JP2009244313A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate assembly work by simplifying wiring for applying a high voltage with respect to a developing unit and an image forming unit, or the like, in an image forming apparatus, such as copying machine, printer and facsimile machine. <P>SOLUTION: The image forming apparatus includes the developing unit (4) and a drum unit (3), provided detachably from the image forming apparatus body, and a circuit board for supplying predetermined voltage, wherein a slender sheet type conductive plate (45) is used as a conductor for applying the voltage from the circuit board to the developing unit or the drum unit; the conductive plate is arranged in a voltage applying unit (40); and one end of the conductive plate is provided to be electrically connected to the developing unit or the drum unit side, and the other end is concurrently made to function as a terminal for electrical connection to the circuit board side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile.

  Many image forming apparatuses such as copiers, printers, and facsimiles have a developing unit, a drum unit, and the like configured in a cartridge type that can be attached to and detached from the main body of the image forming apparatus. These units are provided with a developing roller, a charger, a photosensitive drum, a cleaner, and the like. From a high-voltage power circuit board fixed on the image forming apparatus main body side, a developing bias, a discharging bias, a cleaning bias, etc. Is applied.

  On the other hand, the rotational power for driving the developing unit and the drum unit is transmitted from a rotational drive shaft of a drive device fixed to the image forming apparatus main body. In this case, in order to reduce the size of the device, it is preferable to provide a driving device that is a supply source of driving force for these units and a high-voltage power supply substrate for applying a high voltage on the same side of these units. Many of them are configured as follows.

As this type of image forming apparatus, for example, an apparatus described in Patent Document 1 below is known.
JP 2006-53255 A

  By the way, in an image forming apparatus such as a copying machine, a printer, and a facsimile machine, there are many parts that require high voltage application such as bias control of a charging device and a developing device, and it is necessary to provide many application units in order to improve image accuracy. Therefore, a circuit board for a high-voltage power source serving as a power source is often collected on one side surface portion of the image forming apparatus main body in consideration of productivity and maintainability. For the same reason, the drive unit, the cooling unit, and the like are grouped on the same side. On the other hand, the development unit and the drum unit are energized by a harness connected from a circuit board for high-voltage power supply, but in the configuration as described above, various members are interposed between the high-voltage application unit and the circuit board. Therefore, in order to perform harness processing such as bundling and fixing through the harness between these members, there is a problem that complicated processing is required and the assembly work is inefficient.

  Accordingly, the present invention provides an image forming apparatus that can reduce the wiring processing for supplying voltage to the developing unit, the drum unit, and the like and can simplify the assembling work in consideration of such problems of the conventional image forming apparatus. The purpose is to do.

The first aspect of the present invention is a detachable developing unit;
A detachable drum unit;
A circuit board for supplying a predetermined voltage;
A voltage application unit in which a plate-like conductive member is disposed to apply the voltage from the circuit board to the development unit or the drum unit;
One end of the conductive member is provided so as to be electrically connected to the developing unit or the drum unit, and the other end is formed with a terminal structure for electrical connection to the circuit board. Forming device.

  The second aspect of the present invention is the image forming apparatus according to the first aspect of the present invention, wherein the one end of the conductive member is fixed to the voltage application unit with a screw member.

In the third aspect of the present invention, the voltage application unit is provided with a plurality of guide walls for insulating and guiding the plurality of conductive members,
The plate-like portion excluding the one end portion of the conductive member is arranged in a state where it stands upright on the surface of the voltage application unit,
Inside the guide walls, a support protrusion is provided for contacting the side surface of the plate-like conductive member so as to be positioned at a predetermined position inside the guide wall. 1 is an image forming apparatus according to the first or second aspect of the present invention;

  In addition, according to a fourth aspect of the present invention, the supporting projection is located at a position protruding toward the conductive member disposed on one side of the guide wall and on the other side of the guide wall. The image forming apparatus according to the third aspect of the present invention, wherein the image forming apparatus is arranged such that the positions protruding toward the conductive members arranged are shifted from each other to form a staggered pattern.

