Image forming apparatus

Abstract

To constitute an electric contact by using an elastic member such as a torsion coil spring regardless of an attachment method of a power source substrate.SOLUTION: An image formation apparatus according to the present invention comprises: image formation means which forms an image on a recording material; a printed circuit board on which voltage generation means for generating the voltage applied to a process member is mounted; a conductive member which is provided on the printed circuit board and is applied with the voltage generated by the voltage generation means; and an elastic member which has an arm part that is biased toward the conductive member and connects the conductive member to the process member. The image formation apparatus also comprises a holding unit which can hold the arm part at a position where the arm part of the elastic member does not contact the conductive member.SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The present invention relates to an image forming apparatus including a circuit board.

Background Art

[0002] In an electrophotographic image forming apparatus, an electrostatic latent image is formed on a photoreceptor charged in a charging unit, the electrostatic latent image is developed as a toner image in a developing unit, and the developed toner image is transferred to a recording material in a transfer unit to form an image. Here, high voltages of several hundred volts to several kilovolts are applied to the charging unit, the developing unit, and the transfer unit. Therefore, the image forming apparatus includes a circuit board having a high-voltage power supply circuit that generates a high voltage. ...... Patent Document 1 describes a configuration in which an electrical contact is formed by a jumper wire provided on a circuit board and a torsion coil spring provided on the main body side in order to supply the high voltage generated by the high-voltage power supply circuit to each process member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration described in Patent Document 1, the method of attaching the circuit board to the image forming apparatus is limited. That is, it is necessary to attach the circuit board to the image forming apparatus while pressing the jumper wire provided on the circuit board against the arm portion of the torsion coil spring biased in a predetermined direction. For example, it is necessary to attach the circuit board to the image forming apparatus in such a manner that the circuit board is inserted from the side opposite to the biasing direction of the arm portion of the torsion coil spring. By thus limiting the attachment method, there are cases where the configuration of Patent Document 1 cannot be used depending on the configuration of the image forming apparatus or the circuit board.

[0006] Therefore, the present invention aims to configure electrical contacts using elastic members such as torsion coil springs, regardless of the method of mounting the circuit board. [Means for solving the problem]

[0007] To achieve the above objectives, the present invention is: A method for manufacturing an image forming apparatus, The image forming apparatus is Image forming means for forming an image on a recording material, A printed circuit board on which a voltage generation means for generating a voltage to be applied to the image forming means is mounted, A conductive member provided on the printed circuit board to which a voltage generated by the voltage generating means is applied, An elastic member having an arm portion that is biased toward the conductive member and in contact with the conductive member, the elastic member being electrically connected to the image forming means, The holding part, It has, The aforementioned manufacturing method is A mounting step in which the printed circuit board is mounted while the arm portion is held in a retracted position by the holding portion so as not to come into contact with the conductive member, in a first direction opposite to the direction in which the arm portion is biased toward the conductive member, A removal step is performed after the mounting step, in which the arm portion is removed from the holding portion so that the arm portion comes into contact with the conductive member, including, This is a method for manufacturing an image forming apparatus, characterized by the following features. [Effects of the Invention]

[0008] As described above, according to the present invention, electrical contacts can be configured using elastic members such as torsion coil springs, regardless of the method of mounting the circuit board. [Brief explanation of the drawing]

[0009] [Figure 1] Perspective view of an image forming apparatus [Figure 2] Cross-sectional view of an image forming apparatus [Figure 3] Perspective view illustrating the location of the circuit board [Figure 4] Front perspective view to explain the location of the circuit board [Figure 5] Perspective view of the circuit board and its surrounding components. [Figure 6] Side view of the circuit board and its surrounding components [Figure 7]Top view of the circuit board and its peripheral components [Figure 8] Perspective view for explaining the holding structure of the optical box and the drive motor [Figure 9] Diagram for explaining the electronic components on the circuit board [Figure 10] Block diagram for explaining the functions of the circuit board [Figure 11] Perspective view showing the configuration of the electrical contact [Figure 12] Cross-sectional view showing the configuration of the electrical contact [Figure 13] Top view for explaining the wiring path of the harness [Figure 14] Side view showing the first stage of the process of attaching the circuit board [Figure 15] Side view showing the second stage of the process of attaching the circuit board [Figure 16] Side view showing the third stage of the process of attaching the circuit board [Figure 17] Diagram showing the position of the notch for the electrical contact on the circuit board [Figure 18] Perspective view showing the configuration of the holding part of the arm part of the torsion coil spring in Example 1 [Figure 19] Perspective view showing the configuration of the holding part of the arm part of the torsion coil spring in Example 2 [Figure 20] Perspective view showing the configuration of the holding part of the arm part of the torsion coil spring in Example 3

Mode for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, the mode for carrying out this invention will be illustratively and specifically described based on examples. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment of implementation should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. That is, it is not intended to limit the scope of this invention to the following embodiments of implementation.

