JP2017083684A - Internal unit, and image formation device equipped with internal unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal unit, with a separation mechanism being excluded from an image formation device, in which a connection part such as an electrode can be prevented from contacting to another connected part even if an internal unit such as an intermediate transfer unit is pulled out straight from a loading position, as well as the image formation device equipped with the internal unit.SOLUTION: In an image formation device 10, an internal unit 10 consisting of an image formation unit 40 and an intermediate transfer unit 50 is supported by an enclosure 10A detachably. The intermediate transfer unit includes a unit frame 51 and a plurality of wire terminals 31A-31K. The wire terminals are provided on an upper surface of the unit frame 51, and an electrically connected to connected parts 30A-30K respectively in the enclosure 10A by arrangement of the unit frame 51 at a loading position. Each of the wire terminals is arranged at a position deviated in width direction across an inserting/removing direction, on the upper surface of the unit frame 51.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an internal unit having a connecting portion that is electrically connected to a connected portion provided in an image forming apparatus when mounted at a mounting position, and an image forming apparatus including the internal unit.

  An image forming apparatus that forms an image on a sheet by an electrophotographic method incorporates a plurality of processing apparatuses in order to execute image processing. For example, the charging device charges the surface of the photosensitive drum to a uniform potential. The scanning device forms an electrostatic latent image on the photosensitive drum. The developing device develops the electrostatic latent image using toner. The transfer device transfers the toner image to a sheet that is a recording medium. The fixing device heats and pressurizes the sheet on which the toner image is transferred to fix the image on the sheet. Each of these processing apparatuses forms an image on the sheet.

  Each processing apparatus is formed detachably from the image forming apparatus for each of the plurality of processing apparatuses in order to facilitate assembly of the image forming apparatus and improve maintainability of the image forming apparatus. In particular, in a color image forming apparatus, the same type of processing is executed for each color. For this reason, a plurality of developing devices that perform the same type of processing such as development processing are modularized and integrated into one internal unit.

  In addition, in a plurality of processing apparatuses used for image formation, when an internal unit is mounted, the electrodes of the processing apparatuses that receive voltage supply must be securely connected to the electrodes of the apparatus main body that supplies power. .

  As a method for connecting these electrodes, a configuration in which the electrodes are urged so as to continue to be joined by a spring or the like is known. In such an internal unit, in order to prevent the mounting position of the internal unit and the mounting position of the apparatus main body from deviating from each other while maintaining the joined state by a spring or the like, the fitting that fits with the mounted portion of the apparatus main body. There is an apparatus in which a joint member is formed.

  The color image forming apparatus also includes an intermediate transfer unit that carries the toner images of the respective colors transferred from the respective photosensitive drums. The intermediate transfer unit has a transfer belt carrying a toner image. The toner image on the transfer belt is transferred to a sheet by an intermediate transfer unit. As an example of a conventional color image forming apparatus having an intermediate transfer unit, an apparatus in which the intermediate transfer unit is detachable in a horizontal direction from an opening provided on a side surface of the image forming apparatus is known (see Patent Document 1).

JP 2010-049095 A

  In the conventional image forming apparatus described above, a plurality of electrodes provided in the intermediate transfer unit are arranged side by side along the attaching / detaching direction of the intermediate transfer unit. Therefore, before extracting the intermediate transfer unit from the image forming apparatus, it is necessary to separate the electrode of the intermediate transfer unit from the electrode in the image forming apparatus. Therefore, a conventional image forming apparatus is provided with a separation mechanism that temporarily moves the intermediate transfer unit downward. Without this separation mechanism, in the process of extracting the intermediate transfer unit, the electrodes located on the far side in the mounting direction in the intermediate transfer unit come into contact with all the electrodes in the image forming apparatus. In this case, the electrode may be damaged by excessive contact between the electrode. In addition, in an electrode such as a charging device to which a high voltage is applied, the pressure may remain in the charging device even after power interruption. In this case, when the intermediate transfer unit is pulled out and the electrodes are in contact with each other, The residual voltage may be applied to an unintended device and cause malfunction.

  The object of the present invention is to eliminate the separation mechanism from the image forming apparatus and prevent the connection portion such as the electrode from contacting other connected portions even if the internal unit such as the intermediate transfer unit is straightly extracted from the mounting position. It is an object to provide a possible internal unit and an image forming apparatus including the internal unit.

