JP2020030293A - Apparatus having power supply substrate and image forming apparatus - Google Patents

Abstract

To provide an apparatus that brings a plurality of torsion coil springs into contact with a plurality of electrical contact parts of a power supply substrate to establish an electrical connection between the power supply substrate and a body to be supplied with power, and can improve assembly workability.SOLUTION: A power supply substrate supplying voltage to a body to be supplied with power comprises: a power supply substrate that has a plurality of electrical contact parts; a plurality of torsion coil springs that have conductivity, are in contact with the electrical contact parts at one ends, and are in electrical contact with the body to be supplied with power or a conductor electrically connected to the body to be supplied with power at the other ends; a holding member that is an insulator inserted into annular parts of the plurality of torsion coil springs and holding the plurality of torsion coil springs at an interval; and attachment parts to which the holding member is attached.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an apparatus having a power supply board and an image forming apparatus such as an electrophotographic copying machine and an electrophotographic printer.

  In an electrophotographic image forming apparatus, an electrostatic latent image is formed on a charged photoconductor at a charging unit, the electrostatic latent image is developed as a toner image at a developing unit, and the developed toner image is transferred to a transfer unit. Is transferred to a sheet to form an image. Here, a high voltage of several hundred volts to several kilovolts is applied to the charging unit, the developing unit, and the transfer unit. Therefore, the image forming apparatus includes a power supply board having a high-voltage power supply circuit that generates a high voltage on a printed board.

  When a high-voltage cable is used to connect the power supply board and each section as a power supply path to apply the high voltage generated by the power supply board to each section, the assemblability deteriorates and the cost increases. Therefore, a configuration in which a power supply board and the above-described units are electrically connected without using a high-voltage cable is widely used.

  For example, Patent Literature 1 describes a configuration in which a power supply substrate and a charging unit are electrically connected by a torsion coil spring. Further, in the configuration described in Patent Document 1, a configuration is described in which one end of a torsion coil spring is brought into contact with a jumper wire which is an electrical contact portion provided in a through hole of a power supply board. Thereby, the area of the electric contact portion on the power supply board is reduced, as compared with a configuration in which the coil portion of the compression coil spring is pressed against the electric contact portion of the power supply board to electrically connect the power supply board and the charging section. Space can be saved.

JP-A-2015-142105

  However, in the configuration described in Patent Literature 1, when attaching the torsion coil spring, it is necessary to attach an annular portion of the torsion coil spring to a shaft or the like and further hook the arm. For this reason, in a configuration in which a plurality of electric contact portions are provided on the power supply substrate and the plurality of torsion coil springs are used for electrical connection, the assembling work becomes complicated.

  In view of this, the present invention can improve assembly workability in a configuration in which a plurality of torsion coil springs are brought into contact with a plurality of electrical contact portions of a power supply board to establish an electrical connection between the power supply board and a power-supplied body. It is an object of the present invention to provide a device capable of performing such operations.

  A typical configuration of an image forming apparatus according to the present invention for achieving the above object is a power supply board for supplying a voltage to a power-supplied body, the power supply board having a plurality of electric contact portions, and a conductive board having a plurality of electrical contacts. A plurality of torsion coil springs that contact the electric contact portion at one end and contact the power-supplied body or a conductor electrically connected to the power-supplied body at the other end; A holding member that is an insulator that inserts the annular portion of the torsion coil spring and holds the plurality of torsion coil springs at intervals, and a mounting portion that mounts the holding member.

  ADVANTAGE OF THE INVENTION According to this invention, assembling workability | operativity can be improved in the apparatus which makes a several torsion coil spring contact a several electric contact part of a power supply board, and establishes electrical connection between a power supply board and a to-be-powered body.

FIG. 2 is a schematic sectional view of the image forming apparatus. FIG. 2 is a schematic diagram when the image forming apparatus is viewed from a side. FIG. 3 is a schematic perspective view of the periphery of a power supply board. FIG. 3 is a schematic perspective view of the periphery of a power supply board. FIG. 3 is a schematic perspective view of the periphery of a power supply board. It is an expansion perspective view of the electric contact part of a power supply board. It is a perspective view of a contact spring and a holder. FIG. 3 is a perspective view of a power supply board and an intermediate transfer unit. FIG. 3 is a perspective view of an intermediate transfer unit. It is a perspective view of a contact spring and a contact spring holding member. It is a perspective view of the contact spring attached to the holder. FIG. 9 is an explanatory diagram illustrating an operation of attaching the power supply board. It is a figure showing composition of a modification. It is an expansion perspective view of the contact part of a contact spring, a feeder, and an electric contact part.

