Image forming apparatus

Abstract

To provide an image forming apparatus that can arrange wiring appropriately. [Solution] In each block (110, 120, 130), the ASICs of the control boards (202, 201, 203) and the electrical components to be driven are connected by wiring bundles (810, 820, 830). The control boards having the ASICs and the electrical components to be driven are located in the same block. In at least one block, the wiring of the wiring bundles (810, 820, 830) is secured within the block. That is, the wiring bundles (810, 820, 830) do not cross the boundaries between blocks.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction peripheral.

Background Art

[0002] An image forming apparatus is provided with a plurality of electrical components and a plurality of control boards for controlling them (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an image forming apparatus, many wirings are used to connect a plurality of electrical components and a plurality of control boards. The conventional image forming apparatus has some problems due to these wirings.

[0005] For example, an image forming apparatus can be roughly divided into a plurality of blocks for each function, such as an image forming block for forming an image on a recording material, a supply block for supplying the recording material to the image forming block, and a discharge block for discharging the recording material after image formation to the outside. These image forming blocks, supply blocks, and discharge blocks include various units for realizing various functions, and these units are arranged in a main body frame integrally formed by combining a large number of columns and sheet metals.

[0006] Users perform maintenance on units in each block, and in doing so, they disconnect the wiring harness that electrically connects the unit being maintained to the control board that controls that unit. However, conventionally, the control board connected to the unit being maintained by the wiring harness was sometimes also connected by wiring harnesses to a unit in another block that was not being maintained. In such cases, when a user performed maintenance on a unit electrically connected to the control board, they had to access another block that did not contain the unit being maintained and disconnect the wiring harness, which was time-consuming and cumbersome.

[0007] Another example is the problem that when the control board is far from the electrical components being controlled, the wiring distance increases, which in turn increases the weight of the device.

[0008] This invention has been made in view of the above problems and aims to provide an image forming apparatus that can arrange wiring appropriately. [Means for solving the problem]

[0009] An image forming apparatus according to one embodiment of the present invention is an image forming apparatus for forming an image on a recording material, comprising: an apparatus body having at least a first frame and a second frame arranged in the vertical direction; a first electrical member provided in the first frame and operating physically based on electrical control; a second electrical member provided in the second frame and operating physically based on electrical control; a first control board arranged in the first frame and connected to the first electrical member for controlling the driving of the first electrical member; and a second control board arranged in the second frame and connected to the second electrical member for controlling the driving of the second electrical member.

[0010] An image forming apparatus according to one embodiment of the present invention is an image forming apparatus for forming an image on a recording material, comprising: a first electrical member that operates physically based on electrical control; a second electrical member that operates physically based on electrical control; a first control board that is arranged to overlap the first electrical member when viewed from the rear of the image forming apparatus and is connected to the first electrical member, and controls the driving of the first electrical member; and a second control board that is arranged to overlap the second electrical member when viewed from the rear of the image forming apparatus and is connected to the second electrical member, and controls the driving of the second electrical member. [Effects of the Invention]

[0011] According to the present invention, wiring can be appropriately arranged in an image forming apparatus. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram showing the configuration of the image forming apparatus of this embodiment. [Figure 2] A schematic diagram showing the segmented configuration of an image forming apparatus. [Figure 3] (a) Schematic diagram showing the discharge frame, (b) Schematic diagram showing the image creation frame, (c) Schematic diagram showing the supply frame. [Figure 4] A block diagram showing an example of an electrical system. [Figure 5] This diagram illustrates the drive signals between the ASIC and electrical components, showing the following cases: (a) stepping motor, (b) DC brushless fan, (c) DC brush motor, (d) DC brushless motor, (e) inductor sensor, (f) EEPROM, (g) photo interrupter, and (h) main switch. [Figure 6] This diagram illustrates the control signals between the CPU and the ASIC, showing (a) the bus-based method and (b) the command-based method. [Figure 7] Figure 4 shows the arrangement and wiring of the control board and electrical components in the electrical system. [Figure 8]A block diagram showing another example of an electrical system. [Figure 9] Figure 8 shows the arrangement and wiring of the control board and electrical components in the electrical system. [Modes for carrying out the invention]

[0013] <Image forming apparatus> The following describes this embodiment. First, the schematic configuration of the image forming apparatus of this embodiment will be explained using Figure 1. In the following description, "front" and "rear (back)" refer to the front side of the image forming apparatus and the rear side of the apparatus, respectively, and "right" and "left" refer to the view of the apparatus from the front side. The front side of the apparatus is the side from which the user operates the image forming apparatus when performing maintenance work, for example, the side where the control panel is located, or the side from which the cassette containing the recording material is pulled out. "Vertical direction" refers to the vertical direction when the image forming apparatus is installed on a surface such as the floor. Figure 1 shows the image forming apparatus 1 as viewed from the front side.

[0014] The image forming apparatus 1 shown in Figure 1 is an intermediate transfer type full-color printer in which four image forming units PY, PM, PC, and PK, which form yellow (Y), magenta (M), cyan (C), and black (K) toner images, are arranged facing an intermediate transfer belt 21. The image forming apparatus 1 includes an image forming unit 500, which forms a toner image on the recording material S based on an image signal received from an external terminal such as a document reader that reads an image on a document or a personal computer (not shown). The image forming unit 500 has image forming units PY, PM, PC, PK and an intermediate transfer belt unit 600.

[0015] The conveyance process of the recording material S in the image forming apparatus 1 will be described. The recording material S is stored in a form loaded in one or more (here, two) cassettes 31 and 32, and is started to be conveyed by the supply unit 300. The supply unit 300 has supply rollers 31a and 32a, and the recording material S is supplied one by one from either of the cassettes 31 and 32 to the conveyance path 60 in accordance with the image forming timing by the supply rollers 31a and 32a. In the image forming apparatus 1 of the present embodiment, the conveyance path 60 is provided so as to be able to convey the recording material S from below upward (so-called vertical conveyance method). Note that examples of the recording material S include various types of sheet materials such as plain paper, thick paper, rough paper, embossed paper, coated paper, etc., plastic films, cloth, and the like.

