JP2022161435A - Image forming apparatus - Google Patents

Abstract

To solve the problem in which: a resin sheet may be pasted on the bottom of a housing of an optical scanner to reduce noise generated by rotation of a rotary polygon mirror; however, in assembling an image forming apparatus, as an operator inserts the housing into the image forming apparatus while causing the housing to slide on a metal opposite plate, the sheet and the opposite plate are rubbed with each other and the sheet is electrified with static electricity; during the insertion of the housing into the image forming apparatus, the operator connects a cable to a substrate provided on the housing; at that time, discharge occurs between the substrate and the cable, and an electronic component mounted on the substrate may be damaged.SOLUTION: A conductive member is provided over a housing and a sheet, and the conductive member is brought into contact with a grounded opposite plate to prevent electrification of the housing.SELECTED DRAWING: Figure 7

Description

The present invention relates to an image forming apparatus having an optical scanning device.

2. Description of the Related Art Some electrophotographic image forming apparatuses include an optical scanning device that forms an electrostatic latent image by irradiating a laser beam onto the surface of a charged photosensitive drum. An optical scanning device includes a light source, and optical system components such as a rotating polygon mirror, a mirror, and a lens that deflect a light beam emitted from the light source. The rotating polygon mirror is driven to rotate at a speed of tens of thousands of revolutions per minute by a motor. Therefore, the motor is a source of heat in the optical scanning device. If heat is trapped inside the optical scanning device, the mirrors and lenses may be thermally deformed. Further, when the housing of the optical scanning device is made of resin, the housing of the optical scanning device itself may be deformed. Therefore, an optical scanning device using a metal housing is known. By making the housing metal, the rigidity is enhanced and the heat trapped inside the optical scanning device is efficiently dissipated to the outside of the optical scanning device.

Further, in general, the optical scanning device has a configuration that can be inserted into and removed from the image forming apparatus, as described in Japanese Patent Application Laid-Open No. 2002-200012. A space is formed in the image forming apparatus to accommodate the optical scanning device, and a metal counter plate is provided at the bottom of this space so as to face the optical scanning device accommodated in the space. When assembling the optical scanning device to the image forming apparatus in a factory, a worker slides the optical scanning device on the counter plate from the side of the image forming apparatus to accommodate the optical scanning device in the image forming apparatus. .

By the way, the rotating polygon mirror accommodated in the optical scanning device rotates at a speed of tens of thousands of revolutions per minute. This rotation may cause the optical scanning device itself to vibrate. A motor for rotating the rotating polygon mirror is often provided at the bottom of the optical scanning device. Therefore, it is known that, in particular, the bottom of the optical scanning device vibrates. Due to the vibration of the bottom of the optical scanning device, the surrounding air also vibrates, which causes noise. As a countermeasure against this, a method is adopted in which a soundproof resin sheet is attached to the outside of the bottom of the optical scanning device to suppress the vibration of the surrounding air.

JP 2013-171145 A

However, when assembling the image forming apparatus, an operator slides the optical scanning device on the opposing plate to accommodate the optical scanning device in the image forming apparatus. is charged. If the housing of the optical scanning device is made of metal, the charging of the sheet induces charges to the housing side, and the housing is also charged with static electricity. A substrate on which a light source and electronic components such as an IC for driving the light source are mounted is attached to the outside of the side wall of the housing. The charge charged on the housing is also induced to the substrate, and the substrate has a predetermined potential.

Here, a cable for transmitting drive signals for the electronic components is connected to the board. The process by which an operator attaches the optical scanning device to the image forming apparatus includes (1) housing a portion of the housing of the optical scanning device in the image forming apparatus, and (2) attaching a cable to a substrate provided outside the housing. and (3) housing the entire housing in the image forming apparatus. When an operator connects a cable to the board, there is a risk that electrical discharge will occur due to the difference between the potential of the cable and the potential of the board, damaging the electronic components on the board.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the difference between the potential of the cable and the potential of the board by grounding the housing of the optical scanning device through the opposing plate, thereby reducing the risk of electrical discharge damaging electronic components on the board. is to reduce

An image forming apparatus according to the present invention includes a photoreceptor, an optical scanning device inserted from the side of the image forming apparatus to scan the photoreceptor with a light beam, and a bottom portion of a space into which the optical scanning device is inserted. and a counter plate made of metal and grounded to face the optical scanning device. a rotating polygonal mirror that is driven to rotate and deflects the light beam so that the light beam scans on the photosensitive member; a circuit board having a connector detachable with a cable for transmitting a signal for operating the light source, the electronic component, and the light source and the electronic component; A covering resin sheet and a conductive member provided across the housing and the sheet for grounding the housing by contacting the counter plate during insertion into the image forming apparatus. and.

According to the image forming apparatus of the present invention, by grounding the housing of the optical scanning device through the opposing plate, the difference between the potential of the cable and the potential of the substrate is reduced, and the electrical discharge damages the electronic parts on the substrate. It is possible to reduce the risk of

1 is a schematic configuration diagram for explaining a general configuration of an image forming apparatus; FIG. FIG. 4 is a diagram for explaining a method of inserting an optical scanning device (optical box) into an image forming apparatus; 1 is a perspective view of an optical scanning device; FIG. FIG. 4 is a diagram showing the optical scanning device accommodated in an accommodating portion; FIG. 2 is a diagram for explaining a mounting configuration of an optical scanning device to an image forming apparatus; FIG. 4 is a diagram for explaining a method of positioning an optical scanning device with respect to an image forming apparatus; FIG. 4 is a diagram for explaining the bottom portion of the optical scanning device; FIG. 4 is a diagram for explaining the positional relationship among the rear plate, flexible flat cable, and optical scanning device; FIG. 4 is a diagram for explaining a mechanism for charging an optical scanning device; FIG. 5 is a diagram for explaining that the optical box and the partition plate are electrically connected by the conductive member; FIG. 4 is a diagram for explaining the posture of the optical scanning device when the optical scanning device is attached to the image forming apparatus; FIG. 4 is a diagram for explaining the positional relationship between ribs on the bottom of the optical box and a conductive member;

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to drawings. It should be noted that the dimensions, materials, shapes, relative positions, etc. of the components described below are not intended to limit the scope of the present invention only to them, unless otherwise specified.

