JP7292959B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that exposes a photosensitive drum with an optical print head, which is provided in an electrophotographic image forming apparatus such as a digital copying machine and a facsimile machine.

2. Description of the Related Art Among electrophotographic image forming apparatuses such as laser beam printers and digital copiers, there is an image forming apparatus that uses an LED exposure head as means for exposing a photosensitive member. The LED exposure head is an exposure device that aligns a predetermined number of LEDs in a substantially straight line and collectively exposes the surface of the photosensitive member corresponding to the image width. Compared to a laser scanner unit that exposes the surface of a photoreceptor using a rotating polygon mirror, the LED exposure head requires a smaller housing volume and does not require a driving unit to drive the rotating polygon mirror. This is advantageous in terms of miniaturization and noise reduction of the forming apparatus.

An image forming apparatus equipped with an LED exposure head has a configuration in which a control signal is transmitted from a control section of the image forming apparatus to the LED exposure head via a flexible flat cable in order to operate the LED exposure head. For example, Japanese Patent Application Laid-Open No. 2002-200002 describes a work method for removing an LED exposure head to which a flexible flat cable is connected from an image forming apparatus. In the work method described in Patent Document 1, the operator first pulls out the LED exposure head slightly from the image forming apparatus to the front side of the apparatus. Then, the operator moves to the side of the image forming apparatus, accesses the inside of the apparatus from the side, and removes the flexible flat cable connected to the control unit from the LED exposure head. The operator moves to the front side of the image forming apparatus again and pulls out the LED exposure head to the front side of the image forming apparatus. Thus, the operator can remove the LED exposure head from the image forming apparatus.

However, the conventional configuration requires the following procedures when exchanging the flexible flat cable in the market, for example. That is, the operator needs to access the inside of the image forming apparatus from the lateral direction, remove the flexible flat cable from the LED exposure head, and then pull out the flexible flat cable to the outside of the image forming apparatus. Such a procedure complicates the work. In order to facilitate the work of removing the flexible flat cable, it is preferable to remove the flexible flat cable after the entire LED exposure head is taken out of the image forming apparatus. Therefore, for example, in Patent Document 2, a guide member for accommodating the flexible flat cable is provided to integrate the LED exposure head and the flexible flat cable.

JP 2015-205497 A JP 2017-151413 A

However, since the control board of the control unit is provided behind the rear plate of the image forming apparatus, it is difficult to make the entire area of the flexible flat cable run along the guide member as in the conventional example. Therefore, when the LED exposure head is taken out of the image forming apparatus, the flexible flat cable may rub against the frame of the image forming apparatus or the like, which also complicates the work and lowers the workability.

SUMMARY OF THE INVENTION It is an object of the present invention to improve workability when replacing a flexible flat cable connected to an optical print head.

In order to solve the above problems, the present invention has the following configurations.

(1) An image forming apparatus for forming an image on a recording material, comprising: a plurality of rotating photoreceptors ; a print head, comprising: a plurality of optical print heads for exposing a different one of the plurality of photoreceptors to light emitted from the plurality of light emitting units; and supplying toner to a different one of the plurality of photoreceptors . a plurality of developing units for forming toner images corresponding to the latent images, a transfer unit for transferring the toner images onto the recording material, and a fixing unit for heat-fixing the transferred toner images onto the recording material. a different one of the plurality of photoreceptors, a different one of the plurality of optical print heads, and a different one of the plurality of developing units ; a control unit for outputting a control signal for controlling lighting and extinguishing of the optical print head; and one of the plurality of support portions that is farthest from the fixing portion in an arrangement direction in which the plurality of photoreceptors are arranged. a relay board provided in the controller, connected to the control unit via a first cable, and connected to each of the plurality of optical print heads via a different one of a plurality of second cables; and a relay board for transmitting the control signal output by the control unit to the plurality of optical print heads .

The present invention can improve workability when replacing a flexible flat cable connected to an optical print head.

FIG. 1 is a diagram showing the entire image forming apparatus of Embodiments 1 and 2; FIG. 2 is a sectional view showing the configuration of the image forming apparatus of Examples 1 and 2; The perspective view which shows the front side board of Example 1, 2, and a rear side board. FIG. 2 is a perspective view showing optical print heads of Examples 1 and 2; FIG. 2 is a diagram showing the configuration of the optical print head of Examples 1 and 2; 4 is a perspective view showing the exposure unit, FFC, and tray of Examples 1 and 2; FIG. Sectional views showing exposure units, FFCs, and trays of Examples 1 and 2. FIG. 2 is a bottom view showing the arrangement of trays, FFCs, and relay boards in Example 1; 1 is an exploded perspective view showing the configuration of a tray, a tray connecting member, an FFC rail, and a relay board unit of Embodiment 1, and a perspective view showing an exposure unit group 200; FIG. 2 is a perspective view showing the left rear of the image forming apparatus according to the first embodiment; FIG. 4 is a perspective view showing an assembled state of the tray and the relay board of the first embodiment; The bottom perspective view of the tray of Example 1, the perspective view of a relay board holding member FIG. 2 is an exploded perspective view showing the configuration of the relay board unit of the first embodiment; FIG. 4 is a diagram showing a method of fixing the tray and the tray connecting member according to the first embodiment; FIG. 2 is an exploded perspective view showing the tray and FFC rails of Embodiment 1; 4 is a perspective view showing the vicinity of the exposure unit when the left side cover of Embodiment 1 is open; FIG. FIG. 4 is a diagram showing a state in which the drum unit and developing unit of Embodiment 1 are removed; FIG. 2 is a perspective view showing the structure of the cartridge cover according to the first embodiment; FIG. 4 is a perspective view showing a state in which the exposure unit group of Embodiment 1 is pulled out to the front side of the image forming apparatus; A perspective view showing a hole 6421 of Example 2. A perspective view showing a hole 6421 of Example 2.