[0011] (Example 1) [Overall Configuration of the Image Forming Apparatus] The overall configuration of the image forming apparatus 1 in this embodiment will now be described. The image forming apparatus 1 in this embodiment is a monochrome laser beam printer using an electrophotographic process, and forms an image on the recording material P using a developer (toner) according to image information transmitted from an external device such as a personal computer. Examples of recording material P include recording paper, label paper, OHP sheets, cloth, etc.

[0012] Furthermore, in the following description, the height direction of the image forming apparatus 1 when it is installed on a horizontal surface (the direction opposite to the vertical direction) will be referred to as the Z direction. The direction that intersects the Z direction and is parallel to the axial direction (main scanning direction) of the photosensitive drum 11, which will be described later, will be referred to as the X direction. The direction that intersects the X direction and the Z direction will be referred to as the Y direction. Preferably, the X direction, Y direction and Z direction intersect perpendicularly to each other. Also, for convenience, in the X direction, the positive side will be referred to as the right side and the negative side as the left side, in the Y direction, the positive side will be referred to as the front side and the negative side as the rear side, and in the Z direction, the positive side will be referred to as the upper side and the negative side as the lower side.

[0013] Figure 1 shows a perspective view of the image forming apparatus 1, and Figure 2 shows a cross-sectional view of the image forming apparatus 1 cut in a plane perpendicular to the X direction (the rotation axis direction of the photosensitive drum 11). In Figure 1, the image forming apparatus 1 has a feed cassette 4 in which recording material P is contained, and an output tray 14 on which the discharged recording material P is loaded. When the feed cassette 4 is inserted into the feed port 81, the recording material P contained in the feed cassette 4 becomes ready to be fed into the image forming apparatus 1. The feed cassette 4 can also be pulled out in the Y direction from the feed port 81, allowing the user to replenish the recording material P. The recording material P that has been fed from the feed cassette 4 and on which an image has been formed is discharged from the output port 15 in the output direction (positive Y-axis direction) shown in Figure 1 and loaded onto the output tray 14.

[0014] A front cover 70 is provided on a portion of the end face (part of the front) of the image forming apparatus 1 on the downstream side in the discharge direction, covering the circuit board 100 which will be described later. An outer cover 71 is provided on a portion of the front other than where the front cover 70 is located, as well as on the sides and top of the image forming apparatus 1. The front cover 70, the outer cover 71, and the discharge tray 14 described above all form the housing 75 of the image forming apparatus 1. Here, the housing 75 is a component that covers the entire image forming apparatus 1 and contains process components such as the optical box 50 which will be described later. The feeding port 81 and the discharge port 15 described above are openings formed in a part of the housing 75, and the recording material P is inserted into the inside of the image forming apparatus 1 through the feeding port 81, and the recording material P is discharged to the outside of the image forming apparatus 1 through the discharge port 15.

[0015] The flow of the image formation operation on the recording material P will be explained using the cross-sectional view in Figure 2. When image information is transmitted to the image forming apparatus 1, the photosensitive drum 11 (image carrier), which is a rotating body, is driven to rotate at a predetermined peripheral speed (process speed) in the direction of arrow R based on the print start signal. The optical box 50 irradiates the photosensitive drum 11 with laser light based on the input image information. The optical box 50 is a box-shaped unit that contains components such as a laser oscillator that outputs laser light, a polygon mirror and lens for irradiating the photosensitive drum 11 with laser light, and a scanner motor for rotating the polygon mirror. The photosensitive drum 11 is pre-charged by the charging roller 17, and an electrostatic latent image is formed on the photosensitive drum 11 when irradiated with laser light. Subsequently, this electrostatic latent image is developed by toner by the developing roller 12, and a toner image is formed on the photosensitive drum 11.

[0016] In parallel with the image forming process described above, recording material P is fed from the feeding cassette 4. A pickup roller 3, a feeding roller 5a, and a pair of transport rollers 5c are provided on the transport path of the image forming apparatus 1. The pickup roller 3 (feeding member) contacts the uppermost recording material P contained in the feeding cassette 4, and the roller itself rotates to feed the recording material P in the feeding direction (negative Y-axis direction). The feeding roller 5a and the separation pad 5b that presses against it form a separation nip. If multiple recording materials P are fed into the separation nip due to the frictional force between the recording materials P, the feeding roller 5a and the separation pad 5b separate the multiple recording materials P and feed only the uppermost one downstream.

[0017] The recording material P fed from the feed cassette 4 is transported toward the transfer roller 7 by the transport roller pair 5c. When a transfer bias is applied to the transfer roller 7, the toner image formed on the photosensitive drum 11 is transferred to the recording material P. The recording material P onto which the toner image has been transferred by the transfer roller 7 is heated and pressurized by the fixing device 9, fixing the toner image to the recording material P. The fixing device 9 consists of a heating roller 9a with a built-in heater (not shown) and a pressurizing roller 9b that is biased toward the heating roller 9a. The recording material P with the fixed toner image is then discharged into the discharge tray 14 by the discharge roller pair 10.