(Image forming device)
FIG. 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus 1 according to this embodiment. FIG. 1 shows the internal structure of the image forming apparatus 1 when the image forming apparatus 1 is viewed from the front. Assuming a direction perpendicular to the paper surface in FIG. 1 , the direction from the back side to the front side of the paper coincides with the direction from the back side to the front side of the image forming apparatus 1 . The right side of the page corresponds to the right side of the image forming apparatus 1, the left side of the page corresponds to the left side of the image forming apparatus 1, the upper side of the page corresponds to the upper side of the image forming apparatus 1, and the lower side of the page corresponds to the lower side of the image forming apparatus 1. . A user stands facing the front of the image forming apparatus 1 and operates the image forming apparatus 1 . In FIG. 1, the user stands on the front side of the page and operates the image forming apparatus 1 . At this time, the side of the image forming apparatus 1 facing the user is the front side of the image forming apparatus 1 .

As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment includes four photosensitive drums 50Y, 50Y, and 50Y corresponding to yellow (Y), magenta (M), cyan (C), and black (Bk). 50M, 50C, and 50Bk (hereinafter also collectively referred to as photosensitive drums 50). The image forming apparatus 1 is a tandem color laser beam printer including four image forming units 10Y, 10M, 10C, and 10Bk that form toner images for each color. Further, the embodiment is not limited to a color image forming apparatus having a plurality of photosensitive drums 50 as shown in FIG. 1, but may be a color image forming apparatus having one photosensitive drum 50 or an image forming apparatus that forms a monochrome image. .

The image forming apparatus 1 includes an intermediate transfer belt 20 onto which toner images formed by the image forming units 10Y, 10M, 10C, and 10Bk (hereinafter also simply referred to as image forming units 10) are transferred. The intermediate transfer belt 20 transfers the toner images transferred from the respective image forming units 10 onto the recording paper P. As shown in FIG. The image forming units 10Y, 10M, 10C, and 10Bk are configured substantially identically except that the colors of the toners used in the respective image forming units 10 are different. The image forming unit 10Y will be described below as an example of the image forming unit 10. FIG. Duplicate descriptions of the image forming units 10M, 10C, and 10Bk are omitted.

The image forming unit 10Y develops an electrostatic latent image formed on the photosensitive drum 50Y with toner by a photosensitive drum 50Y, a charging roller 12Y that uniformly charges the photosensitive drum 50Y, and an optical scanning device, which will be described later. and a developing device 13Y for forming an image. The image forming section 10Y also includes a primary transfer roller 15Y that transfers the toner image formed on the photosensitive drum 50Y to the intermediate transfer belt 20. As shown in FIG. The primary transfer roller 15Y forms a primary transfer portion between the intermediate transfer belt 20 and the photosensitive drum 50Y. The toner image formed on the photosensitive drum 50Y is transferred to the intermediate transfer belt 20 by applying a predetermined transfer voltage to the primary transfer roller 15Y.

The intermediate transfer belt 20 is an endless belt looped around a first belt conveying roller 21 and a second belt conveying roller 22, and rotates in the arrow H direction. Toner images formed by the image forming units 10Y, 10M, 10C, and 10Bk are transferred onto the rotating intermediate transfer belt 20 . Here, the four image forming units 10 are arranged in parallel below the intermediate transfer belt 20 in the vertical direction. As a result, a toner image formed on the photosensitive drum 50 is transferred to the intermediate transfer belt 20 according to the image information of each color.

The first belt conveying roller 21 and the secondary transfer roller 60 are pressed against each other with the intermediate transfer belt 20 interposed therebetween. Thereby, the first belt conveying roller 21 forms a secondary transfer portion between itself and the secondary transfer roller 60 via the intermediate transfer belt 20 . The recording paper P is passed through the secondary transfer portion, and the toner image is transferred from the intermediate transfer belt 20 . The transfer residual toner remaining on the surface of the intermediate transfer belt 20 is collected by a cleaning device (not shown).

Here, each image forming unit 10 includes, in the rotation direction (arrow H direction) of the intermediate transfer belt 20, an image forming unit 10Y that forms a yellow toner image, an image forming unit 10M that forms a magenta toner image, and a cyan toner image. An image forming section 10C for forming a toner image and an image forming section 10Bk for forming a black toner image are arranged in this order.

Further, below each image forming unit 10 in the vertical direction, there is light for scanning each photosensitive drum 50 corresponding to each color with a laser beam (light beam) to form an electrostatic latent image on the surface of each photosensitive drum 50. A scanning device is provided.

The optical scanning device referred to here includes an optical box (casing) 40 , a rotary polygon mirror 41 and a reflecting mirror 62 . The optical box 40 is a metal housing. The optical box 40 is manufactured by cutting out a metal block. Since the optical box 40 is made of metal, the heat generated by the polygon motor for rotating the rotary polygon mirror 41 can be efficiently released to the outside of the optical box 40 . Also, the optical box 40 accommodates optical members such as the rotary polygon mirror 41 and the reflecting mirror 62 . Further, the optical box 40 in the present embodiment has four semiconductor lasers (not shown) that emit laser light modulated according to image information of each color. A plurality of semiconductor lasers are light sources for exposing each of the corresponding photosensitive drums 50 . The rotating polygon mirror 41 is rotated at high speed by a polygon motor (not shown). Accordingly, each laser beam emitted from each semiconductor laser is reflected so as to scan the photosensitive drum 50 along the rotation axis direction (main scanning direction) of each photosensitive drum 50 . Each laser beam emitted from the semiconductor laser and reflected by the rotating polygon mirror 41 is guided by optical system components such as lenses arranged inside the optical box 40, and exits through each of the emission ports provided in the upper part of the optical box 40. The light is emitted from the inside of the optical box 40 to the outside through the covering transmission members 42Y, 42M, 42C, and 42Bk (hereinafter also simply referred to as transmission members 42). Laser light emitted from the optical box 40 exposes each photosensitive drum 50 .

On the other hand, the recording paper P is housed in a paper feed cassette 2 arranged at the bottom of the image forming apparatus 1 . Then, the recording paper P is fed by the pickup roller 24 to the separation nip portion formed by the feed roller 25 and the retard roller 26 . Here, the retard roller 26 is driven so as to rotate in the reverse direction when a plurality of sheets of recording paper P are fed by the pickup roller 24 . As a result, multiple feeding of the recording paper P is prevented by conveying the recording paper P one by one. The recording paper P transported one by one by the feeding roller 25 and the retard roller 26 is transported to the transport path 27 extending substantially vertically along the right side surface of the image forming apparatus 1 .

Then, the recording paper P is conveyed from the lower side to the upper side in the vertical direction of the image forming apparatus 1 through the conveying path 27 and conveyed to the registration rollers 29 . The registration rollers 29 temporarily stop the conveyed recording paper P and correct the skew of the recording paper P. As shown in FIG. After that, the registration roller 29 conveys the recording paper P to the secondary transfer portion in synchronization with the timing at which the toner image formed on the intermediate transfer belt 20 is conveyed to the secondary transfer portion. After that, the recording paper P onto which the toner image has been transferred in the secondary transfer portion is conveyed to the fixing device 3, and the toner image is fixed on the recording paper P by being heated and pressurized by the fixing device 3. FIG. Then, the recording paper P on which the toner image is fixed is discharged by the discharge roller 28 to the discharge tray 420 provided outside the image forming apparatus 1 and above the main body of the image forming apparatus 1 .