  An internal unit according to one aspect of the present invention includes a unit main body and a plurality of connection portions. The unit main body is supported so as to be able to be inserted into and removed from the image forming apparatus in a horizontal direction, and is provided between an installation position defined inside the image forming apparatus and an extraction position separated from the installation position in the horizontal direction. It is configured to be movable. The plurality of connection portions are provided on an upper surface of the unit main body, and are electrically connected to each of the plurality of connected portions provided inside the image forming apparatus by disposing the unit main body at the mounting position. Connected. Each of the plurality of connecting portions is arranged at a position shifted in a crossing direction intersecting with the insertion / extraction direction of the unit main body or a position shifted in the vertical direction on the upper surface of the unit main body.

  An image forming apparatus according to another aspect of the present invention includes the internal unit, a unit mounting portion, and a plurality of connected portions. The unit mounting portion supports the internal unit so that the internal unit is mounted at the mounting position and is movable between the mounting position and the extraction position. The plurality of connected portions are provided at positions corresponding to the plurality of connecting portions in the unit mounting portion, and are electrically connected to the plurality of connecting portions, respectively.

  According to the present invention, the separation mechanism is excluded from the image forming apparatus, and even when the internal unit such as the intermediate transfer unit is straightly extracted from the mounting position, the connection portion such as the electrode is prevented from coming into contact with another connected portion. It is possible to do.

FIG. 1 is a perspective view showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the internal structure of the image forming apparatus. FIG. 3A is a diagram illustrating a state in which the internal unit is extracted from the image forming apparatus. FIG. 3B is a diagram illustrating a state where the exterior cover of the image forming apparatus is removed. FIG. 4 is a diagram illustrating a positional relationship between the connection terminals in the image forming apparatus and the connection terminals of the internal unit. 5A and 5B are perspective views showing the configuration of the intermediate transfer unit provided in the internal unit. FIG. 6 is a diagram illustrating a state where the transfer belt is removed from the intermediate transfer unit. FIG. 7 is an enlarged view showing the configuration of the main part VII in FIG. FIG. 8 is an enlarged view showing the configuration of the main part VIII in FIG. FIG. 9 is an enlarged view showing the configuration of the main part IX in FIG. FIG. 10 is an enlarged view showing the configuration of the main part X in FIG. FIG. 11 is a diagram illustrating the left side frame of the intermediate transfer unit. FIG. 12 is a diagram illustrating the right side frame of the intermediate transfer unit. FIG. 13 is a cross-sectional view showing a cross-sectional structure of the base frame of the intermediate transfer unit. 14A and 14B are views showing a state in which the base frame of the intermediate transfer unit is bent around the central portion. 15A and 15B are partially enlarged perspective views showing the structure of the end portion on the center side in the unit frame of the intermediate transfer unit.

  Hereinafter, an image forming apparatus 10 according to an embodiment of the present disclosure will be described with reference to the drawings as appropriate. Embodiment described below is only an example which actualized this invention, and does not limit the technical scope of this invention. For convenience of explanation, the vertical direction is defined as the vertical direction 7 in the installation state in which the image forming apparatus 10 can be used (the state shown in FIG. 1). Further, the front-rear direction 8 is defined with the front surface of the paper cassette 24 shown in FIG. Further, a left-right direction 9 is defined with reference to the front surface of the image forming apparatus 10 in the installed state.

  An image forming apparatus 10 according to an embodiment of the present invention is a tandem color printer having at least a printing function.

  As shown in FIG. 1, the image forming apparatus 10 includes a housing 10A. The housing 10A has a substantially rectangular parallelepiped shape as a whole. Each component constituting the image forming apparatus 10 is provided inside the housing 10A.

  As shown in FIG. 2, the image forming apparatus 10 includes an internal unit 100, an optical scanning device 13, a secondary transfer roller 20, a fixing device 16, a paper discharge tray 18, a paper feed cassette 24, a paper feed mechanism 28, and an operation display. The unit 25, the vertical conveyance path 26, and the control board 2 are provided. Further, the internal unit 100 includes an image forming unit 40 and an intermediate transfer unit 50.

  A paper feed cassette 24 is provided at the bottom of the housing 10A. The paper feed cassette 24 stores printing paper. A paper feed mechanism 28 is provided above the rear portion of the paper feed cassette 24. The paper feed mechanism 28 feeds the printing paper in the paper feed cassette 24 toward the vertical conveyance path.

