JP4568649B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

The present invention relates to an optical scanning device and an image forming apparatus comprising an adjustment equipment for adjusting the position or orientation of the adjusting member contact member is supported in contact.

  In image forming apparatuses such as copying machines, printers, and facsimiles, a latent image is formed on a latent image carrier by irradiating the latent image carrier with writing light according to image information and scanning it. In addition, it is known that an image is obtained by developing this latent image. An optical writing device (optical scanning device) that irradiates and scans with writing light is generally a polygon mirror that deflects and scans writing light from a light source, and writing light that is deflected and scanned by the polygon mirror. And an optical element (such as a lens) for forming an image on the surface of the latent image carrier. In such an optical writing device, the curvature of field of the optical element, the torsion of the housing of the optical writing device, the thermal deformation of various components constituting the optical writing device due to the heat generated by the polygon motor, the latent image carrier, etc. Due to the twisting at the time of mounting, the scanning line on the surface of the latent image carrier due to the writing light is bent or inclined. When the scanning line is bent or inclined, a correct latent image corresponding to the image information cannot be formed on the surface of the latent image carrier, and a normal image cannot be formed. In particular, in a so-called tandem type color image forming apparatus in which images of different colors (visible images) are formed on a plurality of latent image carriers and these images are superimposed on each other to form a color image, each latent image is formed. The relative deviation of the scan line curve and inclination between the image carriers is sensitively recognized by the user as an abnormal image. In other words, even if a single color image is bent or tilted, the user will not recognize it as an abnormal image as long as it is small. On the other hand, in the color image by the tandem image forming apparatus, if the curve or inclination of the scanning line in each latent image carrier is relatively shifted, this appears as a color shift. Even if this color misregistration is slight, it is perceived sensitively to the user as an abnormal image.

Patent Document 1 discloses a scanning optical device that can adjust the inclination of a scanning line. This scanning optical device adjusts the inclination of the scanning line by changing the posture of the folding mirror (adjusted member) provided on the beam path between the laser light source and the latent image carrier. Hereinafter, the specific configuration will be described with reference to FIG.
FIG. 11A is an enlarged view of the mirror holding portion at one end portion in the longitudinal direction (hereinafter, simply referred to as “one end portion”) of the folding mirror as viewed from the longitudinal direction, and FIG. FIG. 3 is an enlarged view of a mirror holding portion at the other end in the longitudinal direction of the folding mirror (hereinafter simply referred to as “the other end”) when viewed from the longitudinal direction.
As shown in FIG. 11A, one end portion of the folding mirror 251 is pressed against the corner portion O of the support portion 268 of the housing 270 by the leaf spring 262 (contact member), and the corner portion O is rotated. As a center, it is supported so as to be rotatable in the direction of arrow A in the figure. Further, the other end of the folding mirror 251 is supported by a folding mirror base 271 fixed to the housing 270, as shown in FIG. The folding mirror base 271 is provided with an adjusting mechanism including an urging member 272 and set screws 273a and 273b, and the other end of the folding mirror 251 is disposed between the urging member 272 and the set screws 273a and 273b. It is sandwiched and supported.

If either one of the set screws 273a and 273b is turned, the rotation position (the rotation position in the direction of arrow A) of the folding mirror 251 with the corner portion O as the rotation center can be adjusted. By this adjustment, the scanning line of the writing light reflected by the folding mirror 251 can be shifted in parallel in the sub-scanning direction.
Further, if the set screws 273a and 273b are turned by the same amount, the other end of the folding mirror 251 can be displaced in the direction of arrow B in FIG. Thereby, the rotation position (the rotation position in the direction of the arrow B) with the corner portion O of the folding mirror 251 as the rotation center can be adjusted. By this adjustment, the scanning line side corresponding to the other end side of the folding mirror 251 can be shifted in the sub-scanning direction, so that the inclination of the entire scanning line of the writing light reflected by the folding mirror 251 can be adjusted. it can.

JP 2001-100135 A

However, when trying to adjust the posture by rotating the folding mirror 251 by the adjusting mechanism, even if the other end side of the folding mirror 251 moves by the adjusting mechanism, the one end side of the folding mirror 251 can follow this. It may not move without it. In this case, there arises a problem that the posture of the folding mirror 251 cannot be adjusted properly.
More specifically, when one of the set screws 273a and 273b is turned to rotate the other end of the folding mirror 251 in the direction of arrow A, the one end of the folding mirror 251 is rotated following the rotation. By doing so, the scanning lines can be shifted in parallel in the sub-scanning direction for the first time. Here, when one end of the folding mirror 251 rotates in the direction of the arrow A with the corner portion O as the rotation center, the contact portion between the leaf spring 262 and the folding mirror 251 slides. Therefore, if the contact pressure of the leaf spring 262 is too strong or the static friction coefficient of the contact portion is too large, the static friction force of the contact portion is too large, and the arrow from the other end of the folding mirror 251 Even if transmitted by the rotational force in the A direction, the contact portion may not slide. In this case, even if one of the set screws 273a and 273b is rotated, the one end side of the folding mirror 251 does not rotate, and the scanning line cannot be shifted in parallel in the sub-scanning direction only by twisting the folding mirror 251. Therefore, appropriate adjustment cannot be made.
Further, when the set screws 273a and 273b are rotated by the same amount to displace the other end of the folding mirror 251 in the direction of arrow B in order to adjust the inclination of the entire scanning line, the leaf spring 262 and the folding mirror 251 The abutting portion of the slides. Therefore, as in the case where the scanning line is shifted in parallel in the sub-scanning direction, if the contact pressure of the leaf spring 262 is too strong or the coefficient of static friction of the contact part is too large, the static friction of the contact part. The force is too large and the contact part does not slide. Therefore, even if the set screws 273a and 273b are rotated by the same amount, the one end portion side of the folding mirror 251 does not move and the folding mirror 251 is bent, and the inclination of the entire scanning line cannot be adjusted.

  The problem similar to the above problem is that when the position or posture of the member to be adjusted supported by the contact member is in contact, the member to be adjusted slides between the member to be adjusted. If it is a simple adjustment device, it occurs similarly. That is, in such an adjusting device, if the contact pressure with the contact member is too strong, or if the coefficient of static friction between the member to be adjusted and the contact member is too large, the static friction at the contact portion is reduced. Power becomes too big. In this case, even if an attempt is made to adjust the position or posture of the member to be adjusted, the contact portion does not slide, so the position or posture of the member to be adjusted does not change, and the same problem as described above that the adjustment cannot be made occurs. .