(Method of Attaching Optical Scanning Device to Image Forming Apparatus)
Next, a method for attaching the optical box 40 to the image forming apparatus 1 will be described.

2(a) and 2(b) are schematic diagrams of the image forming apparatus 1 of FIG. 1 according to the present embodiment. The image forming apparatus 1 in FIG. 2 includes a reading device 418 . Reader 418 was not shown in FIG. The reader 418 has a pressure plate 421 . A method of mounting the optical box 40 on the image forming apparatus 1 will be described below with reference to FIGS. 2(a) and 2(b).

FIG. 2A is a diagram for explaining how the optical box 40 is attached to the image forming apparatus 1. FIG. When assembling the image forming apparatus, the operator inserts the optical box 40 into the optical box accommodating portion 442 from the side of the image forming apparatus 1 . A state in which the optical box 40 is completely inserted into the optical box housing portion 442 is a state in which the optical box 40 is housed in the optical box housing portion 442 .

As shown in FIG. 2A, the image forming apparatus 1 according to the present embodiment includes an apparatus main body 100 and a pressure plate section 421 provided on the upper portion of the apparatus main body 100. As shown in FIG. A discharge tray 420 is provided on the front side (right side in FIG. 2A) of the main body 100 of the apparatus. An opening 419 is formed in the side surface 441 of the device main body 100 . The optical box 40 is inserted through the opening 419 into an optical box accommodating portion 442 that is a space formed inside the apparatus main body 100 of the image forming apparatus 1 . An opening 419 corresponding to the entrance/exit of the optical box accommodating portion 442 is closed by a cover (not shown) rotatably attached to the apparatus main body 100 . That is, the opening 419 is an opening through which the optical box 40 passes when the optical box 40 is attached to the device main body 100 .

The image forming apparatus 1 also has a paper storage section 443 which is a space for storing paper. The paper feed cassette 2 is accommodated in the paper accommodation section 443 . In other words, the paper containing portion 443 is a space for containing the paper feed cassette 2 containing paper. A partition plate 440 partitions the paper storage section 443 and the optical box storage section 442 .

The bottom of the optical box 40 faces the partition plate 440 when the optical box 40 is housed in the optical box housing portion 442 . That is, part of the bottom of the optical box 40 faces the partition plate 440 when the optical box 40 is inserted into the optical box accommodating portion 443 . The partition plate 440 is not limited to one plate, and may be composed of a plurality of plates or a plurality of members. The partition plate 440 constitutes the bottom portion of the optical box accommodating portion 442 and is a part of the frame serving as the skeleton of the apparatus main body 100, and is made of metal. When inserting the optical box 40 into the optical box accommodating portion 442 , the operator slides the optical box 40 on the partition plate 440 and pushes it. In other words, the partition plate 440 also functions as a guide when the optical box 40 is attached to the image forming apparatus 1 .

FIG. 2(b) shows a state in which the optical box 40 is positioned with respect to the apparatus main body 100. FIG. As shown in FIG. 2B, the optical box 40 is attached to the optical box accommodating portion 442 inside the apparatus main body 100 through the opening 419 from the outside of the apparatus main body 100, and is positioned with respect to the apparatus main body 100. be. Incidentally, when the optical box 40 is positioned with respect to the apparatus main body 100 , the optical box 40 is slightly lifted from the partition plate 440 . Details of this configuration will be described later.

Here, each direction of the optical box 40 is defined. Each direction of the optical box 40 is defined when the optical box 40 is attached to the device body 100 . When the optical box 40 is attached to the device main body 100, the right side of the optical box 40 corresponds to the right side of the device main body 100, and the left side of the optical box 40 corresponds to the same left side of the device main body 100. Further, the upper side of the optical box 40 corresponds to the upper side of the device main body 100 , and the lower side of the optical box 40 corresponds to the lower side of the device main body 100 . The front side of the optical box 40 corresponds to the front side of the device body 100 , and the back side of the optical box 40 corresponds to the back side of the device body 100 .

That is, as shown in FIG. 2A, the optical box 40 is inserted into the optical box accommodating portion 419 of the device main body 100 with the right side of the optical box 40 as the leading end. More specifically, first, the right side of the optical box 40 is inserted into the opening 419 (see FIG. 2) of the device main body 100 . After that, the operator pushes the optical box 40 toward the right side of the device main body 100 . At this time, the direction in which the operator pushes in the optical box 40, that is, the direction in which the optical box 40 is inserted from the left side to the right side of the apparatus main body 100 is defined as the "insertion direction". The defined "insertion direction" is as indicated by the arrow in FIG. The “insertion direction” is a direction substantially parallel to the direction perpendicular to the rotation axis of the photosensitive drum 50 and the vertical direction. However, "substantially parallel" does not mean "parallel" in a mathematically strict sense, and an inclination of several degrees is allowed.

As shown in FIG. 3, in this embodiment, the side wall 105 on the right side of the optical box 40 is formed with projections (107F and 107R). The optical box 40 is positioned with respect to the apparatus main body 100 by positioning these projections with respect to the frame of the apparatus main body 100 . The protrusion 107F is provided on the front side of the right side wall of the optical box 40, and the protrusion 107R is provided on the back side of the protrusion 107F, that is, on the back side of the right side wall of the optical box 40. FIG.

FIG. 4 is a diagram showing a state in which the optical box 40 is housed in the optical box housing portion 442. As shown in FIG. Using this figure, a support portion 200F that supports the projection 107F of the optical box 40 and a support portion 200R that supports the projection 107R will be described. As shown in FIG. 4, the support portion 200F and the support portion 200R are provided on a frame 210 fixed to the apparatus main body 100. As shown in FIG.

The device main body 100 includes a side plate 201L and a side plate 201R that form part of the frame. The side plate 201L is a metal plate provided on the left side of the apparatus main body 100. As shown in FIG. Similarly, the side plate 201R is a metal plate provided on the right side of the apparatus main body 100. As shown in FIG. A partition plate 440 connects the side plate 201L and the side plate 201R. The partition plate 440 is also made of sheet metal, and in the present embodiment, the side plate 201L, the side plate 201R, and the partition plate 440 are welded.

An opening 419 is formed in the side plate 201L, and the optical box 40 is attached to and detached from the apparatus main body 100 through the opening 419. As shown in FIG. Here, the side plate 201L and the side plate 201R may each be formed by bending a single sheet metal, or may be formed by combining a plurality of sheet metals. do not have. Since the opening 419 may be formed by combining a plurality of sheet metals, the opening 419 does not have to be a single hole in the side plate 201L, but is a portion forming the passing path of the optical box 40. If there is, it is not limited to holes.

