JP2015069143A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a rotating body provided on an opening/closing member is satisfactorily brought into contact with a contact body and a reaction force due to the contact can be prevented from being applied to the opening/closing member.SOLUTION: First engagement parts 97 of a pair of helical torsion springs 95 are engaged with a pair of engagement parts 68 respectively. Second engagement parts 98 of the pair of helical torsion strings 95 are brought into contact with both end parts of a shaft part 90 of a transfer roller 13 respectively. Parts 50 to be engaged of a pair of side walls 41 are engaged with the pair of engagement parts 68 respectively. The parts 50 to be engaged of the pair of side walls 41 are located opposite the pair of engagement parts 68 across the transfer roller 13. The pair of helical torsion springs 95 urge the transfer roller 13 toward a photosensitive drum 12. Therefore, a reaction force due to urging the transfer roller 13 by the pair of helical torsion springs 95 can be transmitted to the parts 50 to be engaged of the pair of side walls 41 respectively.

Description

  The present invention relates to an image forming apparatus employing an electrophotographic system.

  As an image forming apparatus adopting an electrophotographic system, an image forming apparatus having an openable / closable cover around a conveyance path for discharging a recording medium to a discharge unit is known. When a paper jam occurs in the recording medium in the middle of the conveyance path, the recording medium in the middle of the conveyance path can be taken out by opening the opening / closing cover.

  As such an image forming apparatus, an image forming apparatus in which a transfer roller and a spring are provided on an opening / closing cover is known. In this image forming apparatus, the transfer roller is rotatably supported by the opening / closing cover and is movable with respect to the opening / closing cover. The spring is attached to the opening / closing cover. When the open / close cover is closed, the biasing force of the spring is applied to the transfer roller through the member. The transfer roller contacts the intermediate transfer belt in the apparatus with a pressing force. Thereby, the contact state between the transfer roller and the intermediate transfer belt can be kept good. Further, when a paper jam occurs, the transfer roller and the intermediate transfer belt can be separated by opening the opening / closing cover, and the jammed recording medium can be removed. (For example, refer to Patent Document 1).

JP 2004-20574 A

  However, in the image forming apparatus described in Patent Document 1, a spring for applying a biasing force to the transfer roller is attached to the opening / closing cover. Therefore, a reaction force when the intermediate transfer belt is pressed by the transfer belt is directly applied to the open / close cover via the spring. As a result, the opening / closing cover may be deformed. In particular, when the image forming apparatus is downsized, the open / close cover needs to be downsized and thinned, and the open / close cover may be further deformed.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus capable of suppressing a reaction force caused by the contact from being applied to the opening / closing member while satisfactorily contacting the rotating body provided in the opening / closing member to the contact body. It is in.

(1) In order to achieve the above object, an image forming apparatus of the present invention includes an apparatus main body having an opening, and a pair of side walls that are spaced from each other in the first direction with the opening interposed therebetween. An opening / closing member that is rotatable about a first axis extending in the first direction and that opens and closes the opening by rotating, a rotating body that is rotatably supported with respect to the axis extending in the first direction, and an opening / closing member And a biasing member that biases the opening / closing member in a direction of separating the rotating body when the is closed. The opening / closing member includes an engaging portion. At least one of the pair of side walls includes an engaged portion with which the engaging portion engages. The urging member has one end engaged with the engaging portion, the other end engaged with the rotating body, and urges the rotating body toward the abutting body when the opening / closing member is in the closed state. The engaged portion is located on the opposite side of the rotating body with respect to the engaging portion when the opening / closing member is in the closed state.

  According to such a configuration, one end of the urging member is engaged with the engaging portion, and the other end of the urging member is in contact with the rotating body. The biasing member biases the rotating body toward the contact body when the opening / closing member is in the closed state.

  Therefore, the rotating body can be reliably brought into contact with the contact body.

  The engaged portion is engaged with the engaging portion. The engaged portion is located on the opposite side of the rotating body with respect to the engaging portion when the opening / closing member is in the closed state.

  Therefore, the reaction force when the urging member urges the rotating body can be transmitted to the engaged portion provided on the side wall via the engaging portion.

  As a result, the reaction force from the urging member can be prevented from being directly transmitted to the opening / closing member.

Therefore, it is possible to suppress the reaction force resulting from the urging force of the urging member from being applied to the opening / closing member while the rotator is in good contact with the contact body.
(2) Moreover, at least one of a pair of side walls may have the 1st guide part which guides a rotary body along the urging | biasing direction of an urging | biasing member.

