JP4084361B2 - Image forming apparatus - Google Patents

Description

This invention relates to images formed equipment.

  It consists of a base having an opening and a rotating member that opens and closes the opening, and the rotating member supports the rotating end that is one end of the rotating member on the stationary end that is one end of the opening. The following technique is known as an opening / closing rotation mechanism that is rotatably attached via means.

(A) The configuration of the cover device with the operation panel is outlined, and the outline thereof is attached to the lower hinge 71 attached to the main body 74 and the rotating cover 75 as shown in FIGS. Further, the pin 73 is inserted by aligning the position of the upper hinge 72 to determine the pivot point of rotation, and the cover 75 is opened and closed (see, for example, Patent Document 1).

(B) The configuration of the sheet conveying apparatus and the image forming apparatus, and the outline thereof is that the first opening / closing part is moved to the apparatus main body by the engagement between the hinge piece on the apparatus main body 1 side and the hinge piece on the first opening / closing part side. The first opening / closing member is locked at the open position by clicking means (see, for example, Patent Document 2).
In both of these two known techniques, the rotating member is rotated by a hinge mechanism of a fixed fulcrum having one fixed point as a fulcrum.

Japanese Utility Model Publication 5-85661 JP-A-9-146322

In the prior art, there are many structures that are provided with a pivotable opening / closing section, and when opening / closing the opening / closing section and then performing various operations, the opening / closing rotation is generally performed with a certain point as a stationary center. In a structure that opens and closes around one fixed point, the turning radius of each part of the turning member is fixed. Therefore, a member is placed in the turning area at this turning radius to avoid interference. Can not do it. That is, a certain amount of space is required, and this is an obstacle to further downsizing the apparatus having a rotating member.
The present invention aims that you avoid banding to secure the rigidity of the mounting structure of the optical writing device.

In order to achieve the object, the present invention has the following configuration.
(1). In an image forming apparatus having a plurality of photoconductors arranged in a vertical direction and a plurality of photowriting devices arranged in the vertical direction corresponding to the plurality of photoconductors, the photoconductor longitudinal direction (front-rear direction) 2) having two side plates provided perpendicular to the longitudinal direction of the photoconductor, and a partition plate that is positioned so as to partition the photoconductor and the optical writing device and connects the two side plates ( Claim 1).
(2). In the image forming apparatus according to (1) , the partition plate has a length in a vertical direction across the plurality of photoconductors .

(3). In the image forming apparatus according to (2) , an optical path hole is formed in the partition plate at a portion corresponding to an optical path of a light beam emitted from the optical writing device .

(4). In the image forming apparatus described in (3) , the partition plate and the two side plates are fixed to each other (claim 4).

According to the onset Ming, strength of the support structure of the optical writing device Ru is eliminated it is by banding secured.

[1] Reference Example FIG. 1 shows an outline of a configuration when a full-color image forming apparatus is viewed from the front where an operation unit is located. In FIG. 1, four optical writing devices (hereinafter referred to as optical writing units) 6 are juxtaposed in the vertical direction.

  These four optical writing units 6 have the same configuration, and are arranged in correspondence with the four photoconductor units 5 juxtaposed in the vertical direction in the horizontal direction.

  The uppermost optical writing unit 6 and the uppermost photosensitive unit 5 are paired to form a black image. The other three pairs of the optical writing unit 6 and the photosensitive unit 5 form cyan, magenta, and yellow images, and the configuration is the same as that of the uppermost stage. The outline of image formation will be described as a representative of the writing device 6 and the photoreceptor unit 5.

  The optical writing device 6 scans the light beam Lb on the drum-shaped photoconductor 100 of the photoconductor unit 5, thereby forming an electrostatic latent image on the photoconductor 100. The light beam Lb is generated by a laser diode (not shown) in the optical writing unit 6, scanned by the action of the polygon mirror 101, and formed on the photosensitive member as a target beam spot through an fθ lens, a folding mirror, and the like. .