[0016] The recording material S supplied from the cassettes 31 and 32 to the conveyance path 60 is conveyed to the preregistration roller pair 41 disposed in the middle of the conveyance path 60. The preregistration roller pair 41 corrects the skew of the recording material S. Specifically, the leading end of the recording material S conveyed by the preregistration roller pair 41 hits the nip portion of the stopped registration roller pair 42, and the skew is corrected by the recording material S looping. Above the registration roller pair 42 as a pair of rotating bodies, an intermediate transfer belt 21 is disposed, and the registration roller pair 42 conveys the recording material S from below upward to the secondary transfer portion in accordance with the timing when the toner image on the intermediate transfer belt 21 is transferred to the recording material S. The registration roller pair 42 is disposed at the position closest to the secondary transfer portion on the upstream side of the secondary transfer portion with respect to the conveyance direction (vertical direction) of the recording material S conveyed through the conveyance path 60. The secondary transfer portion is formed by a secondary transfer inner roller 22 and a secondary transfer outer roller 44 facing each other across the intermediate transfer belt 21 as a transfer member (first transfer member, intermediate transfer body), and is a nip portion for transferring the toner image from the intermediate transfer belt 21 onto the recording material S by applying a predetermined pressing force and a secondary transfer voltage.

[0017] For the conveyance process of the recording material S up to the secondary transfer section described above, the image formation process of the image sent to the secondary transfer section at the same timing will be described. First, the image forming sections PY to PK will be described. However, since the image forming sections PY to PK for each color are basically the same except for the color of the toner, hereinafter, the yellow image forming section PY will be described as a representative example.

[0018] The image forming section PY includes a photosensitive drum 11Y, a charger 12Y, an exposure device 13Y, and a developer 14Y. The surface of the rotating photosensitive drum 11Y is uniformly charged in advance by the charger 12Y, and then an electrostatic latent image is formed by the laser light irradiated from the exposure device 13Y driven based on the image signal. Then, the electrostatic latent image formed on the photosensitive drum 11Y is developed into a toner image by the developer 14Y. The developer 14Y develops the electrostatic latent image into a toner image by rotating a developing sleeve carrying a developer containing toner and carrier. Since the toner is consumed during development, the toner bottle 90Y containing replenishing toner is rotationally driven at an appropriate timing, and toner is replenished from the toner bottle 90Y to the developer 14Y.

[0019] The toner image formed on the photosensitive drum 11Y is given a primary transfer voltage by the primary transfer roller 25Y disposed opposite with the photosensitive drum 11Y and the intermediate transfer belt 21 interposed therebetween, and is primarily transferred from the photosensitive drum 11Y to the intermediate transfer belt 21. The primary transfer residual toner remaining on the photosensitive drum 11Y after primary transfer is removed by the photosensitive drum cleaner.

[0020] The intermediate transfer belt 21 is an endless belt that is stretched by the secondary transfer internal rollers 22, drive rollers 23, tension rollers 24, etc., and moves in the direction of arrow A in the figure. The image formation process for each color, which is processed in parallel by the image formation units PY to PK described above, is performed at the timing when the toner images of the colors that were primary transferred upstream in the direction of movement are sequentially superimposed on the intermediate transfer belt 21. As a result, a full-color toner image is ultimately formed on the intermediate transfer belt 21, and the toner image is transported to the secondary transfer unit by the movement of the intermediate transfer belt 21. The primary transfer rollers 25Y to 25K, the intermediate transfer belt 21, the secondary transfer internal rollers 22, the drive rollers 23, and the tension rollers 24 are integrally configured as an intermediate transfer belt unit 600.

[0021] As described above, the transport process and image formation process are used to synchronize the timing of the recording material S and the full-color toner image in the secondary transfer section, and a secondary transfer is performed in which the toner image is transferred from the intermediate transfer belt 21 to the recording material S. Any residual toner remaining on the intermediate transfer belt 21 after passing through the secondary transfer section is removed from the intermediate transfer belt 21 by a belt cleaner. The recording material S, on which the toner image has been transferred, is transported along the transport path 60 to the fuser 50, where the toner image is fixed to the recording material S by applying heat and pressure. The fuser 50 has a fuser roller heated by a heater (not shown) and a pressure roller that contacts the rotating fuser roller to form a fuser nip, and the toner image is fixed to the recording material S by applying heat and pressure to the recording material S as it passes through the fuser nip.

[0022] The recording material S, on which the toner image has been fixed by the fuser 50, is transported further upward along the transport path 60 and discharged to the outside by the discharge unit 700. The discharge unit 700 has discharge rollers 61 and 62 and a flapper 63, and the recording material S is discharged by the discharge rollers 61 and 62 and loaded onto the discharge trays 81 and 82. In this embodiment, when the operating mode is the double-sided mode in which toner images are formed on both sides of the recording material S, the recording material S is transported to the double-sided transport path 701 in order to form a toner image on the opposite side of the recording material S on which an image has been formed on one side. In the double-sided mode, the recording material S is transported by the forward rotation of the discharge roller 61 until its rear end passes the flapper 63, and then the front and rear ends are swapped by the reverse rotation of the discharge roller 61 and the recording material S is transported to the double-sided transport path 701. The recording material S transported to the double-sided transport path 701 is returned to the registration roller pair 42. The subsequent transport and the image formation process on the back side are the same as in the above case, so the explanation is omitted. The recording material S, on which an image has been formed on the opposite side, is discharged to the outside by the discharge unit 700.

[0023] <Device body> Next, the main body 1A of the image forming apparatus 1 will be described using Figures 2 to 3(c) with reference to Figure 1. As shown in Figure 2, the main body 1A is divided into three separable structures: a supply block 110, an image forming block 120, and an output block 130. In this specification, a structure (block) refers to a frame, which is formed by combining numerous pillars, stays (beams), sheet metal, etc., and is equipped with various units having electrical components, individual electrical components, control boards, etc., as described later. Note that one or more electrical components are provided in each of the multiple frame bodies.