Preferred embodiments for carrying out the present invention will be described below with reference to the accompanying drawings. However, the components described in this description are merely examples, and the present invention is not limited to the embodiments described in this description.

[Appearance of image forming apparatus]
FIG. 1 is a perspective view showing the entire electrophotographic image forming apparatus 1 of the first embodiment. An image forming apparatus 1 shown in FIG. 1 is a multifunction machine (MFP: Multi Function Printer) having a reading device for reading a document. A front cover 6 that can be opened and closed is provided on the front side (predetermined side) of the main body of the image forming apparatus 1 . The front cover 6, which is the first door portion, is a cover for opening the front side of the image forming apparatus 1 when a later-described tray (702) is pulled out of the image forming apparatus 1. FIG. When performing maintenance work such as cartridge replacement, a worker such as a user or a serviceman opens the front cover 6 to perform the work.

Note that "front", "back", "up", "down", "right", and "left" of the double-headed arrows shown in FIG. 1 refer to the image forming apparatus 1 shown in FIG. direction. The "front" refers to the side of the image forming apparatus 1 on which the front cover 6 is mounted, and may also be referred to as the front. "Rear" refers to the back side opposite to the front cover 6 of the image forming apparatus 1 and may also be referred to as the back side. Also, “top” refers to the upper side of the image forming apparatus 1 , and “bottom” refers to the lower side of the image forming apparatus 1 . Furthermore, "right" indicates the right side when the image forming apparatus 1 is viewed from the front cover 6 side, and "left" indicates the left side when the image forming apparatus 1 is viewed from the front cover 6 side.

[Configuration of Image Forming Apparatus]
Next, a schematic configuration of the image forming apparatus 1 will be described. FIG. 2 is a schematic cross-sectional view showing the configuration of the image forming apparatus 1 shown in FIG. 1, showing the configuration when the image forming apparatus 1 is viewed from the front cover 6 side. Note that the image forming apparatus 1 to which the first embodiment is applied is a multi-function machine equipped with a reading device, but may be a printer without a reading device. In addition, the image forming apparatus 1 is not limited to a so-called tandem type color image forming apparatus having a plurality of photosensitive drums as shown in FIG. It may be a forming device.

As shown in FIG. 2, the image forming apparatus 1 includes four image forming units 102Y, 102M, 102C, and 102K that form yellow (Y), magenta (M), cyan (C), and black (K) toner images. (a plurality of image forming units). Each of the image forming units 102Y, 102M, 102C, and 102K has the same configuration, and hereinafter, unless a specific image forming unit or a member constituting a specific image forming unit is indicated, the toner color Descriptions of Y, M, C, and K at the end of the symbols indicating are omitted. Note that the image forming unit 102 may also be called a station. The image forming unit 102 includes a photosensitive drum 103 and a charger 104 that charges the photosensitive drum 103 . Each image forming section 102 also includes an exposure unit 500 that uses an LED as an exposure light source for emitting light for exposing the photosensitive drum 103 . As shown in FIG. 2, the exposure unit 500 is a so-called "lower surface exposure type" exposure unit that exposes the photosensitive drum 103 from below. An electrostatic latent image (latent image) is formed on the photosensitive drum 103 by being exposed by the exposure unit 500 . The image forming unit 102 also includes a developing device 106 that develops the electrostatic latent image formed on the photosensitive drum 103 by attaching toner to form a toner image of each color on the photosensitive drum 103 .

The image forming apparatus 1 includes an intermediate transfer belt 107 on which the toner images formed on the respective photosensitive drums 103 are transferred, and an intermediate transfer belt 107 which is provided facing the photosensitive drums 103 to intermediately transfer the toner images formed on the photosensitive drums 103 . A primary transfer roller 108 for transferring onto a belt 107 is provided. The image forming apparatus 1 also includes a secondary transfer roller 109 that transfers the toner image on the intermediate transfer belt 107 onto the recording material S conveyed from the paper feeding unit 101, and a secondary transfer roller 109 that transfers the toner image transferred onto the recording material S to the recording material. A fixing device 100 for fixing to S is provided.

Toner remaining on the surface of the photosensitive drum 103 after being transferred to the intermediate transfer belt 107 is removed by the drum cleaning device 8 , and the removed toner is accumulated in the recovery toner container 5 . Further, toner remaining on the surface of the intermediate transfer belt 107 after being transferred to the recording material S is removed by the belt cleaning device 7 , and the removed toner is accumulated in the recovery toner container 5 .

[Overview of Image Forming Process]
Next, an image forming process in the image forming apparatus 1 will be described. When image formation is performed in the image forming apparatus 1 , first, the surface of the photosensitive drum 103 is charged to a uniform potential by the charger 104 . An electrostatic latent image is formed on the photosensitive drum 103 by exposing the surface of the photosensitive drum 103 according to the image data by the exposure unit 500 . A developing device 106 attaches toner to the electrostatic latent image on the photosensitive drum 103 to form a toner image. The toner images formed on the photosensitive drums 103 of the image forming units 102 are successively superimposed and transferred onto the intermediate transfer belt 107 by the primary transfer rollers 108 to form color toner images.

The recording material S is stacked in the paper feeding unit 101 and is fed to the conveying path 20 in accordance with image forming timing. As for the method of feeding the recording material S, first, the leading end of the recording material S is flipped up by a paper feed roller 80, and a pair of paper separation conveying rollers 9 for preventing double feeding of the recording material S feeds one sheet of recording material. A material S is transported to the transport path 20 . After that, the recording material S pulled out by the conveying roller pair 10 passes through a conveying path 20, is conveyed to a registration roller pair (hereinafter referred to as a registration roller pair) 11, and is temporarily stopped. Then, in the registration roller pair 11, skew correction and timing correction of the recording material S are performed, and then the recording material S is conveyed to the secondary transfer portion T2.