The present invention has been made in view of the above problems, and an object of the present invention is to stably and accurately adjust the position or posture of a member to be adjusted that is supported by the contact member. it is to provide an optical scanning device and an image forming apparatus provided with the Do adjustment equipment.

In order to achieve the above object, the invention of claim 1 is directed to a light source, scanning means for irradiating the light irradiation target with light irradiated from the light source and scanning the light irradiation target, and from the light source to the light irradiation target. A long lens provided on the optical path and an adjustment device for adjusting the posture of the lens, and by adjusting the posture of the lens by the adjustment device, the inclination of the scanning line of the light irradiated to the light irradiation target In the optical scanning device capable of correcting the above, a long bracket for holding the lens, a support base on which the longitudinal center portion of the bottom surface of the lens is placed, and a motor side which is one end side in the longitudinal direction of the bracket Lifting means for contacting the end portion from below and moving it up and down, a plurality of contact members that contact the longitudinal ends of the top surface of the bracket and press each downward, and the top surface of the bracket The plurality of contact members When the top surface of the bracket and the at least one abutting member are directly in contact with each other, the static friction coefficient is lower than the static friction coefficient between them. A vertical surface member provided between the top surface of the bracket and the at least one contact member in the longitudinal direction of the lens. The lens rotates around the longitudinal center of the bottom surface of the lens placed on the support base, thereby changing the posture of the lens, thereby tilting the scanning line. It is characterized by correcting .
According to a second aspect of the present invention, in the optical scanning device according to the first aspect, the smooth surface member is a clip-shaped member that is attached by sandwiching a longitudinal end portion of the bracket, and the top surface of the bracket. The upper surface of the portion sandwiching the side is a smooth surface that imparts the low coefficient of static friction, and the lower surface of the portion sandwiching the back side of the top surface of the bracket is also the smooth surface. The smooth surface member attached to the end of the bracket on the motor side is brought into contact with the lower surface of the portion sandwiching the back side of the top surface of the bracket, and the bracket is moved up and down .
Also, the invention of claim 3 is the optical scanning apparatus according to claim 1 or 2, characterized in that said contact member is a plate spring.
Also, the invention of claim 4, writes the latent image bearing member, a latent image on the latent image bearing member surface by scanning and irradiating a writing light corresponding to image information to latent image bearing member surface An optical writing unit; and a developing unit that develops the latent image formed on the surface of the latent image carrier by the optical writing unit and visualizes the latent image. in an image finally is transferred onto the recording material an image forming apparatus for forming an image on the recording medium, as the optical writing unit, an optical scanning device according to any one of claims 1 to 3 It is characterized by being used.
According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect , a plurality of the latent image carriers are provided, and the visible images formed on the surfaces of the latent image carriers are directly on the recording material so as to overlap each other. Or the image is temporarily transferred onto the intermediate transfer member so as to overlap with each other, and the image on the intermediate transfer member is transferred onto the recording material, thereby finally forming an image on the recording material. To do.

The present invention, by the lifting means when a change in posture of the lens is adjustable member, relates to an improvement in the adjusting device sliding occurs between the abutment member abuts with its lens to is there.
Specifically, by interposing a smooth surface member between the lens and the abutting member, the static friction coefficient of the sliding portion that can occur between them is smaller than the static friction coefficient when these are in direct contact with each other. To do. Thus, compared to the smooth surface member when not interposed between the lens and the contact member, it is possible to reduce the static friction force acting between the lens and the contact member when the adjustment of the posture of the lens, the adjustment The sliding that occurs sometimes can be performed smoothly .

As described above, according to the present invention, as compared with the case of adjusting the can posture directly sliding to the lens between the lens and the contact member is adjustable member, it is possible to perform the adjustment smoothly, There is an excellent effect that the adjustment can be performed stably and accurately.

Embodiment 1
Hereinafter, an embodiment in which the present invention is applied to a printer as an image forming apparatus (hereinafter, this embodiment is referred to as “Embodiment 1”) will be described. In the first embodiment, a so-called intermediate transfer type tandem image forming apparatus will be described as an example, but the present invention is not limited to this.
FIG. 2 is a schematic configuration diagram illustrating the printer according to the first embodiment.
The printer includes an apparatus main body 1 and a paper feed cassette 2 that can be pulled out from the apparatus main body 1. In the central portion of the apparatus main body 1, image forming stations 3Y, 3C, and 3C for forming toner images (visible images) of respective colors of yellow (Y), cyan (C), magenta (M), and black (K). 3M, 3K. Hereinafter, the subscripts Y, C, M, and K of the respective symbols indicate members for yellow, cyan, magenta, and black, respectively.

FIG. 3 is a configuration diagram showing a schematic configuration of a yellow (Y) imaging station. The other image forming stations have the same configuration.
As shown in FIGS. 2 and 3, the image forming stations 3Y, 3C, 3M, and 3K include drum-shaped photoconductors 10Y, 10C, 10M, and 10K as latent image carriers that rotate in the direction of arrow A in the drawing. ing. Each of the photoreceptors 10Y, 10C, 10M, and 10K includes an aluminum cylindrical substrate having a diameter of 40 mm and an OPC (organic photo semiconductor) photosensitive layer that covers the surface of the photoreceptor. Each of the image forming stations 3Y, 3C, 3M, and 3K has charging devices 11Y, 11C, 11M, and 11K that charge the photoconductor around the photoconductors 10Y, 10C, 10M, and 10K, and a latent image formed on the photoconductor. Developing devices 12Y, 12C, 12M, and 12K as developing means for developing an image, and cleaning devices 13Y, 13C, 13M, and 13K for cleaning residual toner on the photoreceptor are provided. Below each image forming station 3Y, 3C, 3M, 3K, an optical writing unit 4 as an optical writing means, which is an optical scanning device that can irradiate the photoconductors 10Y, 10C, 10M, 10K with the writing light L. It has. Above each of the image forming stations 3Y, 3C, 3M, and 3K, an intermediate transfer unit 5 including an intermediate transfer belt 20 to which a toner image formed by each of the image forming stations 3Y, 3C, 3M, and 3K is transferred is provided. ing. Further, a fixing unit 6 is provided for fixing the toner image transferred to the intermediate transfer belt 20 to the transfer paper P as a recording material. In addition, toner bottles 7Y, 7C, 7M, and 7K that store toners of respective colors of yellow (Y), cyan (C), magenta (M), and black (K) are loaded on the upper portion of the apparatus main body 1. . The toner bottles 7 </ b> Y, 7 </ b> C, 7 </ b> M, and 7 </ b> K are configured to be detachable from the apparatus main body 1 by opening a paper discharge tray 8 formed on the upper part of the apparatus main body 1.