[0024] In this embodiment, the main body 1A of the device that realizes a series of functions for forming a toner image on the recording material S has a configuration in which an image-forming block 120 is stacked on top of a supply block 110, and an output block 130 is stacked on top of the image-forming block 120. Although not shown in the figures, the supply block 110 and the image-forming block 120, and the image-forming block 120 and the output block 130 are connected in their stacked state, for example, by fastening a metal plate-shaped member, which is stretched between upper and lower support columns, with screws.

[0025] In this embodiment, a double-sided transport block 70, which forms a double-sided transport path 701, is prepared in advance as a separate structure from the supply block 110, the image block 120, and the discharge block 130. The double-sided transport block 70 is rotatably mounted on the supply block 110 or the image block 120 so as to straddle the image block 120 and the discharge block 130. The double-sided transport block 70 forms a transport path 60 (see Figure 1) between the image block 120 and the discharge block 130. The transport path 60 is formed when the double-sided transport block 70 is closed and is opened when the double-sided transport block 70 is open. As a result, if recording material S gets stuck in the transport path 60, the user can remove the stuck recording material S by opening the double-sided transport block 70. To open the transport path 60, the double-sided transport block 70 is provided with one of the registration roller pair 421, a secondary transfer outer roller 44, and one of the pair of rollers that transport the recording material S in the transport path 60. Furthermore, when the double-sided transport block 70 is closed, it is locked by a locking mechanism (not shown) provided on the discharge block 130 to prevent the transport path 60 from automatically opening.

[0026] <Supply block, image creation block, output block> The supply block 110 is a structure in which the supply unit 300 and the supply transport unit 610 are assembled to the supply frame 100e, which will be described later. The supply block 110 is also equipped with support parts (not shown), such as rail members, that support the cassettes 31 and 32 so that they can slide in the front-rear direction. The image forming block 120 is a structure in which the image forming unit 500, the image transport unit 620, the toner bottles 90Y, 90M, 90C, 90K, and the fuser 50 are assembled to the image forming frame 100f, which will be described later. The image forming unit 500, the toner bottles 90Y to 90K, and the fuser 50 may be detachably attached to the image forming frame 100f. The discharge block 130 is a structure in which the discharge unit 700 and the discharge transport unit 630 are assembled to the discharge frame 100g, which will be described later.

[0027] In this embodiment, the transport path 60 for transporting the recording material S from bottom to top is divided and formed into a supply block 110, an image-making block 120, and a discharge block 130. Specifically, the supply transport unit 610 forms a part of the transport path 60 in the supply block 110, the image-making transport unit 620 forms a part of the transport path 60 in the image-making block 120, and the discharge transport unit 630 forms a part of the transport path 60 in the discharge block 130.

[0028] <Discharge frame, image creation frame, supply frame> Next, the discharge frame 100g, image frame 100f, and supply frame 100e will be explained using Figures 3(a) to 3(c). As shown in Figure 3(a), the discharge frame 100g comprises a right front support 114ga, a rear side plate 115g, an upper right stay 113ga, a lower right stay 113gb, a left stay 113gc, and a front stay 113gd. The right front support 114ga extends in the vertical direction. The upper right stay 113ga and the lower right stay 113gb are arranged vertically alongside the right front support 114ga and are approximately parallel to each other, connecting the right front support 114ga and the rear side plate 115g, respectively. On the rear side plate 115g, the left stay 113gc is positioned approximately perpendicular to the rear side plate 115g, so as to be positioned opposite the lower right stay 113gb, which is approximately parallel to it. The front stay 113gd is positioned parallel to the rear side plate 115g (in the left-right direction) so as to connect the left stay 113gc and the right front support 114g.

[0029] Furthermore, the discharge frame 100g comprises a front support 114gb, an upper stay 113ge, and an upper right stay 113gf. The front support 114gb is positioned to the right of the center of the front stay 113gd, between the left stay 113gc and the lower right stay 113gb, and is approximately parallel to the right front support 114ga. The front support 114gb is connected to the front stay 113gd. The upper stay 113ge is positioned approximately parallel to the upper right stay 113ga so as to connect the front support 114gb and the rear side plate 115g. The upper right stay 113gf is positioned approximately parallel to the front stay 113gd so as to connect the right front support 114ga and the front support 114gb. The aforementioned discharge unit 700 is assembled in the space secured by these components: 114ga, 114gb, 113ga, 113gb, 113ge, 113gf, and the rear plate 115g.

[0030] As shown in Figure 3(b), the image frame 100f comprises a right front support 114fa, a left front support 114fb, a rear side plate 115f, an upper right stay 113fa, a lower right stay 113fb, an upper left stay 113ff, a lower left stay 113fc, an upper front stay 113fe, and a lower front stay 113fd. The right front support 114fa extends vertically. The upper right stay 113fa and the lower right stay 113fb are positioned vertically parallel to the right front support 114fa and are approximately parallel to each other, connecting the right front support 114fa and the rear side plate 115f, respectively. The left front support 114fb extends vertically so as to be positioned opposite the right front support 114fa and approximately parallel to it. The upper left stay 113ff and lower left stay 113fc are positioned vertically alongside the left front support 114fb and are roughly parallel to each other, connecting the left front support 114fb and the rear side plate 115f, respectively. The upper front stay 113fe is positioned parallel to the rear side plate 115f (left-right direction) so as to connect the right front support 114fa and the left front support 114fb at their upper ends. The lower front stay 113fd is positioned parallel to the rear side plate 115f (left-right direction) so as to connect the right front support 114fa and the left front support 114fb at their lower ends. To ensure the strength of the image frame 100f, reinforcing members 1151 corresponding to the supports provided on the right front support 114fa, the left front support 114fb, and the rear side plate 115f are each positioned at the four corners of the frame. The reinforcing members 1151 are provided at both ends in the left-right direction of the rear side plate 115f.