The partition plate 440 has a function of supporting the optical box 40 from the tip side of the optical box 40 being inserted into the opening 419 in the insertion direction until the entire optical box 40 is attached to the device main body 100 . After inserting the front end side of the optical box 40 into the opening 419 , the operator slides the optical box 40 on the partition plate 440 and inserts it toward the right side of the device main body 100 . As a result, the operator can easily push the optical box 40 toward the right side of the apparatus body 100 .

FIG. 4 is a diagram for explaining a state immediately before the optical box 40 is attached to the apparatus main body 100. FIG. The optical box 40 is further pushed to the right side of the device main body from the state shown in FIG. 4, and the attachment of the optical box 40 to the device main body 100 is completed.

As shown in FIG. 4, the frame 210 is formed with openings into which the projections 107F and 107R of the optical box 40 are inserted. A support portion 200F and a support portion 200R that support the projections 107F and 107R, respectively, are formed on the lower edge of the opening. Thus, the frame 210 needs to be provided with a structure for positioning the optical box 40 . Therefore, in the manufacturing process, only the frame 210 is processed such as forming an opening, and then the frame 210 is fixed to the side plate 201R.

As the optical box 40 is inserted through the opening 419, the projection 107F rides on the supporting portion 200F and the projection 107R rides on the supporting portion 200R. Further, the frame 210 is provided with a wire spring 109F so as to overlap the opening 220F in which the support portion 200F is formed in the left-right direction. Specifically, the wire spring 109F is arranged so as to bridge over the opening 220F in which the support portion 200F is formed. More specifically, the wire spring 109R is arranged on one side of the support portion 200R and on the other side of the support portion 200R in the vertical direction perpendicular to both the vertical direction (vertical direction) and the insertion direction (horizontal direction). is erected on

In the insertion direction of the optical box 40, the wire spring 109F is positioned above the opening 220F. The projection 107F inserted into the opening 220F is supported by the support portion 200F at its lower side, and is pressed against the support portion 200F by the wire spring 109F at its upper side. is determined. The positional relationship among the protrusion 107F, the support portion 200F, and the wire spring 109F when the optical box 40 is attached to the device main body 100 will be described later in detail.

Similarly, the frame 210 is provided with a wire spring 109R so as to overlap the opening 220R in which the support portion 200R is formed in the left-right direction. Specifically, the wire spring 109R is arranged so as to bridge over the opening 220R in which the support portion 200R is formed. More specifically, the wire spring 109R is arranged on one side of the support portion 200R and on the other side of the support portion 200R in the vertical direction perpendicular to both the vertical direction (vertical direction) and the housing direction (horizontal direction). is erected on

In the insertion direction of the optical box 40, the wire spring 109R is positioned above the opening 220R. The projection 107R inserted into the opening 220R is supported by the support portion 200R at its lower side, and is pressed against the support portion 200R by the wire spring 109R at its upper side. is determined. The positional relationship among the protrusion 107R, the supporting portion 200R, and the wire spring 109R when the optical box 40 is attached to the device main body 100 will be described later in detail.

The operator screws the left side of the optical box 40 to the left side of the partition plate 440 in a state where the projection 107F of the optical box 40 is supported by the supporting portion 200F and the projection 107R of the optical box 40 is supported by the supporting portion 200R. (205F, 205R) (see FIG. 8). Specifically, when the operator inserts the optical box 40 into the optical box accommodating portion 442, the projection 107F is supported by the support portion 200F and the projection 107R is supported by the support portion 200R. In that state, the operator lifts the right side of the optical box 40. - 特許庁In this state, the optical box 40 is fixed to the partition plate 440 with the screws 205F and 205R. As an embodiment, the left side of the optical box 40 may have a structure in which the portions through which the screws 205</b>F and 205</b>R are inserted function as legs and come into contact with the partition plate 440 . A gap is formed between the partition plate 440 and the bottom of the optical box 40 when the optical box 40 is fixed to the partition plate 440 by the screws 205F and 205R. That is, the left side of the optical box 40 is supported by the screws 205F and 205R. In this way, the right side of the optical box 40 is fixed to the frame 210, and the left side of the optical box 40 is fixed to the left side of the partition plate 440 by screws 205F and 205R.

(Positioning of protrusion to frame)
FIG. 5 is an enlarged view of the periphery of the support portion 200F of the frame 210. As shown in FIG. The attachment of the optical box 40 to the apparatus main body 100 is completed by further pushing the optical box 40 further into the optical box accommodating portion 442 (to the right side of the apparatus main body 100) from the state shown in FIG. Hereinafter, with reference to FIG. 5, how the projection 107F of the optical box 40 fits into the opening 220F and is supported by the supporting portion 200F will be described. The configuration in which the projection 107R fits into the opening 220R and is supported by the support portion 200R is the same as the configuration in which the projection 107F fits into the opening 220F and is supported by the support portion 200F, so description thereof will be omitted.

A wire spring 109F is arranged on the opening 220F. One end of the wire spring 109F is fixed through a hole 109c formed in the frame 210 . The other end side of the wire spring 109F is fastened to the frame 210 by fastening portions 109a and 109b. The retaining portion 109a is a protrusion protruding from the frame 210 and supports the wire spring 109F. On the other hand, the retaining portion 109b fixes the wire spring 109F to the frame 210 so as to restrain the other end side of the wire spring 109F downward from above than the retaining portion 109a. As a result, the wire spring 109F bends downward in the vertical direction with the retaining portion 109a serving as a fulcrum at one end side and the other end side of the retaining portion 109a. That is, the wire spring 109F always presses the retaining portion 109a downward in the vertical direction.

Although details will be described later, when the optical box 40 is further pushed to the right side of the device main body 100 from the state shown in FIG. When the optical box 40 is further pushed to the right side of the device main body 100 from this state, the projection 107F moves to the right side of the device main body 100 while pushing the wire spring 109F upward in the vertical direction. At this time, the wire spring 109F is elastically deformed vertically upward. When the attachment of the optical box 40 to the apparatus main body 100 is completed, the projection 107F is pressed toward the support portion 200F by the restoring force of the elastically deformed wire spring 109 . Thus, the projection 107F is positioned with respect to the frame 210. FIG.

FIG. 6 shows how the optical box 40 is attached to the apparatus main body 100 with the protrusion 107F riding on the supporting portion 200F. A state in which the protrusion 107F rides on the support portion 200F and bends the wire spring 109F will be described below with reference to FIG.