The optical writing unit 4 deflects writing light (laser light) L emitted from a laser diode as a light source by a polygon mirror or the like, and sequentially scans the photosensitive members 10Y, 10C, 10M, and 10K while irradiating them. Detailed description of the optical writing unit 4 will be described later.
The intermediate transfer belt 20 of the intermediate transfer unit 5 is wound around a driving roller 21, a tension roller 22, and a driven roller 23, and is driven to rotate counterclockwise in the drawing at a predetermined timing. The intermediate transfer unit 5 includes primary transfer rollers 24Y, 24C, 24M, and 24K that transfer the toner images formed on the photoreceptors 10Y, 10C, 10M, and 10K to the intermediate transfer belt 20. The intermediate transfer unit 5 cleans the secondary transfer roller 25 that transfers the toner image transferred onto the intermediate transfer belt 20 onto the transfer paper P, and the transfer residual toner on the intermediate transfer belt 20 that has not been transferred onto the transfer paper P. A belt cleaning device 26 is provided.

Next, the process of obtaining a color image in the printer having the above configuration will be described.
First, in the image forming stations 3Y, 3C, 3M, and 3K, the photoreceptors 10Y, 10C, 10M, and 10K are uniformly charged by the charging devices 11Y, 11C, 11M, and 11K. Thereafter, the optical writing unit 4 scans and exposes the laser light L based on the image information to form latent images on the surfaces of the photoreceptors 10Y, 10C, 10M, and 10K. The latent images on the photoconductors 10Y, 10C, 10M, and 10K are developed with toners of the respective colors carried on the developing rollers 15Y, 15C, 15M, and 15K of the developing devices 12Y, 12C, 12M, and 12K, and can be used as toner images. Visualized. The toner images on the photoreceptors 10Y, 10C, 10M, and 10K are sequentially transferred onto the intermediate transfer belt 20 that is rotated counterclockwise by the action of the primary transfer rollers 24Y, 24C, 24M, and 24K. The image forming operation of each color at this time is shifted in timing from the upstream side in the moving direction of the intermediate transfer belt 20 toward the downstream side so that the toner image is transferred to the same position on the intermediate transfer belt 20. Executed. The surfaces of the photoreceptors 10Y, 10C, 10M, and 10K after the completion of the primary transfer are cleaned by the cleaning blades 13a of the cleaning devices 13Y, 13C, 13M, and 13K, and are prepared for the next image formation. The toner filled in the toner bottles 7Y, 7C, 7M, and 7K is placed in the developing devices 12Y, 12C, 12M, and 12K of the image forming stations 3Y, 3C, 3M, and 3K by a conveyance path (not shown) as necessary. A fixed amount is supplied.

  On the other hand, the transfer paper P in the paper feed cassette 2 is transported into the apparatus main body 1 by a paper feed roller 27 disposed in the vicinity of the paper feed cassette 2 and is secondary by a registration roller pair 28 at a predetermined timing. It is conveyed to the transfer unit. Then, the toner image formed on the intermediate transfer belt 20 is transferred to the transfer paper P in the secondary transfer portion. The transfer paper P onto which the toner image has been transferred passes through the fixing unit 6 to fix the image, and is discharged to the paper discharge tray 8 by the discharge roller 29. Similar to the photoconductor 10, the transfer residual toner remaining on the intermediate transfer belt 20 is cleaned by a belt cleaning device 26 that contacts the intermediate transfer belt 20.

Next, the configuration of the optical writing unit 4 will be described.
FIG. 4 is an explanatory diagram showing the configuration of the optical writing unit 4 in the first embodiment.
The optical writing unit 4 includes two polygon mirrors 41a and 41b having a regular polygonal column shape. The polygon mirrors 41a and 41b have reflection mirrors on their side surfaces, and are rotated at a high speed around the central axis of the regular polygonal cylinder by a polygon motor (not shown). Thus, when writing light (laser light) from a laser diode (light source) (not shown) is incident on the side surface, the laser light is deflected and scanned. The optical writing unit 4 includes soundproofing glasses 42a and 42b for the soundproofing effect of the polygon motor, and fθ lenses 43a and 43b that change the equiangular motion of the laser scanning into a constant velocity linear motion by the polygon mirrors 41a and 41b. The mirrors 44a, 44b, 44c, 44d, 46a, 46b, 46c, 46d, 47a, 47b, 47c, and 47d for guiding the laser beam to the photoconductors 10Y, 10C, 10M, and 10K and the surface tilt of the polygon mirror are corrected. Long lens units 50a, 50b, 50c, and 50d as members to be adjusted are provided, and dust-proof glasses 48a, 48b, 48c, and 48d that prevent dust and the like from falling into the housing are provided. In FIG. 4, reference characters La, Lb, Lc, and Ld indicate optical paths of writing light applied to the respective photoconductors 10Y, 10C, 10M, and 10K.

Next, the configuration of the adjusting device that adjusts the bending and inclination of the scanning line by the optical writing unit 4 will be described.
In the first embodiment, the bending of the scanning line is adjusted by forcibly deforming the long lenses of the long lens units 50a, 50b, 50c, and 50d. On the other hand, the inclination of the scanning line is adjusted by changing the postures of the long lens units 50a, 50b, 50c, and 50d. In the first embodiment, a mechanism for adjusting the bending of the scanning line is provided in all the long lens units 50a, 50b, 50c, and 50d. On the other hand, a mechanism for adjusting the inclination of the scanning line is provided in the long lens units 50a, 50b, and 50c corresponding to the photoreceptors 10Y, 10C, and 10M of yellow (Y), cyan (C), and magenta (M). However, the long lens unit 50d corresponding to black (K) is not provided. Hereinafter, the long lens unit 50a corresponding to the yellow (Y) photoreceptor 10Y will be described as an example. However, in the following description, the color code is omitted.