[0031] As shown in Figure 3(c), the supply frame 100e comprises a right front support 114ea, a left front support 114eb, a rear side plate 115e, an upper right stay 113ea, a lower right stay 113eb, an upper left stay 113ef, a lower left stay 113ec, an upper front stay 113ee, and a lower front stay 113ed. The right front support 114ea extends vertically. The upper right stay 113ea and the lower right stay 113eb are positioned vertically parallel to the right front support 114ea and are approximately parallel to each other, connecting the right front support 114ea and the rear side plate 115e, respectively. The left front support 114eb extends vertically so as to be positioned opposite the right front support 114ea and approximately parallel to it. The upper left stay 113ef and the lower left stay 113ec are positioned vertically alongside the left front support 114eb, approximately parallel to each other, and connect the left front support 114eb to the rear side plate 115e, respectively. The upper front stay 113ee is positioned parallel to the rear side plate 115g (left-right direction) so as to connect the right front support 114ea and the left front support 114eb at their upper ends. The lower front stay 113ed is positioned parallel to the rear side plate 115e (left-right direction) so as to connect the right front support 114ea and the left front support 114eb at their lower ends. In the vertical direction, the connection position of the upper right stay 113ea to the right front support 114ea and the connection position of the upper left stay 113ef to the left front support 114eb are lower than the connection positions of the upper front stay 113ee to the right front support 114ea and the left front support 114eb. To ensure the strength of the frame, the supply frame 100e has reinforcing members 1152, which correspond to the columns provided on the right front support 114ea, the left front support 114eb, and the rear side plate 115e, each positioned at the four corners of the frame. The reinforcing members 1152 are provided at both ends in the left-right direction on the rear side plate 115e.

[0032] As an example, the image-forming block 120 is mounted on the supply block 110 with the right front support 114fa of the image-forming frame 100f resting on the right front support 114ea of ​​the supply frame 100e, the left front support 114fb of the image-forming frame 100f resting on the left front support 114eb of the supply frame 100e, and the reinforcing material of the rear side plate 115f of the image-forming frame 100f resting on the reinforcing material of the rear side plate 115e of the supply frame 100e. As an example, the discharge block 130 is mounted on the image-forming block 120 with the right front support 114ga of the discharge frame 100g resting on the right front support 114fa of the image-forming frame 100f, and the reinforcing material of the rear side plate 115g of the discharge frame 100g resting on the reinforcing material of the rear side plate 115f of the image-forming frame 100f.

[0033] As described above, the image forming apparatus 1 of this embodiment comprises three divisible structures: a supply block 110, an image forming block 120, and an output block 130. Each of these supply block 110, image forming block 120, and output block 130 has a supply frame 100e, an image forming frame 100f, and an output frame 100g, respectively, and various units having electrical components, individual electrical components, control boards, etc., are provided in the frame of each block. In this way, the apparatus body 1A can be assembled by stacking the supply block 110, image forming block 120, and output block 130, each with various units, individual electrical components, control boards, etc., assembled in each block, thereby significantly reducing the assembly man-hours for the apparatus body 1A and improving the product quality of the apparatus body 1A. In this specification, electrical components refer to those that operate physically based on electrical control according to a drive signal, such as motors, sensors, switches, heaters, etc.

[0034] <Electrical System> Next, an example of an electrical system for controlling the operation of the image forming apparatus 1 will be described using Figure 4 with reference to Figure 2. The electrical system shown here consists of a system controller board 111, an image formation control board 201, a supply control board 202, and an ejection control board 203. The supply control board 202, the image formation control board 201, and the ejection control board 203 are arranged on the back side of the supply frame 100e, the image formation frame 100f, and the ejection frame 100g, respectively. The supply control board 202, the image formation control board 201, and the ejection control board 203 may be arranged to overlap with the electrical components to be controlled when viewed from the back.

[0035] <System Controller Board> The system controller board 111 is equipped with an external interface 115 (external I / F) for inputting and outputting signals to the outside, and executes various control processes in response to instructions from the operation unit 200 connected via the external interface 115. The system controller board 111 also has a system CPU (Central Processing Unit) 112, a ROM (Read Only Memory) 113 for storing control programs, and a RAM (Random Access Memory) 114 for temporarily storing data. The system CPU 112 centrally manages the operation of the entire image forming apparatus based on the control programs stored in the ROM 113.

[0036] The system controller board 111, which serves as the main control board, is installed in the controller box unit 100 together with a solid-state drive or hard disk drive (SSD / HDD 122). The SSD / HDD 122 is a large-capacity storage device for storing electronic data, and mainly stores image processing programs, digital image data, and ancillary information of the digital image data. The controller box unit 100 is arranged on the rear side of the supply frame 100e, image frame 100f, and discharge frame 100g, spanning one or more of the supply block 110, image block 120, and discharge block 130. If the area of ​​the system controller board 111 is larger than the area of ​​the image control board 201, supply control board 202, and discharge control board 203, the system controller board 111 is positioned on the main body 1A of the image forming apparatus 1 such that, when viewed from the rear of the apparatus 1, a portion of the system controller board 111 overlaps with one of the control boards (see Figure 7 below).

[0037] <Image creation control board> The image formation control board 201, which performs image formation control to form a toner image on the recording material S, is installed in the image formation block 120. The image formation control board 201 includes an engine CPU 204, a ROM 206 for storing programs to control each part, a RAM 207 for temporarily storing data, and ASICs (Application Specific Integrated Circuits) 205a and 205b. The engine CPU 204, which is the image formation engine, executes various control processes in the image formation block 120 based on the control program stored in the ROM 206, in accordance with the control of the system CPU 112. Furthermore, the engine CPU 204 comprehensively controls the image formation process, including the supply of the recording material S, the formation of an image on the recording material S, and the ejection of the recording material S, in accordance with the control of the system CPU 112. In other words, the engine CPU 204 can be described as the overall control unit for image formation. Specifically, the engine CPU 204 controls the ASICs 205a and 205b, which are located on the same board, as well as the control units (ASICs 205c and 205d) on other boards in the other blocks.

[0038] ASIC205a is electrically connected by bundled wires to electrical components (second electrical components) such as a developer drive 210 that drives the developer unit 14, a toner density sensor 211 that detects the toner density in the developer unit 14, a drum drive 212 that drives the photosensitive drum 11, and an intermediate transfer drive 213 that drives the intermediate transfer belt unit 600. On the other hand, ASIC205b is electrically connected by bundled wires to electrical components such as a fuser drive 214 that drives the fuser unit 50, a toner bottle drive 215 that drives the toner bottle 90, and a toner bottle memory 216 that stores the remaining amount of toner in the toner bottle 90. In other words, ASIC205a and 205b of the image control board 201 control the electrical components by emitting drive signals that drive the electrical components provided in the same image block 120 as the image control board 201, based on control signals from the engine CPU 204.