In the fifth aspect of the present invention, the conductive member is disposed on the surface of the voltage application unit opposite to the development unit or the drum unit side.
The one end portion of the conductive member passes through a through hole provided in the voltage applying unit so that the one end portion of the conductive member can be directly connected to the electrical connection portion on the developing unit or the drum unit side. Any one of the first to fourth aspects that protrudes toward the developing unit or the drum unit, and is curved so as to be elastically contacted when the protruding tip is in contact with the electrical connection portion. This is the image forming apparatus of the present invention.

  The present invention has an effect of providing an image forming apparatus that can reduce wiring processing for supplying voltage to a developing unit, a drum unit, or the like and that can simplify the assembling work.

  Hereinafter, a printer as an example of an image forming apparatus of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a printer as an embodiment. A developing unit, a drum unit, a high-voltage power supply circuit board, etc., which will be described later, are provided inside the main body of the printer 1. A predetermined image is transferred and sent out from the discharge port.

  FIG. 2 is an explanatory diagram of a schematic configuration of the printer according to the first embodiment of the present invention. As shown in FIG. 2, the printer 1 in this embodiment includes a paper tray 2 that stores paper for printing, a drum unit 3 that forms an image on the paper supplied from the paper tray 2, and an upstream side of the drum unit 3. The developing unit 4 provided, the fixing unit 5 provided on the downstream side of the drum unit 3, the discharging means 6 for discharging the paper that has passed through the fixing unit 5, and the paper discharged from the discharging means 6 are placed. And a discharge tray 7.

  The paper tray 2 is provided with a paper feeding means 8 composed of rollers for supplying paper to the drum unit 3.

  The paper tray 2 is disposed at the bottom of the printer 1 of the present embodiment, and the drum unit 3 is disposed above the paper tray 2. In addition, the discharge means 6 is disposed at the upper part on the back side of the printer, and the discharge tray 7 is disposed on the upper surface of the printer.

  Next, the drum unit 3 will be described. The drum unit 3 removes the charged charges by applying light to the surface of the photosensitive drum 15 other than the portion where the image is formed, and the charger 18 for charging the surface of the photosensitive drum 15 and the surface of the photosensitive drum 15. And an exposure device 19 for forming an electrostatic latent image.

  Further, the image transfer unit 10 applies a charge opposite to that of the toner from the opposite side of the photosensitive drum 15 to the conveyed paper, and transfers the toner to the paper by electrostatic force, and the surface of the photosensitive drum 15. And a cleaner 23 for removing toner remaining on the photosensitive drum 15 without being transferred.

  Further, on the upstream side of the drum unit 3, the developing roller 20 of the developing unit 4 that faces the photosensitive drum 15 and attaches toner to the electrostatic latent image formed on the surface of the photosensitive drum 15 to form a visible image. Is provided.

  The fixing unit 5 includes a fixing roller 24 having a heater and a pressure roller 25 that is in pressure contact with the fixing roller 24.

  The printer 1 has a sheet reversing unit that conveys the sheet on which the image is formed on one side by the drum unit 3 to the discharge unit 6 and conveys the sheet conveyed to the discharge unit 6 to the drum unit 3 again. is set up.

  Next, the operation of the printer of this embodiment will be described. In the printer 1, when print data is transmitted from a computer or the like (not shown) connected to a network or the like (not shown), the print data is stored in a memory (not shown).

  A part of the surface of the photosensitive drum 15 is uniformly charged by the charger 18 and is exposed by the exposure device 19 based on the print data, and the charge of portions other than the image is removed to form an electrostatic latent image. . Then, the developing roller 20 of the developing unit attaches toner, which is colored fine particles charged with a polarity opposite to that of the electrostatic latent image, to the electrostatic latent image to form a visible image. Along with this operation, the sheet is conveyed from the sheet tray 2 at the bottom of the image forming apparatus to between the photosensitive drum 15 located above the sheet tray 2 and the transfer unit 21.