FIGS. 5A and 5B are perspective views of the long lens unit 50. FIG. 6 is an exploded view of the long lens unit 50.
The long lens unit 50 includes a long lens 51 that corrects surface tilt of the polygon mirrors 41a and 41b, a bracket 52 that holds the long lens 51, a bending adjustment leaf spring 53, a long lens 51, and a bracket. 52, fixing plate springs 54 and 55, a driving motor 56 for automatically adjusting the scanning line inclination, a driving motor holder 57, a screw receiving portion 58, a housing fixing member 59, and a unit supporting plate. It comprises springs 60, 61, 62, smooth surface members 63, 64 as friction coefficient reducing means, a bending adjustment screw 65, and the like.

When the long lens unit 50 is assembled, first, the clip-like smooth surface member 63 is attached to the longitudinal direction end portion on the drive motor 56 side (hereinafter referred to as “motor side end portion”). Thereby, as shown in FIG. 5, the smooth surface 63a of the smooth surface member 63 is exposed to the top surface side of the bracket. On the other hand, the back surface of the smooth surface member 63 (the surface opposite to the smooth surface 63a) is located on the back surface side of the top surface of the bracket. A screw receiving portion 58 is fixed to the back surface of the smooth surface member 63. The screw receiving portion 58 is provided with an insertion hole into which a lifting screw attached to the motor shaft of the drive motor 56 is inserted. The top of the elevating screw is attached to the screw receiving portion 58 so as to abut against the inner bottom surface of the insertion hole of the screw receiving portion 58. The drive motor 56 is attached to a drive motor holder 57 fixed to the housing, and when the drive motor 56 rotates, the lifting screw is raised or lowered depending on the rotation direction.
Further, the smooth surface member 64 is caulked and fixed to the top surface side of the free end portion of the bracket 52. Thereby, as shown in FIG. 5, it attaches so that the smooth surface 64a of the smooth surface member 64 may be exposed to the top | upper surface of a bracket.

  When the long lens 51 is attached to the bracket 52, the long lens 51 is temporarily positioned on the bracket 52, and then the long lens 51 and the bracket 52 are connected by the U-shaped fixing plate springs 54 and 55. These are fixed at both longitudinal ends so as to be sandwiched. Further, a projection 51b is provided at the longitudinal center of the long lens 51. As shown in FIG. 7, a bending adjustment leaf spring 53 is attached so as to sandwich the projection 51b and the bracket 52. . The long lens 51 is positioned in a state of being pressed against the top surface side of the bracket 52 by the urging force of the fixing plate springs 54 and 55 and the bending adjustment plate spring 53. Further, a screw hole is provided in a portion where the bending adjustment leaf spring 53 is attached on the top surface of the bracket 52. As shown in FIG. 7, a bending adjustment screw 65 inserted through the hole of the bending adjustment leaf spring 53 is attached to the screw hole.

The long lens unit 50 assembled in this manner has a kamaboko-shaped support fixed to the housing at the center in the longitudinal direction on the bottom surface of the long lens 51 (the surface located on the opposite side of the top surface of the bracket 52). Place on table 66. The drive motor holder 57 holding the drive motor 56 is fixed to the housing by the housing fixing member 59. Then, by inserting the elevating screw on the motor shaft of the drive motor 56 into the screw receiving portion 58 attached to the motor side end portion of the bracket 52, the motor side end portion of the long lens unit 50 is in the direction of the optical path L. Movement to is regulated.
On the other hand, a protrusion 51 a is provided on the end surface of the end of the long lens 51 opposite to the motor side end (hereinafter referred to as “free end”). As shown in FIG. 8, one of the two side surfaces of the protrusion 51a perpendicular to the optical path L abuts on the fixing portion 67 of the housing, and the other abuts on the unit support leaf spring 60 fixed to the housing. With such a configuration, the free end portion of the long lens 51 is positioned in a state of being pressed against the fixing portion 67 of the housing by the unit supporting leaf spring 60. As a result, the movement of the free end portion of the long lens unit 50 in the direction of the optical path L is also restricted.

  Further, unit supporting leaf springs 61 and 62 fixed to the housing are in contact with both longitudinal ends of the top surface of the bracket 52. Due to the urging force of the unit supporting leaf springs 61 and 62, both ends in the longitudinal direction of the top surface of the bracket 52 receive a force that is pushed down toward the bottom surface side. As a result, the long lens unit 50 includes the elevating screw of the drive motor 56, the plate spring 61 for supporting the unit, and the support base in the direction (vertical direction) orthogonal to both the longitudinal direction of the long lens 51 and the direction of the optical path L. 66, supported by a unit supporting leaf spring 62.

Next, a method for adjusting the curve of the scanning line in the first embodiment will be described.
FIG. 9 is an explanatory diagram of a method for adjusting the bending of the scanning line.
The scanning line bending adjustment is performed when the printer is shipped. A specific adjustment method is as follows. In a state where the bending adjustment screw 65 is not tightened, the central portion in the longitudinal direction of the long lens 51 is urged toward the top surface side of the bracket 52 by the bending adjustment plate spring 53. When the bend adjusting screw 65 is tightened from this state, the apex of the bend adjusting screw 65 comes into contact with the central portion of the long lens 51 in the longitudinal direction, and the distance between this portion and the top surface of the bracket 52 increases. . Both ends of the long lens 51 in the longitudinal direction are fixed to the bracket 52 by fixing plate springs 54 and 55, and the rigidity of the long lens 51 is lower than that of the bracket 52. Therefore, by tightening the bending adjustment screw 65, the long lens 51 is bent in the longitudinal direction as shown in FIG. When the long lens 51 is bent in this manner, the degree of bending of the scanning line by the laser light passing through the long lens 51 changes according to the amount of bending. Therefore, by adjusting the tightening amount of the bend adjustment screw 65, it is possible to correct the bend of the scanning line that was initially generated.