The color toner image superimposed and transferred onto the intermediate transfer belt 107 is conveyed to the secondary transfer portion T2 where the recording material S is nipped between the intermediate transfer belt 107 and the secondary transfer roller 109 . By applying a transfer voltage to the secondary transfer roller 109 , the toner image on the intermediate transfer belt 107 is transferred onto the recording material S conveyed from the paper feeding unit 101 . The recording material S onto which the toner image has been transferred at the secondary transfer portion T2 is conveyed to the fixing device 100, and the fixing device 100 heats and presses the unfixed toner image on the recording material S to thereby transfer the toner image onto the recording material. The toner image is fixed on S. Then, the recording material S on which the toner image has been fixed by the fixing device 100 is discharged to the discharge section 111 .

In addition, as shown in FIG. 2, the image forming apparatus 1 includes a toner container 4 provided corresponding to each image forming section 102 . When the toner amount in the developing unit 641 (to be described later) decreases due to image formation, the toner is supplied from the toner container 4 corresponding to each image forming section 102 to each developing unit 641 through a pipe (not shown). That is, in the developing unit 641 included in the image forming apparatus 1 of the first embodiment, new toner is replenished from the toner container 4, and part of the excess toner is conveyed to the collection toner container 5 as residual toner. .

[Drum unit and developing unit]
A drum unit 518, which is a replaceable unit, is attached to each image forming section 102 of the image forming apparatus 1 shown in FIG. The drum unit 518 includes a photosensitive drum 103 rotatably supported with respect to the frame of the drum unit 518 . The drum unit 518 is a cartridge that is replaced by an operator such as a user or a serviceman.

Each image forming section 102 of the image forming apparatus 1 is provided with a developing unit 641 which is a replaceable unit separate from the drum unit 518 . The developing unit 641 is a cartridge in which the developing device 106 shown in FIG. 2 and the toner container are integrated. The developing device 106 includes a developing sleeve, which is a developer carrier that carries toner (developer). The developing unit 641 is provided with a plurality of gears for rotating a screw that agitates the toner and carrier. Remove it from the main body and replace it. A certain amount of toner is removed from the developing unit 641 as residual toner, and the removed toner is conveyed to the recovery toner container 5 . Note that the drum unit 518 and the developing unit 641 described above may be a process cartridge in which the drum unit 518 and the developing unit 641 are integrated.

[Front side plate and rear side plate]
FIG. 3 is a perspective view of a main part explaining the front side plate 642 and the rear side plate 643 provided in the image forming apparatus 1. FIG. The image forming apparatus 1 includes a front plate 642 made of sheet metal and a rear plate 643 made of sheet metal. The front side plate 642 is a side wall provided on the front side of the image forming apparatus 1 . A rear side plate 643 is a side wall provided on the rear side of the image forming apparatus 1 . As shown in FIG. 3, the front side plate 642 and the rear side plate 643 are arranged facing each other, and a sheet metal (not shown) as a beam is bridged between them. The front side plate 642 , the rear side plate 643 , and the beam (not shown) each constitute a part of the frame of the image forming apparatus 1 . A front side plate 642 and a rear side plate 643 support the drum unit 518 , the development unit 641 and the exposure unit 500 . That is, the front side plate 642 and the rear side plate 643 support the photosensitive drum 103 and the optical print head 105 . The optical print head 105 is fixed to the front side plate 642 and the rear side plate 643 in the state of being attached to the image forming apparatus 1 . A control unit (main body control board, which will be described later) for controlling the image forming apparatus 1 is further behind the rear side plate 643 of the image forming apparatus 1, that is, between the rear side plate 643 and the rear surface (rear upper cover, which will be described later). are placed.

An opening 6425 is formed in the front side plate 642 so that the drum unit 518, developing unit 641, and exposure unit 500 can be inserted and removed from the front side of the image forming apparatus 1. FIG. The drum unit 518 , developing unit 641 and exposure unit 500 are mounted at predetermined positions of the main body of the image forming apparatus 1 via openings 6425 . A cartridge cover 558 is provided for each color cartridge. The cartridge cover 558 is a cover that covers the front sides of the drum unit 518, the developing unit 641, and the exposure unit 500 mounted at the mounting positions. One end of the cartridge cover 558 is fixed to the main body of the image forming apparatus 1 by a hinge (not shown), and is rotatable with respect to the main body of the image forming apparatus 1 by the hinge. FIG. 3 shows a state in which all cartridge covers 558 are open and access to the drum unit 518, developing unit 641 and exposure unit 500 is possible.

[Configuration of optical print head]
Next, the optical print head 105 included in the exposure unit 500 will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a diagram showing the optical print head 105. As shown in FIG. FIG. 5 is a diagram showing a schematic configuration of the optical print head 105 included in the image forming apparatus 1 of the first embodiment. Among the exposure methods used in electrophotographic image forming apparatuses, a beam emitted from a semiconductor laser is deflected by a rotating polygonal mirror or the like, and is irradiated onto a photosensitive drum via an f-θ lens or the like for exposure. There is a laser beam scanning exposure method. The "optical print head 105" described in the first embodiment employs an LED exposure method that exposes the photosensitive drum 103 using light-emitting elements such as LEDs arranged along the rotation axis direction of the photosensitive drum 103. This exposure method is different from the laser beam scanning exposure method described above.

As described above, the exposure unit 500 of the first embodiment is an exposure unit that exposes the photosensitive drum 103 from below. Therefore, the optical print head 105 is provided below the rotational axis of the photosensitive drum 103 in the vertical direction, and the LED 503 of the optical print head 105 exposes the surface of the photosensitive drum 103 from below. As shown in FIG. 4, the optical print head 105 has a lens array 506 and a lens mounting portion 701 to which the lens array 506 is mounted. The optical print head 105 also has a holder 505 that holds a substrate 502 (see FIG. 5) on which the LEDs 503 are mounted, and a flexible flat cable (hereinafter referred to as FFC) connector 504 .