  Then, the toner attached to the surface of the photosensitive drum 15 is transferred onto the sheet by the transfer unit 21. The charge on the surface of the photosensitive drum 15 transferred to the paper is removed by the static eliminator 22, and the remaining toner is removed by the cleaner 23. The portion where the toner has been removed is charged again and the above-described operation is repeated.

  On the other hand, the sheet on which the image has been transferred passes between the heated fixing roller 24 and the pressure roller 25, whereby the toner adhering to the sheet surface is fixed on the sheet.

  When the printer 1 of the present embodiment has not received a double-sided printing instruction from a computer or the like, the control unit drives the roller pair 29 and the roller pair 30 in the forward direction, and the sheet is discharged from the leading end of the discharge tray 7. Discharged to the top.

  On the other hand, when the printer is instructed to perform double-sided printing, after the trailing edge of the sheet passes between the first shaft roller 26 and the second shaft roller 27, the control means reversely rotates the roller pair 29. And the roller pair 30 is driven.

  By driving the roller pairs 29 and 30 in the reverse direction, the sheet passes from the rear end side through the sheet reverse conveyance path 28 to the sheet conveyance path 31 and is conveyed in the sheet conveyance path 31. Subsequently, as in the case where an image is formed on one side, an image is formed on the other side by the drum unit 3 on the sheet.

  Then, the sheet passes through the fixing unit 5 and is discharged onto the discharge tray 7.

  Next, the structure of the energization part for the developing unit 4 and the drum unit 3 will be described. FIG. 3 is a perspective view showing the developing unit 4 and the drum unit 3, and FIG. 4 is a view (a front view) seen from the direction of the arrow Y in FIG. The developing unit 4 and the drum unit 3 are arranged in parallel, and constitute an image forming unit 33 as a whole. The image forming unit 33 in FIG. 4 is represented as a view seen from the arrow X direction in FIG.

  As shown in FIG. 4, at the end of the image forming unit 33 composed of the developing unit 4 and the drum unit 3 on the front side (the diagonally lower right side in FIG. 3), driving for transmitting rotational power to each unit. As input units, a developing unit drive input unit 35 and a photosensitive drum drive input unit 36 are provided. When these units are mounted on the printer main body, the output shaft (not shown) of a drive unit with a drive motor provided in the printer main body is fitted and connected to the drive input units 35 and 36 to develop the driving force. This is transmitted to the unit 4 and the drum unit 3.

  With respect to the internal frame (not shown) of the main body (not shown) in which the end of the image forming unit 33, which is a combined body of the developing unit 4 and the drum unit, is inserted and held at a predetermined position. The voltage application unit 40 shown in FIGS. 5, 6, and 7 is attached by the screw member 32. In this voltage application unit 40, a conductive plate disposing portion 42 is integrally provided on a main frame 41, and an elongated metal plate-like conductive plate 45 excellent in conductivity is provided on the conductive plate disposing portion 42. It is attached.

  5 is a front view of the voltage application unit 40, FIG. 6 is a perspective view of the voltage application unit 40, and FIG. 7 is an exploded perspective view of the conductive plates 45a to 45e attached to the voltage application unit 40. It is.

  As shown in detail in FIGS. 8 and 9, a plurality of guide walls 46 are formed on the plate surface of the conductive plate arrangement portion 42 on the surface of the conductive plate arrangement portion 42 of the voltage application unit 40. The conductive plate 45 is disposed perpendicular to the plate surface 42 a of the conductive plate disposing portion 42 in the space between the guide walls 46. The conductive plates 45a to 45e replace the conventional harness, and a total of five plates (three (45a to 45c) on the left side in FIG. 6 and two (45d and 45e) on the right side are arranged). .

  8 is an enlarged plan view of the Z portion shown in FIG. 5, and FIG. 9 is an enlarged perspective view of the Z portion and its peripheral portion.