  According to such a configuration, at least one of the pair of side walls has the first guide portion.

  Therefore, when the opening / closing member is in the closed state, the rotating body can be guided in the biasing direction by the first guide portion.

As a result, the rotating body can be reliably brought into contact with the contact body.
(3) Further, the urging member is a torsion coil spring and includes a winding portion formed by winding a wire, and one end portion extends in the tangential direction from the winding portion, and the other end portion. However, it may extend in the tangential direction from the winding portion and may extend in a direction different from the direction in which the one end portion extends.

  According to such a configuration, the urging member is configured by a torsion coil spring.

For this reason, the torsion coil spring can efficiently transmit the reaction force to the engaged portion while urging the rotating body toward the contact body.
(4) Moreover, the 1st axis line may be located inward of a winding part.

  According to such a configuration, the first axis is located inside the winding portion of the torsion coil spring.

  Therefore, the biasing direction of the torsion coil spring and the opening / closing direction of the opening / closing member can be the same direction.

As a result, when the opening / closing member is opened, the biasing force of the torsion coil spring can be used, and the opening / closing member can be opened smoothly. Further, when closing the opening / closing member, the opening / closing member is closed against the urging force of the torsion coil spring, so that the opening / closing member can be prevented from closing suddenly.
(5) Moreover, at least one of a pair of side walls may have the 2nd guide part which guides an engaging part to an to-be-engaged part.

  According to such a configuration, at least one of the pair of side walls includes the second guide portion.

Therefore, when the opening / closing member is closed, the engaging portion can be guided to the engaged portion by the second guide portion, and the engaging portion can be reliably engaged with the engaged portion.
(6) Further, when the opening / closing member is in the closed state, the engaging portion is movable to a first position where the engaging portion is engaged with the engaged portion and a second position where the engagement with the engaged portion is released. It may be.

  According to such a configuration, the engaged portion can be engaged with the engaged portion by moving the engaging portion to the first position. Further, the engagement with the engaged portion can be released by moving the engaging portion to the second position.

Therefore, the operation of moving the engagement portion to the first position or the second position can cause the engagement portion to engage with the engaged portion or release the engagement of the engaging portion with the engaged portion. it can.
(7) Moreover, you may further provide the support part which the other end part supports a rotary body rotatably. One end of the support portion may be rotatably supported by the opening / closing member with a second axis extending in the first direction as a fulcrum. The second axis may be located inside the winding part.

  According to such a configuration, the opening / closing member includes the support portion that rotatably supports the rotating body.

  Therefore, the rotating body can be stably supported by the support portion.

  The second axis is located inside the winding portion of the torsion coil spring.

  Therefore, the rotation direction of the support portion and the urging direction of the torsion coil spring can be the same direction.

As a result, the support portion can be smoothly moved using the biasing force of the torsion coil spring.
(8) Moreover, the opening / closing member may include a restricting portion that restricts a rotation range of the support portion with respect to the opening / closing member.

  According to such a configuration, the rotation range of the support portion is restricted by the restriction portion.

Therefore, the support portion can be rotated within an appropriate range.
(9) The contact body may be a photosensitive drum on which a developer image is formed on the outer peripheral surface, and the rotating body may be a transfer roller that transfers the developer image formed on the photosensitive drum to a recording medium. Good.

  According to such a configuration, the contact body is configured as a photosensitive drum, and the rotating body is configured as a transfer roller.

  Therefore, when the opening / closing member is in the closed state, the transfer roller can be brought into contact with the photosensitive drum while the transfer roller is biased toward the photosensitive drum by the biasing member. When the opening / closing member is in the open state, the transfer roller can be separated from the photosensitive drum.

  In the image forming apparatus of the present invention, the rotating body provided in the opening / closing member can be satisfactorily brought into contact with the contact body, and the reaction force caused by the contact can be suppressed from being applied to the opening / closing member.

FIG. 1 is a right side view showing a printer as an embodiment of an image forming apparatus of the present invention. FIG. 2 is a perspective view showing the opening / closing cover, the side wall, and the transfer roller when the opening / closing cover is closed in the printer shown in FIG. FIG. 3 is a perspective view showing an opening / closing cover and a transfer roller of the printer shown in FIG. FIG. 4 is a perspective view showing the opening / closing cover, the side wall, and the transfer roller when the opening / closing cover is in the open state in the printer shown in FIG. 1. FIG. 5 is a perspective view showing a state in which the slide cover is moved upward in the opening / closing cover, the side wall, and the transfer roller shown in FIG. FIG. 6 is a perspective view showing a state in which the opening / closing cover is slightly opened in the opening / closing cover, the side wall, and the transfer roller shown in FIG. 2. FIG. 7 is a perspective view showing an opening / closing cover and a transfer roller in a modification of the printer shown in FIG.