  In the photoconductor unit 5, around the photoconductor 100, a charging unit 102, a developing unit 103, a cleaning unit 104, and a group of parts necessary for image formation and having a replacement life are provided. The position on the photoconductor 100 between the charging unit 102 and the developing unit 103 constitutes an exposure unit irradiated with the light beam Lb. A transfer belt 105 that conveys transfer paper is positioned oppositely on the photosensitive member 100 between the developing unit 103 and the cleaning unit 104. The transfer belt 105 is configured with a long span in the vertical direction so as to face each photoconductor of the four photoconductor units 5 juxtaposed in the vertical direction in common.

  The developing means 103 of the four photoconductor units 5 juxtaposed in the vertical direction are filled with toners of black, cyan, magenta, and yellow in order from the top, and are transferred from the paper feeding unit 10 by the transfer belt 105. A full color image is obtained by superimposing four color images on the fed sheet in order from the lowermost photosensitive unit 5, and is discharged from a discharge roller 107 through a fixing unit 106.

  In such an image forming apparatus, since the optical writing unit 6 is disposed in a short vertical direction with a short juxtaposition distance, the optical writing unit 6 has a structural feature that is disposed at a position relatively distant from the photoreceptor 100. is doing.

  As shown in FIG. 2A, the image forming apparatus includes a front side plate 1, a rear side plate 2, a bottom plate 90 (see FIG. 16), a left reference stay 3 that connects the front side plate 1 and the rear side plate 2, and a right reference stay. 4 (see FIG. 1, not shown in FIG. 2A) and the like. The main body structure 110 is an example of a substrate according to the present invention. Around these main body structures, exterior covers such as a rear cover 35 and a left cover 36 as illustrated in FIG. 9 are appropriately provided.

  A rectangular hole 108 formed in the front side plate 1 is an exchange port for exchanging four photoconductor units 5 juxtaposed in the vertical direction. As shown in FIG. 22, the photoconductor unit to be exchanged is provided. 5 is drawn. Further, in FIG. 2A, four holes 109 formed in the vertical direction on the rear side plate 2 are for providing a driving unit for the photoconductor 100.

  In FIG. 2B, the left end portion of the main body structure 110 has a rectangular opening due to the left end portions of the bottom plate 90 (see FIG. 16), the front plate 1, the rear plate 2, and the like. A portion 111 is formed. An electrical bracket 7 having a substantially rectangular plate shape is provided so as to close the opening 111.

  An end portion on one end side of the electrical bracket 7, that is, an end portion R in the rear direction, and an end portion on one end side of the opening portion 111, that is, the rear end portion S in the opening portion, are provided via a rotation support means described later. The electrical bracket 7 is connected to the main body structure 110 and can open and close the opening 111. FIG. 3 schematically shows an open state (two-dot chain line) and a closed state (solid line) of the electrical equipment bracket 7. Here, the end S of the opening 111 is also the end of the rear plate 2 at the same time.

  The electrical bracket 7 is mounted with electrical components such as a drive power source for driving the photosensitive unit 5 and the optical writing unit 6 and a control device for performing various controls for image formation. Specifically, a power supply unit 8 as an electrical component, a control board 9 and the like are mounted. In addition, the optical writing unit 6 described above is disposed at the back of the opening 111 where the electrical bracket 7 opens and closes.

Hereinafter, an example in which the rear plate 2 and the electrical bracket 7 are made of sheet metal will be described.
2 to 9, the end portion R of the electrical bracket 7 has a shape such that the plate material is bent in an L shape so that the ridgeline is along the vertical direction, and the upper end portion of the end portion R is a horizontal plane. The support member 24 is formed of a rectangular plate-like member formed by being bent so as to form parallel surfaces, and is provided integrally (or integrally) with the electrical equipment bracket 7.

  Further, the rear end S of the opening 111 has a shape such that the plate member is bent in a U shape so that the ridge line is along the vertical direction, and the upper end of the end S is a plane parallel to the horizontal plane. The support member 21 is formed of a rectangular plate-like member that is bent so as to form the rear plate 2 and is provided integrally (or integrally) with the rear plate 2. The support member 21 is approximately the same size as the support member 24 so that the support member 24 can be rotated on the support member 21, and both of the opposing surfaces that come into contact with each other are flat. Formed on the surface.

  A plate-shaped attachment member 113 that is bent so as to face the support portion 21 is formed at the lower end portion of the end portion S of the rear side plate 2. The attachment member 113 is fixed to the bottom plate 90 (see FIG. 16) constituting the main body structure 110 by screws 114.