Next, the substrate 502 held by the holder 505 will be described. FIG. 5A is a schematic perspective view showing the shape of the substrate 502. FIG. FIG. 5(b1) shows the arrangement of a plurality of LED chips 639 provided on the substrate 502. FIG. FIG. 5(b2) is an enlarged view of FIG. 5(b1). An LED chip 639 having a plurality of LEDs 503 is mounted on the substrate 502 . As shown in FIG. 5A, an LED chip 639 is mounted on one surface of the substrate 502, and a long FFC connector is mounted on the other surface (the surface opposite to the side where the LEDs 503 are arranged). 504 is provided. The FFC connector 504 is attached to the lower surface of the board 502 so that its longitudinal direction is along the longitudinal direction of the board 502 . The substrate 502 is provided with wiring for supplying signals from the FFC connector 504 to each LED chip 639 . One end of an FFC as an example of a cable is connected to the FFC connector 504 .

The main body of the image forming apparatus 1 includes a board having a control section for controlling the image forming apparatus 1 and a connector. The other end of the FFC is connected to a connector provided on the board of the control section, and the FFC electrically connects the control section and the board 502 . A control signal (driving signal) output from the control unit of the main body of the image forming apparatus 1 is input to the board 502 via the FFC and the FFC connector 504 . The LED chip 639 mounted on the substrate 502 is driven by the input control signal. The image forming apparatus 1 according to the first embodiment includes a relay board and two FFCs arranged between the control unit and the board 502, the details of which will be described later.

The LED chip 639 mounted on the substrate 502 will be described in more detail. As shown in FIGS. 5B1 and 5B2, on one surface of the substrate 502, for example, 29 LED chips 639-1 to 639-29 having a plurality of LEDs 503 are arranged. Inside each LED chip 639, 516 LEDs 503 are arranged in a line in the longitudinal direction. A center-to-center distance k<b>2 between adjacent LEDs 503 in the longitudinal direction inside the LED chip 639 corresponds to the resolution of the image forming apparatus 1 . The resolution of the image forming apparatus 1 of Example 1 is, for example, 1200 dpi, and the LEDs 503 are arranged such that the center-to-center distance k2 between adjacent LEDs 503 in the longitudinal direction inside each LED chip 639 is 21.16 μm. . As a result, the exposure range of the optical print head 105 of Example 1 is approximately 316 mm (≈21.16 μm×516 pieces×29 pieces). On the other hand, the photosensitive layer on the surface of the photosensitive drum 103 exposed by the optical print head 105 is formed with a width of 316 mm or more. Since the length of the long side of A4 size recording paper and the length of the short side of A3 size recording paper are 297 mm, the optical print head 105 of Example 1 can be used for both A4 size recording paper and A3 size recording paper. has an exposure range in which image formation is possible.

The LED chips 639-1 to 639-29 are alternately arranged in two rows along the rotation axis direction of the photosensitive drum 103. FIG. That is, as shown in FIG. 5(b1), the odd-numbered LED chips 639-1, 639-3, . there is In addition, even-numbered LED chips 639-2, 639-4, . . . 639-28 counted from the left side in FIG. That is, the odd-numbered LED chips 639-1, 639-3, . . . 639-29 and the even-numbered LED chips 639-2, 639-4, . are arranged at predetermined intervals. By arranging in this way, in the longitudinal direction of the LED chips 639, the distance k2 between the centers of the LEDs 503 arranged at the ends of the LED chips 639 adjacent to each other and the distance k1 between the centers of the adjacent LEDs 503 within the LED chips 639 can be equated with In addition, although the configuration using the LED 503 as the light source is shown in the first embodiment, the light source is not limited to the LED, and for example, an organic EL (Organic Electro Luminescence) may be used as the light source.

Next, the lens array 506 will be described. FIG. 5C1 is a schematic diagram showing the configuration of the lens array 506 mounted on the optical print head 105 when viewed from the photosensitive drum 103 side. FIG. 5C2 is a perspective view (schematic diagram) showing a schematic shape of the lens array 506. As shown in FIG. As shown in FIG. 5(c1), the lenses in the lens array 506 are arranged in two rows along the direction in which the LEDs 503 in the corresponding LED chips 639 are arranged. Each lens in lens array 506 is alternately arranged to contact adjacent lenses in the same row and also to contact one of the lenses in the other row. In Example 1, each lens in the lens array 506 is a cylindrical rod lens made of glass, but the material of the lens is not limited to glass and may be made of plastic, and the shape of the lens is also limited to a cylindrical shape. For example, it may be a polygonal prism such as a hexagonal prism.

A dotted line Z shown in FIG. 5C2 indicates the optical axis of the lens of the lens array 506 . The optical print head 105 can be moved in a direction (vertical direction) generally along the optical axis of the lens indicated by the dotted line Z by a moving mechanism (not shown). The "optical axis of the lens" as used herein means a line connecting the center of the light exit surface of the lens and the focal point of the lens. A light beam emitted from the LED 503 enters a lens included in the lens array 506 . The lenses of the lens array 506 have the function of converging the incident light beams on the surface of the photosensitive drum 103 . Therefore, the mounting position of the lens array 506 with respect to the lens mounting portion 701 (see FIG. 4) is adjusted during assembly of the optical print head 105 so that the lens array 506 is positioned as follows. That is, the mounting position of the lens array 506 is determined by the distance between the light emitting surface of the LED 503 of the LED chip 639 and the light incident surface of the lens of the lens array 506, and the distance between the light emitting surface of the lens of the lens array 506 and the surface of the photosensitive drum 103. and the distance are adjusted to be substantially equal.