1. Overall Configuration of Printer As shown in FIG. 1, a printer 1 as an example of an image forming apparatus includes a main body casing 2 as an example of an apparatus main body and an image forming unit 3.

  In the following description, when referring to the direction of the printer 1, the state in which the printer 1 is horizontally placed is used as the upper and lower reference. That is, the upper side of the drawing in FIG. 1 is the upper side, and the lower side of the drawing is the lower side. Further, the left side of FIG. 1 is the front, and the right side of FIG. 1 is the rear. In addition, when the printer 1 is viewed from the front, the left and right reference is used. That is, the back of the page of FIG. 1 is the left side, and the front side of the page is the right side.

  The main casing 2 has a substantially box shape extending in the left-right direction. The main body casing 2 includes a paper placement unit 4, a paper discharge tray 5, and an opening 20.

  The paper placing portion 4 is located at the bottom of the main casing 2 and has a substantially box shape. In the paper placement unit 4, the paper P is placed.

  The paper discharge tray 5 is located in the front part of the upper wall of the main body casing 2. The paper discharge tray 5 is recessed downward from the upper surface of the main casing 2 so that the paper P is placed thereon.

  The opening 20 opens the rear wall of the main casing 2. The opening 20 communicates the external space and the internal space of the main casing 2. The opening 20 is closed by an opening / closing cover 21 as an example of an opening / closing member.

  The open / close cover 21 is located at the rear end of the main casing 2. The opening / closing cover 21 has a substantially rectangular plate shape when viewed from the back. A lower end portion of the opening / closing cover 21 is rotatably attached to a rear lower end portion of the main body casing 2. Thereby, the opening / closing cover 21 can be rotated around the lower end, and the opening 20 is opened or closed by rotating. The open / close cover 21 is normally kept closed.

  The image forming unit 3 includes a process unit 6, a transfer roller 13 as an example of a rotating body, a scanner unit 7, and a fixing unit 8.

  The process unit 6 is located at the approximate center of the main casing 2 in the vertical direction. The process unit 6 includes a drum unit 10 and a developing unit 11.

  The drum unit 10 includes a photosensitive drum 12 as an example of a contact body and a scorotron charger 14.

  The photosensitive drum 12 has a substantially cylindrical shape extending in the left-right direction. The photosensitive drum 12 is rotatably supported at a rear portion of the drum unit 10.

  The scorotron charger 14 is positioned above the photosensitive drum 12 with an interval.

  The developing unit 11 includes a developing roller 15, a supply roller 16, and a layer thickness regulating blade 17.

  The developing roller 15 is rotatably supported at the rear end portion of the developing unit 11. The rear upper end of the developing roller 15 is in contact with the front lower end of the photosensitive drum 12.

  The supply roller 16 is located in front of and below the developing roller 15. The supply roller 16 is rotatably supported at a rear portion of the developing unit 11. The rear upper end portion of the supply roller 16 is in contact with the front lower end portion of the developing roller 15.

  The layer thickness regulating blade 17 is located in front of the developing roller 15. The layer thickness regulating blade 17 has a substantially rectangular shape when viewed from the front. The layer thickness regulating blade 17 is supported at the rear end of the developing unit 11. The lower end portion of the layer thickness regulating blade 17 is in contact with the front end portion of the developing roller 15.

  Toner is accommodated in a space in front of the supply roller 16 and the layer thickness regulating blade 17.

  The transfer roller 13 is located behind the photosensitive drum 12. The transfer roller 13 is rotatably supported by a pair of arms 80 described later. The front end portion of the transfer roller 13 is in contact with the rear end portion of the photosensitive drum 12.

  The scanner unit 7 is located in front of the process unit 6 at a distance in the approximate center of the main body casing 2 in the vertical direction. The scanner unit 7 emits a laser beam based on image data toward the photosensitive drum 12 to expose the peripheral surface of the photosensitive drum 12.

  The fixing unit 8 is located above the process unit 6 at the rear upper end of the main casing 2. The fixing unit 8 includes a heating roller 18 and a pressure roller 19 that comes into contact with the heating roller 18 from the front and upper side.

  When the image forming operation is started in the printer 1, the toner in the developing unit 11 is frictionally charged between the supply roller 16 and the developing roller 15, and the thickness is regulated by the layer thickness regulating blade 17, so that the constant thickness is reached. A thin layer is carried on the surface of the developing roller 15.