  In FIG. 4, a screw hole 22 and a guide groove 23 are formed in the support member 21. The guide groove 23 includes a linear groove 23S along the left-right direction and a curved groove 23R. The groove 23S and the groove 23R are formed with the same width, and are 6 mm in this example. The left end of the groove 23S communicates with the end of the groove 23R. The screw hole 22 is a position further leftward than the left end of the groove 23S, and is on the center line in the width direction of the groove 23S.

  In this example, the groove 23R has a shape along an arc centered on the point O. The position of the point O is a distance y from the hole 22 in the left direction and x in the rear direction. If the radius from the center of the hole 22 to the intersection of the center line of the groove 23R and the groove 23S is Ra, and the radius from the point O to the center line of the groove 23R is Rb, in this example, Ra = 10 mm, Rb = 20 mm, x = 2.5 mm, and y = 10 mm.

  In FIG. 5, a guide groove 25 is formed in the support member 24. The guide groove 25 is a linear groove along the left-right direction. A protrusion 26 as a guide shaft is formed at a position further shifted to the right than the right end of the guide groove 25.

  This protrusion 26 has a shape (burring shape) in which the bottom of the drawing shape of the press is removed, and is constituted by a cylindrical shaft portion as shown in FIG. The protruding portion 26 has a configuration in which the shaft portion protrudes from the lower surface of the support member 24. The protrusion 26 is a guide shaft that is inserted into the guide groove 23 of the support member 21, and the outer diameter d of the shaft portion is sized to be slidably inserted into the guide groove 23 without rattling. In this example, the outer diameter d is about 6 mm and the protruding amount h is 2 mm. In addition, it can also be set as the structure which replaced with the protrusion 26 and planted the pin by caulking.

  In FIG. 5, a stopper 80 is provided integrally with the support member 24. The stopper 80 is formed by a bent sheet metal part integrated with the electrical equipment bracket 7, and has a vertical surface orthogonal to the longitudinal direction (left-right direction) of the guide groove 25. Similarly, in FIG. 4, a stopper 81 is provided integrally with the support member 21. The stopper 81 is formed from a bent sheet metal part integrated with the rear plate 2, is formed of a vertical plane perpendicular to the longitudinal direction (left-right direction) of the groove 23, and the electrical bracket 7 is attached to the rear plate 2. Originally, the stopper 81 is in a positional relationship facing the stopper 80.

The attachment of the electrical equipment bracket 7 to the rear side plate 2 will be described.
As shown in FIGS. 2A, 7A, and 7B, the support member 24 is overlaid on the support member 21, and the protrusion 26 is inserted into the guide groove 23 as shown in FIG. 10A. The At the same time, the stepped screw 112 shown in FIG. 6B is screwed into the screw hole 22 through the guide groove 25 as shown in FIG. 10B. Here, the stepped screw 112 includes a head portion 112a, a shaft portion 112b as a guide shaft, and a screw portion 112c. The shaft portion 112b has a diameter of 6 mm which is slidably fitted into the guide groove 25. The shaft portion 112 b is positioned in the guide groove 25 when the screw portion 112 c is formed and screwed into the screw hole 22.

The opening / closing operation | movement of the electrical equipment bracket 7 is demonstrated.
First position:
When the image forming apparatus is in a normal state, the electrical bracket 7 is in a closed state, and a stopper 80 is pressed against the stopper 81 as shown in FIG. In addition, both stoppers are fixed by screws 115. The part shown by the code | symbol 81a in FIG. 4 is the screw seat formed as a screwing part of the screw 81a.

  As shown in FIG. 7A, the position of the electrical bracket 7 when the electrical bracket 7 is in the state where the opening 111 is closed is referred to as a first position. In this first position, the protrusion 26 is located near the right end of the groove 23S. Further, the shaft portion 112 b is located in the vicinity of the left end of the guide groove 25.

  When it is necessary to maintain the electrical components attached to the electrical bracket 7, or to replace the writing unit 6 shown in FIG. 1, the electrical bracket 7 must be opened. As shown in FIG. 9, the outermost surface of the main body structure 110 is covered with a rear cover 35 and a left cover 36 that are exterior covers. Therefore, only the left cover 36 is removed leaving the rear cover 35. Then, the screw 115 etc. which fix the electrical equipment bracket 7 are removed. Even in the removed state, the electrical bracket 7 remains in the first position.