As shown in FIG. 6(a), a part of the frame 210 is bent 90 degrees to the right (the part corresponding to the "fold" is indicated by reference character C). A state in which the first inclined portion 107a (first region) of the projection 107F rides on the support portion 200F means a state in which the first inclined portion 107a is in contact with the fold line C. As shown in FIG. Since the frame 210 is bent so as to smooth the crease, even if the optical box 40 moves in the insertion direction while the first inclined portion 107a is on the support portion 200F, the first inclined portion 107a smoothly rides on the supporting portion 200F and moves. The "insertion direction" referred to here is a direction that coincides with the "moving direction of the protrusion 107F" shown in FIG.

FIG. 6A shows a state in which the tip of the optical box 40 is inserted into the opening 419 and the bottom surface of the optical box 40 is moving to the right side of the device body 100 while contacting the partition plate 440. FIG. At this time, the projection 107F and the support portion 200F are out of contact. Here, the projection 107F includes a first inclined portion 107a (first area), a second inclined portion 107b (second area), a first flat portion 107c (third area), and a second flat portion 107d (second area). 4 regions) and As shown in FIG. 6A, the projection 107F is formed with a first inclined portion 107a and a second inclined portion 107b, and the distal end side of the projection 107F is tapered. The first inclined portion 107a is inclined upward in the insertion direction of the optical box 40, ie, the direction from the left side to the right side of the device main body 100. As shown in FIG. In addition, the second inclined portion 107b is inclined downward in the housing direction of the optical box 40, that is, in the direction from the left side to the right side of the device main body 100. As shown in FIG. Thus, the first inclined portion 107a and the second inclined portion 107b are inclined toward the downstream side in the insertion direction so as to approach each other. Specifically, a first inclined portion 107a and a second inclined portion 107b are formed so that the right end of the protrusion 107F is sharp. In this embodiment, the angle between the first inclined portion 107a and the insertion direction is 28°, and the angle between the second inclined portion 107b and the insertion direction is 10°.

Also, the height of the first inclined portion 107a in the vertical direction and the height of the second inclined portion 107b in the vertical direction need to be adjusted by the spring coefficient of the wire spring 109F. For example, the larger the spring coefficient of the wire spring 109F, the larger the restoring force can be obtained with a small amount of deformation, so the amount of elastic deformation of the wire spring 109F may be small. However, the smaller the deformation of the spring, the greater the influence of its tolerances. Therefore, in order to obtain an arbitrary restoring force resulting from the elastic deformation of the spring, it is common to largely deform a spring having a small spring coefficient to obtain a predetermined restoring force. Therefore, in this embodiment, the second inclined portion 107b is provided at the tip of the projection 107F.

The first flat portion 107c is provided upstream of the first inclined portion 107a in the direction in which the optical box 40 is inserted into the opening 419 . Also, the first flat portion 107c is formed on a portion of the protrusion 107F so that the inclination angle with respect to the insertion direction is smaller than that of the first inclined portion 107a. In this embodiment, the first plane portion 107c is a plane parallel to the insertion direction.

The second flat portion 107d is provided upstream of the second inclined portion 107b in the insertion direction of the optical box 40 into the opening 419 and vertically above the first flat portion 107c. In addition, the second flat portion 107d is formed on a part of the protrusion 107F so that the angle of inclination with respect to the insertion direction is smaller than that of the second inclined portion 107b. In this embodiment, the second plane portion 107d is a plane parallel to the insertion direction.

FIG. 6(b) shows a state in which the optical box 40 is further inserted toward the right side of the apparatus main body 100 from the state shown in FIG. 6(a). As the optical box 40 moves toward the right side of the apparatus main body 100, the first inclined portion 107a abuts against the support portion 200F at position C, as shown in FIG. 6(b). Here, as described above, the first inclined portion 107a is inclined upward in the vertical direction from the left side to the right side. Therefore, when the optical box 40 is further inserted while the first inclined portion 107a and the support portion 200F are in contact with each other, the first inclined portion 107a climbs over the support portion 200F, and the optical box 40 moves upward as shown in FIG. 6B. Move in the direction of the arrow in . Since the first inclined portion 107a also functions as a taper, the operator can easily place the projection 107F on the support portion 200F. At this time, the second inclined portion 107b and the wire spring 109F are out of contact. Further, the optical box 40 is pushed in, and the first inclined portion 107a rides on the supporting portion 200F, so that the second inclined portion 107b abuts against the wire spring 109F.

FIG. 6(c) shows a state in which the second inclined portion 107b and the wire spring 109F are in contact with each other. When the protrusion 107F moves in the direction of the arrow in FIG. 6C from this state, the second inclined portion 107b elastically deforms the wire spring 109F further upward in the vertical direction. As the projection 107F moves in the direction of the arrow in FIG. 6C while the first inclined portion 107a rides on the support portion 200F, the wire spring 109F is pushed upward in the vertical direction and elastically deformed. At the same time, the second inclined portion 107b receives the restoring force of the elastically deformed wire spring 109F, and the protrusion 107F is pressed toward the support portion 200F. At this time, the operator presses the optical box 40 in the insertion direction against the force of the wire spring 109F pressing the projection 107F downward in the vertical direction and the gravity of the optical box 40. . Compared to the case where the second inclined portion 107b is not provided, the amount of deformation of the wire spring 109F when the first inclined portion 107a rides on the support portion 200F is greater in the case where the second inclined portion 107b is provided. is small. That is, compared to the case where the second inclined portion 107b is not provided, the optical box 40 is more stable when the first inclined portion 107a rides on the support portion 200F when the second inclined portion 107b is provided. On the other hand, the load felt by the operator can be small.

FIG. 6(d) shows a state in which the optical box 40 is further pushed toward the right side of the device main body 100 from the state shown in FIG. 6(c). The projection 107F elastically deforms the wire spring 109F further vertically upward against the restoring force of the elastically deformed wire spring 109F. At this time, the first plane portion 107c is on the support portion 200F. That is, when the optical box 40 moves in the insertion direction while the second inclined portion 107b is in contact with the wire spring 109F, the rear end of the first inclined portion 107a rides on the support portion 200F, and then the first flat portion 107c contacts the support portion 200F. Thus, in the state shown in FIG. 6D, the second inclined portion 107b is pressed toward the support portion 200F by the wire spring 109F elastically deformed upward in the vertical direction, and the first flat portion 107c is pushed toward the support portion 200F. Supported by

FIG. 6(e) is a diagram showing a state in which the optical box 40 is further pushed toward the right side of the device main body 100 from the state shown in FIG. 6(d). When the first flat portion 107c and the support portion 200F are in contact with each other, the portion of the protrusion 107F that contacts the wire spring 109F changes from the second inclined portion 107b to the second flat portion 107d. At this time, the second plane portion 107d is pressed toward the support portion 200F by the wire spring 109F elastically deformed upward in the vertical direction, and the first plane portion 107c is supported by the support portion 200F. The protrusion 107F is pressed toward the support portion 200F by the restoring force of the elastically deformed wire spring 109F, and the optical box 40 is positioned with respect to the frame 210. FIG. The optical box 40 and the frame 210 are fixed with screws (not shown) while a part of the optical box 40 abuts against a part of the frame 210 .