Next, a method for adjusting the inclination of the scanning line in the first embodiment will be described.
FIG. 1 is an explanatory diagram of a method for adjusting the inclination of a scanning line according to the first embodiment.
The inclination of the scanning line is adjusted at the time of shipment of the printer, and at a predetermined timing such as a timing when the number of prints reaches a predetermined number or a timing when a user instruction is received during operation of the printer. A specific adjustment method is as follows.
When adjusting the inclination of the scanning line in this printer, first, a latent image of a predetermined inclination adjustment pattern is formed on each of the photoconductors 10Y, 10C, 10M, and 10K by the same operation as the normal image forming operation. To do. Then, the inclination adjustment pattern latent image of each color is developed to form an inclination adjustment pattern (toner image) and transferred to the intermediate transfer belt 20 in the same operation as in a normal image forming operation. Thereafter, the inclination adjustment pattern of each color transferred to the intermediate transfer belt 20 is detected by a pattern sensor (optical sensor) (not shown). Based on the detection result, each positional deviation amount between the black (K) inclination adjustment pattern and the other color (Y, C, M) inclination adjustment patterns is grasped. Then, the inclination amount of the scanning line for other colors (Y, C, M) with respect to the scanning line for black (K), which can minimize the respective positional deviation amounts, is calculated, and the result is shown in the inclination control not shown. To the output. The tilt control unit controls the rotation angle of the drive motor 56 based on the calculation result. As a result, the lifting screw attached to the rotating shaft of the drive motor 56 moves up and down, and the motor side end of the long lens unit 50 moves in the direction of arrow C in FIG. Specifically, when the lifting screw is raised, the motor side end of the long lens unit 50 is raised against the urging force of the unit supporting leaf spring 61. Accordingly, the long lens unit 50 rotates clockwise in FIG. 1 with the support base 66 as a fulcrum, and changes its posture. On the other hand, when the lifting screw is lowered, the motor side end of the long lens unit 50 is lowered by the urging force of the unit supporting leaf spring 61. Accordingly, the long lens unit 50 rotates counterclockwise in FIG. 1 with the support base 66 as a fulcrum, and changes its posture.

  When the posture of the long lens unit 50 changes in this way, the position where the laser light L enters the incident surface of the long lens 51 changes. In the long lens 51 according to the first embodiment, when the incident position of the laser light L with respect to the incident surface of the long lens 51 changes in a direction (vertical direction) perpendicular to the longitudinal direction of the long lens 51 and the direction of the optical path, The laser beam emitted from the exit surface of the long lens 51 has a characteristic that the angle (exit angle) with respect to the vertical direction changes. Due to this characteristic, when the posture of the long lens unit 50 is changed by the elevating screw, the emission angle of the laser light emitted from the emission surface of the long lens 51 is changed accordingly. As a result, the photosensitive member by this laser light is changed. The slope of the upper scan line changes. According to such an inclination adjusting mechanism, as compared with the case of adjusting the inclination by displacing one end of the folding mirror 251 in the direction of arrow B in FIG. Has the following advantages. That is, in the tilt adjustment described in Patent Document 1, since the optical path length of the laser light changes in the longitudinal direction of the folding mirror 251, a magnification error deviation occurs in the main scanning direction. On the other hand, since the optical path length does not change in the tilt adjustment according to the first embodiment, no magnification error deviation occurs in the main scanning direction.

  Here, when performing the above-described tilt adjustment, the posture of the long lens unit 50 cannot be appropriately changed even when the lifting screw is moved up and down, and proper tilt adjustment may not be performed. That is, in order to properly adjust the inclination, the long lens unit 50 must be accurately rotated by a rotation amount corresponding to the lift amount of the lifting screw with the support base 66 as the rotation center. Therefore, it is important for proper tilt adjustment that the long lens unit 50 can smoothly rotate about the support base 66 as the center of rotation according to the elevation of the elevation screw. In particular, when obtaining an image quality of 600 dpi or more, for example, if the inclination adjustment is performed within the scanning line interval or less, an adjustment accuracy of 42 μm or less is required at the minimum.

  As shown in FIG. 12, the inventor has devised a configuration in which the unit supporting leaf springs 61 and 62 are directly brought into contact with the top surface of the bracket 52 without providing the smooth surface members 63 and 64 as shown in FIG. However, with this configuration, the long lens unit 50 cannot be smoothly rotated about the support base 66 as the center of rotation in accordance with the elevation of the elevation screw, and appropriate tilt adjustment cannot be performed. It has been found that this is because the static frictional force at the sliding portion indicated by symbol E in FIG.

  This cause will be described in detail. For example, when the elevating screw is raised and the motor side end of the long lens unit 50 is moved in the direction of the arrow D in the figure, if smooth sliding occurs at the sliding portion E. The top surface of the bracket 52 smoothly moves relative to the unit support leaf spring 62 in the longitudinal direction, and the long lens unit 50 can smoothly rotate about the support base 66 as a rotation center. That is, as shown in FIG. 13A, when the motor side end of the long lens unit 50 is raised by α from the state before adjustment by the lifting screw, the long lens unit 50 rotates the support base 66. If it rotates about the center, its free end will be lowered by that α. However, if the static frictional force acting on the sliding portion E is too large, the sliding of the top surface of the bracket 52 and the unit supporting leaf spring 62 does not occur at the sliding portion E. In this case, as shown in FIG. 13B, the long lens unit 50 rotates around the free end where the sliding portion E is present as the rotation center, so that proper inclination adjustment can be performed. Can not.

As described above, the reason why the tilt adjustment cannot be properly performed is that the static friction force acting on the sliding portion E is too large. Therefore, if this static friction force can be reduced, the proper tilt adjustment can be performed. It becomes.
As a method of reducing the static frictional force acting on the sliding portion E, firstly, it is conceivable to reduce the urging force by the unit supporting leaf spring 62. However, the vibration generated during the image forming operation of the printer may be transmitted to the long lens unit 50 and the long lens unit 50 may vibrate in the vertical direction. The unit supporting leaf spring 62 functions to suppress this vibration. Therefore, if the urging force by the unit supporting leaf spring 62 is reduced, there is a drawback that this function may not be sufficiently exhibited.
As a second method, it is conceivable that a material is selected so that the top surface of the bracket 52 is smooth and a processing method is devised, or that the entire bracket 52 is coated with fluorine to provide a lubricating layer. . The bracket 52 of the first embodiment is made of a material (SECC-CrF-E16 / E16) made of an electrogalvanized steel sheet (chrome-free) having a plate thickness of 0.4 mm to 3.2 mm, like a conventional general bracket. It is processed into a predetermined bracket shape, and the top surface has a large surface roughness. The notation “E16 / E16” in the material indicates the amount of zinc deposited. Since such a bracket 52 can be manufactured at low cost, it has the effect of reducing the manufacturing cost of the printer, but on the other hand, the coefficient of static friction with the unit supporting leaf spring 62 is increased, and as described above, proper inclination adjustment is performed. There may be a problem that it cannot be performed. This problem can be improved by devising the material selection and processing method of the bracket 52 or providing a lubricating layer as described above. However, in this case, there is a drawback that the manufacturing cost of the bracket 52 increases, and the original manufacturing cost suppressing effect disappears.