  A paper discharge tray 18 is provided on the upper surface of the housing 10A. The printing paper on which an image is formed by the image forming unit 40 passes through the fixing device 16 and is then discharged from the sheet discharge port 27 to the paper discharge tray 18.

  The control board 2 is provided in the upper part of the internal space of the housing 10A. Specifically, the control board 2 is provided in the vicinity of the back surface of the paper discharge tray 18. The control board 2 is configured by a flat printed board or the like, and is supported by an upper frame 10B (see FIG. 3B) or the like inside the housing 10A in a horizontal state.

  The optical scanning device 13 is provided on the upper side of the paper feed cassette 24. Further, an internal unit 100 is provided on the upper side.

  FIG. 2 shows a state in which the internal unit 100 is mounted in the space 49 in the housing 10A. The internal unit 100 is provided in a space 49 surrounded by the optical scanning device 13 and the control board 2 in the housing 10A. The internal unit 100 has a configuration in which the image forming unit 40 and the intermediate transfer unit 50 are vertically connected by a well-known fixing tool. The image forming unit 40 is disposed on the lower side, and the intermediate transfer unit is disposed on the upper side. A unit 50 is arranged. As shown in FIG. 3, the internal unit 100 is supported so as to be insertable / removable in the horizontal direction with respect to the housing 10 </ b> A of the image forming apparatus 10. Here, FIGS. 3A and 3B show a state in which the internal unit 100 is pulled out from the housing 10A.

  In the present embodiment, the internal unit 100 is detachable from the housing 10A. Specifically, the internal unit 100 has a mounting position (position shown in FIG. 2) defined inside the housing 10A and an extraction position (shown in FIGS. 3A and 3B) spaced forward from the mounting position. It is supported so that it can be moved between In other words, the housing 10A supports the internal unit 100 so as to be movable between the mounting position and the extraction position. The housing 10A that supports the internal unit 100 in this way is an example of the unit mounting portion of the present invention.

  As a mechanism that supports the internal unit 100 so as to be movable, for example, a known rail support mechanism can be applied. The rail support mechanism is provided in the side frame 10C of the housing 10A and the internal unit 100. For example, rails are provided on both side surfaces in the width direction of the unit frame 51 of the intermediate transfer unit 50 of the internal unit 100, and rail guide grooves that support the rails on the side frames 10C of the housing 10A so as to be slidable in the front-rear direction. Is provided. The rail support mechanism supports the unit frame 51 movably in the horizontal direction (front-rear direction 8) between the mounting position and the extraction position in the housing 10A. Thereby, in the housing 10A, the internal unit 100 can be slid in the horizontal direction.

  As shown in FIG. 2, the image forming unit 40 includes four image forming units 4 (4C, 4M, 4Y, 4K). Each of the image forming units 4 (4C, 4M, 4Y, 4K) includes a photosensitive drum 11, a charging device 12, a developing device 14, and the like. Each image forming unit 4 is supported by a housing frame 41 (see FIG. 3A) of the image forming unit 40. The image forming units 4 are juxtaposed along the front-rear direction 8 and form a color image based on a so-called tandem method. Specifically, toner images corresponding to C (cyan) in the image forming unit 4C, M (magenta) in the image forming unit 4M, Y (yellow) in the image forming unit 4Y, and K (black) in the image forming unit 4K are formed. Is done. Cyan image forming unit 4C, magenta image forming unit 4M, yellow image forming unit 4Y, and black image forming unit 4K in this order from the downstream side in the transfer belt 5 movement direction (arrow 19 direction) to be described later. Are arranged in a line in that order. The charging device 12, the developing device 14, and the secondary transfer roller 20 are examples of the second conductive portion of the present invention, and these are all members to which a voltage is applied, that is, conductive members that are conductive. It is.

  In each of the image forming units 4, the photosensitive drum 11 is uniformly charged to a predetermined potential by the charging device 12. Next, the optical scanning device 13 irradiates the surface of each photoconductive drum 11 with laser light based on the image data, thereby forming an electrostatic latent image on the surface of each photoconductive drum 11. The electrostatic latent image is developed (visualized) as a toner image by the developing device 14. The toner images of the respective colors formed on the photosensitive drum 11 are transferred to the transfer belt 5 while being sequentially superimposed on each of the primary transfer rollers 15 described later. Next, the color image on the transfer belt 5 is transferred to the printing paper conveyed from the paper feed cassette 24 via the vertical conveyance path 26 by the electric field formed between the transfer belt 5 and the secondary transfer roller 20. The