[Removal Configuration of Optical Print Head]
Next, a mechanism for attaching and detaching the optical print head 105 to and from the photosensitive drum 103 will be described. The optical print head 105 can be pulled out of the image forming apparatus 1 from the front side of the image forming apparatus 1 . As described above, the optical print head 105 is arranged close to the photosensitive drum 103 and has the function of exposing the photosensitive drum 103 . A position where the optical print head 105 is arranged in proximity to the photosensitive drum 103 so that an electrostatic latent image can be formed on the photosensitive drum 103 is hereinafter referred to as an exposure position. A position where the optical print head 105 can be taken out of the image forming apparatus 1 is hereinafter referred to as a retracted position. When the drum unit 518 is taken out of the main body of the image forming apparatus 1 for maintenance or the like of the image forming apparatus 1, if the optical print head 105 remains at the exposure position, the following problem occurs. That is, the optical print head 105 may interfere with the removal operation when the drum unit 518 is removed. For this reason, the optical print head 105 of the first embodiment has a detachable function so that it is at a close position (exposure position) during exposure, but is moved to a retracted position during maintenance of the image forming apparatus 1 .

[Connection between optical print head and relay board by FFC]
Next, paths of FFC 160 and FFC 161 connecting the FFC connector 504 of the optical print head 105 and the controller of the image forming apparatus 1 via the relay board 211 will be described. First, the configuration in which the optical print head 105 and the relay board 211 are connected by the FFC 160, which is the second cable, will be described. The relay board 211 is a board for transmitting the control signal output from the control section to the optical print head 105 . The relay board 211 is fixed to a tray 702 which will be described later. FIG. 6A is a perspective view showing connection and arrangement of the FFC 160 with respect to the exposure unit 500. FIG. FIG. 6B is a perspective view showing the arrangement of the exposure unit 500 and the tray 702. FIG. FIG. 7 is a cross-sectional view showing the arrangement of the exposure unit 500 and the tray 702. As shown in FIG. FIG. 8 is a bottom view showing the arrangement of the FFC 160 and the relay board 211 with respect to the tray 702. FIG. 6 and 7 show only black (K) stations for convenience of explanation.

(tray)
The tray 702 will now be described. A tray 702 as a support member supports the optical print head 105 when the optical print head 105 is pulled out of the image forming apparatus 1 . The trays 702 are provided corresponding to the four image forming units 102, respectively, and the four trays 702 are connected and integrated. The tray 702 is mounted inside the image forming apparatus 1 and fixed to the front side plate 642 and the rear side plate 643 when the tray is not pulled out.

The tray 702 is positioned with respect to the front side plate 642 and the rear side plate 643 (see FIG. 3). The tray 702 serves as a guide when the exposure unit 500 , the drum unit 518 and the development unit 641 are inserted into and removed from the image forming apparatus 1 . Note that the tray 702 does not support the optical print head 105 when the optical print head 105 is attached to the image forming apparatus 1 (at the exposure position). On the other hand, the tray 702 supports the optical print head 105 when the optical print head 105 moves to the retracted position.

(Relay board)
In Example 1, the relay board 211 is fixed to the tray 702 corresponding to the image forming unit 102 for yellow as shown in FIG. The FFC 160 has one end connected to the FFC connector 504 as shown in FIG. 6 and is arranged directly below the optical print head 105 . The FFC guide 713 is attached to the U-shaped frame 526 as shown in FIG. The FFC 160 is bent along the longitudinal direction of the U-shaped frame 526 inside the FFC guide 713 . Specifically, the FFC 160 is first bent along the U-shaped frame 526 toward the rear. The FFC 160 is routed rearward by a predetermined distance, changes its orientation by forming a loop in the flexure region C, and is now routed forward of the U-shaped frame 526 . As shown in FIG. 6, the FFC guide 713 is provided with an FFC cover 714 for restricting downward movement of the FFC 160 when the optical print head 105 moves from the exposure position to the retracted position. . As shown in FIG. 7, the FFC 160 wired to face the front of the U-shaped frame 526 passes through the FFC guide 713 and through the FFC opening 715 provided in the tray 702 . This causes FFC 160 to exit downward from the interior of tray 702 .

Here, the unit in which the tray 702, the FFC 160, and the relay board 211 are integrated is called an exposure unit group 200. FIG. FIG. 9A is an exploded perspective view showing the structure of the exposure unit group 200 viewed from below. 9B is a perspective view of the exposure unit group 200. FIG. An FFC rail 716 is arranged below the tray 702 so as to straddle the Y station, M station, C station, and K station. FFC 160 passing through FFC opening 715 is laid on FFC rail 716 . As a result, the FFC 160 passes under the K-station tray 702K to the Y-station tray 702K, and then moves toward the rear of the image forming apparatus 1 along the Y-station tray 702Y. The FFC 160, one end of which is connected to the FFC connector 504K of the K station, has the other end connected to the connector 212 of the relay board 211 (see FIG. 8) arranged between the Y station and the left side wall of the image forming apparatus 1. be. FFCs 160C, 160M and 160Y of C station, M station and Y station are connected to connectors 213, 214 and 215, respectively. This is the wiring route of the FFC 160 from the optical print head 105 to the relay board 211 (see FIG. 8). Note that the connector 216 and the FFC 161 in FIG. 8 will be described later. Also, the tray connecting member 230 and the relay board unit 210 shown in FIG. 9A will be described later.