(1st Embodiment)
<Image forming apparatus>
Hereinafter, the overall configuration of the image forming apparatus according to the first embodiment will be described with reference to the drawings together with the operation during image formation. The dimensions, materials, shapes, relative arrangements, and the like of the components described below are not intended to limit the scope of the present invention only to them unless otherwise specified.

  The image forming apparatus according to the present exemplary embodiment is configured to transfer four color toners of yellow Y, magenta M, cyan C, and black K to an intermediate transfer belt, and then transfer the image to a sheet such as paper to form an image. This is a photographic image forming apparatus. In the following description, members using the toners of the respective colors are given subscripts of Y, M, C, and K, except for the configuration and operation of each member except that the color of the toner used is different. Since they are substantially the same, suffixes are omitted as appropriate unless necessary to distinguish them.

  As shown in FIG. 1, an image forming apparatus A includes an image forming unit that transfers a toner image to a sheet such as paper to form an image, a sheet feeding unit that supplies a sheet to the image forming unit, and a sheet feeding unit. A fixing unit for fixing the toner image to the toner image.

  The image forming unit includes a photosensitive drum 2 (2Y, 2M, 2C, 2K) as a photosensitive member, a charging roller 3 (3Y, 3M, 3C, 3K) as a charging unit for charging the surface of the photosensitive drum 2, and a developing unit as a developing unit. A developing device 5 (5Y, 5M, 5C, 5K) is provided. Further, it includes a primary transfer roller 7 (7Y, 7M, 7C, 7K) as a transfer unit, a laser scanner unit 4 as an exposure unit, a cleaning blade 6 (6Y, 6M, 6C, 6K), and an intermediate transfer unit 40. The photosensitive drum 2, the charging roller 3, and the developing device 5 are unitized as a cartridge 100 that can be attached to and detached from the apparatus main body of the image forming apparatus A.

  The intermediate transfer unit 40 includes an intermediate transfer belt 8, a secondary transfer roller 11, a secondary transfer opposing roller 9, and a tension roller 10. The intermediate transfer belt 8 is an endless belt stretched over the secondary transfer facing roller 9 and the tension roller 10, and the secondary transfer facing roller 9 is rotated by a driving force of a driving source, and is driven by the rotation. Move around.

  Next, the image forming operation will be described. First, when a control unit (not shown) receives an image forming job signal, the sheet S stacked and stored in the sheet stacking unit 16 by the feed roller 17, the transport roller 18, and the registration roller 19 is transferred to the secondary transfer roller 11 and the secondary transfer roller. The sheet is sent to a secondary transfer section formed by the opposing roller 9.

  On the other hand, in the image forming unit, first, a charging bias is applied to the charging roller 3 as a charging unit, so that the surface of the photosensitive drum 2 as a photosensitive member is uniformly charged. After that, the laser scanner unit 4 as an exposure unit irradiates the surface of the photosensitive drum 2 of each color with laser light L for exposure in accordance with image data transmitted from an external device (not shown). As described above, the laser scanner unit 4 as an exposure unit exposes the photosensitive drum 2 as a photosensitive member, whereby an electrostatic latent image is formed on the surface of the photosensitive drum 2.

  Thereafter, a developing bias is applied to the developing sleeve 12 (12Y, 12M, 12C, 12K) of the developing device 5 as a developing unit. As a result, the toner of each color adheres to the electrostatic latent image formed on the surface of the photosensitive drum 2 by the laser scanner unit 4 as an exposure unit. As a result, a toner image is formed on the surface of the photosensitive drum 2.

  Next, the toner image formed on the surface of the photosensitive drum 2 is primary-transferred to an intermediate transfer belt 8 as a transfer object by applying a primary transfer bias to a primary transfer roller 7 as a transfer unit. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 8 as the transfer target. The toner adhered to the surface of the photosensitive drum 2 after the primary transfer is scraped off by the cleaning blade 6 and removed.