  On the other hand, the surface of the photosensitive drum 12 is uniformly charged by the scorotron charger 14 and then the laser beam L is emitted by the scanner unit 7. Thereby, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 12. The toner carried on the developing roller 15 is supplied to the electrostatic latent image on the surface of the photosensitive drum 12, so that the toner image is carried on the surface of the photosensitive drum 12.

  The paper P placed on the paper placement unit 4 is fed between the photosensitive drum 12 and the transfer roller 13 one by one at a predetermined timing by the rotation of various rollers. Then, when the paper P passes between the photosensitive drum 12 and the transfer roller 13, the toner image is transferred to form an image.

  Subsequently, the sheet P is heated and pressed when it passes between the heating roller 18 and the pressure roller 19. At this time, the image is thermally fixed on the paper P. Thereafter, the paper P is discharged to the paper discharge tray 5.

  In this way, the paper P is transported from the paper placement unit 4 to the paper discharge tray 5 through a substantially C-shaped transport path in a side view in the image forming operation of the printer 1.

At this time, when the paper P is jammed in the conveyance path of the paper P, the user rotates the opening / closing cover 21 rearward to open the opening 20. In this state, the jammed sheet P is removed by the user removing the jammed sheet P.
2. Details of Main Body Casing and Opening / Closing Cover (1) Side Wall As shown in FIGS. 2 and 4, the main body casing 2 includes a pair of side walls 41. The pair of side walls 41 are located at a distance from each other in the left-right direction. Each of the pair of side walls 41 has a substantially flat plate shape that is substantially rectangular in a side view, and extends in the front-rear direction. A space between the rear ends of the pair of side walls 41 is defined as the opening 20. Each of the pair of side walls 41 includes a first recess 42, a rear protrusion 43, and a second recess 44.

  The first recess 42 is a rear end portion of the pair of side walls 41 and is located at a portion slightly below the upper end. The first recess 42 is recessed forward from the rear end edge of the pair of side walls 41 and has a substantially U-shape in side view. The first recess 42 has an upper inner edge 42A, a front inner edge 42B, and a lower inner edge 42C.

  The upper inner edge 42 </ b> A is an upper inner edge of the first recess 42 and extends forward from the rear edge of each of the pair of side walls 41.

  The front inner edge 42B is an inner edge on the front side of the first recess 42, and extends downward from the front end of the upper inner edge 42A.

  The lower inner edge 42C is an inner edge on the lower side of the first recess 42, and extends rearward from the lower end of the front inner edge 42B.

  The rear protrusion 43 protrudes upward from the rear end portion of the lower inner edge 42 </ b> C of the first recess 42. The rear protrusion 43 has a tapered shape that tapers upward in a side view. The rear protrusion 43 includes an engaged portion 50 and an inclined portion 51 as an example of a second guide portion.

  The engaged portion 50 is an inner edge of the rear protrusion 43 and extends upward from the lower inner edge 42 </ b> C of the first recess 42. In the front-rear direction, the dimension between the engaged portion 50 and the front inner edge 42B of the first recess 42 is slightly larger than the diameter of the engaging portion 68 described later. The engaged portion 50 is located on the opposite side of the transfer roller 13 with respect to an engaging portion 68 described later when the open / close cover 21 is in a closed state.

  The inclined portion 51 is an outer edge of the rear projection 43 and extends from the upper end of the engaged portion 50 so as to be inclined rearward and downward. The lower end of the inclined portion 51 is continuous with the rear ends of the pair of side walls 41. The continuous portion of the inclined portion 51 and the engaged portion 50 is the tip of the rear projection 43. In the vertical direction, the dimension from the tip of the rear projection 43 to the upper inner edge 42A of the first recess 42 is described later. It is larger than the diameter of the joint portion 68.

  The second recessed portion 44 is located at the rear end portion of the pair of side walls 41 and at the substantially central portion in the vertical direction, and is located below the first recessed portion 42. The second recessed portion 44 includes a receiving portion 53 and a guide portion 54 as an example of a first guide portion.

  The receiving portion 53 is a rear end edge of the pair of side walls 41 and is recessed forward from a substantially central portion in the vertical direction, and has a substantially U shape in a side view.