[0018] When forming an image on both sides of the recording material P, the discharge roller pair 10 guides the recording material P to the double-sided transport path 16 by switching back the recording material P on which the image has been formed on the first side. The recording material P guided to the double-sided transport path 16 is then transported again toward the transfer roller 7 by the double-sided transport roller pair 5d. After an image is formed on the second side of the recording material P by the transfer roller 7, it is discharged from the machine by the discharge roller pair 10. After the toner image has been transferred to the recording material P, any toner remaining on the photosensitive drum 11 is cleaned by the cleaning unit 13.

[0019] As shown in Figure 2, the image forming apparatus 1 has a circuit board 100. The circuit board 100 consists of a printed circuit board 101 made of an insulator and a group of electronic components 111 and 121 soldered to the printed circuit board 101. Since the printed circuit board 101 has conductive wiring, the group of electronic components 111 and 121 are electrically connected. The circuit board 100 is equipped with a converter circuit (not shown) that rectifies the voltage supplied from outside the image forming apparatus 1 and converts the voltage to obtain a predetermined voltage value required for the image forming process.

[0020] As shown in Figure 2, the circuit board 100 is positioned such that the surface of the printed circuit board 101 on which the electronic component groups 111 and 121 are mounted intersects with the discharge direction. Furthermore, the printed circuit board 101 is located between the front cover 70 and the optical box 50 in the discharge direction. The electronic component groups 111 and 121 are located on the surface of the printed circuit board 101 facing the optical box 50.

[0021] [Circuit board layout] The arrangement of the circuit board 100 in this embodiment will be explained in detail with reference to Figures 3 to 8. Figure 3 is a perspective view of the image forming apparatus 1 to illustrate the arrangement of the circuit board 100, and unlike Figure 1, the front cover 70 and outer cover 71 are omitted. As shown in Figure 3, the circuit board 100 is installed on the front side, and the optical box 50 and drive motor 60 are provided further back (negative side in the Y direction) from the circuit board 100. Note that in Figure 3, the optical box 50 and drive motor 60 are in a position that is not actually visible, so they are shown with dotted lines.

[0022] As shown in Figure 3, the image forming apparatus 1 has a right-side plate frame 72 (first side plate frame), a left-side plate frame 73 (second side plate frame), and a base frame 74. The right-side plate frame 72 supports the right end (first end) of the photosensitive drum 11 in the X direction, and the left-side plate frame 73 supports the left end (second end) of the photosensitive drum 11 in the X direction. The base frame 74 is provided on the bottom surface and supports the right-side plate frame 72 and the left-side plate frame 73 from below.

[0023] The circuit board 100 is supported by these frame members and mounted on the image forming apparatus 1 such that its surface is approximately parallel to the XZ plane. Bent portions 72a and 73a are formed at the ends of the right plate frame 72 and the left plate frame 73 in the Y direction, respectively, for reinforcement. The bent portion 72a is bent toward the positive X direction so as to be approximately parallel to the XZ plane, and the bent portion 73a is bent toward the negative X direction so as to be approximately parallel to the XZ plane. In other words, the bent portions 72a and 73a are bent to conform to the surface of the printed circuit board 101. By bending both side plate frames toward the outside of the image forming apparatus 1 (away from the photosensitive drum 11 in the X direction), electronic components can be mounted over a larger area of ​​the printed circuit board 101.

[0024] Figure 4 is a front perspective view of the image forming apparatus 1 to illustrate the arrangement of the circuit board 100. As shown in Figure 4, the distance L1 between the inner surfaces of the right plate frame 72 and the left plate frame 73 in the X direction is shorter than the length L2 of the circuit board 100 in the X direction. The printed circuit board 101 is positioned on the positive side (front side) in the Y direction relative to the bent portions 72a and 73a, and the printed circuit board 101 is in contact with the bent portions 72a and 73a, respectively. When viewed from the front, the circuit board 100 and the bent portions 72a and 73a overlap. In Figure 4, the bent portions 72a and 73a, the optical box 50, and parts of the drive motor 60 are not actually visible, so they are shown with dotted lines.

[0025] [Positional relationship between electronic components and optical boxes] Next, the positional relationship between the electronic component group 111 and the optical box 50 will be explained in detail using Figures 5 to 7.

[0026] Figure 5 is a perspective view of the circuit board 100 from the rear of the main unit. The group of electronic components 111, which is larger in size in the Y direction compared to other components, is concentrated at the bottom of the printed circuit board 101 to make effective use of space and is mounted so that it fits in the lower part of the optical box 50. More specifically, the group of electronic components 111 is located below the center of the printed circuit board 101 in the vertical direction. A power input section 115 is provided at the end of the printed circuit board 101. The power input section 115 is connected to an inlet (not shown) and receives power from the commercial power supply.

[0027] Figure 6 is an enlarged side view of the circuit board 100 as seen from the left side of the main unit. The optical box 50 is positioned in the optimal location for irradiating the photosensitive drum 11 with laser light, indicated by the dashed line. Furthermore, no components such as the group of electronic components 111 that protrude significantly from the board surface are placed at the point where the optical box 50 and the printed circuit board 101 are closest in the Y direction. In other words, the optical box 50 and the group of electronic components 111 are offset in the Z direction so as not to interfere with each other.