(Structure of Bottom of Optical Scanning Device)
A rotating polygonal mirror 41 housed in the optical box 40 rotates at high speed. In recent years, image forming apparatuses are required to have a higher printing speed, and it is not uncommon for a rotary polygonal mirror to rotate 40,000 to 50,000 times per minute. When the rotating polygon mirror is rotated at high speed, the optical box 40 itself slightly vibrates due to the rotation. It is known that when the polygon motor for rotating the rotating polygon mirror 41 is provided at the bottom of the optical box 40 as in this embodiment, the vibration at the bottom of the optical box 40 is particularly large. Due to the vibration of the bottom of the optical box 40, the surrounding air also vibrates, resulting in noise. Therefore, there is a method of attaching a sheet so as to cover the bottom of the optical box 40 as a countermeasure.

FIG. 7 is a diagram for explaining the structure of the bottom of the optical box 40. As shown in FIG. FIG. 7A is a schematic diagram of the sheet 102 attached to the bottom of the optical box 40. FIG. FIG. 7B is a perspective view from the bottom side of the optical box 40 to which the sheet 102 is attached. FIG. 7C is a diagram for explaining the configuration of the optical box 40. As shown in FIG.

First, the sheet 102 shown in FIG. 7A will be described. The raw material of the sheet 102 attached to the bottom of the optical box 40 is mainly polyethylene terephthalate. That is, the sheet 102 is made of resin. One side of the sheet 102 is sticky and acts like a seal. The shape of the edge of the sheet 102 generally follows the shape of the edge of the bottom of the optical box 40 . The bottom of the optical box 40 is uneven to increase its rigidity. Specifically, some areas inside the bottom of the optical box 40 are recessed. Therefore, when the sheet 102 is attached to the bottom of the optical box 40 , the entire surface of the sheet 102 is not evenly attached to the bottom of the optical box 40 . Since the shape of the edge of the sheet 102 roughly follows the shape of the edge of the bottom of the optical box 40 , the edge of the sheet 102 sticks to the edge of the bottom of the optical box 40 . Since the shape of the bottom of the optics box 40 has a recess, some of the inner region of the sheet 102 is spaced from the bottom of the optics box 40 .

FIG. 7(b) shows the optical box 40 to which the sheet 102 is attached. By attaching the resin sheet 102 so as to cover the outside of the bottom of the optical box 40 as in the present embodiment, noise caused by the vibration of the bottom of the optical box 40 can be suppressed. As shown in FIG. 7(b), the sheet 102 does not completely cover the bottom of the optical box 40. As shown in FIG. As shown in this figure, notches are formed in the four corners of the sheet 102 , and when the sheet 102 is attached to the bottom of the optical box 40 , the four corners of the bottom of the optical box 40 are aligned with the four corners of the sheet 102 . exposed from In other words, the term "cover" used here does not only mean a configuration in which the bottom of the optical box 40 is completely hidden from view, but may be a configuration in which a part of the optical box 40 is provided with an opening. A part of the bottom of the optical box 40 may be exposed from the sheet 102 when the bottom of the optical box 40 is viewed. However, from the viewpoint of suppressing noise, it is preferable to use the sheet 102 that covers 90% or more of the area of the bottom of the optical box 40 . As described above, since the sheet 102 is partially formed with an opening, when the sheet 102 is attached to the bottom of the optical box 40, the air trapped by the sheet 102 can be released. . From the viewpoint of facilitating the assembly work, it is preferable to form an opening in a part of the sheet 102 .

As shown in FIGS. 7(b) and 7(c), the optical box 40 has substrates 104a and 104b on the outside of the rear sidewall (the substrates 104a and 104b are collectively referred to as the substrate 104. The substrate 104 is an example of a circuit board). Substrate 104a includes light source 51a and light source 51b. Light emitted from each light source is deflected by a rotating polygon mirror 41 so as to scan the photosensitive member. Similarly, substrate 104b includes light source 51c and light source 51d. Light emitted from each light source is deflected by a rotating polygon mirror 41 so as to scan the photosensitive member. An IC 52 for driving each light source is provided on the substrate 104a and the substrate 104b. IC52 is an example of an electronic component. In addition to ICs, various electronic components such as capacitors and coils are mounted on the substrate. In addition, in this embodiment mode, it is divided into two substrates, but it may be constituted by one substrate. In other words, one substrate 104 may have four light sources.

(Regarding static electricity generated when the optical scanning device is attached to the image forming apparatus)
As described above, since the sheet 102 is made of a resin containing polyethylene terephthalate as a main component, when the optical box 40 is slid on the partition plate 440, the sheet 102 and the partition plate 440 rub against each other. 102 is charged with static electricity. A substrate 104 is attached to the outside of the side wall of the optical box 40, and the optical box 40 and the substrate 104 are electrically connected. In the optical scanning device of this embodiment, the substrate 104 is screwed to the optical box 40 . A wiring pattern called a ground wire is formed on the portion where the screw is fastened to ground the substrate. In other words, the substrate 104 has the same potential as the optical box 40 through the screws.

Electronic components such as the light sources 51 a to 51 d and the IC 52 are driven based on signals transmitted via a flexible flat cable 54 extending from the control board of the apparatus body 100 . Therefore, the operator connects the flexible flat cable 54 to the connector 501 of the board 104a during the assembly work of the image forming apparatus 1. FIG. A connector 501 is a component mounted on a substrate 42 provided in the optical box 40, and a flexible flat cable 54 can be detachably attached thereto. The cable for transmitting signals is not limited to the flexible flat cable 54, and any type of cable such as a coaxial cable can be used as long as it can transmit signals. However, the flexible flat cable 54 is very thin, can be easily processed such as bending, and is excellent in handleability. The work of connecting the flexible flat cable 501 to the connector 501 must be performed in a space-limited place, and ease of work for workers is important. In terms of cable cost, flexible flat cables are often cheaper than coaxial cables and the like. In consideration of these issues comprehensively, the image forming apparatus 1 of the present embodiment employs a flexible flat cable as a cable for transmitting signals to the optical scanning device.