  Thereafter, the toner image is sent to the secondary transfer unit by the orbital movement of the intermediate transfer belt 8 as the transfer object. Then, a secondary transfer bias is applied to the secondary transfer roller 11 in the secondary transfer section, so that the toner image on the intermediate transfer belt 8 as a transfer target is transferred to the sheet S.

  Next, the sheet S to which the toner image has been transferred is subjected to a heating and pressing process in the fixing device 20, whereby the toner image on the sheet S is fixed to the sheet S. Thereafter, the sheet S on which the toner image is fixed is discharged to a discharge unit 24 by a discharge roller 23 of the image forming apparatus A.

<Power supply configuration to cartridge>
Next, a configuration for supplying power to the cartridge 100 will be described.

  FIG. 2 is a schematic diagram when the image forming apparatus A is viewed from the side. As shown in FIG. 2, in the image forming apparatus A, a power supply board 51 is provided above the cartridge 100 (+ Z side). The power supply board 51 includes a transformer (not shown), and a circuit for generating a high voltage based on electric power supplied from a commercial power supply is mounted on a printed circuit board. Supply voltage to sleeve 12 etc.

  The power supply substrate 51 is horizontally disposed above the intermediate transfer belt 8 at a position between the front side plate 25 and the rear side plate 26 which are frames of the image forming apparatus A. The power supply board 51 and the cartridge 100 are electrically connected via eight power supply lines 43 which are wires and conductors. In addition, since the power supply line 43 which is a wire and also is a conductor is made of a soft wire material having no insulating coating such as a solder-plated soft copper wire, even if the power supply paths are different from each other, one type of the power supply line 43 may be used. Can be addressed.

  The eight power supply lines 43, which are wires and conductors, are first routed through the eight openings 26 a of the rear plate 26 to the rear side (the + Y direction side) of the image forming apparatus A. Next, at a position between the drive unit 28 having a motor and gears for driving members in the cartridge 100 and the rear plate 26, the cartridge 100 is crawled in the vertical direction (-Z direction) with respect to the power supply board 51. Next, the sheet is crawled to the front side (−Y side) of the image forming apparatus A through the eight openings 26 b of the rear side plate 26 and is connected to the cartridge 100. The power supply line 43, which is a wire and a conductor, is routed through the back surface of the rear plate 26 so as to bypass the intermediate transfer belt 8.

  Further, the intermediate transfer unit 40 including the power supply substrate 51 and the intermediate transfer belt 8 is connected via two power supply lines 43 different from the above-described eight power supply lines 43 for electrically connecting the power supply substrate 51 and the cartridge 100. It is electrically connected. The two power supply lines 43 are first routed to the rear side (the side in the + Y direction) of the image forming apparatus A through the two openings 26 a of the rear plate 26. Next, at a position between the drive unit 28 and the rear side plate 26, the power supply board 51 is crawled in a vertical direction (−Z direction). Next, the two power supply lines 43 are electrically connected to the intermediate transfer unit 40 via contact springs 71 (FIG. 10) protruding from the openings 26d of the rear plate 26. The configuration for supplying power to the contact spring 71 and the intermediate transfer unit 40 will be described later in detail.

  3, 4, and 5 are schematic perspective views around the power supply board 51. 3 to 5, in order to show the connection relationship between the power supply board 51 and the cartridge 100, the intermediate transfer unit 40, the cartridge 100, the front plate 25 and the rear plate 26 which are the frame of the image forming apparatus A, and the like. Is omitted as appropriate. FIG. 6 is an enlarged perspective view of the electric contact portion of the power supply board 51.

  As shown in FIGS. 3 to 6 and FIG. 14, the electrical connection between the cartridge 100 and the power supply line 43 is performed through eight springs 41 which are conductive compression coil springs. The spring 41 contacts the power supply line 43 at one end, and contacts the power supply plate 101 or the power supply plate 102 which is an electrical contact portion of the cartridge 100 at the other end. The power supply plate 101 is electrically connected to the developing sleeve 12 of the developing device 5 serving as a power supply target, and the power supply plate 102 is electrically connected to the charging roller 3 serving as a power supply target.