  FIG. 4 is a perspective view showing the internal unit 100, and FIGS. 5A and 5B are perspective views showing the intermediate transfer unit 50. As shown in FIGS. 4 to 5B, the intermediate transfer unit 50 is provided on the upper part of the housing frame 41 that houses the four image forming units 4. The intermediate transfer unit 50 includes a transfer belt 5 (an example of a belt member of the present invention), a driving roller 5A, a driven roller 5B, and four primary transfer rollers 15 corresponding to the respective colors (an example of a first conductive portion of the present invention, FIG. 2), and a unit frame 51 (an example of a unit main body of the present invention) that supports them.

  The transfer belt 5 is stretched by a driving roller 5A and a driven roller 5B so as to extend in the front-rear direction 8. A plurality of photosensitive drums 11 are arranged in the front-rear direction 8 along the transfer belt 5 below the transfer belt 5. The transfer belt 5 carries a toner image composed of a plurality of color toner images (four colors in this embodiment). The transfer belt 5 is an annular belt member to which toner images of respective colors formed on the respective photosensitive drums 11 are primarily transferred by a primary transfer roller 15. The transfer belt 5 holds the toner image primarily transferred from the photosensitive drum 11. The transfer belt 5 is rotatably supported by the unit frame 51 by a driving roller 5A and a driven roller 5B. The transfer belt 5 is driven to rotate by the driving roller 5 </ b> A and the driven roller 5 </ b> B, so that the surface thereof moves (runs) while being in contact with the surface of each photosensitive drum 11. When the transfer belt 5 is rotationally driven, the surface thereof passes between the photosensitive drum 11 and the primary transfer roller 15. A predetermined voltage is applied to each primary transfer roller 15 from wire terminals 31 </ b> A to 31 </ b> D described later, so that a potential difference is formed between the primary transfer roller 15 and the photosensitive drum 11. Due to this potential difference, the toner images of the respective colors carried on the respective photosensitive drums 11 are sequentially transferred from the photosensitive drum 11 to the transfer belt 5 so as to be superimposed.

  A front cover 46 is provided on the front surface of the housing 10 </ b> A of the image forming apparatus 10. The front cover 46 is configured to be openable and closable with respect to the front surface of the housing 10A. FIG. 2 shows a state in which the front cover 46 is closed with respect to the front surface of the housing 10A. 3A and 3B show a state in which the front cover 46 and the paper feed cassette 24 are removed from the housing 10A.

  The secondary transfer roller 20 is provided at a position facing the drive roller 5A on the rear side of the housing 10A. An image is transferred from the transfer belt 5 to the printing paper by the secondary transfer roller 20. When the intermediate transfer unit 50 is mounted at the mounting position, the transfer belt 5 is sandwiched between the drive roller 5 </ b> A and the secondary transfer roller 20.

  The fixing device 16 is provided on the upper side of the secondary transfer roller 20. The fixing device 16 includes a heating roller 16 </ b> A that is heated by a heating device, and a pressure roller 16 </ b> B that is disposed to face the heating roller 16 </ b> A, and printing that is conveyed from the secondary transfer roller 20 to the fixing device 16. Fix the color image on the paper.

  In the present embodiment, as shown in FIG. 4, when the internal unit 100 is mounted at the mounting position in the housing 10A, 11 spring terminals 30A provided on the lower surface of the upper frame 10B of the housing 10A. ˜30K are electrically connected to 11 wire terminals 31 </ b> A to 31 </ b> K provided in the intermediate transfer unit 50, respectively. The spring terminals 30 </ b> A to 30 </ b> K are so-called connection terminals, and are examples of connected parts of the present invention. The wire terminals 31 </ b> A to 31 </ b> K are so-called connection terminals and are examples of the connection portion of the present invention. The spring terminals 30A to 30K and the wire terminals 31A to 31K will be described later.

  Hereinafter, the unit frame 51 of the intermediate transfer unit 50 will be described in detail.

  FIG. 6 shows a state where the transfer belt 5 is removed from the intermediate transfer unit 50. As described above, the unit frame 51 supports the transfer belt 5, the drive roller 5A, and the like. As shown in FIG. 6, the base frame 52 to which the transfer belt is attached (an example of the base portion of the present invention). And side frames 53A and 53B (an example of a support member of the present invention). Hereinafter, for convenience of explanation, the side frames 53A and 53B may be collectively referred to as the side frame 53.