[Connection by FFC between relay board and controller]
Next, the wiring route of the FFC 161, which is the first cable from the relay board 211 to the control section of the image forming apparatus 1, will be described. FIG. 10A is a view showing the left side and back of the image forming apparatus 1, with a left cover 1001 provided on the left side, a left rear cover 1002 provided on the rear of the left side, and a cover 1002 provided on the upper part of the back. The rear top cover 1003 is shown. A left side cover 1001, which is a second door, is a cover for opening the side opposite to the side where the transport path 20 is provided in order to access the relay board 211 and the FFC 161. FIG. The left side cover 1001 is opened by rotating about the lower shaft and pulling the upper side toward the operator (left side in the figure), similarly to the front cover 6 . On the other hand, the left rear cover 1002 and the rear upper cover 1003 are covers that can be removed from the image forming apparatus 1 .

FIG. 10B shows a state in which the left side cover 1001 of the image forming apparatus 1 is opened and the left rear cover 1002 and the rear upper cover 1003 are removed. A control section of the image forming apparatus 1 is mounted on a body control board 170 arranged on the rear side (rear side) of the image forming apparatus 1 . One end of the FFC 161 is connected to the connector 216 on the relay board 211 . The FFC 161 extends from the connector 216 toward the rear of the image forming apparatus 1, is bent along the left side wall at a portion 161a, and extends upward. After that, the FFC 161 is further bent at the portion 161b, directed leftward, and connected to the connector 171 of the main body control board 170 provided rearward and upward. Here, the image forming apparatus 1 is provided with a guide portion 650 that guides the FFC 161 so that the FFC 161 does not fall inside the image forming apparatus 1 even if both ends of the FFC 161 are disconnected. FFC 161 is guided by guide portion 650 from portion 161a to portion 161b.

[Unit integrated with tray, FFC and relay board]
As shown in FIG. 9A, the exposure unit group 200 is composed of four trays 702 corresponding to four stations, four FFCs 160, FFC rails 716, a relay board unit 210, and a tray connecting member 230. ing. The exposure unit group 200 is all arranged below the tray 702 (bottom side).

11 is a perspective view showing the relay board unit 210 and the relay board holding member 220. FIG. FIG. 12(a) is a perspective view showing the tray 702Y of the Y station. FIG. 12(b) is a perspective view showing the relay board holding member 220. FIG. The relay board unit 210 is supported by engaging the relay board holding member 220 with the tray 702Y of the Y station. Specifically, the claws 7021 and 7022 of the tray 702Y fit into the rectangular holes 221 and 222 of the relay board holding member 220, thereby supporting the relay board unit 210 on the tray 702Y of the Y station.

13 is an exploded perspective view of the relay board unit 210 having the relay board 211 and the relay board holding member 220. FIG. The relay board 211 is fixed to the relay board holding member 220 with screws 217 and 218 . Further, a sheet 240 is provided to protect the relay board 211 so as to prevent contact with other parts of the image forming apparatus 1 during replacement work, which will be described later. Note that the sheet 240 is fixed to the relay board holding member 220 with screws 219 .

(Tray connecting member)
FIG. 14(a) is a perspective view showing the configuration of the front side of the tray connecting member 230. FIG. The tray connecting member 230 is positioned and fixed to the tray 702 in each of the front and rear directions. Specifically, the position is determined by fitting the hole 2302 provided in the front connecting portion 2301 with the boss 7023 of the tray 702 . Also, screws 2310 are inserted into the holes 2303 provided in the front connecting portion 2301 and the holes 7024 of the tray 702 to fasten and fix.

FIG. 14(b) is a perspective view showing the configuration of the rear side of the tray connecting member 230. As shown in FIG. The position of the rear side of the tray connecting member 230 is determined by fitting the hole 2305 provided in the rear side connecting portion 2304 with the boss 7025 of the tray 702 in the same manner as the front side. Also, screws 2311 are inserted into the holes 2306 provided in the rear connecting portion 2304 and the holes 7026 of the tray 702 to fasten and fix.

(FFC rail)
FIG. 15 is a perspective view showing the configuration of the FFC rail 716. As shown in FIG. Positioning and fixing of the FFC rail 716 and the tray 702 are determined by fitting the hole 7161 provided in the FFC rail 716 with the boss 7027 of the tray 702 . Screws 7163 are inserted into the holes 7162 provided in the FFC rails 716 and the holes 7028 of the tray 702 to fasten and fix.

[Procedure for replacing FFC161]
A replacement procedure for the FFC 161 connecting the relay board 211 and the main body control board 170 will be described.

<Step 1>
As described with reference to FIG. 10A, the operator opens the left cover 1001 provided on the left side of the image forming apparatus 1 .

<Step 2>
FIG. 16A is a diagram showing a state in which the left side cover 1001 of the image forming apparatus 1 is opened, and shows a state in which the inside of the image forming apparatus 1 is visible. When the left cover 1001 is opened, the front side plate 642 of the image forming apparatus 1 is exposed. Since the connector 216 of the relay board 211 is exposed when the left cover 1001 is opened, the FFC 161 connected to the connector 216 of the relay board 211 can be removed. The operator removes the FFC 161 from the connector 216 .

<Step 3>
The operator removes the left rear cover 1002 and the rear upper cover 1003 described with reference to FIG. 10(a). When the left rear cover 1002 is removed, the portion where the FFC 161 is wired from the relay board 211 toward the main body control board 170 from the bottom to the top is exposed as described in FIG. 10B. When the rear upper cover 1003 is removed, the body control board 170 and the connector 171 are exposed as described with reference to FIG. 10(b).

<Step 4>
Since the connector 171 of the main body control board 170 is exposed in step 3, the operator removes the FFC 161 connected to the connector 171 of the main body control board 170 from the connector 171 . One end of the FFC 161 is removed from the connector 216 in step 2, and the other end of the FFC 161 is removed from the connector 171 in step 4. Therefore, both ends of the FFC 161 are unconnected when step 4 is completed. . However, since the FFC 161 is guided by the guide portion 650 as described with reference to FIG. 10B, it does not fall into the image forming apparatus 1 even if both ends are disconnected.