[0028] Figure 7 is an enlarged top view of the circuit board 100 as seen from the top of the main unit. In this figure, the optical box 50 and the group of electronic components 111 are positioned so that they partially overlap each other. As mentioned above, the optical box 50 is above the group of electronic components 111, so the group of electronic components 111 cannot normally be seen from this direction. In Figure 7, to make the positional relationship between the two components easier to understand, the optical box 50 is shown with a dotted line, and the group of electronic components 111 is shown as if viewed through it.

[0029] By arranging the electronic component group 111 in the above-mentioned positions, the distance between the circuit board 100 and the optical box 50 in the Y direction (front-to-back direction) can be shortened, and the image forming apparatus 1 can be miniaturized.

[0030] [Positional relationship between electronic components and drive motor] Next, the positional relationship between the electronic component group 111 and the drive motor 60 will be explained in detail using Figures 5 to 7. The drive motor 60 is responsible for rotating the components for feeding and transporting the recording material P (such as the pickup roller 3, feeding roller 5a, and transport roller pair 5c) and the photosensitive drum 11.

[0031] As shown in Figure 5, the drive motor 60 protrudes to the negative side in the X direction, and the printed circuit board 101 is positioned in front of the drive motor 60. It can be seen that the electronic component group 111 is mounted to avoid interference with the drive motor 60. As shown in Figure 6, when viewed from the left side of the main body, the drive motor 60 and the electronic component group 111 are positioned so that they partially overlap each other. And, as shown in Figure 7, when viewed from the top of the main body, the drive motor 60 and the electronic component group 111 are offset in the X direction so that they do not interfere with each other.

[0032] By arranging the electronic component group 111 in the above-mentioned positions, the distance between the circuit board 100 and the drive motor 60 in the Y direction (front-to-back direction) can be shortened, and the image forming apparatus 1 can be miniaturized.

[0033] [Mounting configuration for the main unit] Next, Figure 8 will be used to describe in detail the mounting configuration of the optical box 50 and the drive motor 60 to the main body. Figure 8 is the same as the perspective view of Figure 5, but with the addition of the right-side plate frame 72 and the scanner holding member 40. The left-side plate frame 73 and the base frame 74 are omitted.

[0034] The optical box 50 is held by the scanner holding member 40. The scanner holding member 40 is fixed to the right plate frame 72 and the left plate frame 73 (not shown in Figure 8), respectively, and is configured to bridge the two frames. On the other hand, the drive motor 60 is attached to the right plate frame 72, and the gear connected to the drive motor 60 is located on the positive X-direction side (right side) of the right plate frame 72. The driving force of the drive motor 60 is transmitted to the feed roller 5a and the photosensitive drum 11 via this gear.

[0035] [Circuit board configuration] Next, the configuration of the circuit board 100 will be explained using Figure 9. Figure 9 is a rear view of the circuit board 100 as seen from the rear of the main unit. In Figure 9, not only the circuit board 100 but also the optical box 50 and the drive motor 60 are shown together.

[0036] The circuit board 100 consists of a power input unit 115 that takes in AC voltage from an external power source, the commercial power supply, a low-voltage power supply unit 110 that converts the AC voltage into DC voltage, and a high-voltage power supply unit 120 that supplies the high voltage necessary for image formation to each process component. In this embodiment, the low-voltage power supply unit 110 and the high-voltage power supply unit 120 are mounted on the same board.

[0037] The low-voltage power supply unit 110 includes a low-voltage power transformer 112, a heat sink 113, and an electrolytic capacitor 114 as a group of electronic components 111 that are large in size in the Y direction. The high-voltage power supply unit 120 includes a charging transformer 122, a developing transformer 123, and a transfer transformer 124 as a group of electronic components 121 that are large in size in the Y direction. As described above, in order to make use of the space inside the image forming apparatus 1, the electronic component groups 111 and 121 that are large in size in the Y direction are both mounted on the inside side (negative side in the Y direction) of the image forming apparatus 1, avoiding the positions of the optical box 50 and the drive motor 60.

[0038] [Functions of the circuit board] Next, the functions of the low-voltage power supply unit 110 and the high-voltage power supply unit 120 will be explained using Figures 9 and 10. Figure 10 is a block diagram illustrating the functions of the circuit board 100.

[0039] First, the low-voltage power supply unit 110 receives power from the commercial power supply via the power input unit 115 mounted on the end of the circuit board 100, and converts the AC voltage into a stable DC voltage using a rectifier and smoothing circuit including an electrolytic capacitor 114. Then, the low-voltage power supply unit 110 converts the DC voltage into a high-frequency AC voltage using switching elements such as transistors, and then inputs the high-frequency AC voltage to the low-voltage power transformer 112. The low-voltage power transformer 112 converts the input voltage, the high-frequency AC voltage, into an AC voltage with a desired voltage value. The low-voltage power supply unit 110 converts the AC voltage back into a DC voltage and outputs the resulting DC voltage to the high-voltage power supply unit 120, the optical box 50, etc. In addition, since power loss from individual circuit components in the low-voltage power supply unit 110 manifests as heat, a heat sink 113 made of aluminum or iron is provided to dissipate the heat.

