal direction of the reflection member, the reflection member is sandwiched between the projected support portions. An optical scanning device characterized in that the projected abutting portions are present on both sides in the short direction of . In an optical scanning device in which a light beam emitted from a light source is deflected by a polygon mirror, reflected by a reflecting member via an imaging lens system, and scanned by a scanning object.
A housing for housing each optical component;
A reflection surface provided at the housing and supporting the reflection surface on one end side in the longitudinal direction outside the light beam scanning region of the reflection member arranged with the longitudinal direction set to the light beam scanning direction or the back surface of the reflection surface at one point. 1 support means;
Second support means provided in the housing and supporting the reflection surface on the other end side in the longitudinal direction of the reflection member outside the light beam scanning region or the back surface of the reflection surface at two points in the short direction of the reflection member. When,
A pressing means for pressing the reflecting surface or the back surface of the reflecting member supported by the first supporting means and the second supporting means toward the first supporting means and the second supporting means;
A regulating member that protrudes from the wall surface of the housing and abuts against an end surface of the reflecting member in the longitudinal direction on the first support means side to regulate vibration of the reflecting member;
With
Contact portion between the end surface of the reflective member and the regulating member, and projecting the supporting portion of the first supporting means in the longitudinal direction of the reflecting member, when relative to the said support portion is projected, the projection the optical scanning apparatus in which the abutment portion which is, characterized in that over the other side from the one side in the lateral direction of the reflecting member with respect to the reference.   The regulating member is in contact with the end surface of the reflecting member from the one side to the reference, and is in contact with the end surface of the reflecting member from the other side to the reference. The optical scanning device according to claim 2, wherein the length is equal.   4. The optical scanning device according to claim 1, wherein an optical path of the light beam is formed in at least one of the upper and lower sides of the light beam scanning region of the reflecting member inside the housing. 5.   5. The optical scanning device according to claim 1, wherein the reflection member is a final reflection member that finally reflects a light beam inside the housing and reaches the object to be scanned.   In the longitudinal direction of the reflecting member, the pressing means is pressed at two positions offset by a predetermined distance on both sides with respect to the position where the first supporting means and the second supporting means support the reflecting member. The optical scanning device according to claim 1, wherein: The pressing means is
An attachment portion that is in contact with and fixed to the housing;
A pressing portion that presses the reflecting surface or the back surface of the reflecting member with two contact portions;
An elastic part disposed between the attachment part and the pressing part and elastically deforming to displace the pressing part in a predetermined direction;
With
The optical scanning device according to claim 1, wherein the predetermined direction is disposed in the housing such that the predetermined direction is orthogonal to a reflection surface of the reflection member.   The optical scanning device according to claim 1, wherein at least one of the regulating member or the pressing member is bonded to an end portion in a longitudinal direction of the reflecting member.

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