Displacement from the first position to the second position:
At the first position, the stopper 80 and the stopper 81 are in close contact with the mating surface 31 as described above. Therefore, even if it is going to rotate the electrical equipment bracket 7 in this state, the stopper 81 interferes with both stoppers 81 and cannot be rotated.

  Therefore, in order to leave a space between the stoppers 80 and 81, an operator who faces the electrical bracket 7 in the left direction, that is, in the right direction at the left side position of the main body structure, places the electrical bracket 7 on the near side (left direction). ). Accordingly, the electrical bracket 7 is displaced in a direction (leftward) away from the opening 111 with the first position as a reference. This displacement is performed by the protrusion 26 being guided in the groove 23S and the shaft portion 112b being guided in the guide groove 25, and the electrical bracket 7 is translated in the left direction.

  The movement of the electrical bracket 7 is restricted at the position where the protrusion 26 contacts the groove 23S. The position of the electrical bracket 7 at this time is the second position shown in FIG.

  In the second position, the shaft portion 112b can be moved in the left-right direction between the end portion of the guide groove 25 and the shaft portion 112b with the protrusion 26 in contact with the groove 23S. The distance is kept. Further, the end of the groove 23R (the center of the protrusion 26 when the protrusion 26 abuts) is positioned on a straight line passing through the center of the screw hole 22 and parallel to the front-rear direction.

Displacement from the second position to the third position:
Under the second position shown in FIG. 7B, when the front part of the electrical bracket 7 is grasped and pulled toward the front (left side), the electrical bracket 7 protrudes with the shaft portion 112b as a fulcrum. Begins to rotate along the groove 23R. A state in the middle of this rotation is shown in FIG. As shown in FIG. 8A, the electrical bracket 7 protrudes and the projection 26 rotates along the groove 23R. At the same time, the position of the shaft portion 112b is also displaced in the guide groove 25 in this displacement process. The entire bracket 7 rotates around the shaft portion 112b while moving in the forward direction. The shaft portion 112b, which is a pivot point of rotation, is displaced to the front side when observed from the main body structure 110 (rear side plate 2) that is a stationary system.

  When the electrical bracket 7 is further rotated from the position shown in FIG. 8A, the protrusion 26 eventually comes into contact with the end of the groove 23R as shown in FIG. 8B. At this time, although the shaft portion 112b is in the middle position of the guide groove 25, the longitudinal direction of the guide groove 25 about to rotate together with the electrical bracket 7 with the protrusion 26b serving as a fulcrum is just the moment direction of the electrical bracket 7. Because of the orthogonal relationship, the electrical bracket 7 is prevented from further rotating by the positional relationship between the protrusion 26 and the groove 23R, and the shaft portion 112b and the guide groove 25. At this time, the electrical equipment bracket 7 is rotated 90 ° from the first position, and the opening 111 is opened. Such a position of the electrical bracket 7 is referred to as a third position. The protrusion 26 and the shaft portion 112b are located on a straight line parallel to the front-rear direction.

  In this way, maintenance of electrical components is performed with the electrical unit 7 opened. Alternatively, the writing unit 6 shown in FIG. 1 is replaced.

Displacement from the third position to the first position:
When maintenance of the electrical equipment is performed, or the exchange of the writing unit 6 is completed, the electrical equipment bracket 7 is returned from the third position to the first position. At this time, the reverse procedure of the above steps is taken.

  The characteristic of the rotation operation of the electrical bracket 7 is that the pivot point of the electrical bracket 7 is not fixed at a fixed position but is displaced during the rotation process. Then, by shifting the fulcrum position of the rotation, the rotation locus of the electrical equipment bracket 7 can be set to the inside as compared with the case where the fulcrum is fixed.

  In this embodiment, as described with reference to FIG. 4, Ra = 10, Rb = 20, x = 2.5, and y = 10 are set, and the electrical bracket 7 at that time is a stopper when rotating. The rotation trajectory of the end point 32 of 80 is as shown by reference numeral 33 in FIG. For comparison, if the groove 23R is formed with Ra = Rb, x = 0, y = 0, that is, the end point of the stopper 80 when the electrical bracket 7 is rotated with the rotation fulcrum as one point of the screw hole 22. When the rotation locus of 32 is shown, it is as shown by reference numeral 34 in FIG.