Therefore, in the first embodiment, the smooth surface member 64 is interposed between the top surface of the bracket 52 in the long lens unit 50 and the unit supporting leaf spring 62. As the smooth surface member 64, for example, one formed of SUS can be used. The coefficient of static friction with the unit support leaf spring 62 as compared with the coefficient of static friction when the unit support leaf spring 62 is brought into direct contact with the top surface of the bracket 52 by the smooth surface 64a of the smooth surface member 64. Becomes smaller. That is, the smooth surface 64 a has higher smoothness than the top surface of the bracket 52. As a result, the static frictional force acting on the sliding portion E during the tilt adjustment can be reduced, and the sliding generated during the adjustment can be performed smoothly. As a result, an appropriate tilt adjustment can be performed.
In addition, in the first embodiment, proper inclination adjustment can be performed even if the urging force of the unit supporting leaf spring 62 is set to such a strength that the vibration suppressing function is sufficiently fulfilled.
Furthermore, in the first embodiment, the bracket 52 itself is used as it is without being changed, and the smooth surface member 64 is attached only to the sliding portion E and its peripheral portion. Therefore, the material selection and processing method of the bracket 52 itself can be devised. Compared with the case where a lubricating layer is provided on the entire bracket 52, an increase in manufacturing cost can be suppressed.

[Embodiment 2]
Next, another embodiment in which the present invention is applied to a printer as an image forming apparatus (hereinafter, this embodiment is referred to as “second embodiment”) will be described. Since the second embodiment is the same as the first embodiment except that the configuration of the tilt adjustment mechanism is different, only the parts specific to the second embodiment will be described below.

FIG. 10 is an explanatory diagram of a method of adjusting the inclination of the scanning line in the second embodiment.
In the second embodiment, the posture of the long lens unit 50 is not reduced without generating the sliding friction coefficient instead of reducing the static friction coefficient of the sliding portion E shown in FIG. 12 as in the first embodiment. The tilt can be adjusted by smoothly changing. Specifically, a coil spring 162 fixed to a spring support portion 168 of the housing is used instead of the unit support leaf spring 62 in FIG. The coil spring 162 is fixed to the top surface at the free end of the bracket 52 of the long lens unit 50. The coil spring 162 has a configuration that can be deformed in the sliding direction (left-right direction in the figure) generated at the sliding portion E in FIG. The magnitude of the force resisting the deformation of the coil spring 162 is smaller than the static friction force acting between the long lens unit 50 and the unit supporting plate spring 62 shown in FIG.

In the second embodiment, for example, when the lifting screw is raised by the drive motor 56, the motor side end of the long lens unit 50 rises against the urging force of the unit supporting leaf spring 61. Accordingly, the long lens unit 50 rotates clockwise in FIG. 1 with the support base 66 as a fulcrum, and changes its posture. At this time, the free end of the long lens unit 50 moves downward and simultaneously moves to the right side in the figure. Since the coil spring 162 is deformed following the movement of the free end portion of the long lens unit 50, the long lens unit 50 can smoothly rotate about the support base 66. As a result, appropriate tilt adjustment can be performed.
In the second embodiment, the proper inclination adjustment can be performed even if the biasing force of the coil spring 162 is set to such a strength that the vibration suppressing function is sufficiently fulfilled. There is no drawback like the first method described above for reducing the static frictional force acting on E.
Furthermore, in the second embodiment, the bracket 52 itself is used as it is without being changed, and the coil spring 162 is used in place of the unit support leaf spring 62. Therefore, the material selection and processing method of the bracket 52 itself can be devised, Compared with the case where a lubricating layer is provided on the whole 52, an increase in manufacturing cost can be suppressed. Therefore, there is no defect like the above-mentioned second method for reducing the static friction force acting on the sliding portion E.