  The base frame 52 is formed in an elongated shape in the front-rear direction 8 (a direction that matches the insertion / extraction direction of the internal unit 100). The width of the base frame 52 in the left-right direction 9 is formed to a size corresponding to the width of the printing paper on which an image is formed. Here, the front-rear direction 8 matches the insertion / extraction direction of the internal unit 100. The left-right direction 9 coincides with the width direction of the unit frame 51 and the base frame 52. An annular transfer belt 5 is wound around the base frame 52.

  The side frames 53 are attached to both ends of the base frame 52 in the width direction. The side frame 53A is attached to the left end portion of the base frame 52, and the side frame 53B is attached to the right end portion of the base frame 52. Each side frame 53 is formed in a shape that is long in the front-rear direction 8. Each side frame 53 supports both ends of the base frame 52 in the width direction. Specifically, the side frames 53 are fixed to the both ends of the base frame 52 by a fixing tool such as a screw. The base frame 52 is reinforced by fixing the side frames 53 to both ends of the base frame 52. That is, the side frame 53 is a reinforcing member for the base frame 52. Since the side frame 53 is provided, the base frame 52 has increased strength against twisting and the like.

  The rear end portion and the front end portion of the side frame 53 protrude outward in the front-rear direction 8 from the base frame 52, respectively. In the present embodiment, the driving roller 5 </ b> A is rotatably supported at the rear end portion of the side frame 53, and the driven roller 5 </ b> B is rotatably supported at the front end portion of the side frame 53. The transfer belt 5 is rotatably supported by the driving roller 5A and the driven roller 5B so that the base frame 52 is disposed therein.

  A plurality of wire terminals 31 </ b> A to 31 </ b> K are provided on the upper surface of the unit frame 51. Each of the wire terminals 31 </ b> A to 31 </ b> K is electrically connected to each of the plurality of spring terminals 30 </ b> A to 30 </ b> K provided inside the housing 10 </ b> A by arranging the internal unit 100 at the mounting position. As the spring terminals 30 </ b> A to 30 </ b> K, for example, a metal wire having electrical conductivity that is bent and provided with elasticity is applicable. Moreover, wire terminal 31A-31K is provided so that a metal wire which has electroconductivity may be passed to the width direction orthogonal to the said insertion / extraction direction in the groove | channel extended in the front-back direction 8 formed in the upper surface of the unit frame 51, for example. Can be applied. Of course, the spring terminals 30A to 30K and the wire terminals 31A to 31K are not limited to those having the above-described configuration.

  By the way, in the conventional image forming apparatus, a plurality of electrodes provided in the intermediate transfer unit are arranged side by side along the attaching / detaching direction of the intermediate transfer unit. Therefore, before extracting the intermediate transfer unit from the image forming apparatus, it is necessary to separate the electrodes of the intermediate transfer unit from the electrodes in the image forming apparatus. Therefore, a conventional image forming apparatus is provided with a separation mechanism that temporarily moves the intermediate transfer unit downward. Without this separation mechanism, in the process of extracting the intermediate transfer unit, the electrodes located on the far side in the mounting direction in the intermediate transfer unit come into contact with all the electrodes in the image forming apparatus. In this case, the electrode may be damaged by excessive contact between the electrode. In addition, in an electrode such as a charging device to which a high voltage is applied, the pressure may remain in the charging device even after power interruption. In this case, when the intermediate transfer unit is pulled out and the electrodes are in contact with each other, The residual voltage may be applied to an unintended device and cause malfunction. For this reason, in the present embodiment, while the separation mechanism is excluded from the image forming apparatus 10, the wire terminals 31 </ b> A to 31 </ b> K are spring terminals even if the internal unit 100 including the intermediate transfer unit 50 is pulled out straight and horizontally from the mounting position. It is comprised so that it may not contact 30A-30K.

  The wire terminals 31 </ b> A to 31 </ b> K are provided outside the both ends of the base frame 52 in the width direction on the upper surface of the unit frame 51. Specifically, the wire terminals 31A to 31G are provided on the upper surface 55 of the side frame 53A. The wire terminals 31H to 31K are provided on the upper surface 56 of the side frame 53B.