  As can be seen by comparing the rotation trajectory 33 and the rotation trajectory 34, if the pivot point of the rotation is shifted during the rotation process of the electrical bracket 7 as in this embodiment, the rotation is restricted in a certain region. Can be inside the case of the fixed fulcrum.

  As shown in FIG. 9, the distance between the rear cover 35 and the turning locus of the end point 32 requires a gap D when the present invention is not applied. In particular, as shown in FIG. 1, the electrical bracket 7 is equipped with an electrical component-related power supply unit 8 and a control board 9, so that a clearance through which the harness passes is necessary. Therefore, in addition to the gap D, a further gap can be secured if the turning locus 33 is located inside the turning locus 34 at the portion facing the rear cover 35 as in this embodiment. Further, if the same gap D as in the prior art is ensured, the position of the rear cover 35 can be moved to the front side by the amount the rotation locus is shifted inward, so that the space efficiency of the image forming apparatus is increased, and the size of the image forming apparatus is increased. The thickness can be reduced.

In these examples, the combination of the guide groove 25 and the shaft portion 112b that engages with the guide groove 25 is an example of a first engagement guide means, and a guide groove 23 and a protrusion 26 that engages with the guide groove 23, This combination is an example of second engagement guide means. Then, the support members 21 and 24 constituting these first engaging guide means and the second engagement guide means is an example of a rotation support unit.

  The guide shaft and the guide groove constituting the first engagement guide means are provided by being distributed between the support members 21 and 24 as in the above example. However, the arrangement position is the same as in the above example. It may be replaced. Similarly, in the second engagement guide means, the guide shaft and the guide groove may be interchanged between the support members 21 and 24.

  The shape of the curved groove 23R has been described as a shape along an arc. However, the shape is not limited to this, and the turning trajectory of the turning member is inside the fixed region as compared with the case of turning around a fixed point. It shall include all the curves of shapes that can be

  In the above example, the image forming apparatus has been described. However, the present invention is not limited to this, and the rotation support that can be opened and closed and the apparatus that has the base structure that supports the rotation member are also supported by the rotation according to this example. A means can be comprised and apparatus space efficiency can be improved.

[2] Reference Example All the contents described in [1] can be applied to this example. As already described, the support member 24 integral with the electrical equipment bracket 7 is overlaid on the support member 21 integral with the rear plate 2. Therefore, since the supporting member 21 integrated with the rear side plate that forms a part of the main body structure 110 receives the load of the heavy electrical equipment bracket 7 that supports the electrical equipment, a special means for receiving the load is provided. This is not necessary and the complexity of the configuration can be avoided.

  As in the example described in the above [1], when the load is received by the combination of the support members 21 and 24, the strength of the support portion is insufficient when the electrical bracket 7 is increased or the load of the electrical component is increased. Therefore, the rotation may become unstable. In such a case, if a plurality of support members having the same combination as the support members 21 and 24 are provided, the load to be shared is reduced, so that the rotating member can be stably supported.

As described above, since the fulcrum of the opening / closing rotation mechanism becomes unstable when the rotating member becomes large, an example in which another surface is provided in addition to the support member 21 of the rear plate 2 will be described.
11 and 12, the configuration of the electrical bracket 7 and the rear side plate 2 is the same as the configuration described in FIGS. 2 to 9 except for the newly provided support portion. The same reference numerals are given.

  In FIG. 10, below the support member 21, a rectangular plate-shaped lower support member 41 is provided as another support member formed by bending the rear side plate 2. The lower support member 41 is provided with a guide groove 43 that is exactly the same as the guide groove 23 formed in the support member 21.

  Further, the electrical bracket 7 is formed by bending the electrical bracket 7 below the support member 24 in the electrical bracket 7 so as to overlap the surface of the lower support member 41 at a position overlapping the lower support member 41. A rectangular plate-like lower support member 44 as one support member is provided.