  A predetermined contact pressure is generated between the spring 41 and the power supply plate 101 or the power supply plate 102 and between the spring 41 and the power supply line 43 by the elastic force of the spring 41. The spring 41 is formed of a wire generally called a spring material, such as a spring steel material, a piano wire, a stainless steel wire, or the like. In the present embodiment, the spring 41 is a compression coil spring, but may be another type of spring such as a torsion coil spring.

  The power supply line 43 is held by the holder 300. The holder 300 is an insulating resin member, is arranged at a position between the rear side plate 26 and the drive unit 28, and is fixed to the rear side plate 26 with screws 80. The screw 80 is inserted into the screw hole 300a of the holder 300 and the screw hole 26c of the rear plate 26. By using the holder 300 as an insulating member in this way, even when the rear plate 26 and the drive unit 28 are conductive members, and the holder 300 is in contact with the holder 300, these members and the power supply line 43 held by the holder can be used. Is cut off by the holder 300. Accordingly, insulation between the power supply line 43 and the rear plate 26 or the drive unit 28 can be achieved. Although ten power supply lines 43 are shown in FIG. 4, two of the power supply lines 43 are used for electrical connection between a power supply substrate 51 and a primary transfer roller 7 described later.

  The holder 300 has a holding portion 301 that guides and holds the power supply line 43 and a holding portion 302 as a tubular body that holds the spring 41 that is a compression coil spring. The spring 41, which is a compression coil spring, is inserted and fitted inside (inside the cylinder) of the holding section 302 as a cylindrical body so that its helical axis is parallel to the generatrix of the holding section 302 as a cylindrical body. You. Further, two slits V for inserting the power supply line 43 are formed in the holding portion 302 as a cylindrical body, respectively. In the holding portion 302a, the power supply line 43 enters the inside of the holding portion 302 along the slit V, and thereafter the spring 41 is inserted into the holding portion 302, so that the power supply line 43 and the spring 41 come into contact with each other. That is, the spring 41 is fitted and held inside the holding portion 302a in which the slit V is formed, and the power supply line 43 enters the inside of the holding portion 302a from the slit V of the holding portion 302a and comes into contact with the spring 41. .

  The electrical connection between the power supply board 51 and the power supply line 43 is made via a plurality of contact springs 61 which are conductive torsion coil springs. As shown in FIG. 14, one end of the contact spring 61 is in contact with the power supply line 43, and the other end is in contact with the electrical contact portion 52 which is a jumper wire attached to the power supply board 51. . The jumper wire as the electrical contact portion 52 is soldered to the power supply board 51 and connected to a conductive pattern formed on the power supply board 51. Although ten contact springs 61 are shown in FIG. 4, two contact springs 61 are used for electrical connection between a power supply substrate 51 and a primary transfer roller 7 described later.

  A predetermined contact pressure is generated between the contact spring 61 and the electrical contact portion 52 and between the contact spring 61 and the power supply line 43 by the elastic force of the contact spring 61. That is, the contact spring 61 is in pressure contact with the power supply board 51. The contact spring 61 is formed of a wire material generally called a spring material, such as a spring steel material, a piano wire, a stainless steel wire, or the like.

  The plurality of contact springs 61 are held at intervals by a contact spring holding member 42 as a holding member. The contact spring holding member 42 as a holding member is made of resin, is a solid cylindrical insulator having a large number of recesses formed on its surface, and has insulation with an adjacent contact spring 61. Is to be done. This is so thick that the contact spring holding member 42, which is an insulator, can be inserted into the annular portion 61c of the contact spring 61 while securing rigidity, and a groove can be formed so that the contact spring 61 does not move in the insertion direction after insertion. Is necessary. For this reason, the contact spring holding member 42 needs to have a certain thickness. Therefore, in order to reduce the cost as much as possible, a large number of hollows are formed on the surface. Therefore, if the rigidity of the contact spring holding member 42 can be ensured, a hollow shaft may be used.