[0039] <Supply control board> The supply control board 202, which controls the supply of recording material S contained in cassettes 31 and 32, is located in the supply block 110. The supply control board 202 has an ASIC 205c. The ASIC 205c is electrically connected by bundled wires to electrical components such as a supply drive 220 that drives the supply unit 300, a lift drive 221 that drives a lifter that is vertically movable within cassettes 31 and 32, and a remaining amount sensor 223 that detects the remaining amount of recording material S contained within cassettes 31 and 32. The ASIC 205c is also electrically connected by bundled wires to the engine CPU 204. In other words, the ASIC 205c of the supply control board 202 controls electrical components located in the same supply block 110 as the supply control board 202 by emitting drive signals that drive these electrical components based on control signals from the engine CPU 204.

[0040] <Emission control board> The discharge control board 203 that controls the discharge of the recording material S to the outside is disposed in the discharge block 130. The discharge control board 203 has an ASIC 205d. The ASIC 205d is electrically connected by a bundle of wires to electrical components such as a discharge drive 230 that drives the discharge unit 700. Also, the ASIC 205d is electrically connected by a bundle of wires to the engine CPU 204. That is, based on a control signal from the engine CPU 204, the ASIC 205d of the discharge control board 203 issues a drive signal to drive electrical components provided in the same discharge block 130 as the discharge control board 203 and controls those electrical components.

[0041] In the present embodiment, based on cooperative control by the system CPU 112 of the system controller board 111 and the engine CPU 204 of the image formation control board 201, the ASICs 205a, 205b, 205c, and 205d control the operation of the above-described electrical components. The system CPU 112 and the engine CPU 204 are electrically connected by a bundle of wires.

[0042] Although not shown in the drawings, the image forming apparatus 1 may be configured such that the recording materials S set in the manual tray are supplied one by one to the conveyance path 60. The manual tray and the manual feed unit having a manual feed roller that feeds the recording material S from the manual tray are provided in the supply block 110. In this case, the ASIC 205c is also connected to a manual drive 222 (electrical component) that drives the manual feed unit. Also, in the image forming apparatus 1, a discharge cooling fan 231 for cooling the recording material S discharged to the outside may be provided in the discharge block 130. In that case, the ASIC 205d is also connected to the discharge cooling fan 231.

[0043] <Regarding the drive signal between the ASIC and the electrical component> Next, the drive signals between the ASIC205 (205a, 205b, 205c, 205d) and the electrical components to be driven, which are electrically connected to these ASIC205s by wire bundles, will be explained using Figures 5(a) to 5(h) with reference to Figure 4. Note that the wire bundles connecting the ASIC205s and the electrical components to be driven include at least communication lines capable of transmitting drive signals and may be bundled with power supply lines and the like.

[0044] Figure 5(a) shows the case where the electrical component to be driven is a stepping motor 411, and is applied to the developing drive 210, supply drive 220, manual feed drive 222, and ejection drive 230. The ASIC205 is connected to the "STMDrv" IC401 for operating the stepping motor 411, and controls the stepping motor 411 via the "STMDrv" IC401 with the following signals. The "STM_CLK" signal is a PWM signal with a "Duty 50%" and advances the electrical angle of the stepping motor 411 by one with each pulse. The "STM_VREF" signal is a PWM signal with a "100KHz" and is used to determine the output current of the stepping motor 411. These PWM signals are smoothed by an RC filter circuit (not shown) and input to the "STMDrv" IC401 as DC signals. The "STMDrv" IC401 determines the drive current of the stepping motor 411 according to the voltage level of the input DC signal.

[0045] The "STM_DIR" signal is used to determine the rotation direction of the stepping motor 411. When the "STM_DIR" signal outputs "H", the stepping motor 411 rotates in the forward direction, and when the "STM_DIR" signal outputs "L", the stepping motor 411 rotates in the reverse direction. The "STM_MODE" signal is used to set the excitation mode of the stepping motor 411, and is, for example, a 2-bit DC signal. For example, when "MODE0:1="H:H"", it is set to 2-phase excitation mode, and when "MODE0:1="H:L"", it is set to 1-2 phase excitation mode. The stepping motor 411 is output according to the settings of the "STMDrv" IC401 based on these signals.

[0046] Figure 5(b) shows the case where the driven electrical component is a DC brushless fan 412, and is applied to the exhaust cooling fan 231. When the ASIC 205 outputs a "FAN_ON" signal, the field-effect transistor (FET) 402 is turned "ON", and a DC voltage of "+24V" is input to the DC brushless fan 412. When a DC voltage of "+24V" is input, the DC brushless fan 412 starts to rotate. When the DC brushless fan 412 starts to rotate, it outputs a "FAN_LOCK" signal. The ASIC 205 detects the rotation operation of the DC brushless fan 412 by the "FAN_LOCK" signal.

[0047] Figure 5(c) shows the case where the electrical component to be driven is a DC brush motor 413, and is applied to the toner bottle drive 215 and the lift drive 221. The ASIC 205 is connected to the "DCBM Drv" IC 403 for operating the DC brush motor 413, and controls the DC brush motor 413 via the "DCBM Drv" IC 403 by the following signals. The "BM_CLK" signal is a 20kHz variable duty cycle PWM signal, and the "DCBM Drv" IC 403 controls the rotation speed of the DC brush motor 413 by the duty cycle ratio of the PWM signal. The "BM_DIR" signal is a signal for determining the rotation direction of the DC brush motor 413. When the "BM_DIR" signal outputs "H", the DC brush motor 413 rotates in the forward direction, and when the "BM_DIR" signal outputs "L", the DC brush motor 413 rotates in the reverse direction.