The guide portion 54 is recessed forward from a substantially central portion in the vertical direction of the front end edge of the receiving portion 53, and has a substantially U shape in a side view. The vertical dimension of the guide part 54 is smaller than the vertical dimension of the receiving part 53 and slightly larger than the diameter of the shaft part 90 of the transfer roller 13 described later. The guide portion 54 is located at substantially the same position as the photosensitive drum 12 in the vertical direction. The front end of the guide portion 54 is located slightly behind the photosensitive drum 12.
(2) Open / Close Cover The open / close cover 21 is located between the rear end portions of the pair of side walls 41 in a state where the opening 20 is closed, that is, in the closed state. The open / close cover 21 includes a base cover 60 and a slide cover 61. In the following description, the case where the open / close cover 21 is in the closed state will be described as a reference unless otherwise specified.

  The base cover 60 has a substantially rectangular flat plate shape when viewed from the back, and extends in the left-right direction. The inner surface of the base cover 60 faces the main body casing 2, and the outer surface of the base cover 60 faces the rear outside of the main body casing 2. The lower end portion of the base cover 60 is rotatably supported between the lower end portions of the pair of side walls 41. Specifically, bosses 99 are provided at the lower ends of the base cover 60 and at both ends in the left-right direction. Each of the pair of bosses 99 penetrates the rear lower end portion of the pair of side walls 41 and protrudes outward in the left-right direction from the pair of side walls 41. As a result, the opening / closing cover 21 is rotatably supported between the rear lower ends of the pair of side walls 41 with the axis S as an example of the first axis and the second axis as a fulcrum. The base cover 60 includes a slide opening 62, a pair of cover recesses 63, a pair of compression springs 64, and a pair of rotation restricting portions 69.

  The slide opening 62 is located on the upper end side of the base cover 60, that is, on the free end side. The slide opening 62 has a substantially rectangular shape in rear view and extends in the left-right direction. The slide opening 62 penetrates the base cover 60 in the thickness direction.

  Each of the pair of cover recesses 63 is located on the outer side in the left-right direction of the slide opening 62. Each of the pair of cover recesses 63 is recessed from the inner surface of the base cover 60 toward the outer surface side of the base cover 60. Each of the pair of cover recesses 63 communicates the slide opening 62 and the space outside the base cover 60 in the left-right direction.

  Each of the pair of compression springs 64 is located inside the slide opening 62 between an upper end of a protruding plate 66 described later and an upper end portion of the slide opening 62 in the base cover 60.

  As shown in FIG. 3, each of the pair of rotation restricting portions 69 is located at a lower end portion of the base cover 60 and at both left and right end portions. Each of the pair of rotation restricting portions 69 is a lower end portion of the base cover 60 and protrudes outward from both left and right end portions. Each of the pair of rotation restricting portions 69 has a substantially rectangular flat plate shape in rear view.

  As shown in FIGS. 2 and 4, the slide cover 61 is located inward of the slide opening 62. The slide cover 61 is positioned so as to be slidable in the vertical direction inside the slide opening 62. The slide cover 61 includes a slide plate portion 65 and a protruding plate 66.

  The slide plate portion 65 has a flat plate shape that is substantially rectangular when viewed from the back, and extends in the left-right direction. The slide plate portion 65 has a horizontal dimension slightly smaller than the horizontal dimension of the slide opening 62, and a vertical dimension smaller than the vertical dimension of the slide opening 62. The slide plate portion 65 has a grip opening 67.

  The gripping opening 67 is located slightly above the vertical center of the slide plate portion 65 and is positioned at the horizontal center. The grip opening 67 has a substantially rectangular shape extending in the left-right direction, and penetrates the slide plate portion 65 in the thickness direction.

  The protruding plate 66 protrudes inward from the inner surface of the lower end portion of the slide plate portion 65. The protruding plate 66 has a substantially rectangular flat plate shape when viewed from the front, and extends in the left-right direction. The protruding plate 66 is configured integrally with the slide plate portion 65. As described above, the pair of compression springs 64 are located between the upper end of the protruding plate 66 and the upper end portion of the slide opening 62 in the base cover 60, and the slide cover 61 is always attached downward. It is energized. As a result, the slide cover 61 is positioned below the slide opening 62 in the base cover 60. The protruding plate 66 includes a pair of engaging portions 68.

Each of the pair of engaging portions 68 protrudes outward in the left-right direction from both left and right ends of the protruding plate 66. Each of the pair of engaging portions 68 has a substantially cylindrical shape. Each of the pair of engaging portions 68 extends outward in the left-right direction from the protruding plate 66 through the inside of each of the pair of cover recesses 63.
(3) Arms As shown in FIGS. 2, 3, and 4, a pair of arms 80 as an example of a support portion is located between the left and right ends of the opening / closing cover 21 and the pair of side walls 41. doing.