As described above, the adjusting device according to the first embodiment is supported by the support mechanism that supports the unit supporting plate spring 62 as the contact member by contacting the long lens unit 50 as the member to be adjusted. And a tilt adjusting mechanism as an adjusting means for adjusting the position or posture of the long lens unit 50. When the posture of the long lens unit 50 is changed by the tilt adjusting mechanism, the long lens unit 50 is adjusted. 50 and the unit supporting plate spring 62 are configured to slide. In this adjustment device, the static friction coefficient between the long lens unit 50 and the unit support leaf spring 62 is larger than the static friction coefficient between the long lens unit 50 and the unit support leaf spring 62 when the long lens unit 50 and the unit support leaf spring 62 are in direct contact with each other. A smooth surface member 64 is provided between them as a friction coefficient reducing means for reducing the friction coefficient. Accordingly, the long lens unit 50 and the unit support are adjusted when the posture of the long lens unit 50 is adjusted as compared with the case where the smooth surface member 64 is not interposed between the long lens unit 50 and the unit supporting leaf spring 62. The static friction force acting between the plate springs 62 can be reduced, and the sliding generated during the adjustment can be performed smoothly. Accordingly, it is possible to adjust the inclination of the appropriate scanning line. In the first embodiment, the case where the inclination of the scanning line is adjusted by adjusting the posture of the long lens unit 50 has been described as an example. However, the present invention is not limited to the member to be adjusted such as the long lens unit 50. The same applies when adjusting the position.
Further, in the first embodiment, the smooth surface member 64 used as the friction coefficient reducing means is attached to the long lens unit 50 which is one member, and the unit supporting leaf spring 62 which is the other member. It is a smooth member having a static friction coefficient with respect to the long lens unit 50 at a contact portion that is in contact with the long lens unit 50 and the unit supporting leaf spring 62 that are in direct contact with each other. By using a smooth surface member 64 that is configured separately from the long lens unit 50 and the unit supporting leaf spring 62 as a friction coefficient reducing means, a simple addition of the smooth surface member 64 to the existing configuration can be used. Appropriate posture adjustment or position adjustment of the scale lens unit 50 can be performed. The same applies to such a smooth member attached to the unit supporting leaf spring 62.
Further, the friction coefficient reducing means may be a surface layer formed on one of the long lens unit 50 and the unit supporting leaf spring 62. At this time, for example, when this surface layer is formed on the long lens unit 50, the surface layer is in contact with the unit support plate spring 62 at the contact portion that contacts the unit support plate spring 62 which is the other member. It is assumed that the static friction coefficient is smaller than the static friction coefficient when the long lens unit 50 which is one member and the unit supporting leaf spring 62 are in direct contact with each other. Also in this case, it is possible to perform proper posture adjustment or position adjustment of the long lens unit 50 only by providing a surface layer in the existing configuration. The same is true if such a surface layer is formed on the unit supporting leaf spring 62.
In the first embodiment, the abutting portion (smooth surface 64 a) of the smooth surface member 64 that abuts the unit supporting plate spring 62 is a flat surface, and the abutting portion of the unit supporting leaf spring 62 that abuts on this is a flat surface. It is convex. Thereby, compared with the case where the contact portion of the unit support leaf spring 62 is a flat surface, the contact area with the smooth surface member 64 is reduced, and the static friction coefficient between them can be reduced. Therefore, smoother sliding is possible, and more appropriate inclination adjustment of the scanning line can be performed. The same effect can be obtained when the contact portion of the smooth surface member 64 is convex and the contact portion with the unit supporting leaf spring 62 is a flat surface.
Further, the friction coefficient reducing means may be a lubricant such as grease applied to one of the long lens unit 50 and the unit supporting leaf spring 62. Also in this case, it is possible to perform proper posture adjustment or position adjustment of the long lens unit 50 only by applying the lubricant to the existing configuration.
In the first embodiment, the contact member of the support mechanism that supports the long lens unit 50 is the unit support leaf spring 62 that applies a pressing force to the long lens unit 50. Thereby, the vibration of the long lens unit 50 in the contact direction can be absorbed by the leaf spring and the vibration can be suppressed.
In the second embodiment, the long lens unit 50 does not reduce the static friction coefficient of the sliding portion E shown in FIG. 12 as in the first embodiment, but does not cause the sliding itself. It is possible to adjust the position or posture of the camera. Specifically, the abutting portion between the long lens unit 50 and the abutting member, which was the sliding portion E, is fixed, and the abutting direction of the abutting member generated before the abutting member is fixed. It replaces with the coil spring 162 which can deform | transform into. The magnitude of the force resisting the deformation of the coil spring 162 is smaller than the static frictional force acting between the long lens unit 50 and the unit supporting plate spring 62 before the replacement as shown in FIG. . According to the second embodiment, the posture adjustment of the long lens unit 50 can be smoothly performed without causing the sliding between the long lens unit 50 and the contact member that has been in contact with the long lens unit 50. As a result, it is possible to appropriately adjust the inclination of the scanning line. In the second embodiment, the case where the inclination of the scanning line is adjusted by adjusting the posture of the long lens unit 50 has been described as an example. However, the present invention is not limited to the member to be adjusted such as the long lens unit 50. The same applies when adjusting the position.
In particular, if the coil spring 162 configured to be deformable in the sliding direction at the time of tilt adjustment before the fixing is used as the abutting member fixed to the long lens unit 50 as in the second embodiment, it is appropriate. It is possible to easily and inexpensively adjust the inclination of the scanning line.
In the first embodiment and the second embodiment, the support mechanism causes the unit supporting leaf spring 62 to abut on one end portion (free end portion) of the long long lens unit 50 in the longitudinal direction. And the posture of the long lens unit 50 is adjusted by displacing the other longitudinal end portion (motor side end portion) of the long lens unit 50. In such a configuration, the force due to the displacement of the end portion on the motor side is transmitted in the longitudinal direction of the long lens unit 50, and this force is generated by the unit support of the long lens unit 50 generated on the free end portion side. This is a force for sliding them against the static frictional force with the plate spring 62. At this time, if the long lens unit 50 is long in the longitudinal direction as in the first embodiment and the second embodiment, the force due to the displacement of the motor side end portion is not easily transmitted to the free end side, so that The force that slides between the long lens unit 50 and the unit supporting leaf spring 62 generated on the end side becomes small. Therefore, in such a configuration, the smooth surface member 64 is interposed between the long lens unit 50 and the unit support leaf spring 62 as in the first embodiment, or for unit support as in the second embodiment. If the coil spring 162 is provided instead of the leaf spring 62, the effect of the present invention can be effectively utilized.
In the first embodiment and the second embodiment, the tilt adjusting mechanism having the above-described configuration is used as a tilt adjusting unit of the long lens unit 50 mounted on the optical writing unit 4 as an optical scanning device. Yes. Specifically, a laser diode as a light source, and a polygon mirror 41a as a scanning unit that irradiates the photoconductors 10Y, 10C, and 10M as light irradiation targets and scans them with laser light emitted from the laser diode. 41b, a long lens unit 50 provided on the optical paths La, Lb, and Lc from the laser diode to the photoconductors 10Y, 10C, and 10M, and an adjustment device that adjusts the position or posture of the long lens unit 50. This is applied to the optical writing unit 4. In such an optical writing unit 4, it is necessary to adjust the position or orientation of the long lens unit 50 with high accuracy, so that the effects of the present invention can be effectively utilized.
In the first embodiment and the second embodiment, the optical writing unit 4 is mounted on a printer that is an image forming apparatus, and laser light that is writing light according to image information is applied to the surface of the photoreceptor. It is used as optical writing means for writing a latent image on the surface of the photosensitive member by irradiating and scanning. Specifically, a plurality of photoreceptors 10Y, 10C, 10M, and 10K as latent image carriers are provided, and toner images formed on the surfaces of the photoreceptors are placed on an intermediate transfer belt 20 as an intermediate transfer body so as to overlap each other. Once transferred, the image on the intermediate transfer belt is transferred onto the transfer paper P, which is a recording material, so that an image is finally formed on the transfer paper P. Such a printer is a so-called intermediate transfer type tandem image forming apparatus, and a slight slight inclination between the scanning lines of each photoconductor by the optical writing means causes color misregistration to the user as an abnormal image. Easy to be recognized. Therefore, it is necessary to adjust the relative inclination between the scanning lines of each photoconductor with high accuracy. Therefore, the effect of the present invention can be effectively used by using the above-described optical writing unit 4 as the optical writing means in such a printer.
In a so-called direct transfer type tandem image forming apparatus that forms an image on the transfer paper P by transferring the toner images formed on the surfaces of the photoconductors directly onto the transfer paper P so as to overlap each other. Similarly, the effects of the present invention can be effectively utilized.