  The lower support member 44 is provided with the same protrusion 46 as the protrusion 26 described above, and engages with the guide groove 43 in the same positional relationship as the protrusion 26 engages with the guide groove 23. Here, as shown in FIG. 10B, a stepped screw 112 is screwed into the screw hole 22 in the support member 21, but the lower support member 41 protrudes along the guide groove 43. As long as 46 does not slide out of the guide groove 43 when it slides, it is not necessary to provide a stepped screw in the lower support member 41. Therefore, it is not necessary to provide a screw hole for its attachment.

A modification will be described with reference to FIGS.
In FIG. 12A, a rectangular plate-shaped lower support member 51 is provided below the support member 21 as another support member formed by bending the rear side plate 2. The lower support member 51 is provided with a guide groove 53 similar to the guide groove 23 formed in the support member 21.

  Further, the electrical bracket 7 is formed by bending the electrical bracket 7 below the support member 24 in the electrical bracket 7 so as to overlap the surface of the lower support member 51 at a position overlapping the lower support member 51. A rectangular plate-shaped lower support member 54 as one support member is provided.

  The lower support member 54 is provided with a bent portion 56 instead of the protrusion 46 in FIG. The bent portion 56 is engaged with the guide groove 53 in the same positional relationship as the protrusion 26 is engaged with the guide groove 23. FIG. 12B shows the state of engagement.

  In the example shown in FIGS. 11 and 12, the support member 24, the lower support members 44, 54 and the like are formed integrally with the electrical bracket 7, and the support member 21, the lower support members 41, 51 are connected to the rear side plate 2. By configuring integrally, it is possible to obtain a mechanism that can be stably opened and closed with a simple configuration without increasing the number of parts.

[3] Reference Example In the example of the opening / closing rotation mechanism described in [1] and [2], when the opening / closing rotation of the electrical bracket 7 is closed, the electrical bracket 7 is displaced from the second position to the third position. A mode when the structure 110 is attached to the normal position will be described.

  As shown in FIGS. 13 and 14, the upper edge of the rectangular plate-like portion that is a part of the electrical bracket 7 and closes the opening 111 is folded 90 ° to the right from the vertical plane at the third position. An eaves-like portion 61 having a constant width and having a length in the front-rear direction is formed.

  The eaves-like portion 61 overlaps with the upper end edge 3a on the left side of the left reference stay 3 forming a part of the main body structure 110 from above as the electrical bracket 7 is displaced from the second position to the third position. , It has a function of supporting the load of the electrical equipment bracket 7 at the first position and the second position.

  In the third position, as described with reference to FIG. 8B, the electrical bracket 7 is displaced by 90 ° from the second position to open the opening 111, and the eaves-shaped portion 61 is the upper edge 3a. Completely separated from In this example, in order to smoothly run the eaves-like portion 61 on the upper edge portion 3a when the electrical bracket 7 is rotated in the closing direction from this separated state, in this example, the free end side of the eave-like portion 61 is used. Was tilted upward with a constant width and an inclination of θ with respect to the horizontal to form an inclined plate portion 62.

  When the inclined plate portion 62 is thus provided, the electrical bracket 7 is displaced from the open state at the third position to the closed state at the second position as shown in FIGS. Thus, as shown in FIG. 15, the inclined plate portion 62 rides on the upper edge 3 a of the left reference stay 3 in accordance with the displacement of the electrical equipment bracket 7 from 7 a to 7 b to 7 c.

  When the electrical bracket 7 is disengaged from the left reference stay 3, that is, in an open state, the power supply unit 8 and the control board 9 are usually weighted in addition to the weight of the electrical bracket 7 itself. 7 goes down.

  However, by providing the inclined plate portion 62 that is bent at an angle θ, when the electrical bracket 7 is closed, the left reference stay 3 can be easily used by utilizing the fact that the closer to the fulcrum is less lowered. And can be returned to the normal mounting position.

  During these mutual displacements between the first position and the second position and between the second position and the first position, the state in which the eaves-like part 61 rides on the upper edge 3a is maintained. By providing the eaves upper part 61 and the inclined plate part 62, a displacement between the second position and the third position, that is, whether the electrical bracket 7 is opened or closed, a sudden load is applied to the rotation support means. The change can be suppressed, and thus the member can be protected from damage.