[0048] Figure 5(d) shows the case where the electrical component to be driven is a DC brushless motor 414, and is applied to the drum drive 212, intermediate transfer drive 213, and fixing drive 214. The "BLM_CLK" signal is a PWM signal with a "Duty 50%" and is used to transmit the set speed to the DC brushless motor 414. The "BLM_DIR" signal is used to determine the rotation direction of the DC brushless motor 414. When the "BLM_DIR" signal outputs "H", the DC brushless motor 414 rotates in the forward direction, and when the "BLM_DIR" signal outputs "L", the DC brushless motor 414 rotates in the reverse direction. The "BLM_BRAKE" signal is used to activate the short brake of the DC brushless motor 414. When the "BLM_BRAKE" signal outputs "H", the DC brushless motor 414 activates the short brake by short-circuiting the coils of the motor in order to shorten the stopping time required for rotation to stop.

[0049] Figure 5(e) shows the case where the driven electrical component is an inductor sensor 415, and is applied to the toner density sensor 211. The "INDUC_VREF" signal is a signal for generating a reference voltage for the inductor sensor 415, and is transmitted to the inductor sensor 415 after its level is amplified by the operational amplifier circuit 405. The inductor sensor 415 detects the ratio of toner to carrier in the developer contained in the developer unit 14 and outputs an "INDUC_OUT" signal corresponding to the ratio. The "INDUC_OUT" signal is converted to the "3.3V range" by the operational amplifier circuit 405 and input to the ASIC 205 as an "INDUC_SNS" signal. The ASIC 205 has a built-in A / D conversion circuit and converts the input "INDUC_SNS" signal into a digital value to detect the voltage value.

[0050] Figure 5(f) shows the case where the electrical component to be driven is an EEPROM (Electrically Erasable Programmable Read-Only Memory) 416, and is applied to the toner bottle memory 216. Data communication between the ASIC 205 and the EEPROM 416 is performed using serial communication such as I2C communication, and the ASIC 205 reads / writes data to the EEPROM 416.

[0051] Figure 5(g) shows the case where the electrical component to be driven is the photointerrupter 417, and is applied to the remaining amount sensor 223. The "PI_SNS" signal is a signal output by the photointerrupter 417, which outputs "L" when light is transmitted and "H" when light is blocked. By receiving the "PI_SNS" signal, the ASIC 205 can detect the remaining amount of recording material S.

[0052] Figure 5(h) applies when the electrical component to be driven is the main switch 233. The "SW_SNS" signal is output by the main switch 232, and the main switch 233 outputs "L" when switched on and "H" when switched off. By receiving the "SW_SNS" signal, the ASIC 205 can detect the on / off state of the main switch 233.

[0053] <Regarding control signals between the engine CPU and ASIC> Next, the control signals between the engine CPU 204 of the image control board 201 and the ASICs 205c and 205d, which are electrically connected to the engine CPU 204 by a bundle of wires, will be explained using Figures 6(a) and 6(b) with reference to Figure 4. In this embodiment, either a "bus method" or a "command-based method" may be adopted as the method for transferring data between the engine CPU 204 and the ASICs 205c and 205d. The bundle of wires connecting the engine CPU 204 and the ASICs 205c and 205d includes at least communication lines capable of transmitting control signals. Furthermore, the control signals sent from the engine CPU 204 are digital signals represented by a combination of two logical values.

[0054] Figure 6(a) shows the cases where the engine CPU 204 and ASIC 205 are connected in parallel and serial using the "bus method". First, we will describe the case where the engine CPU 204 and ASIC 205 are connected in parallel. The engine CPU 204 transmits signals such as address signals, control data, and read / write instructions to the ASIC 205 simultaneously via multiple communication lines. The multiple communication lines are parallel transfer-capable buses that have an address bus (ABUS), a data bus (DBUS), and a control bus (CTRL) with read enable signals (RE) and write enable signals (WE).

[0055] For example, when the engine CPU 204 sends an address signal and a read instruction (execution instruction) to the ASIC 205, the ASIC 205 reads the data stored at the address corresponding to the address signal from its own memory and sends the read data to the engine CPU 204. The engine CPU 204 stores the data read from the ASIC 205's memory in the RAM 207. On the other hand, when the engine CPU 204 sends an address signal, a write instruction (execution instruction), and data to the ASIC 205, the ASIC 205 writes the received data to the address corresponding to the address signal in its own memory. The ASIC 205 (205c, 205d) controls electrical components by referencing the data stored in its own memory and issuing drive signals to drive those components.

[0056] Next, we will describe the case where the engine CPU 204 and ASIC 205 are connected in serial mode. When the command (CMD) of the engine CPU 204 is a write instruction (WR), it sends the write instruction, address signal (ADR), and data (DATA) in chronological order via the communication line (serial bus TX). In this case, the ASIC 205 writes the received data to the address corresponding to the address signal in its internal memory. Then, the ASIC 205 sends an acknowledgment signal (ACK) to the engine CPU 204 via the communication line (serial bus RX) indicating whether or not it was able to write the data corresponding to the write instruction correctly.

[0057] On the other hand, when the command (CMD) of the engine CPU 204 is a read instruction (RD), it sends the read instruction and address signal (ADR) to the ASIC 205 in chronological order via the communication line (serial bus TX). When the ASIC 205 receives the read instruction and address signal from the engine CPU 204, it reads the data stored at the address corresponding to the address signal from the memory within the ASIC 205 and sends the read data (DATA) to the engine CPU 204 via the communication line (serial bus RX). Subsequently, the ASIC 205 sends a response signal (ACK) via the communication line (serial bus RX) to the engine CPU 204 indicating whether or not it was able to read the data corresponding to the read instruction correctly. In this way, even with a serial connection that reduces the number of communication lines between the engine CPU 204 and the ASIC 205, it is possible to send and receive control signals in the same way as in the parallel connection described above.