  FIG. 7 is a partially enlarged view showing the upper surface 55 of the side frame 53A. As shown in FIG. 7, each of the wire terminals 31 </ b> A to 31 </ b> G is disposed at a position shifted in the front-rear direction 8 on the upper surface 55. In the present embodiment, as shown in FIGS. 7 and 11, the upper surface 55 has an upper step surface 55 </ b> A provided on the front side and a lower step surface 55 </ b> B provided on the rear side. In the up-down direction 6, the upper step surface 55A is located higher than the lower step surface 55B. The upper surface 55 is divided into an upper step surface 55A and a lower step surface 55B in the vicinity of the center in the front-rear direction 8.

  As FIG.7 and FIG.8 shows, wire terminal 31A-31D is provided in 55 A of upper stage surfaces among wire terminal 31A-31G. In the upper surface 55A, each of the wire terminals 31A to 31D is provided at a position shifted in the front-rear direction 8 and is disposed at a position shifted in the width direction. Here, the width direction is an example of a direction that intersects the insertion / extraction direction of the internal unit 100. In the present embodiment, the wire terminals 31A to 31D are relay terminals for supplying a voltage to the charging device 12 corresponding to each color. By providing the wire terminals 31A to 31D on the upper surface 55A, the wire terminals 31A to 31D are arranged at positions shifted in the vertical direction 6 with respect to the wire terminals 31E to 31G. The up-down direction 6 coincides with the vertical direction.

  As FIG.7 and FIG.9 shows, wire terminal 31E-31G is provided in the lower surface 55B among wire terminals 31A-31G. On the lower surface 55B, the wire terminals 31E to 31G are provided at positions shifted in the front-rear direction 8 and are disposed at positions shifted in the width direction. In the present embodiment, the wire terminal 31E is a contact terminal for supplying a voltage to each of the three primary transfer rollers 15 for color toner. That is, the primary transfer roller 15 is a conductive member that is conductive. The wire terminal 31F is a contact terminal for supplying a voltage to the primary transfer roller 15 for black toner. The wire terminal 31 </ b> G is a relay terminal for applying a voltage to the secondary transfer roller 20.

  FIG. 10A is a partially enlarged view showing the upper surface 56 of the side frame 53B. FIG. 10B is an enlarged view of a main part XB in FIG. 10A. As shown in FIGS. 10A and 12, each of the wire terminals 31 </ b> H to 31 </ b> K is provided at a position shifted in the front-rear direction 8 on the upper surface 56 and is disposed at a position shifted in the width direction. Yes. In the present embodiment, the wire terminals 31 </ b> H to 31 </ b> K are relay terminals for supplying voltages to the developing devices 14 of the respective colors.

  Further, as shown in FIG. 4, spring terminals 30 </ b> A to 30 </ b> K are provided on the upper frame 10 </ b> B of the housing 10 </ b> A at positions corresponding to the 11 wire terminals 31 </ b> A to 31 </ b> K, respectively. The spring terminals 30 </ b> A to 30 </ b> K are arranged at positions shifted in the width direction or the vertical direction 6 according to the arrangement positions in the width direction and the arrangement positions in the vertical direction 6 of the wire terminals 31 </ b> A to 31 </ b> K.

  Thus, since the wire terminals 31A to 31K provided on the unit frame 51 are arranged at positions shifted in the width direction on the upper surface of the unit frame 51, the internal unit 100 including the intermediate transfer unit 50 is Even if the wire terminals 31A to 31K are pulled out straight and horizontally from the mounting position, the contact of the wire terminals 31A to 31K with the spring terminals 30A to 30K is prevented.

  Further, the wire terminals 31A to 31D are provided on the upper step surface 55A, and the wire terminals 31E to 31G are provided on the lower step surface 55B. Therefore, even if the wire terminals 31A to 31D are provided at the same position as the wire terminals 31E to 31G in the width direction, the wire terminals 31E to 31G become the spring terminals 30A of the wire terminals 31A to 31D when the internal unit 100 is pulled out. Contact with ~ 30D is prevented.

  13 to 14B are sectional views of the base frame 52 of the unit frame 51. In the present embodiment, the base frame 52 is configured to be divided into two at the central portion 60 in the longitudinal direction. Specifically, as shown in FIG. 13, the base frame 52 includes a first division portion 52A provided on the front side and a second division portion 52B provided on the rear side.