  A plurality of support protrusions 47 are integrally provided on the inner side of the guide wall 46 shown in FIG. 8 (the side facing the conductive plate 45), and the conductive plate in which the tips of the support protrusions 47 are in a vertical state. 45 is in contact with the side surface. For this reason, the conductive plate 45 is securely held at a predetermined position (the center position in the illustrated example) inside the guide wall 46. The plurality of support protrusions 47 are arranged in a staggered manner in which the positions are shifted on both sides of the guide wall 46, as shown in FIG. For this reason, the creeping distance between the conductive plates 45 on both sides is increased, and the insulation is improved accordingly.

  One end of each of the plurality of conductive plates 45 is led to a predetermined application unit (A, B, C, D, E), and a tip thereof is a plane parallel to the plate surface of the conductive plate disposing unit 42. Each of which is fixed to the conductive plate disposing portion 42 with a screw member 49. Since the conductive plate 45 is formed of a metal plate, it is easy to form the tip portion as a fixed portion 48 having a predetermined shape (a plane parallel to the surface 42a of the conductive plate disposing portion 42).

  Describing the arrangement of the plurality of conductive plates 45a to 45e, the leftmost first conductive plate 45 among the three on the left side in FIGS. 5 and 6 is guided to the application section A of the voltage application unit 40. The central second conductive plate 45 is guided to the application unit B and fixed. These application units A and B are voltage application units for the drum unit 3 and are connected to application units A ′ and B ′ on the image forming unit 33 side in FIG. 4 via connection spring members 55 described later, respectively. Is.

  On the other hand, among the three on the left side, the right third conductive plate 45 is guided and fixed to the application section C for the developing unit 4.

  Further, the conductive plate 45d shown in FIG. 5 is guided and fixed to the application unit D, and the conductive plate 45e is guided to the application unit E and fixed. These application units C, D, and E are voltage application units for the developing unit, and are connected to the application units C ′, D ′, and E ′ in FIG. 4 via connection spring members 55, respectively. .

  As described above, one end portion (tip portion) of the conductive plate 45 is formed in a flat plate shape parallel to the plate surface of the conductive plate disposing portion 42, and is respectively applied to a predetermined application portion of the voltage application unit 40. Although fixed, the other end is connected to the side of the lead wire 50 drawn from a circuit board (not shown) that supplies high-voltage power.

  FIG. 10 shows a connection portion between the conductive wire 50 from the circuit board and the conductive plate 45, and a fastener 51, which is a member for wiring connection, is fixed to the leading end portion of the conductive wire 50. Further, the end portion of the conductive plate 45 itself is integrally formed as a connection terminal 53 in the form of a coupling terminal for fasteners by sheet metal processing. By fitting and fixing the connection terminal 53 of the conductive plate 45 to the fastener 51, the two are reliably connected by a simple operation. Since the conductive plate 45 is formed of a metal plate, the connection terminal 53 can be easily formed integrally.

  In FIG. 10, illustration of a protective sleeve 52 for insulating and protecting the fastener 51 is omitted.

  As described above, by forming the conductive plate 45 in the shape of a long and thin metal plate, the end portion thereof can be integrally formed into a desired terminal shape, so that it is not necessary to prepare a separate terminal member, and also from the viewpoint of work. It becomes economically preferable. Here, the conductive plate 45 can be easily manufactured by punching a metal plate such as stainless steel into a desired shape and bending the metal plate.

  Since the voltage application unit 40 is assembled in the main body internal frame as described above, electrical connection and drive system connection are made when the image forming unit 33 is inserted into the apparatus main body. The connection from the application units A, B, C, D, E of the voltage application unit 40 to the application units A ′, B ′, C ′, D ′, E ′ of the image forming unit 33 is shown in FIGS. This is done via the connecting spring member 55 shown.