<Step 5>
The operator removes the FFC 161 from the guide portion 650 and takes it out of the image forming apparatus 1 . Since both ends of the FFC 161 are unconnected, the FFC 161 can be removed from the guide section 650 . Further, in procedure 5, the tray 702 and the like are still mounted in the image forming apparatus 1 .

As described above, the relay board 211 is arranged between the Y station and the left side wall of the image forming apparatus 1 (see FIG. 16A, etc.). Therefore, when the left cover 1001 is opened, the relay board 211 and the FFC 161 are exposed on the front side as viewed from the left side. In other words, it is not necessary to access the inside of the image forming apparatus 1 with the front cover 6 open, remove the FFC 161 from the FFC connector 504 of the optical print head 105, and pull it out of the image forming apparatus 1, unlike the conventional art. Therefore, in the first embodiment, the workability of replacing the FFC 161 is improved. Although the left side cover 1001 is removed first in the first embodiment, the left rear cover 1002 and the rear upper cover 1003 may be removed first. For example, the work may be performed in the order of procedure 3→procedure 4→procedure 1→procedure 2→procedure 5.

[Procedure for replacing the exposure unit group 200]
Next, a procedure for exchanging the exposure unit group 200 will be described.

<Step 1>
As described with reference to FIG. 10A, the operator opens the left cover 1001 provided on the left side of the image forming apparatus 1 . As a result, the connector 216 and the FFC 161 of the relay board 211 are exposed as described with reference to FIG. 16(a).

<Step 2>
The operator removes the FFC 161 connected to the connector 216 on the relay board 211 from the connector 216, as described with reference to FIG. 16(a).

<Step 3>
The operator opens the front cover 6 and the cartridge cover 558 so that the exposure unit group 200 can be removed from the image forming apparatus 1 . Here, the exposure unit 500 moves to the retracted position, and the tray 702 supports the exposure unit 500 (optical print head 105). Here, FIG. 16B is a view of the image forming apparatus 1 viewed from the left side, and shows a state (open state) in which the front cover 6 and the left side cover 1001 are opened. When the left side cover 1001 is opened, the FFC 161 and the left side of the exposure unit group 200 are exposed. An operator who performs maintenance opens the front cover 6 , further opens all the cartridge covers 558 , and takes out the drum unit 518 or developing unit 641 in the image forming apparatus 1 .

<Step 4>
An operator removes the drum unit 518 and the developing unit 641 from the front side of the image forming apparatus 1 . This makes it possible to access the exposure unit group 200 arranged below the drum unit 518 and developing unit 641 .

<Step 5>
FIG. 17 is a perspective view showing a state in which work has been performed up to the middle of procedure 4, and shows a state in which the cartridge cover 558K of the black station is in an open state. Also, the black drum unit 518K and developing unit 641K are removed to expose the exposure unit 500K. The black cartridge cover 558K is not shown in FIG. 17 for ease of viewing. The operator removes the fixing screw 710 . The fixing screw 710 is a screw for fastening both the tray 702 (here for black) and the exposure unit 500 (here for black) to the front side plate 642 .

(cartridge cover)
FIG. 18(a) is a diagram showing a state in which the cartridge cover 558 is in an open state. A right rotating shaft 559 and a left rotating shaft 560 of the cartridge cover 558 are fitted to a right bearing 711 and a left bearing 712 provided on the tray 702, respectively. Since the right bearing 711 and the left bearing 712 are arranged coaxially, the cartridge cover 558 can rotate around the axis of the right rotation shaft 559 and the left rotation shaft 560 .

A cylindrical slide pressure shaft 561 projects from the right side to the left side of the cartridge cover 558 . 18B is a perspective view showing the cartridge cover 558 and the exposure unit 500. FIG. The slide pressure shaft 561 is housed in a shaft housing space 562 provided below the slide cam member 539 of the exposure unit 500 . When removing the exposure unit group 200, the fixing screw 710 fixed to the front side plate 642 is removed. At this time, since the engagement between the slide pressure shaft 561 of the cartridge cover 558 and the slide movement cam member 539 of the exposure unit 500 is lost, the optical print head 105 is in the retracted state. This allows the exposure unit group 200 to be pulled out.

<Step 6>
Since the fastening between the tray 702 and the exposure unit 500 and the front side plate 642 is released by procedure 5, the exposure unit group 200 can be pulled out from the image forming apparatus 1 . The operator pulls out the exposure unit group 200 to the front side (front side) of the image forming apparatus 1 and takes it out of the image forming apparatus 1 . FIG. 19 is a perspective view showing a state in which the exposure unit group 200 is pulled forward of the image forming apparatus 1. As shown in FIG. As described above, since the four stations are fixed by the tray connecting member 230 (FIG. 9(a)), the four stations are integrated and pulled forward. At this time, since the FFC 160 is wired along the FFC rail 716 and the relay board 211, it is housed inside the exposure unit group 200 (see FIGS. 8 and 9B). As a result, the FFC 160 is prevented from rubbing against the frame of the image forming apparatus 1 or getting caught. When the exposure unit group 200 is completely pulled out from the front side plate 642 , the FFC 160 and the optical print head 105 can be replaced without being affected by other parts of the image forming apparatus 1 .

In the first embodiment, the relay board 211 is fixed to the tray 702Y corresponding to the yellow image forming unit 102Y, which is the image forming unit farthest from the side on which the transport path 20 is provided among the four image forming units 102. ing. The arrangement of the relay board 211 is not limited to the arrangement described above. For example, if the conveying path from the paper feed roller 80 to the secondary transfer portion T2 is on the left side of the image forming apparatus 1, it can be arranged between the right side wall of the image forming apparatus 1 and the station adjacent to the right side wall. good. In other words, the relay board may be arranged between the station which is the farthest in the horizontal direction of the image forming apparatus 1 from the conveying path from the paper feed roller 80 to the secondary transfer portion T2 and the side wall adjacent to the station. In this way, the relay board 211 can be arranged in various ways according to the features of the image forming apparatus 1 . Further, regarding the arrangement of the relay board 211 in the front-rear direction of the image forming apparatus 1, it is desirable to arrange it on the rear side plate 643 side between the front side plate 642 and the rear side plate 643 as in the first embodiment. Any position between the front side plate 642 and the rear side plate 643 is acceptable.