  The base frame 52 is pivotally supported at the central portion 60 so that the first divided portion 52A and the second divided portion 52B can be relatively bent. In the present embodiment, the first divided portion 52A has an arm portion 62 (see FIG. 10A) that protrudes rearward from the rear end portion 61 on the rear side. The arm portion 62 is provided at each of both ends in the width direction at the rear end portion 61. The arm portion 62 is provided with a support shaft 64 extending in the width direction. Further, the second divided portion 52B is formed with a rectangular cutout groove 69 (see FIG. 10A) into which the arm portion 62 is inserted at the front end portion 65 on the front side (center portion 60 side). The notch grooves 69 are provided at both ends in the width direction at the front end portion 65. A shaft hole (not shown) for rotatably supporting the support shaft 64 is formed on the inner surface of the notch groove 69. By inserting the support shaft 64 into the shaft hole of the notch groove 69, the first divided portion 52A can rotate around the support shaft 64 with respect to the second divided portion 52B. As a result, the base frame 52 can be bent around the central portion 60 within a predetermined angle range. Since the base frame 52 is bent around the support shaft 64, the transfer belt 5 can be easily attached to the base frame 52 as will be described later, and the transfer from the base frame 52 when the transfer belt 5 is replaced. The belt 5 can be easily removed. In addition, the arm part 62 may be supported so that it can expand and contract in the protruding direction with respect to the first divided part 52A. Thereby, in the rotation range of the 1st division part 52A, interference with the 1st division part 52A and the 2nd division part 52B is prevented, and it contacts the 2nd division part 52B at the time of rotation of the 1st division part 52A. Is prevented.

  FIG. 14A shows a state in which the first divided portion 52A is rotated approximately 45 degrees in the counterclockwise direction around the support shaft 64 with the second divided portion 52B being stationary. FIG. 14B shows a state in which the first divided portion 52A is rotated approximately 135 degrees in the counterclockwise direction around the support shaft 64 with the second divided portion 52B being stationary. FIG. 14B shows a state where the transfer belt 5 is removed. As shown in FIGS. 14A and 14B, when the first divided portion 52 </ b> A is rotated with respect to the second divided portion 52 </ b> B, the transfer belt 5 supported on the upper surface of the base frame 52 is bent in the base frame 52. The shape changes according to the state, and the tension of the transfer belt 5 is loosened. When the first dividing portion 52A is further rotated to the state shown in FIG. 14B, the transfer belt 5 can be easily detached from the base frame 52. In this state, when the transfer belt 5 is attached to the base frame 52 and then the base frame 52 is straightened as shown in FIG. 13, a predetermined tension is applied to the transfer belt 5. Thus, the transfer belt 5 is attached to the base frame 52.

  When the transfer belt 5 is mounted on the base frame 52, as shown in FIG. 14A, when the first divided portion 52A and the second divided portion 52B are bent, the front end portion 65 of the second divided portion 52B The upper portion 65A contacts the back surface of the transfer belt 5. That is, the upper portion 65 </ b> A is a portion that contacts the back surface of the transfer belt 5 when the base frame 52 is bent at the central portion 60. For this reason, in the present embodiment, the upper portion 65A of the front end portion 65 is formed in a curved surface shape. For example, the upper part 65 </ b> A is formed in a cross-sectional arc shape centering on the axis of the support shaft 64 over the entire width direction. If the upper portion 65A is not formed in a curved shape, the corner portion of the upper portion 65A may come into contact with the back surface of the transfer belt 5 every time the transfer belt 5 is replaced, and the transfer belt 5 may be damaged. As described above, if the upper portion 65A is formed in a curved surface shape, damage to the transfer belt 5 can be prevented.

  The portion formed in the curved shape is a portion that contacts the back surface of the transfer belt 5 when the base frame 52 is bent, and the other portions need not be formed in the curved shape. In the present embodiment, since the arm portion 62 of the first divided portion 52A is pivotally supported by the second divided portion 52B, the upper portion 65A of the front end portion 65 has a curved shape, but for example, the second divided portion In the configuration in which the arm portion is provided in the portion 52B and the mechanism for supporting the arm portion is provided in the first divided portion 52A, the upper portion of the rear end portion 61 of the first divided portion 52A is formed in a curved shape. Is done.

  As described above, when the base frame 52 can be divided and can be bent at the central portion 60, the side frame 53 is in a state where the base frame 52 is in a straight shape shown in FIG. It is fixed to each of both ends. As a result, even if the base frame 52 can be divided, it is properly reinforced by the side frames 53, so that the base frame 52 is not bent at the central portion 60 but held straight. As a result, the transfer belt 5 is securely held by the base frame 52 while maintaining an appropriate shape for image formation.