[0040] The converter circuit of the low-voltage power supply unit 110 outputs DC voltages of 24V, 3.3V, and 5V. The 24V DC voltage is supplied to the high-voltage power supply unit 120, while the 3.3V and 5V DC voltages are supplied to the optical box 50, drive motor 60, engine control unit 130, video controller 140, etc. The DC voltage output from the low-voltage power supply unit 110 is supplied to the high-voltage power supply unit 120, optical box 50, drive motor 60, engine control unit 130, video controller 140, etc. via power distribution components such as patterns and harnesses on the printed circuit board 101.

[0041] The high-voltage power supply unit 120 converts the voltage (e.g., 24V) supplied from the low-voltage power supply unit 110 into a high voltage required for image formation processes such as charging, developing, and transfer. The charging transformer 122 converts the voltage supplied from the low-voltage power supply unit 110 into a voltage for charging, and the converted voltage is then supplied to the charging roller 17. The developing transformer 123 converts the voltage supplied from the low-voltage power supply unit 110 into a voltage for developing, and the converted voltage is then supplied to the developing roller 12. The transfer transformer 124 converts the voltage supplied from the low-voltage power supply unit 110 into a voltage for transfer, and the converted voltage is then supplied to the transfer roller 7.

[0042] The optical box 50, drive motor 60, engine control unit 130, and video controller 140 operate using a voltage (for example, 3.3V or 5V) supplied from the low-voltage power supply unit 110. Here, the engine control unit 130 is responsible for the overall control of various process components. The engine control unit 130 includes a CPU (not shown), RAM (not shown) used for calculations and temporary storage of data necessary for controlling the image forming apparatus 1, and ROM (not shown) for storing programs and various data that control the image forming apparatus 1. The engine control unit 130 may be located on a separate board from the circuit board 100, or on the same board. The video controller 140 communicates with external devices such as a personal computer to receive print data and notifies the engine control unit 130 of the results of analyzing the print data.

[0043] [Configuration of electrical contacts] Next, the configuration of the electrical contacts for supplying the voltage output from the high-voltage power supply unit 120 to each process component will be explained using Figures 11 to 12. Figure 11 shows a perspective view of the charging contact portion 159 provided on the edge of the printed circuit board 101, and Figure 12 shows a cross-sectional view of the charging contact portion 159 provided on the edge of the printed circuit board 101. Although the configuration of the electrical contacts for charging is explained here, the electrical contacts for developing and transferring have a similar configuration.

[0044] As described above, the high-voltage power supply unit 120 converts the voltage supplied from the low-voltage power supply unit 110 into a high voltage for charging by a charging converter circuit (not shown) including a charging transformer 122. In other words, the high-voltage power supply unit 120 functions as a voltage generation means that generates a high voltage for charging. This high voltage is then supplied to the jumper wire 150 shown in Figure 11. The jumper wire 150 (conductive member) is provided so as to straddle a notch 153 that penetrates the component side and solder side of the printed circuit board 101. The arm portion 152 of the charging contact spring 151 (elastic member) is structured to fit into this notch 153, and when the arm portion 152 fits in, the jumper wire 150 and the arm portion 152 make contact.

[0045] As shown in Figure 12, the electrostatic contact spring 151 has a torsion coil spring shape, and the arm portion 152 is set to act in the direction of the jumper wire 150. As a result, the arm portion 152 is configured to push the jumper wire 150 in the direction of the arrow 155 shown in Figures 11 and 12, thereby stabilizing it as an electrical contact.

[0046] Furthermore, as shown in Figure 12, the electrostatic contact spring 151 has two arms. One arm 152 is structured to contact the jumper wire 150 as described above, and the other arm 154 is connected to the electrostatic roller 17 (not shown in Figure 12). Therefore, when the arm 152 contacts the jumper wire 150 and functions as an electrical contact, the high voltage generated by the electrostatic converter circuit can be supplied to the electrostatic roller 17 via the jumper wire 150 and the electrostatic contact spring 151.

[0047] [Installing the circuit board] Next, we will explain how to attach the circuit board 100 to the image forming apparatus 1 using Figure 13. Figure 13 is a top view of the circuit board 100 as seen from above the image forming apparatus 1.

[0048] Figure 13 shows a board-side connector 161 mounted on a printed circuit board 101, a motor-side connector 162 of the drive motor 60, and a harness 160 connecting the board-side connector 161 and the motor-side connector 162. By mounting the board-side connector 161, to which the harness 160 is connected, on the same surface as the electronic component groups 111 and 112, and staggering the wiring path of the harness 160 and the process components (optical box 50, etc.), the space inside the housing can be effectively utilized. Furthermore, by bringing the distance between the board-side connector 161 and the motor-side connector 162 closer together, the required length of the harness 160 can be shortened, reducing the space required for wiring. Therefore, in order to miniaturize the image forming apparatus 1, it is desirable for the board-side connector 161 to be close to the motor-side connector 162.