As described above, according to the first embodiment, it is possible to improve workability when exchanging the flexible flat cable connected to the optical print head.

The second embodiment differs from the first embodiment in the position where the connector 216 of the relay board 211 is provided. The same reference numerals are assigned to the same parts as in the first embodiment, and the description thereof is omitted. FIG. 20 is a horizontal cross-sectional view at a predetermined position of hole 6421. FIG. In the second embodiment, the connector 216 on the relay board 211 is arranged on the front side of the left side, while the connector 216 on the relay board 211 is arranged on the rear side of the left side in the first embodiment. is provided. As described above, in the second embodiment, the relay board 211 is fixed to the tray 702Y corresponding to the yellow image forming unit 102Y, and is further fixed to the front side in the front-rear direction. The hole 6421 is large enough to insert the operator's hand. As a result, the operator can insert his/her hand through the hole 6421 to remove the FFC 161 from the connector 216 on the relay board 211 . As shown in FIG. 20, the connector 216 of the relay board 211 is arranged on the front side, that is, on the front cover 6 side in the second embodiment. A hole 6421 is provided on the left side, and an operator can insert his/her hand from the left side to the right side of FIG. .

[Procedure for replacing the exposure unit group 200]
A working procedure of the second embodiment will be described.

<Step 1>
The operator opens the front cover 6 arranged in front of the image forming apparatus 1 and further opens all the cartridge covers 558 . The exposure unit 500 moves to the retracted position, and the tray 702 supports the exposure unit 500 .

<Step 2>
The operator removes the drum unit 518 and developing unit 641 .

<Step 3>
The operator removes the left cover 1001 , inserts his/her hand into the hole 6421 , and removes the FFC 161 connected to the connector 216 on the relay board 211 from the connector 216 . FIG. 21 is a view showing the left side of the image forming apparatus 1 with the left cover 1001 removed to expose the relay board 211, the connector 216, the FFC 161, and the hole 6421. FIG.

<Step 4>
The operator removes the fixing screws 710 to release the fastening between the tray 702 and the exposure unit 500 and the front side plate 642 .

<Step 5>
The operator pulls out the exposure unit group 200 to the front side (front side) of the image forming apparatus 1 and takes it out of the image forming apparatus 1 .

As described above, in the second embodiment, there are five procedures for drawing out the exposure unit group 200, and it is possible to reduce one procedure from the procedure described in the first embodiment. Regarding the layout of the relay board 211 in the front-rear direction of the image forming apparatus 1 , it is desirable that the connector 216 is located between the front side plate 642 and the rear side plate 643 on the side of the front side plate 642 . However, any place between the front side plate 642 and the rear side plate 643 may be used as long as the worker can access the connector 216 by inserting a working means such as a hand or a tool through the hole 6421 .

As described above, according to the second embodiment, it is possible to improve workability when exchanging the flexible flat cable connected to the optical print head.

103 Photosensitive drum 105 Optical print head 160 Flexible flat cable 161 Flexible flat cable 170 Main body control board 211 Relay board 702 Tray

Claims (6)

An image forming apparatus for forming an image on a recording material,
a plurality of rotating photoreceptors;
A plurality of optical print heads each having a plurality of light emitting units arranged along a rotation axis direction of the plurality of photoreceptors, wherein one of the plurality of photoreceptors is different depending on the light emitted by the plurality of light emitting units. a plurality of optical printheads for exposing the
a plurality of developing units that supply toner to a different one of the plurality of photoconductors to form a toner image corresponding to the latent image;
a transfer unit that transfers the toner image onto the recording material;
a fixing unit that heats and fixes the toner image transferred onto the recording material onto the recording material;
a plurality of supporting portions for respectively supporting a different one of the plurality of photoreceptors, a different one of the plurality of optical print heads, and a different one of the plurality of developing portions;
a control unit that outputs a control signal for controlling lighting and extinguishing of the plurality of optical print heads;
A relay substrate provided on one of the plurality of support portions that is farthest from the fixing portion in an arrangement direction in which the plurality of photoreceptors are arranged, the relay substrate being provided via the control portion and a first cable. a relay connected to each of the plurality of optical printheads through a different one of a plurality of second cables, and transmitting the control signal output by the control unit to the plurality of optical printheads. a substrate;
An image forming apparatus comprising : Equipped with a transport path for transporting the recording material,
2. The image forming apparatus according to claim 1 , wherein the relay board is provided on the support portion located farthest from the transport path in the arrangement direction . a first door portion provided on a front side surface of the image forming apparatus and capable of withdrawing the plurality of support portions to the outside of the image forming apparatus in an open state;
a second door portion provided on a side surface of the image forming apparatus in the left-right direction and capable of accessing the relay board in an open state;
2. The image forming apparatus according to claim 1 , comprising: a front side plate provided on the front side of the image forming apparatus and supporting one end of the plurality of support portions ;
a rear side plate provided to face the front side plate and supporting the other ends of the plurality of support portions ;
with
2. An image forming apparatus according to claim 1 , wherein said optical print head is fixed to said front side plate and said rear side plate in a state of being attached to said image forming apparatus. 5. The image forming apparatus according to claim 4 , wherein the supporting section does not support the optical print head when the optical print head is attached to the image forming apparatus. 5. The image forming apparatus according to claim 4 , wherein the control unit is arranged in a direction opposite to the front plate with respect to the rear plate.

Images