  Each of the pair of arms 80 is provided integrally with an arm plate 81, a rotating portion 82, and a support portion 83.

  The arm plate 81 has a substantially flat plate shape that is long.

  The rotating part 82 is located at one end of the arm plate 81. The rotation part 82 has a substantially annular shape in a side view. A boss 99 of the base cover 60 is inserted through the rotating portion 82.

  The support portion 83 is located at the other end portion of the arm plate 81. The support part 83 has a substantially annular shape in a side view. The inner diameter of the support portion 83 is slightly larger than the diameter of a shaft portion 90 of the transfer roller 13 described later.

Each of the rotating portions 82 of the pair of arms 80 is rotatably supported with the axis S as a fulcrum by inserting each of the pair of bosses 99 of the base cover 60. Accordingly, each of the pair of arms 80 uses the axis S that is the rotation axis of the opening / closing cover 21 as the rotation axis. That is, each of the pair of arms 80 has a rotation axis common to the opening / closing cover 21.
(4) Transfer Roller The transfer roller 13 includes a shaft portion 90 and a roller portion 91.

  The shaft portion 90 has a substantially cylindrical shape extending in the left-right direction. Both end portions in the left-right direction of the shaft portion 90 are inserted through the respective support portions 83 of the pair of arms 80. Thus, the shaft portion 90 is supported by the pair of arms 80 so as to be rotatable with respect to the axis T extending in the left-right direction.

  The outer peripheral surface of the shaft part 90 is covered with a roller part 91 except for both ends in the left-right direction.

The transfer roller 13 is movable so as to rotate with respect to the opening / closing cover 21 with the axis S as a fulcrum by both ends of the shaft 90 in the left-right direction being rotatably supported by a pair of arms 80.
(5) Torsion coil spring A pair of torsion coil springs 95 as an example of an urging member is located outward in the left-right direction of the pair of side walls 41.

  Each of the pair of torsion coil springs 95 is integrally provided with a winding portion 96, a first engagement portion 97, and a second engagement portion 98.

  The winding part 96 is configured by winding a metal wire, and has a substantially ring shape in a side view. Each of the pair of winding portions 96 is supported by each of a pair of bosses 99 projecting outward in the left-right direction from the rear lower ends of the pair of side walls 41 so as to be rotatable about the axis S. Has been. That is, each of the pair of torsion coil springs 95 is supported by each of the bosses 99 at the rear lower end of the pair of side walls 41 so as to be rotatable about the axis S.

  The first engaging portion 97 is a metal wire, and extends in a tangential direction from the winding portion 96 in a side view. The distal end portion of the first engagement portion 97 is bent in a substantially L shape. Each of the front end portions of the pair of first engaging portions 97 is engaged with each of the pair of engaging portions 68 of the opening / closing cover 21 from the front.

The second engagement portion 98 is a metal wire, and extends in a tangential direction from the winding portion 96 in a side view and in a direction different from the first engagement portion 97. The second engaging portion 98 is located on the opposite side of the winding portion 96 from the first engaging portion 97. The distal end portion of the second engagement portion 98 is bent in a substantially U shape. Each of the front end portions of the pair of second engaging portions 98 is engaged with both end portions of the shaft portion 90 of the transfer roller 13 from the rear.
3. As shown in FIG. 2, when the open / close cover 21 is closed, each of the pair of engaging portions 68 of the open / close cover 21 is connected to each of the engaged portions 50 of the pair of side walls 41. The pair of side walls 41 are positioned between the front inner edges 42B. Each of both end portions of the shaft portion 90 of the transfer roller 13 enters each of the guide portions 54 of the pair of side walls 41. Further, as described above, each of the first engagement portions 97 of the pair of torsion coil springs 95 is engaged with each of the pair of engagement portions 68 of the opening / closing cover 21 from the front, and Each of the second engaging portions 98 of the torsion coil spring 95 is engaged with each of both end portions of the shaft portion 90 of the transfer roller 13 from the rear. In each of the pair of torsion coil springs 95, the first engagement portion 97 and the second engagement portion 98 are kept in close proximity.