[0049] However, if the board-side connector 161 is positioned close to the motor-side connector 162, as explained with reference to Figures 3 to 6, it is difficult for an operator to connect the board-side connector 161 and the motor-side connector 162 when the circuit board 100 is attached to the image forming apparatus 1. The board-side connector 161 is hidden behind the printed circuit board 101 when viewed from the front, and hidden behind the drive motor 60 when viewed from the right side. Furthermore, since the optical box 50 and the tall electronic component group 121 are located above the drive motor 60, the space available for an operator to access the board-side connector 161 from above is limited.

[0050] In this configuration, where the wiring route of the harness 160 is designed to utilize the space inside the housing in order to miniaturize the image forming apparatus 1, it is difficult to perform the wiring work of the harness 160 with the circuit board 100 attached to the image forming apparatus 1. Therefore, in this embodiment, the wiring work of the harness 160 is performed before attaching the circuit board 100.

[0051] Figures 14 to 16 are side views illustrating the procedure for attaching the circuit board 100 to the image forming apparatus 1 while connecting the harness 160. As mentioned above, wiring work cannot be performed with the circuit board 100 attached to the image forming apparatus 1. Therefore, as shown in Figure 14, the circuit board 100 is first laid down, and the wiring work for the lower section of the image forming apparatus 1 is performed. With the circuit board 100 laid down, a workspace is created on the top side (positive Z-direction side) of the image forming apparatus 1, allowing for the wiring work between the harness 160 and the board-side connector 161 in the lower section.

[0052] As shown in Figure 13, the electronic component group 111 is located to the left (negative X-direction) of the board-side connector 161. Therefore, a portion of the board-side connector 161 is not visible in the side views of Figures 14 to 16. However, for explanatory purposes, the board-side connector 161 is shown in Figures 14 to 16 as if seen through the electronic component group 111.

[0053] Next, as shown in Figure 15, the circuit board 100 is partially raised, and the wiring work for the middle section is performed, connecting the harness 163 to the board-side connector 164. Finally, as shown in Figure 16, with the circuit board 100 attached to the image forming apparatus 1, the wiring work for the upper section is performed, connecting the harness 166 to the board-side connector 167. By attaching the circuit board 100 to the image forming apparatus 1 in a raised position, the length of the harness 160 can be shortened while still allowing for wiring work with the board-side connector 161.

[0054] Here, we have mainly described the connector 161 and harness 160 connected to the drive motor 60 as an example, but the wiring procedure is not limited to this. For example, in a configuration where a board-side connector 164 connected to the connector 165 of the optical box 50, and a board-side connector 167 connected to the connector 168 of a process material (not shown) are provided on the lower side, these wiring operations may be performed before the wiring operations for the drive motor 60.

[0055] [Position of notches on a circuit board] Next, using Figure 17, the positions of the notches in the circuit board 100 provided for electrical contacts will be explained. Figure 17 is a rear view of the circuit board 100 as seen from the rear of the main body.

[0056] As shown in Figure 17, a notch 153, which constitutes part of the charging contact portion 159 described using Figures 11 and 12, is provided on the positive X-side edge of the circuit board 100. A jumper wire 150 is provided so as to straddle this notch 153. In addition, a developing jumper wire 200 and notch 201, and a transfer jumper wire 202 and notch 203 are provided on the positive X-side edge of the circuit board 100. Hereafter, when simply referred to as a notch, it includes the notches 153, 183, and 193 that constitute the electrical contacts for charging, developing, and transfer, respectively.

[0057] In this configuration, conventionally, the circuit board 100 was attached to the image forming apparatus 1 by, for example, inserting it from the negative X-direction side. On the other hand, when attaching the circuit board 100 using the procedure described with reference to Figures 14 to 16, there is a risk that the circuit board 100 and the arm portion of the torsion coil spring may interfere with each other when raising the circuit board 100. Therefore, countermeasures such as increasing the size of the notch or shaping the arm portion of the torsion coil spring to match the trajectory are necessary.

[0058] Furthermore, even if the size of the notch provided in the circuit board 100 is increased to prevent interference between the circuit board 100 and the torsion coil spring, the jumper wire and the arm portion may still come into contact at an angle, potentially leading to unstable electrical contact connections. In addition, increasing the size of the notch may reduce the rigidity of the circuit board 100 and reduce the mounting space available for the circuit board 100. Moreover, in the configuration of this embodiment, wiring work is performed in parallel with raising the circuit board 100, so it is undesirable to perform wiring work while the circuit board 100 is in an unstable state due to the repulsive force from the torsion coil spring.

[0059] For the reasons stated above, in this embodiment, a holding part for holding the arm portion of the torsion coil spring is provided on the image forming apparatus 1.

[0060] [Configuration of the retaining part for the arm portion of a torsion coil spring] Figure 18 is a perspective view showing the configuration of the retaining part for holding the arm portion of the torsion coil spring in this embodiment. While the configuration of the retaining part for the electrically charged contact described using Figures 11 and 12 is explained here, the retaining part for the electrically charged contacts in developing and transfer processes has a similar configuration.