FIG. 8 is a view of the optical box 40 as viewed through the opening 419 of the optical box accommodating portion 442. FIG. As shown in FIG. 8, the flexible flat cable 54 is connected to a connector 501 on the substrate 104a attached to the optical box 40. As shown in FIG. As shown in FIG. 8, the optical box 40 and the rear plate 53 are very close to each other. Therefore, it is difficult to connect the flexible flat cable 54 to the connector 501 when the optical box 40 is completely accommodated in the optical box accommodating portion 442 . Therefore, the connection work between the flexible flat cable 54 and the connector 501 is performed with the connector 501 exposed to the outside of the opening 419 of the optical box accommodating portion 442 . The specific work procedure is as follows.

First, the operator inserts the optical box 40 into the optical box accommodating portion 442 . The insertion operation is temporarily stopped before the connector 501 provided in the optical box 40 is positioned inside the opening 419 . In other words, the connector 501 is exposed from the optical box accommodating portion 442 . The operator connects the flexible flat cable 54 extending from the apparatus body 100 to the connector 501 in this state. After that, the optical box 40 is pushed into the optical box accommodating portion 442 again until the positioning described above is achieved.

Since the flexible flat cable 54 is connected to the connector 501 while the optical box 40 is being inserted into the optical box accommodating portion 442, the flexible flat cable 54 may not be connected to the connector 501 if the substrate 104a is charged with static electricity. When they are brought close to each other, an electric discharge may occur between the two, which may damage the electronic components mounted on the board.

Here, the mechanism by which discharge occurs between the flexible flat cable 54 and the connector 501 will be briefly described with reference to FIG.

FIG. 9(a) is a schematic diagram showing the state of electric charges that the optical box 40, the sheet 102, and the partition plate 440 are charged before the optical box 40 is housed in the optical box housing portion 442. FIG. At this time, since the optical box 40, the sheet 102, and the partition plate 440 are all in an electrically neutral state, they have the same number of positive charges and negative charges. It should be noted that FIG. 9 is only for simply explaining the discharge mechanism. Therefore, for example, when the number of charges is said to be equal, it does not mean that they are equal in a strict mathematical sense.

FIG. 9B shows how the optical box 40 is being inserted into the optical box accommodating portion 442 . Friction between diaphragm 440 and sheet 102 causes negative charge to move from diaphragm 440 to sheet 102 . Such movement of charge due to friction between two types of members is generally called triboelectrification. Whether triboelectrification transfers negative charge from one of the two members to the other depends on the electrical properties of each member. When the negative charge moves from the partition plate 440 to the sheet 102, the partition plate 440 is temporarily in a state of having many positive charges, and the other sheet 102 is in a state of having many negative charges. However, since the partition plate 440 is grounded in this embodiment, the partition plate 440 immediately becomes electrically neutral (FIG. 9(c)).

Further, since the sheet 102 is in a state of having many negative charges, the optical box 40 to which the sheet 102 is attached and which is integrated with the sheet 102 is induction-charged. Inductive charging is a phenomenon in which when a charged substance comes close to a conductor, the conductor, which was originally in an electrically neutral state, is also charged. Due to this induction charging, positive charges gather in the vicinity of the sheet 102 in the optical box 40, and negative charges gather in a portion away from the sheet 102 (FIGS. 9B and 9C).

When the flexible flat cable 54, which is electrically independent of the optical box 40, approaches while the optical box 40 is inductively charged, an electric repulsive force from the sheet 102, which has a large amount of negative charges, is generated. As a result, negative charges move from the optical box 40 to the flexible flat cable 54 via the substrate 104a. The greater the potential difference between the side of the optical box 40 or the substrate 104a and the side of the flexible flat cable 54, the greater the amount of negative charge that moves. That is, the amount of discharge increases. As a result, electronic components such as the IC 52 provided on the substrate 104a and the substrate 104b may be damaged.

(Optical scanning device with antistatic measures)
Refer to FIG. 7(b) again. As shown in FIG. 7(b), a conductive member is attached to a part of the sheet 102 attached to the bottom of the optical box 40 from one end side of the side wall 105 on the tip side of the optical box 40 in the insertion direction. 500 are provided. In other words, the conductive member 500 electrically connects the optical box 40 and the sheet 102 . It should be noted that the conductive member 500 in this embodiment is an aluminum tape. If it is an aluminum tape, it is easy to handle, and the operator can easily achieve a configuration that ensures conduction from the side wall 105 of the optical box 40 to the outside of the sheet 102 .

FIG. 10A is a view of the process of attaching the optical box 40 to the apparatus main body 100 as seen from the rear side of the image forming apparatus 1. FIG. 10(b) is a diagram showing a state in which the optical box 40 is placed on the partition plate 440, that is, a state in which the optical box 40 is being inserted into the optical box accommodating portion 442. FIG. In the state shown in FIG. 10B, the connector 501 is exposed to the outside from the optical box accommodating portion 442. As shown in FIG. The operator connects the flexible flat cable 54 to the connector 501 in this state.

When pushing the optical box 40 , the conductive member 500 is sandwiched between the sheet 102 and the partition plate 440 . In other words, while the optical box 40 is placed on the partition plate 440 and the operator pushes the optical box 40 , the optical box 40 and the partition plate 440 are electrically connected. Since the partition plate 440 is grounded (earthed), the optical box 40 is also grounded via the conductive member 500 and the partition plate 440 . As a result, the optical box 40 is grounded as long as the conductive member 500 and the partition plate 440 are in contact with each other. That is, even if the flexible flat cable 54 is brought closer to the connector 501 in this state, the potential difference between the flexible flat cable 54 and the substrate 104a or the optical box 40 is almost zero, so the possibility of discharge is extremely low.

FIG. 11A shows a situation in which an operator actually inserts the optical box 40 into the optical box housing portion 442, and shows a state in which only the rear side of the optical box 40 is in contact with the partition plate 440. FIG. . The front side (right side in the drawing) of the optical box 40 is being lifted by the operator. As described above, in actual work, it is rare that the bottom of the optical box 40 is kept parallel to the partition plate 440 when the optical box 40 is inserted into the optical box accommodating portion 442 through the opening 419 .

In this embodiment, since a portion of the conductive member 500 is positioned on the front end side of the optical box 40, the conductive member 500 and the partition plate 440 may contact each other when the optical box 40 is inserted into the optical box housing portion 442. can enhance sexuality. Since the conductive member 500 extends from the side wall 105 to the front side of the optical box 40 , when the operator inserts the optical box 40 into the optical box housing portion 442 , the conductive member 500 and the partition plate 440 are separated from each other. A contact state can be maintained. That is, the optical box 40 can be grounded until the flexible flat cable 54 is connected to the connector 501 while the optical box 40 is being inserted into the optical box accommodating portion 442 . For example, if the conductive member 500 is provided only on the front end side of the optical box 40 in the insertion direction (the right side of the optical box 40), depending on how the operator handles the optical box 40, the conductive member 500 and the partition The possibility of separation from the plate 440 cannot be ignored. Specifically, when the operator applies a load to the left side of the optical box 40 while the optical box 40 is positioned on the partition plate 440, the tip side of the optical box 40 is lifted from the partition plate 440, The optical box 40 cannot be grounded.