[4] Embodiments Conventionally, as shown in FIG. 21A, the optical writing unit 6 is arranged in a relatively short distance in the vertical direction, so that the front plate 1 constituting the main body structure 110 is arranged. It is attached on a support plate 116 having a bridge structure that is fixed between the rear plate 2 and the rear plate 2. Specifically, in order to prevent the four color images from being tilted and superimposed, an adjusting means for adjusting the tilt of the scanning line of the light beam emitted from the optical writing unit is attached, but the illustration is omitted here. is doing.

  In the mounting structure of the optical writing unit 6 based on such a simple bridge structure, the vibration of the driving device of the polygon mirror 101 and other driving sources are transmitted to the optical writing unit 6 via the front and rear side plates, and the entire image forming unit vibrates. End up. Basic vibration modes include a vertical vibration mode shown in FIG. 21B and a torsional vibration mode shown in FIG.

  When such vibration occurs, a periodic displacement of the light beam position on the photoconductor 100 is caused, and scanning pitch unevenness in the sub-scanning direction according to the resonance frequency occurs. This is periodic density unevenness in the sub-scanning direction on the image, and is called banding.

  Banding is visually discriminated in the vicinity of a 0.5 mm pitch, but has a characteristic that vibration becomes higher in frequency and difficult to discriminate visually when the pitch on the image is narrowed. For this reason, when the resonance frequency in the above-described vibration mode is low, it is easy to visually discriminate, and the image quality may be seriously impaired.

  In this example, in order to eliminate such banding, the strength of the support structure of the optical writing unit 6 is ensured as follows.

When the electrical bracket 7 is in the first position and the image forming apparatus is in a normal use state, when the main body structure 110 is viewed with the rear side plate 2 removed, FIG. as shown in the front plate 1, bottom plate 90, rear plate 2 and the mutually fastened schematic shape seen L-shaped partition plate 13 and the like. With the vertical surface of the partition plate 13 as a fastening portion, four writing lower stays 14 are provided in a shelf shape on the left side of the vertical surface.

  The four optical writing units 6 described in FIG. 1 are fastened and fixed onto these four lower stays 14. As shown in FIG. 17, the electrical bracket 7 is located on the left side of each optical writing unit 6. By fastening the electrical equipment bracket 7 to the front side plate 1, the rear side plate 2, and the writing lower stay 14, the electrical equipment bracket 7 becomes integral with the main body structure 110, and the main body structure 110 itself can be strengthened. .

The mutual fastening relationship between these members will be specifically described with reference to FIG.
Each writing lower stay 14 is fixed to the partition plate 13 with screws 117, fixed to the front plate 1 with screws 119, and fixed to the rear plate 2 with screws 118, The bracket 7 is fixed with screws 120. Further, the electrical bracket 7 is fixed to the front side plate 1 with screws 121. As described with reference to FIG. 7A, the electrical bracket 7 is fixed to the rear plate 2 with the screw 115 at the portion of the rotation support means.

  In this way, the partition plate 13 as a reinforcing structural member is provided between the adjacent optical writing units 6 (writing devices), and the electrical bracket 7 and the constituent members of the main body structure pair 110 are fastened via the partition plate 13. As a possible structure, the main body structure 110 itself can be strengthened.

  From the positional relationship of FIGS. 1, 2, 16, etc., the optical writing unit 6 is disposed behind the opening 111 in the main body structure pair 110. In this way, the power supply unit 8 and the control board 9 can be replaced with the electrical equipment bracket 7 closed (first position), and the writing unit 6 with the electrical equipment bracket 7 opened (third position). Can be easily exchanged.

  As shown in FIGS. 19A and 19B, when the electrical bracket 7 is attached to the rear plate 2 with screws 115 and the front plate 1 with screws 121, and the power supply unit 8 and the control board 9 are relatively small. By screwing the left reference stay 3 with the screw 122, the main body structure can be firmly configured by screwing the three members.

However, as shown in FIGS. 20 (a) and 20 (b), when the power supply unit 8 and the control board 9 are relatively large and have to be arranged so as to cover the portion of the screw 122, that is, When the left reference stay 3 cannot be screwed, it is screwed to the front plate 1 and the rear plate 3 in such a positional relationship that the surface of the eaves-like portion 61 presses the left reference stay 3. In this case, the left reference stay 3 can be sufficiently pressed and fixed, and the main body structure can be firmly configured.
By the above example, vibration can be reduced and banding can be prevented.