  15A and 15B are cross-sectional views when the unit frame 51 is cut in the width direction at the central portion 60. FIG. 15A is a diagram illustrating a left end portion of the front end portion 65 of the second divided portion 52B, and FIG. 15B is a diagram illustrating a right end portion of the front end portion 65 of the second divided portion 52B. As shown in FIGS. 15A and 15B, meandering prevention guides 70 are attached to the back surfaces of both end portions in the width direction of the transfer belt 5, respectively. The meandering prevention guide 70 is attached to the transfer belt 5 with, for example, a double-sided tape or an adhesive. The meandering prevention guide 70 is a narrow and long plate-like member made of a resin member, and is affixed to the entire circumferential direction of the transfer belt 5. In this embodiment, the meandering prevention guide 70 is disposed further outside the end portion 58 on the outer side in the width direction of the base frame 52. On the upper surface of the base frame 52, a stepped portion 59 is formed on the outer side of the end portion 58 so as to be spaced downward from the upper surface of the base frame 52. A meandering prevention guide 70 is affixed to the transfer belt 5 so as to be disposed above the stepped portion 59. As a result, even if the base frame 52 of the unit frame 51 is bent at the central portion 60, the meandering prevention guide 70 does not contact the upper portion 65A of the front end portion 65. Damage during assembly is prevented.

  In the above-described embodiment, the configuration in which the internal unit 100 is detachable from the housing 10A has been described, but the present invention is not limited to this configuration. For example, the present invention can be applied to a configuration in which the intermediate transfer unit 50 of the internal unit 100 is configured to be detachable from the housing 10A alone.

5: transfer belt 10: image forming apparatus 10A: housing 12: charging device 14: developing device 15: primary transfer roller 20: secondary transfer roller 30A-30K: spring terminal 31A-31K: wire terminal 40: image forming unit 50 : Intermediate transfer unit 51: Unit frame 52: Base frame 53: Side frame

Claims (8)

A unit main body that is supported so as to be insertable / removable in the horizontal direction with respect to the image forming apparatus and is movable between a mounting position defined inside the image forming apparatus and a pulling position separated from the mounting position in the horizontal direction. When,
A plurality of connection portions provided on the upper surface of the unit main body and electrically connected to each of a plurality of connected portions provided in the image forming apparatus by disposing the unit main body at the mounting position. And comprising
Each of the plurality of connecting portions is an internal unit arranged on the upper surface of the unit main body at a position shifted in a crossing direction intersecting the insertion / extraction direction of the unit main body or a position shifted in the vertical direction. A belt member attached to the unit body;
2. The internal unit according to claim 1, wherein the plurality of connecting portions are provided on the upper surface of the unit main body from both ends of the belt member in the intersecting direction. The unit main body includes a base portion that is long in the insertion / extraction direction around which the belt member is wound, and a pair of support members that support both ends of the base portion in the width direction,
The internal unit according to claim 2, wherein the plurality of connection portions are provided on the upper surfaces of both or one of the pair of support members. The base portion is divided into a first divided portion and a second divided portion at a central portion in the insertion / extraction direction so that the first divided portion and the second divided portion can be bent at the central portion. It is pivotally supported,
4. The internal unit according to claim 3, wherein a contact portion with the belt member at an end portion on the central portion side of either or both of the first divided portion and the second divided portion is formed in a curved shape.   The internal unit according to claim 4, wherein the contact portion is a portion that contacts the belt member when the base portion is bent at the central portion.   The support member supports both ends in the width direction of the first divided portion and the second divided portion in a state where the first divided portion and the second divided portion of the base portion are straightened. The internal unit according to claim 4 or 5, wherein the internal unit is held in a straight shape. A first electrically conductive portion used for image forming processing executed by the image forming apparatus;
At least one of the plurality of connection portions is a connection terminal for supplying a voltage to the first conductive portion, and the other connection portion is a second conductive portion provided in the image forming apparatus. The internal unit according to claim 1, wherein the internal unit is a relay terminal for relaying a voltage supplied to. An internal unit according to any of claims 1 to 7;
A unit mounting portion for mounting the internal unit at the mounting position and movably supporting the internal unit between the mounting position and the extraction position;
An image forming apparatus comprising: a plurality of connected portions that are provided at positions corresponding to the plurality of connecting portions in the unit mounting portion and are electrically connected to the plurality of connecting portions, respectively.

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