At this time, each urging force of the pair of torsion coil springs 95 is applied to each of the pair of engaging portions 68 and both ends of the shaft portion 90 of the transfer roller 13. Specifically, each of the pair of engaging portions 68 is urged rearward by each of the pair of torsion coil springs 95. Accordingly, each of the pair of engaging portions 68 engages with each of the engaged portions 50 of the pair of side walls 41 from the front. The biasing force applied to each of the pair of engaging portions 68 is applied to each of the engaged portions 50 of the pair of side walls 41. That is, the urging force toward the rear of each of the pair of torsion coil springs 95 is received by each of the engaged portions 50 of the pair of side walls 41. Further, both end portions of the shaft portion 90 of the transfer roller 13 are urged forward by a pair of torsion coil springs 95. As a result, the transfer roller 13 contacts the photosensitive drum 12 with an urging force directed forward.
4). Opening / Closing Operation of the Opening / Closing Cover When the opening / closing cover 21 is changed from the closed state to the open state, the user holds the holding opening 67 of the slide cover 61 and urges the pair of compression springs 64 as shown in FIG. The slide cover 61 is moved upward against this.

  Then, as shown in FIG. 6, the engagement state between each of the pair of engaging portions 68 and each of the engaged portions 50 of the pair of side walls 41 is released and a pair of torsion coil springs With the urging force of 95, each of the pair of engaging portions 68 is moved rearward. That is, the opening / closing cover 21 rotates rearward with the axis S as a fulcrum. Further, the contact state between the transfer roller 13 and the photosensitive drum 12 is released. At this time, the pair of engaging portions 68 are located at the second position on the free end side of the base cover 60 in the slide opening 62 of the base cover 60.

  Next, as shown in FIG. 4, when the opening / closing cover 21 is rotated approximately 90 ° rearward from the closed state, the opening 20 is opened and the opening / closing cover 21 is opened.

  At this time, each of the pair of arms 80 rotates forward with respect to the opening / closing cover 21 with the axis S as a fulcrum, and engages with each of the pair of rotation restricting portions 69 from the rear as shown in FIG. . Each of the pair of arms 80 is restricted by the pair of rotation restricting portions 69 from rotating more than a certain amount with respect to the opening / closing cover 21. Thus, in each of the pair of torsion coil springs 95, the first engagement portion 97 and the second engagement portion 98 are maintained in a separated state as compared to when the open / close cover 21 is in the closed state. The transfer roller 13 moves so as to rotate forward with the axis S as a fulcrum, and is kept away from the opening / closing cover 21 compared to when the opening / closing cover 21 is in the closed state.

  When the opening / closing cover 21 is changed from the open state to the closed state, the user rotates the opening / closing cover 21 forward about the axis S while holding the holding opening 67 of the slide cover 61.

  Then, each of the pair of engaging portions 68 comes into contact with each of the inclined portions 51 of the pair of side walls 41. Further, both end portions of the shaft portion 90 of the transfer roller 13 enter the respective receiving portions 53 of the pair of side walls 41.

  Next, as shown in FIG. 6, the user further presses the open / close cover 21 forward against the urging forces of the pair of torsion coil springs 95.

  Then, each of the pair of engaging portions 68 is guided by the respective inclined portions 51 of the pair of side walls 41, against the urging force of the pair of compression springs 64 against the base cover 60, It moves upward, that is, to the free end side of the base cover 60. Further, each of both end portions of the shaft portion 90 of the transfer roller 13 enters each of the guide portions 54 of the pair of side walls 41. Then, the transfer roller 13 comes into contact with the photosensitive drum 12 from behind and presses the photosensitive drum 12 from the rear toward the front.

  Next, as shown in FIG. 5, each of the pair of engaging portions 68 contacts the front inner edge 42 </ b> B of the pair of side walls 41. The transfer roller 13 contacts the photosensitive drum 12 from the rear with a constant nip pressure.

As shown in FIG. 2, when the user releases the grip opening 67 of the slide cover 61 being gripped, the slide cover 61 moves downward by the biasing force of the pair of compression springs 64. Each of the pair of engaging portions 68 abuts on each of the lower inner edges 42 </ b> C of the pair of side walls 41. At this time, the pair of engaging portions 68 are located at the first position on the fixed end side of the base cover 60 in the slide opening 62 of the base cover 60. As a result, the open / close cover 21 is closed, and the opening 20 is closed.
5. Operation and Effect (1) According to the printer 1, as shown in FIG. 2, each of the first engaging portions 97 of the pair of torsion coil springs 95 is engaged with each of the pair of engaging portions 68. . Each of the second engaging portions 98 of the pair of torsion coil springs 95 abuts on both ends of the shaft portion 90 of the transfer roller 13. Each of the pair of torsion coil springs 95 urges the transfer roller 13 toward the photosensitive drum 12 when the opening / closing cover 21 is closed.