  FIG. 11 is a cross-sectional view schematically showing the structure of the portion of the conductive plate 45 attached to the voltage application unit 40. The connecting spring member 55 in the illustrated example includes a small-diameter tip side coil spring 55a and the coil spring 55a. Further, it is formed as a conductive two-stage coil spring integrally formed with a coaxial base-side coil spring 55b having a larger diameter than that of the coil spring. The connecting spring member 55 made of a coil spring is inserted into a two-stage diameter through hole 57 formed in the conductive plate disposing portion 42 of the voltage application unit 40, and the rear end portion of the large-diameter base side coil spring 55b is electrically conductive. It is pressed by the flat end face of the adhesive plate 45. For this reason, the distal end portion of the connection spring member 55 that is a coil spring is elastically pressed by the voltage application portion of the image forming unit 33 and is in close contact with the application portion.

  Next, FIG. 12 shows a form of a connecting leaf spring member 55 ′ as an example different from the example shown in FIG. 11. In this embodiment, the tip of the conductive plate 45 itself is formed into a curved shape. Thus, the connecting leaf spring member 55 ′ is formed integrally with the conductive plate 45. For this reason, the connecting spring member 55 formed of a coil spring as in the above embodiment is not necessary, and the number of components can be reduced. Since the conductive plate 45 is a metal plate, molding in this case is easy. Further, in this case, the conductive plate 45 has elasticity by using a spring material, and is elastically pressed against the voltage application unit of the image forming unit 33, so that the adhesion (conductivity) to the application unit is high. Can also be adequately secured.

  As described above, according to the structure of the high voltage application unit, one end of the conductive plate 45 is provided so as to be electrically connected to the developing unit 4 or the drum unit 3 side, and the other end serves as a high voltage power source. Since it also serves as the connection terminal 53 for electrical connection with the circuit board side, it is not necessary to prepare a separate connection terminal, the connection structure can be simplified and the number of components can be reduced.

  A plurality of guide walls 46 for insulating and guiding the plurality of conductive plates 45 are provided in the voltage application unit 40, and a plate-like portion excluding one end of the conductive plate 45 is perpendicular to the surface of the voltage application unit 40. The support wall is arranged in a standing state and is supported inside the guide walls 46 so as to be in contact with the side surface of the plate-like conductive plate 45 and to be positioned at a predetermined position inside the insulating guide wall. If the protrusions 47 are provided, not only the conductive plates can be easily arranged, but also the plate-like conductive plates 45 are not easily displaced, and insulation can be ensured.

  In this case, the supporting protrusion 47 is positioned on one side with the guide wall 46 interposed therebetween, and the position of the supporting protrusion 47 disposed on the other side with the guide wall 46 interposed therebetween. It is preferable to dispose them in a staggered pattern because it is advantageous in securing the necessary creepage distance.

  As described above, in the image forming apparatus according to the present invention, the conductive member constituting the wiring for applying the voltage from the circuit board is formed in an elongated plate shape, and this conductive member is used as the voltage application unit. Since it is arranged, processing such as bundling (harness processing) like a conventional harness is unnecessary, it can be easily fixed, and the assembly work is also easy.

  In the above-described embodiment, the case where the conductive plate 45 is disposed vertically has been described. However, the present invention is not limited to this.

  In the above embodiment, the case where one end portion of the conductive plate 45 is fixed by the screw member 49 has been described. However, the present invention is not limited to this. For example, the conductive plate 45 protrudes in advance from the conductive plate arrangement portion 42 side formed by resin molding. It is good also as a structure which comprises a part, and after making it fit with the hole formed in the one end part of the electroconductive plate 45, heat-deforms a projection part to an umbrella shape and heat-welds.

  Moreover, although the case where the one end part of the electroconductive plate 45 was fixed with the screw member 49 was demonstrated in the said embodiment, it does not restrict to this, For example, it fixes at the center part of the one end part and the other end part of the electroconductive plate 45 You may fix it in several places.

  In the above embodiment, the case where the guide wall is provided has been described. However, the present invention is not limited to this. For example, the electrical space distance and the creeping distance between the adjacent conductive plates 45 can be sufficiently secured. For example, the guide wall may be omitted.