  The contact spring holding member 42 is configured to be detachable from the holder 300. The bearing portion 304 (FIG. 7), which is a mounting portion of the contact spring holding member 42 in the holder 300, is provided so as to be exposed from the opening 26 a of the rear plate 26 to the inside (−Y side) of the apparatus main body. Thus, after the holder 300 is fixed to the rear plate 26, the contact spring holding member 42 can be mounted from the inside of the main body.

  That is, when the contact spring holding member 42 is attached to the holder 300 before the holder 300 is attached to the rear plate 26, in a configuration in which a plurality of small openings 26a are continuous, the contact spring holding member 42 is exposed when the contact spring holding member 42 is exposed from the opening 26a. 42 is hooked. For this reason, it is necessary to communicate the opening 26a in the longitudinal direction of the contact spring holding member 42, and the strength of the rear plate 26 is impaired. However, in the configuration of the present embodiment, the holder 300 is first attached to the rear plate 26 to expose the bearing portion 304, which is the mounting portion of the contact spring holding member 42 of the holder 300, from the opening 26a. Attach. Therefore, a configuration in which a plurality of small openings 26a are provided in the rear plate 26 for each contact spring 61 can be adopted, and a decrease in the strength of the rear plate 26 can be suppressed.

<How to attach the contact spring 61>
Next, a method of attaching the contact spring 61 to the holder 300 will be described.

  FIG. 7 is a perspective view of the contact spring 61 and the holder 300. Here, FIG. 7A shows a state before the contact spring 61 is attached, and FIG. 7B shows a state after the contact spring 61 is attached.

  As shown in FIG. 7, when the contact spring 61 is attached, first, the annular portions 61c of the ten contact springs 61 are coaxially arranged at predetermined intervals, and the contact spring holding member 42 which is an insulator is provided on the annular portion 61c. Through. At this time, the arm portions 61a and 61b of the contact spring 61 are in a free state.

  Next, both ends of the contact spring holding member 42 are gripped by a mounting tool (not shown), and both the contact spring 61 and the contact spring holding member 42 are gripped. The mounting tool has a shape that can be positioned so that the intervals between the plurality of contact springs 61 in the axial direction of the contact spring holding member 42, which is an insulator, are constant. The interval between the contact springs 61 is an interval that ensures a creeping distance that does not leak from each other when a high voltage is applied.

  Next, the contact spring holding member 42 is moved in the direction of the arrow K <b> 1, and the arm portion 61 a of the contact spring 61 is brought into contact with the tip of the contact portion 303 of the holder 300 to make contact. Thereafter, the contact spring holding member 42 is pushed in the direction of the arrow K1 while pressing the arm portion 61a against the contact portion 303. Thereby, the arm portion 61a is bent toward the electric contact portion 52 by the contact portion 303. That is, the contact portion 303 comes into contact with the arm portion 61a of the contact spring 61, and bends the arm portion 61a toward the electric contact portion 52.

  Next, both ends of the contact spring holding member 42 are fitted into the groove-shaped bearing portions 304 of the holder 300. At this time, the convex portion 305 as a projection is formed on the holder 300, and the contact spring holding member 42 is fitted over the bearing portion 304 after climbing over the convex portion 305 as the projection. The projection 305 as a protrusion restricts movement of the contact spring holding member 42 in a direction in which the contact spring holding member 42 comes off, so that the contact spring holding member 42 does not easily come off the bearing 304. In other words, the protrusion 305 as a protrusion abuts on the contact spring holding member 42 mounted on the bearing 304 to restrict the contact spring holding member 42 from being fitted into the bearing 304. The position of the contact spring holding member 42 in the rotation axis direction is determined by contacting the holder 300. In this way, the contact spring 61 is mounted on the bearing portion 304 of the holder 300 as a mounting portion.

  The plurality of contact springs 61, which are torsion coil springs, are integrally held by the contact spring holding member 42, and the contact spring holding member 42 is mounted on the bearing 304 of the holder 300 as a mounting portion. Accordingly, when attaching the contact spring 61 to the image forming apparatus A, it is not necessary to attach the annular portions 61c of the contact spring 61 one by one to the shaft portion or the like, thereby improving the assembling workability as compared with the conventional configuration. Can be done. Even when an unintended force is applied to the contact spring 61 due to the replacement work of the power supply board 51 or the like, the contact spring 61 does not fall off the contact spring holding member 42, so that a contact failure due to the fall can be prevented.