[0058] Figure 6(b) shows the case where the engine CPU 204 and ASIC 205 (205c, 205d) are connected in serial mode using the "command-based method". When controlling electrical components, the engine CPU 204 sends a predetermined control command (CMD(ACT)) corresponding to the electrical component to be driven to the ASIC 205 via the communication line (serial bus TX). When the ASIC 205 receives a control command from the engine CPU 204, it sends a response signal (ACK) to the engine CPU 204 via the communication line (serial bus RX) indicating whether it was received correctly. Upon receiving the control command from the engine CPU 204, the ASIC 205 controls the electrical components by issuing drive signals to drive them. For example, when receiving a detection result from the remaining amount sensor 223 (when reading the sensor value), the engine CPU 204 sends a sensor value read command (CMD(SNS)) to the ASIC 205. When the ASIC 205 receives a sensor value read command from the engine CPU 204, it receives the sensor value from the remaining charge sensor 223 and sends the received sensor value (DATA) to the engine CPU 204. Subsequently, the ASIC 205 sends a response signal (ACK) to the engine CPU 204 indicating whether the sensor value reception operation of the remaining charge sensor 223 was performed correctly.

[0059] <Regarding the arrangement and wiring of the control board and electrical components> Next, the arrangement and wiring of the control board and electrical components in the electrical system shown in Figure 4 will be explained using Figures 7 to 9, with reference to Figures 3 and 4. As shown in Figure 7, the image forming apparatus 1 is composed of three blocks from bottom to top: a supply block 110, an image-forming block 120, and an output block 130. A supply control board 202, an image-forming control board 201, and an output control board 203 are installed in the frame of each block.

[0060] In this embodiment, as described above, the supply control board 202 located in the supply block 110 controls the electrical components provided in the supply block 110. The image creation control board 201 located in the image creation block 120 controls the electrical components provided in the image creation block 120. The discharge control board 203 located in the discharge block 130 controls the electrical components provided in the discharge block 130 (excluding the main switch 233). That is, the electrical components that are the targets of the supply control board 202, the image creation control board 201, and the discharge control board 203 are located in the same blocks as the respective control boards. This is to keep the wiring bundles that electrically connect each control board to the target electrical components within the wiring of each block. In some blocks, the wiring connecting the control board and the target electrical components may pass outside the block. It is sufficient that the wiring network connecting the control board and the target electrical components in at least one block is enclosed within that block.

[0061] As shown in Figure 7, the supply control board 202 (specifically ASIC205c) and the supply drive 220, lift drive 221, manual feed drive 222, and remaining amount sensor 223, which are the targets of the supply control board 202, are electrically connected by a bundle of wires 810. The bundle of wires 810 is located within the wiring inside the supply frame 100e of the supply block 110 (inside the frame). The bundle of wires 810 is detachably provided on at least one of the supply control board 202 (specifically ASIC205c) and the supply drive 220, lift drive 221, manual feed drive 222, and remaining amount sensor 223.

[0062] Furthermore, the image control board 201 (specifically ASIC205a, 205b) and the developing drive 210, toner density sensor 211, drum drive 212, intermediate transfer drive 213, fuser drive 214, toner bottle drive 215, and toner bottle memory 216, which are the targets of the image control board 201, are electrically connected by a bundle of wires 820. The bundle of wires 820 is contained within the wiring of the image frame 100f of the image block 120. The bundle of wires 820 is detachably provided on at least one of the image control board 201 (specifically ASIC205a, 205b) and the developing drive 210, toner density sensor 211, drum drive 212, intermediate transfer drive 213, fuser drive 214, toner bottle drive 215, and toner bottle memory 216.

[0063] Furthermore, the discharge control board 203 (specifically ASIC205d) and the discharge drive 230 and discharge cooling fan 231, which are driven by the discharge control board 203, are electrically connected by a wiring bundle 830. The wiring bundle 830 is contained within the wiring of the discharge frame 100g of the discharge block 130. The wiring bundle 830 is detachably provided on at least one of the discharge control board 203 (specifically ASIC205d) and the discharge drive 230 and discharge cooling fan 231. In this way, each control board and the electrical components to be driven are connected by wiring bundles 810, 820, and 830. As described above, by arranging each control board and the electrical components to be driven in the same block, the wiring of the wiring bundles 810, 820, and 830 can be completed within each block.

[0064] On the other hand, the image control board 201 (specifically the engine CPU 204) and the ASIC 205c of the supply block 110 are electrically connected by a wiring harness 800. The wiring harness 800 is routed across the boundary between the image frame 100f of the image block 120 and the supply frame 100e of the supply block 110. Furthermore, the image control board 201 (specifically the engine CPU 204) and the ASIC 205d of the discharge block 130 are electrically connected by a wiring harness 801. The wiring harness 801 is routed across the boundary between the image frame 100f of the image block 120 and the discharge frame 100g of the discharge block 130. In this way, the image control board 201 equipped with the engine CPU 204 and the supply control board 202 and discharge control board 203, which do not have the engine CPU 204 but only have ASICs 205c and 205d, are connected only by bundled wires 800 and 801 (control communication lines), thereby enabling connection between blocks in a simple configuration.

[0065] In the above embodiment, the image control board 201 has two ASICs, ASIC205a and ASIC205b. For electrical components that transmit signals to the system CPU 112 and engine CPU 204, such as the main switch 233, it is not always best to complete the electrical connection by bundling wires within the same block. That is, as shown in Figure 7, the main switch 233 and the image control board 201 (specifically ASIC205d) are electrically connected by a bundle of wires 850 that spans the discharge frame 100g of the discharge block 130 and the image frame 100f of the image block 120. In such a case, by dividing the configuration into ASIC205a, whose connection is completed within the image block 120, and ASIC205b, which has a connection to the discharge control board 203, the wiring of the bundle of wires 820 is completed within the image block 120 for at least one ASIC205a.

[0066] In contrast, as shown in Figure 8, for example, the main switch 233 may be driven by the ASIC 205d of the discharge control board 203, and the main switch 233 and the discharge control board 203 may be electrically connected by a wire bundle 860, as shown in Figure 9. In this case, the detection signal from the main switch 233 is transmitted to the ASIC 205c of the discharge control board 203, and is configured to be detectable by the engine CPU 204 through communication between the engine CPU 204 and the ASIC 205c. Furthermore, the engine CPU 204 is configured to notify the system CPU 112 of the status of the main switch 233 through communication. In this configuration, as shown in Figure 9, the wire bundle 860 connecting the main switch 233 and the discharge control board 203 can be kept within the wiring of the discharge block 130 without crossing the image frame 100f of the image block 120 and the discharge frame 100g of the discharge block 130.