[0061] Figure 18 shows a holding part 170 that holds an arm portion 152, which is part of a torsion coil spring-shaped electrostatic contact spring 151 (not shown in Figure 18). The holding part 170 temporarily holds the arm portion 152 in a position where it does not come into contact with the jumper wire 150 (hereinafter referred to as the retracted position) so that the arm portion 152 does not get caught in the track when the circuit board 100 is mounted.

[0062] The holding part 170 is provided on the main body of the image forming apparatus 1 and is fixed, for example, to the right side plate frame 72 (shown in Figure 8, etc.). The holding part 170 has a receiving part 171 that receives force acting on the arm part 152 in the direction of arrow 175, and furthermore, the holding part 170 has an L-shaped notch 172 formed therein. As described above, the arm part 152 is biased toward the jumper wire 150 by the action of a torsion coil spring.

[0063] With the arm portion 152 held by the holding portion 170, the operator attaches the circuit board 100 to the image forming apparatus 1 in the procedure shown in Figures 14 to 16, and then removes the arm portion 152 from the holding portion 170. This allows the arm portion 152 and the jumper wire 150 to make stable contact, as shown in Figure 11.

[0064] Furthermore, the notch 153 provided in the printed circuit board 101 has a shape that widens towards the edge of the printed circuit board 101. This widened portion is a guide portion 156, which is configured to guide the arm portion 152, which has been detached from the holding portion 170, to the jumper wire 150.

[0065] Based on the above, according to this embodiment, electrical contacts can be configured using elastic members such as torsion coil springs, regardless of the method of mounting the circuit board.

[0066] Furthermore, by mounting the circuit board using the procedure shown in Figures 14 to 16, the space inside the housing of the image forming apparatus can be effectively utilized. In addition, by using torsion coil springs to configure the electrical contacts, the area required for the contacts on the circuit board can be reduced. As a result, the image forming apparatus can be further miniaturized.

[0067] (Example 2) As described in Example 1, the arm portion 152 is held in a retracted position by the holding portion 170 until the circuit board 100 is attached to the image forming apparatus 1 and the arm portion 152 is connected to the jumper wire 150. However, vibrations during assembly or accidental touching of the arm portion 152 by the assembler may cause the arm portion 152 to detach from the holding portion 170. When the arm portion 152 detaches from the holding portion 170, the force of the torsion coil spring causes the arm portion 152 to slide inside the image forming apparatus 1. In this state, the circuit board 100 cannot be attached to the image forming apparatus 1, requiring the arm portion 152 to be returned to the holding portion 170, which increases the effort required for the installation process.

[0068] Figure 19 is a perspective view showing the configuration of the holding part for holding the arm portion of the torsion coil spring in this embodiment. Note that the same configuration as in Embodiment 1 will not be described, and only the differences from Embodiment 1 will be explained.

[0069] Figure 19 shows a holding part 180 that holds an arm portion 152, which is part of a torsion coil spring-shaped electrostatic contact spring 151 (not shown in Figure 19). In addition to the receiving portion 181 and notch 182 described in Embodiment 1, the holding part 180 includes a projection 182 that extends from a part of the receiving portion 181 in the direction opposite to the jumper wire 150. The projection 182 prevents the arm portion 152 held by the holding part 180 from coming off due to vibration or the like. This prevents the increase in the effort required for the installation work described above.

[0070] Based on the above, this embodiment provides the following additional effects in addition to those of Embodiment 1. Specifically, by providing the projection 182, it is possible to prevent the arm portion 152 from easily detaching from the holding portion 180 due to vibration or unintended contact when attaching the circuit board 100 to the image forming apparatus 1, thereby preventing an increase in the installation work.

[0071] The shape of the projection 182 in this embodiment is just one example and is not limited to this. Any other shape is acceptable as long as it prevents the arm portion 152 from easily detaching from the holding portion 180.

[0072] (Example 3) As explained in Example 1, before attaching the circuit board 100 to the image forming apparatus 1, the arm portion 152 of the torsion coil spring must be moved to the retracted position beforehand. On the other hand, when removing the attached circuit board 100, the arm portion 152 must be moved from the position where it is in contact with the jumper wire 150 (contact position) to the retracted position. In both cases, the operator needs to move the arm portion 152, but in order to make the image forming apparatus 1 compact, the holding portion 170 also needs to be made as small as possible. If the holding portion 170 becomes smaller, the size of the notch 172 will also become smaller, making it difficult for the operator to insert the arm portion 152 into the holding portion 170.

[0073] Figure 20 is a perspective view showing the configuration of the holding part for holding the arm portion of the torsion coil spring in this embodiment. Note that the same configuration as in Embodiment 1 will not be explained, and only the differences from Embodiment 1 will be described.

[0074] Figure 20 shows a holding part 190 that holds an arm portion 152, which is part of a torsion coil spring-shaped electrostatic contact spring 151 (not shown in Figure 20). In addition to the receiving portion 191 and notch 192 described in Embodiment 1, the holding part 190 is equipped with a guide portion 193 near the entrance of the notch 192. The notch 192 in this embodiment has a shape that widens towards the jumper wire 150, and this widened portion is the guide portion 193. The shape of the guide portion 193 makes it easier for the worker to move the arm portion 152 from the contact position to the retracted position (making it easier to hold it in the holding part 190), thus improving work efficiency.