<Power supply configuration to primary transfer roller>
Next, a power supply configuration from the power supply substrate 51 to the primary transfer roller 7 as a power-supplied body will be described.

  FIG. 8 is a perspective view of the power supply board 51 and the intermediate transfer unit 40. FIG. 9 is a perspective view of the intermediate transfer unit 40 in which some members such as the intermediate transfer belt 8 are omitted.

  As shown in FIGS. 8 and 9, both ends of the primary transfer roller 7 are rotatably supported by bearings 206 (206Y, 206M, 206C, 206K), and a spring 205 (205Y, 205M, 205C, 205K). Powered by The spring 205 and the bearing 206 are formed of a conductive material.

  In the intermediate transfer unit 40, two power supply plates 203, which are electrical contact portions and are made of a metal plate such as stainless steel, and two power supply lines 204 which are wires having no insulating coating such as a solder-plated soft copper wire or a steel wire. Is provided. The power supply line 204 is in contact with the power supply plate 203 at one end, and is in contact with each of the four springs 205 at the other end. That is, the primary transfer roller 7 is electrically connected to the power supply plate 203 via the spring 205, the bearing 206, and the power supply line 204.

  The power supply plate 203 is in contact with the contact spring 71, which is a torsion coil spring. The contact spring 71 is in contact with the end of the power supply line 43 that contacts the contact spring 61. That is, the primary transfer roller 7 is electrically connected to the power supply board 51 via the spring 205, the bearing 206, the power supply line 204, the power supply plate 203, the contact spring 71, the power supply line 43, and the contact spring 61. The shape and material of the contact spring 71 are the same as those of the contact spring 61.

<How to attach the contact spring 71>
Next, a method of attaching the contact spring 71 to the holder 300 will be described.

  FIG. 10 is a perspective view of the contact spring 71 and a contact spring holding member 200 that holds the contact spring 71. As shown in FIG. 10, the two contact springs 71 are held by the contact spring holding member 200 by inserting the shaft portion 200 a of the contact spring holding member 200 formed of an insulating resin into the annular portion 71 c. .

  The contact spring holding member 200 holding the contact spring 71 is moved in the direction of arrow K2, and the shaft 200a is engaged with the bearing 308a of the holder 300 projecting from the opening 26d of the rear plate 26. Then, the snap fit part 200b of the contact spring holding member 200 is inserted into the mounting hole 308b, and the mounting is completed.

<Installation structure of the intermediate transfer unit>
Next, the mounting configuration of the intermediate transfer unit 40 will be described.

  FIG. 11 is a perspective view of the contact spring 71 attached to the holder 300. Here, FIG. 11A is a view showing a state where the intermediate transfer unit 40 is not attached, and FIG. 11B is a view showing a state where the intermediate transfer unit 40 is attached.

  As shown in FIG. 11, before the intermediate transfer unit 40 is attached, the arm portion 71a of the contact spring 71 is in a state of abutting against the abutting rib 308c of the holder 300. When attaching the intermediate transfer unit 40, the power supply plate 203 of the intermediate transfer unit 40 is slid in the direction of the arrow K3 (horizontal direction) while being in contact with the contact spring 71. As a result, the contact spring 71 is bent, and the contact spring 71 is pressed against the power supply plate 203. Thereby, the primary transfer roller 7 and the contact spring 71 conduct.

  The plurality of contact springs 71, which are torsion coil springs, are integrally held by the contact spring holding member 200, and the contact spring holding member 200 is attached to the holder 300, whereby the contact spring 71 is assembled. Thereby, the plurality of contact springs 71 can be easily assembled, and assembling workability can be improved.

<How to attach the power supply board>
Next, a method of attaching the power supply board 51 to the holder 300 will be described.

  FIG. 12 is an explanatory diagram for explaining the mounting operation of the power supply board 51. Here, FIG. 12A is a diagram showing a state where the contact spring 61 is attached before attaching the power supply substrate 51 to the holder 300, and FIG. 12B is a diagram showing a state after attaching the power supply substrate 51 to the holder 300. .