[0067] As described above, in this embodiment, in each block (110, 120, 130), the ASIC 205 of each control board (202, 201, 203) and the electrical component to be driven are electrically connected by bundled wires (810, 820, 830). Since each control board having an ASIC 205 is placed in the same block frame (100e, 100f, 100g) as the electrical component to be driven, the wiring of the bundled wires (810, 820, 830) can be secured within each block frame (100e, 100f, 100g). That is, the bundled wires (810, 820, 830) are wired without crossing the frame (100e, 100f, 100g). This allows the wiring bundles that span across the frame bodies (100e, 100f, 100g) to be limited to the wiring bundles 800, 801 connecting the engine CPU 204 of the image control board 201 to the ASIC 205c of the supply control board 202 and the ASIC 205d of the discharge control board 203. As a result, when the user removes the wiring bundles (810, 820, 830) connected to the electrical components to be maintained that are electrically connected to the control board, they do not need to access other frame bodies that do not contain the electrical components to be maintained. Therefore, the ease of maintenance of electrical components by the user can be improved. [Explanation of Symbols]

[0068] 1…Image forming apparatus, 1A…Apparatus body, 100e…Frame (supply frame), 100f…Frame (image forming frame), 100g…Frame (discharge frame), 111…Main control board (system controller board), 201…Control board (image forming control board), 202…Control board (supply control board), 203…Control board (discharge control board), 204…Engine CPU (overall control unit), 205a, 205b, 205c, 205d…Control unit (ASIC), 210, 211, 212, 213…Electrical components, 220, 221, 222, 223…Electrical components, 230, 231, 233…Electrical components, 800, 801…Control communication lines (bundles), 810, 820, 830…Communication lines (bundles), S…Recording material

Claims

1. An image forming apparatus for forming an image on a recording material, The apparatus body comprises at least a first frame and a second frame arranged in the vertical direction, A first electrical member provided in the first frame and which operates physically based on electrical control, A second electrical component provided in the second frame and which operates physically based on electrical control, A first control board is arranged in the first frame and connected to the first electrical component, and controls the driving of the first electrical component. The second control board is disposed on the second frame and connected to the second electrical component, and controls the driving of the second electrical component, An image forming apparatus characterized by the following features.

2. The connection between the first control board and the object controlled by the first control board is closed within the first frame. The image forming apparatus according to feature 1.

3. The connection between the second control board and the object controlled by the second control board is closed within the second frame. The image forming apparatus according to feature 2.

4. The first control board has a first control unit that generates a drive signal to the first electrical component provided in the first frame, The first control unit and the first electrical component are wired within the first frame and connected by a communication line that transmits the drive signal emitted from the first control unit. The image forming apparatus according to feature 1.

5. The first control board has a first control unit that generates a drive signal for the first electrical component, The second control board has a second control unit that generates a drive signal for the second electrical component, The first control board further includes a control unit that transmits control signals to the first control unit and the second control unit. The image forming apparatus according to feature 1.

6. The connection between the first control board and the object controlled by the first control board is closed within the first frame, The connection between the second control board and the object controlled by the second control board is closed within the second frame. The connection between the central control unit of the first control board and the second control unit of the second control board is made across the boundary between the first frame and the second frame. The image forming apparatus according to feature 5.

7. The first control unit and the first electrical component are wired within the first frame and connected by a first communication line that communicates the drive signal emitted from the first control unit. The second control unit and the second electrical component are wired within the second frame and connected by a second communication line that transmits the drive signal emitted from the second control unit. The central control unit of the first control board and the second control unit of the second control board are connected by a control communication line that is wired across the boundary between the first frame and the second frame and transmits control signals emitted from the central control unit. The image forming apparatus according to feature 5.

8. The control signal is a signal that includes an execution command for controlling the second control unit of the second control board, The second control unit generates a drive signal to drive the second electrical component provided on the second frame in accordance with the execution command sent from the main control unit. The image forming apparatus according to feature 7.

9. The drive signal includes a signal for driving the motor included in the first electrical component. The control signal includes a digital signal which includes at least one of an address signal, a read command, a write command, and control data. The image forming apparatus according to feature 7.

10. The first communication line is detachably provided to at least one of the first control unit and the second electrical component. The second communication line is detachably provided to at least one of the second control unit and the second electrical component. The image forming apparatus according to feature 7.

11. The image forming apparatus further comprises a main control board that controls the operation of the entire image forming apparatus, The main control board has a larger area than the first control board and the second control board. When the image forming apparatus is viewed from the rear, a portion of the main control board overlaps with the first control board. The image forming apparatus according to feature 1.

12. An image forming apparatus for forming an image on a recording material, A first electrical component that operates physically based on electrical control, A second electrical component that operates physically based on electrical control, Viewed from the rear of the image forming apparatus, a first control board is positioned so as to overlap the first electrical component and is connected to the first electrical component, and controls the driving of the first electrical component. The image forming apparatus, when viewed from the rear, is positioned so as to overlap the second electrical component and is connected to the second electrical component, and includes a second control board that controls the driving of the second electrical component. An image forming apparatus characterized by the following features.

13. The first control board has a first control unit that generates a drive signal for the first electrical component, The second control board has a second control unit that generates a drive signal for the second electrical component, The first control board further includes a control unit that transmits control signals to the first control unit and the second control unit. The image forming apparatus according to feature 12.

14. The first control unit and the first electrical component are connected by a first communication line that communicates the drive signal emitted from the first control unit. The second control unit and the second electrical component are connected by a second communication line that communicates the drive signal emitted from the second control unit. The overall control unit of the first control board and the second control unit of the second control board are connected by a control communication line that transmits control signals emitted from the overall control unit. The image forming apparatus according to feature 13.

15. The control signal is a signal that includes an execution command for controlling the second control unit of the second control board, The second control unit generates a drive signal to drive the second electrical component in accordance with the execution command sent from the main control unit. The image forming apparatus according to feature 14.

16. The drive signal includes a signal for driving the motor included in the first electrical component. The control signal includes a digital signal which includes at least one of an address signal, a read command, a write command, and control data. The image forming apparatus according to feature 14.

Images