  In the above-described first and second embodiments, an example in which the problem of the tilt adjustment caused by the static frictional force of the sliding portion E on the top surface of the bracket 52 at the free end of the long lens unit 50 is improved is taken as an example. As mentioned above, when the problem of tilt adjustment occurs similarly due to the static frictional force at other sliding locations, it can also be applied to that location. For example, as shown in FIG. 8, between the fixed portion 67 and the protruding portion 51a of the housing that holds the protruding portion 51a provided on the end surface of the free end of the long lens 51, or the unit supporting leaf spring 60 and the protruding portion The portion between the portion 51a also slides when the posture of the long lens unit 50 is changed by adjusting the inclination. If the static frictional force is too large in these places, sliding does not occur, and the long lens unit 50 rotates around the free end as a rotation center, so that proper tilt adjustment cannot be performed. Therefore, also in these places, a friction coefficient reducing means such as the smooth surface member 64 is interposed as in the first embodiment, or instead of the unit support leaf spring 60 as in the second embodiment, or in the housing. If the coil spring 162 is provided in place of the fixed portion 67, the long lens unit 50 can be smoothly rotated and an appropriate tilt adjustment can be performed.

FIG. 3 is an explanatory diagram of a method for adjusting the inclination of a scanning line by the optical writing unit of the printer according to the first embodiment. FIG. 2 is a schematic configuration diagram illustrating the printer. FIG. 2 is a configuration diagram illustrating a schematic configuration of an image forming station of the printer. Explanatory drawing which shows the structure of the optical writing unit. (A) And (b) is a perspective view of the elongate lens unit mounted in the optical writing unit. The exploded view of the same long lens unit. The block diagram which shows the bending adjustment mechanism of the elongate lens unit. The block diagram which shows the support mechanism by the side of the free end of the same elongate lens unit. Explanatory drawing of the method of the curve adjustment of the scanning line in the optical writing unit. FIG. 10 is an explanatory diagram of a method for adjusting the inclination of a scanning line in the second embodiment. (A) is an enlarged view when the mirror holding | maintenance part in the longitudinal direction one end part of a folding mirror in the conventional apparatus is seen from the longitudinal direction. (B) is an enlarged view when the mirror holding | maintenance part in the longitudinal direction other end part of the same folding mirror is seen from the longitudinal direction. Explanatory drawing which shows the structure of the inclination adjustment mechanism devised before this inventor made this invention. (A) is explanatory drawing which shows the inclination of a elongate lens when appropriate inclination adjustment is made. (B) is explanatory drawing which shows the inclination of a long lens when sliding generate | occur | produces in a sliding location.

Explanation of symbols

4 Optical writing unit 10Y, 10C, 10M, 10K Photoconductor 11Y, 11C, 11M, 11K Charging device 12Y, 12C, 12M, 12K Developing device 20 Intermediate transfer belt 41a, 41b Polygon mirror 50a, 50b, 50c, 50d Long Lens unit 51 Long lens 52 Bracket 53 Bend adjustment leaf spring 56 Drive motor 60, 61, 62 Unit support leaf spring 63, 64 Smooth surface member 63a, 63b Smooth surface 65 Bend adjustment screw 66 Support stand 162 Coil spring 168 Spring support

Claims (5)

A light source, a scanning unit that irradiates a light irradiation target with light emitted from the light source and scans it, a long lens provided on an optical path from the light source to the light irradiation target, and an attitude of the lens An optical scanning device capable of correcting the inclination of the scanning line of the light irradiated to the light irradiation target by adjusting the posture of the lens by the adjusting device.
A long bracket to hold the lens;
A support base on which the longitudinal center of the bottom surface of the lens is placed;
Elevating means for abutting from the lower side to the motor side end which is one end side in the longitudinal direction of the bracket, and raising and lowering this,
A plurality of abutting members that abut against both longitudinal ends of the top surface of the bracket and press each downward;
These brackets are interposed between the top surface of the bracket and at least one contact member of the plurality of contact members, and the top surface of the bracket and the at least one contact member are in direct contact with each other. A smooth surface member that imparts a static friction coefficient therebetween that is lower than the static friction coefficient therebetween,
By raising and lowering the motor side end of the bracket by the elevating means, the top surface of the bracket and the at least one contact member are placed on the support base while sliding in the longitudinal direction of the lens. An optical scanning device, wherein the lens rotates around a central portion in the longitudinal direction on the bottom surface of the lens, thereby correcting the inclination of the scanning line by changing the posture of the lens .   The optical scanning device according to claim 1.
  The smooth surface member is a clip-shaped member that is attached by sandwiching the longitudinal end portion of the bracket, and the upper surface of the portion that sandwiches the top surface side of the bracket provides the low static friction coefficient. And the lower surface of the portion sandwiching the back side of the top surface of the bracket is also the smooth surface,
  The elevating means raises and lowers the bracket by abutting against the lower surface of the portion of the smooth surface member attached to the motor side end of the bracket that sandwiches the back side of the top surface of the bracket. apparatus. The optical scanning device according to claim 1 or 2 ,
The optical scanning device , wherein the contact member is a leaf spring. A latent image carrier;
Optical writing means for writing a latent image on the surface of the latent image carrier by irradiating and scanning the surface of the latent image carrier with writing light according to image information;
A developing means for developing the latent image formed on the surface of the latent image carrier by the optical writing means into a visible image;
In an image forming apparatus for finally transferring a visible image on the surface of the latent image carrier onto a recording material to form an image on the recording material,
As the optical writing unit, the image forming apparatus characterized by using the optical scanning device according to any one of claims 1 to 3. The image forming apparatus according to claim 4 .
A plurality of the latent image carriers are provided,
Visible images formed on the surface of each latent image carrier are directly transferred onto the recording material so as to overlap each other, or are temporarily transferred onto the intermediate transfer member so as to overlap each other, and an image on the intermediate transfer member is recorded. An image forming apparatus, wherein an image is finally formed on a recording material by being transferred onto the material.

Images