Thus, one end side of the conductive member 500 is provided on the side wall 105 on the tip side of the optical box 40 . On the other hand, the other end side of the conductive member 500 is provided at the bottom of the optical box 40 corresponding to the position of the connector 501 . Specifically, the other end side of the conductive member 500 is provided at a position where a virtual plane (virtual plane S in FIG. 11A) perpendicular to the insertion direction of the optical box 40 passing through the connector 501 and the sheet 102 overlap. there is As shown in FIG. 11A, when the optical box 40 sliding on the partition plate 440 is viewed from the front side of the image forming apparatus 1, the conductive member 500 is optically distributed up to the point where the dotted line S and the sheet 102 overlap. It extends from the tip side of the box 40 .

FIG. 11B is a diagram for explaining a state in which the operator applies a load to the front side of the optical box 40 while the optical box 40 is being inserted into the optical box accommodating portion 442 . For example, when an operator inserts the optical box 40 into the optical box housing portion 442, the work may proceed with a load applied to the upstream side of the optical box 40 (left side of the optical box 40) in the insertion direction. In other words, the optical box 40 may be inserted into the optical box accommodating portion 442 with the downstream side of the optical box 40 in the insertion direction floating from the partition plate 440 . Further, for example, although there is work to connect the flexible flat cable 54 to the connector 501, the optical box 40 may be inserted into the optical box accommodating portion 442 until the connector 501 is hidden in the optical box accommodating portion 442. be.

In such a case, the operator needs to pull out the optical box 40 again from the optical box accommodating portion 442 until the connector 501 is exposed from the optical box accommodating portion 442 . At that time, a load is applied to the front side of the optical box 40, and the optical box 40 may tilt as shown in FIG. 11(b). Even if the flexible flat cable 54 were to be connected to the connector 501 in this state, since the conductive member 500 is in contact with the partition plate 440, the possibility of discharge occurring is extremely low.

Both the work of mounting the optical box 40 to the apparatus main body 100 and the work of connecting the flexible flat cable 54 to the connector 501 are performed manually by the operator. Therefore, it is necessary to reduce as much as possible the possibility that the conductive member 500 and the partition plate 440 are not electrically connected due to the attitude of the optical box 40 .

FIG. 12 is a diagram for explaining a more effective position as a position where the conductive member 500 is attached. FIG. 12(a) is a view showing one end side of the bottom portion of the optical box 40. FIG. A sheet 102 is attached in this figure. 12(b) shows the bottom of the optical box 40 with the sheet 102 not shown. Inside the optical box 40, a large number of parts such as a rotating polygon mirror 41, mirrors and lenses are accommodated. These parts are restricted in their positions due to the relationship with the optical path of the laser beam emitted from the light source. Therefore, the shape of the optical box 40 is inevitably complicated.

Further, in order to prevent deformation of the optical box 40 due to vibration caused by driving the motor for rotating the rotating polygon mirror 41 and the weight of the optical box 40 itself, the optical box 40 should have the highest possible height. Rigidity is required. Therefore, the rigidity of the optical box 40 is increased by forming the above-described rib 503 or the like on the bottom of the optical box 40 or the like.

For the reasons described above, the bottom of the optical box 40 is not flat but has an uneven shape.

FIG. 11(c) is a cross section of the optical box 40 taken along a plane passing through the ribs 503. FIG. As shown in FIG. 11C, it is attached to the sheet 102 so as to overlap the ribs 503 with the sheet 102 interposed therebetween. As a result, when the optical box 40 is slid on the partition plate 440 , the portion where the conductive member 500 is attached is sandwiched between the rib 503 and the partition plate 440 . Then, since the conductive member 500 is pressed against the partition plate 440 by the rib 503, the conduction between the conductive member 500 and the partition plate 440 can be ensured. In general, strong contact between conductors tends to reduce the contact resistance between them. This is because the conductive member 500 is crushed and the contact area increases. Therefore, by providing the conductive member 500 at a position overlapping the rib 503, the optical box 40 can be grounded more reliably.

As described above, the optical box 40 can be grounded via the conductive member 500 and the partition plate 440 by providing the conductive member 500 from the outside of the resin sheet 102 to the side wall of the optical box 40 . As a result, even when the flexible flat cable 54 is connected to the connector 501 while the optical box 40 is being accommodated in the optical box accommodating portion 442, the risk of electric discharge occurring between the flexible flat cable 54 and the substrate 104 can be reduced. . As a result, it is possible to reduce the risk of damage to electronic components such as a driver IC provided on the substrate 104 .

Reference Signs List 1 image forming apparatus 40 optical box 41 rotating polygon mirror 100 apparatus body 102 sheet 104 substrate 419 opening 440 partition plate (opposing plate)
442 optical box housing portion 500 conductive member 501 connector 503 rib

Claims (5)

a photoreceptor;
an optical scanning device that is inserted from the side of the image forming apparatus and scans the photoreceptor with a light beam;
a counter plate that forms the bottom of the space into which the optical scanning device is inserted, is made of metal and is grounded, and faces the optical scanning device;
The optical scanning device is
a light source that emits the light beam;
an electronic component that drives the light source;
a rotating polygonal mirror that is rotationally driven by a motor and deflects the light beam so that the light beam scans the photoreceptor;
A housing of the optical scanning device, which is provided outside a side wall of the housing made of metal, and detachably attaches a cable for transmitting the light source, the electronic component, and a signal for operating the light source and the electronic component. a circuit board having a connectable connector;
A resin sheet provided at the bottom of the housing to cover the bottom;
a conductive member provided across the housing and the sheet for grounding the housing by contacting the opposing plate during insertion into the image forming apparatus;
An image forming apparatus characterized by: 2. The image forming apparatus according to claim 1, wherein the conductive member is provided from the front end side to the rear end side of the housing in the insertion direction. 3. The image forming apparatus according to claim 2, wherein said conductive member is provided from said front end side of said housing to a position of said bottom portion corresponding to a position of said connector in said insertion direction. 4. The image forming apparatus according to claim 1, wherein said conductive member is an aluminum tape. A rib is formed on the bottom portion so as to protrude from the bottom portion and extend in the insertion direction, and the conductive member is provided at a position overlapping the rib when the conductive member is viewed along the rotation axis direction of the rotary polygon mirror. 5. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus comprises:

Images