[0075] Based on the above, this embodiment provides the following additional effects in addition to those of Embodiment 1. Specifically, by providing the guide portion 193, the workability when removing the circuit board 100 from the image forming apparatus 1 can be improved.

[0076] Note that the shape of the guide portion 193 in this embodiment is just one example and is not limited to this. Any other shape is acceptable as long as it allows the arm portion 152 to be guided into the notch 192 of the holding portion 190.

[0077] (modified version) In the above embodiments 1 to 3, it was explained that all electrical contacts for charging, developing, and transferring have the same configuration. However, of course, only one of these may have the configuration of embodiments 1 to 3, and the others may have different configurations. Also, as explained with reference to Figure 17, in embodiments 1 to 3, the jumper wires and notches for the electrical contacts for charging, developing, and transferring were provided on the positive X-side edge of the circuit board 100. However, this is not limited to this. For example, charging may be provided on the positive X-side edge, while developing and transferring may be provided on the negative X-side edge.

[0078] Furthermore, in the above-described embodiments 1 to 3, the charging roller 17, developing roller 12, and transfer roller 7 were used as examples of image forming means, but the invention is not limited to these. For example, the configuration of the present invention may be applied to electrical contacts for applying voltage to components such as the drive motor 60 and the optical box 50. In other words, the configuration of the present invention is not limited to the electrical contacts of the high-voltage power supply unit 120, but may also be applied to the electrical contacts of the low-voltage power supply unit 110.

[0079] Furthermore, although torsion coil springs were used as the elastic members in the above embodiments 1 to 3, the invention is not limited to these, and conductive members with an elastic structure, such as leaf springs, may also be used. The conductive members are not limited to linear members such as jumper wires, but may also be flat metal members, for example. Moreover, the shape of the notch is not limited to a square shape; it may be circular, elliptical, or polygonal.

[0080] Furthermore, while the above embodiments 1 to 3 show a configuration in which the circuit board 100 is attached to the image forming apparatus 1 by raising the circuit board 100, the invention is not limited to this. For example, the circuit board 100 may be attached by inserting it into the image forming apparatus 1, or by rotating the circuit board 100 relative to the image forming apparatus 1.

[0081] Furthermore, while the above embodiments 1 to 3 described a configuration in which the low-voltage power supply unit 110 and the high-voltage power supply unit 120 are provided on the same substrate (circuit board 100), the invention is not limited to this. The two power supply units may be provided on separate substrates. The substrates for both the low-voltage power supply unit 110 and the high-voltage power supply unit 120 may be provided on the front side of the image forming apparatus 1 shown in Figure 3. Alternatively, only the substrate for the low-voltage power supply unit 110 may be provided on the front side, and the substrate for the high-voltage power supply unit 120 may be provided at a different location. Alternatively, only the substrate for the high-voltage power supply unit 120 may be provided on the front side, and the substrate for the low-voltage power supply unit 110 may be provided at a different location. [Explanation of symbols]

[0082] 1. Image forming apparatus 17 Electrostatic roller 101 Printed circuit board 120 High-voltage power supply unit 150 Jumper wires 151 Electrostatic contact spring 152 Arm section 170 Holding part

Claims

1. A method for manufacturing an image forming apparatus, The image forming apparatus is Image forming means for forming an image on a recording material, A printed circuit board on which a voltage generation means for generating a voltage to be applied to the image forming means is mounted, A conductive member provided on the printed circuit board to which a voltage generated by the voltage generating means is applied, An elastic member having an arm portion that is biased toward the conductive member and in contact with the conductive member, the elastic member being electrically connected to the image forming means, The holding part, It has, The aforementioned manufacturing method is A mounting step in which the printed circuit board is mounted while the arm portion is held in a retracted position by the holding portion so as not to come into contact with the conductive member, in a first direction opposite to the direction in which the arm portion is biased toward the conductive member, A removal step is performed after the mounting step, in which the arm portion is removed from the holding portion so that the arm portion comes into contact with the conductive member, including, A method for manufacturing an image forming apparatus, characterized by the above.

2. The method for manufacturing an image forming apparatus according to claim 1, characterized in that a notch is provided on the edge of the printed circuit board, and the conductive member is a jumper wire provided so as to straddle the notch.

3. The method for manufacturing an image forming apparatus according to claim 2, characterized in that the notch has a shape that widens toward the edge of the printed circuit board.

4. The method for manufacturing an image forming apparatus according to any one of claims 1 to 3, characterized in that the elastic member is a torsion coil spring having a second arm portion in addition to the arm portion, and the second arm portion is connected to the image forming means.

5. The method for manufacturing an image forming apparatus according to any one of claims 1 to 4, characterized in that the image forming means is one of a charging means for charging an image carrier, a developing means for forming an image on the image carrier, and a transfer means for transferring the image formed on the image carrier to a recording material.

Images