  In the above embodiment, the case where the supporting protrusion is provided on the guide wall has been described. However, the present invention is not limited to this. For example, when the conductive plate 45 is disposed in a plane, or is fixed at a plurality of positions with screw members. If so, there is no need to provide it.

  In the above embodiment, the case where the conductive plate of the present invention is adopted for the electrical connection between the drum unit and the developing unit has been described. However, the present invention is not limited to this. For example, the electrical connection with any one of the units is performed. The structure which employ | adopts the electroconductive plate of this invention may be sufficient.

  In the above-described embodiment, the case of a printer has been described. However, the present invention is not limited to this. For example, any apparatus may be used as long as it is an image forming apparatus such as a copying machine or a facsimile.

  The image forming apparatus according to the present invention can be effectively used as a voltage applying unit in an image forming apparatus such as a copying machine, a printer, or a facsimile.

1 is a perspective view illustrating an appearance of a printer as an embodiment of the present invention. FIG. 2 is a schematic configuration explanatory diagram illustrating a structure of a printer according to the present embodiment. FIG. 3 is a perspective view of an image forming unit including a developing unit and a drum unit in the present embodiment. It is a front view of the image formation unit in this Embodiment. It is a front view of the voltage application unit in this Embodiment. It is a perspective view of the voltage application unit in this Embodiment. It is a perspective view showing the decomposition | disassembly state of the voltage application unit in this Embodiment. It is an enlarged front view showing the guide wall and support protrusion of the voltage application unit in this Embodiment. It is an expansion perspective view showing the guide wall and support protrusion of the voltage application unit in this Embodiment. It is an expansion perspective view showing the connection part with the circuit board side wiring of the electroconductive plate in this Embodiment. It is sectional drawing which represents typically the connection structure of the electroconductive plate in this Embodiment and the image formation unit side. It is sectional drawing which represents typically the another connection structure of the electroconductive plate in this Embodiment, and the image formation unit side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 2 Paper tray 3 Drum unit 4 Developing unit 5 Fixing unit 6 Ejecting means 7 Ejecting means 7 Ejecting tray 8 Feeding means 10 Image transfer part 15 Photosensitive drum 20 Developing roller 24 Fixing roller 25 Pressure roller 33 Image forming unit 40 Voltage applying unit 45 Conductive plate 46 Guide wall 47 Support protrusion 49 Screw member

Claims (5)

A development unit detachably provided;
A detachable drum unit;
A circuit board for supplying a predetermined voltage;
A voltage application unit in which a plate-like conductive member is disposed to apply the voltage from the circuit board to the development unit or the drum unit;
One end of the conductive member is provided so as to be electrically connected to the developing unit or the drum unit, and the other end is formed with a terminal structure for electrical connection to the circuit board. Forming equipment.   The image forming apparatus according to claim 1, wherein the one end portion of the conductive member is fixed to the voltage application unit with a screw member. The voltage application unit is provided with a plurality of guide walls for insulating and guiding the plurality of conductive members, respectively.
The plate-like portion excluding the one end portion of the conductive member is arranged in a state where it stands upright on the surface of the voltage application unit,
The support protrusion for supporting it so that it may contact | abut to the side surface of the said plate-shaped electroconductive member and to be located in the predetermined position inside the said guide wall is provided inside the said guide walls. The image forming apparatus according to 1 or 2.   The support protrusion protrudes toward the conductive member disposed on one side of the guide wall, and faces the conductive member disposed on the other side of the guide wall. The image forming apparatus according to claim 3, wherein the image forming apparatus is arranged so as to be staggered with respect to a protruding position. The conductive member is disposed on the surface of the voltage application unit on the side opposite to the development unit or the drum unit side,
The one end portion of the conductive member passes through a through hole provided in the voltage applying unit so that the one end portion of the conductive member can be directly connected to the electrical connection portion on the developing unit or the drum unit side. Any one of claims 1 to 4, which protrudes toward the developing unit or the drum unit and is curved so as to be elastically contacted when the protruding tip is in contact with the electrical connection portion. An image forming apparatus according to claim 1.

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