  As shown in FIG. 12, when attaching the power supply board 51, the power supply board 51 is first turned obliquely downward, and while the power supply board 51 is moved in the direction of arrow K4, the contact spring 61 is formed in the notch 53 formed in the power supply board 51. Is introduced. Thereby, the electric contact part 52 of the power supply board 51 and the arm part 61a of the contact spring 61 come into contact.

  Next, while rotating the power supply board 51 in the direction of the arrow R <b> 1, the front end of the power supply board 51 is pushed so as to be sandwiched in the concave portion 306 of the holder 300. Thus, the tip of the power supply board 51 is positioned.

  Next, the two positioning holes 54 formed in the power supply board 51 shown in FIG. 6 are fitted into the two bosses 307 of the holder 300, respectively. After that, the power supply board 51 is fastened to the stay 27 with screws 55 also serving as the ground, and the attachment of the power supply board 51 is completed.

  Next, as a modified example of the present embodiment, an example in which the shape of the contact spring holding member 42 is changed will be described. FIG. 13 is a perspective view of a contact spring holding member 42 according to a modification. Here, FIG. 13A is a diagram before the contact spring holding member 42 is inserted into the contact spring 61, and FIG. 13B is a diagram after the contact spring holding member 42 is inserted.

  As shown in FIG. 13, a groove 42 a for positioning the contact spring 61 is formed in a portion where the contact spring 61 is mounted on the outer peripheral surface of the contact spring holding member 42 which is a columnar member. As a result, the annular portion 61c of the contact spring 61 falls into the groove 42a, and the contact spring 61 can be positioned in the axial direction.

3. Charging roller (power-supplied body, charging section)
7. Primary transfer roller (power-supplied body, transfer section)
42 ... contact spring holding member (holding member)
42a: groove 43: power supply line (conductor)
51: power supply board 52: electric contact part 61: contact spring (torsion coil spring)
61c: annular part 300: holder 304: bearing part (mounting part)
A: Image forming apparatus S: Sheet

Claims (12)

A power supply board for supplying a voltage to a power-supplied body, the power supply board having a plurality of electrical contact portions,
A plurality of torsion coil springs having conductivity and being in contact with the electric contact portion at one end and contacting the power-supplied body or a conductor electrically connected to the power-supplied body at the other end When,
A holding member that is an insulator that penetrates the annular portions of the plurality of torsion coil springs and holds the plurality of torsion coil springs at intervals.
A mounting portion for mounting the holding member,
An apparatus comprising:   The apparatus according to claim 1, wherein the holding member is detachable from the mounting unit.   The apparatus according to claim 1, wherein the mounting portion is a groove into which the holding member is fitted.   The apparatus according to claim 3, wherein the mounting portion has a protrusion that comes into contact with the holding member and restricts release of the holding member into the groove.   The device according to claim 1, wherein the conductor is a wire. The other end of the plurality of torsion coil springs contacts the wire,
The wire is in contact with a compression coil spring electrically connected to the power-supplied body,
The compression coil spring is fitted and held inside a tubular body having a slit formed therein, and the wire enters the inside of the tubular body from the slit of the tubular body and forms the compression coil spring. Apparatus according to claim 5, characterized in that it is in contact.   The image forming apparatus according to claim 1, wherein the holding member is a solid cylindrical member made of resin.   The device according to claim 7, wherein the holding member has a groove formed on an outer peripheral surface thereof for positioning the torsion coil spring.   When the holding member is mounted on the mounting portion, a contact portion that comes into contact with each arm portion of the plurality of torsion coil springs and bends the arm portion toward the electric contact portion is provided. Apparatus according to any of the preceding claims.   The device according to any one of claims 1 to 9, wherein the torsion coil spring is in pressure contact with the electrical contact portion. A charging unit for charging the photoconductor,
An exposure unit that exposes the photoconductor charged by the charging unit to form an electrostatic latent image,
A developing unit that develops the electrostatic latent image as a toner image;
A transfer unit that transfers the toner image formed on the photoconductor to a transfer target body,
An apparatus according to any one of claims 1 to 10,
With
The image forming apparatus, wherein the power-supplied body is any one of the charging unit, the developing unit, and the transfer unit.   The image forming apparatus according to claim 11, wherein a plurality of the charging units, the developing units, and the transfer units are provided, respectively.