1 is a diagram illustrating an outline of a configuration of an image forming apparatus. 2A is an exploded perspective view of the main body structure and the electrical bracket, and FIG. 2B is an exploded view of the main body structure shown in FIG. 2A from left to right. It is a schematic structure figure when it looks toward. It is a top view explaining the mode of opening and closing of an electrical equipment bracket. It is a top view of a supporting member integral with a back side board. It is a top view of the supporting member integral with an electrical equipment bracket. FIG. 6A is a cross-sectional view of the support member showing the protruding portion, and FIG. 6B is a front view of the stepped screw. FIG. 7A is a diagram illustrating the relationship between the two support members at the first position, and FIG. 7B is a diagram illustrating the relationship between the two support members at the second position. FIG. 8A is a diagram illustrating the relationship between two support members in the middle of transition from the second position to the third position, and FIG. 8B is a diagram illustrating the relationship between the two support members at the third position. FIG. It is the figure which compared and showed the locus | trajectory at the time of rotation of an electrical equipment bracket while showing the relationship of the two support members in a 1st position. FIG. 10A is a cross-sectional view of the engaging portion between the protrusion and the groove, and FIG. 10B is a cross-sectional view of the engaging portion between the stepped screw and the groove. It is the disassembled perspective view which showed the example which provided the supporting member in the upper and lower two steps | paragraphs by the relationship between a rear side board and an electrical equipment bracket. 12A is an exploded perspective view showing another example in which the supporting members are provided in two upper and lower stages in relation to the rear side plate and the electrical bracket, and FIG. 12B is an engaging portion between the bent portion and the groove. FIG. FIG. 13 (a) is a perspective view for explaining the middle of closing the electrical bracket, and FIG. 13 (b) is a perspective view in a closed state. It is sectional drawing explaining the relationship between a left reference stay and an eaves-like part. It is a figure explaining the closing process of an electrical equipment bracket. It is the perspective view explaining a part of main body structure. 1 is a diagram illustrating an outline of a configuration of an image forming apparatus. It is a figure explaining the screwing part between a writing lower stay, an electrical equipment bracket, and front and back side plates. FIG. 19A is a plan view illustrating the mounting state of the electrical component with respect to the electrical bracket, and FIG. 19B is a front view illustrating the mounting state of the electrical component with respect to the electrical bracket. FIG. 20A is a plan view illustrating the mounting state of the electrical component with respect to the electrical bracket, and FIG. 20B is a front view illustrating the mounting state of the electrical component with respect to the electrical bracket. 21A is a diagram for explaining the support state of the optical writing unit, FIG. 21B is a diagram for explaining the vertical vibration mode of the optical writing unit, and FIG. 21C is a diagram for explaining the torsional vibration mode of the optical writing unit. FIG. FIG. 6 is a perspective view illustrating a taken-out state when the photosensitive unit is replaced. FIG. 23A is a perspective view illustrating a conventional structure for supporting a rotating member, and FIG. 23B is an exploded perspective view of the support structure.

Explanation of symbols

8 Electrical brackets 23 and 25 (as rotating members) Guide grooves 26 and 46 Protrusions 21 and 24 Support members (which constitute rotating support means) 56 Bending portions 110 Main body structures (as base bodies) 111 Openings

Claims (4)

In an image forming apparatus having a plurality of photoconductors arranged in a vertical direction, and a plurality of photowriting devices arranged in the vertical direction corresponding to the plurality of photoconductors, respectively.
  Two side plates provided perpendicular to the longitudinal direction of the photoconductor in the longitudinal direction (front-rear direction) of the photoconductor, and the photoconductor and the optical writing device are positioned so as to partition and connect the two side plates. An image forming apparatus having a partition plate. The image forming apparatus according to claim 1 .
The image forming apparatus, wherein the partition plate has a length in a vertical direction across the plurality of photosensitive members . The image forming apparatus according to claim 1, wherein
The image forming apparatus, wherein the partition plate is formed with an optical path hole in a portion corresponding to an optical path of a light beam emitted from the optical writing device. The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus, wherein the partition plate and the two side plates are fixed to each other .

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