  Therefore, the transfer roller 13 can be reliably brought into contact with the photosensitive drum 12.

  Each of the engaged portions 50 of the pair of side walls 41 is engaged with each of the pair of engaging portions 68. Each of the engaged portions 50 of the pair of side walls 41 is located on the opposite side of the transfer roller 13 with respect to each of the pair of engaging portions 68 when the opening / closing cover 21 is in a closed state.

  Therefore, the reaction force when each of the pair of torsion coil springs 95 urges the transfer roller 13 is transmitted to each of the engaged portions 50 of the pair of side walls 41 via each of the pair of engaging portions 68. I can tell each one.

  As a result, the reaction force from each of the pair of torsion coil springs 95 can be prevented from being directly transmitted to the opening / closing cover 21.

Therefore, it is possible to suppress the reaction force resulting from the respective urging forces of the pair of torsion coil springs 95 from being applied to the opening / closing cover 21 while the transfer roller 13 is in good contact with the photosensitive drum 12.
(2) Also, according to the printer 1, as shown in FIG. 2, each of the pair of side walls 41 has the guide portion 54.

  Therefore, when the opening / closing cover 21 is in the closed state, the transfer roller 13 can be guided in the urging direction by each of the pair of guide portions 54.

As a result, the transfer roller 13 can be reliably brought into contact with the photosensitive drum 12.
(3) Further, according to the printer 1, as shown in FIG. 2, each of the pair of engaging portions 68 and each of the both end portions of the shaft portion 90 of the transfer roller 13 is a pair of torsion coils. Each spring 95 is biased.

Therefore, each of the pair of torsion coil springs 95 efficiently urges the transfer roller 13 toward the photosensitive drum 12 and transmits the reaction force to each of the engaged portions 50 of the pair of side walls 41. Can do.
(4) Also, according to the printer 1, as shown in FIG. 4, the rotation axis of the opening / closing cover 21 is the axis S, and each rotation axis of the pair of torsion coil springs 95 is the axis S. . That is, the opening / closing cover 21 and each of the pair of torsion coil springs 95 share a rotation axis. In other words, the axis S is located inside each of the winding portions 96 of the pair of torsion coil springs 95.

  Therefore, the urging directions of the pair of torsion coil springs 95 and the opening / closing direction of the opening / closing cover 21 can be the same direction.

As a result, when the opening / closing cover 21 is opened, the biasing forces of the pair of torsion coil springs 95 can be used, and the opening / closing cover 21 can be opened smoothly. Further, when the open / close cover 21 is closed, the open / close cover 21 is closed against the urging forces of the pair of torsion coil springs 95, so that the open / close cover 21 can be prevented from closing suddenly.
(5) Further, according to the printer 1, each of the pair of side walls 41 includes the inclined portion 51 as shown in FIG. 4.

Therefore, when closing the open / close cover 21, each of the pair of engaging portions 68 is guided to each of the engaged portions 50 of the pair of side walls 41 by the inclined portions 51 of the pair of side walls 41. Each of the pair of engaging portions 68 can be reliably engaged with each of the engaged portions 50 of the pair of side walls 41.
(6) Further, according to the printer 1, as shown in FIG. 5, the slide cover 61 is moved downward by the urging force of the pair of compression springs 64, whereby each of the pair of engaging portions 68 is moved. It can be engaged with each of the engaged portions 50 of the pair of side walls 41. Further, by moving the slide cover 61 upward against the urging force of the pair of compression springs 64, each of the pair of engaging portions 68 and each of the engaged portions 50 of the pair of side walls 41 are provided. Can be released.

Therefore, each of the pair of engaging portions 68 is engaged with each of the engaged portions 50 of the pair of side walls 41 by the operation of moving each of the pair of engaging portions 68 in the vertical direction, or The engagement can be released.
(7) According to the printer 1, as shown in FIG. 3, the opening / closing cover 21 includes a pair of arms 80 that rotatably support the transfer roller 13.

  Therefore, the transfer roller 13 can be stably supported by the pair of arms 80.

  The rotation axes of the pair of arms 80 are the axis S, and the rotation axes of the pair of torsion coil springs 95 are the axis S. That is, each of the pair of arms 80 and each of the pair of torsion coil springs 95 share a rotation axis. In other words, the axis S is located inside each of the winding portions 96 of the pair of torsion coil springs 95.

  Therefore, the rotation directions of the pair of arms 80 and the urging directions of the pair of torsion coil springs 95 can be the same direction.

As a result, it is possible to smoothly move each of the pair of arms 80 using each biasing force of the pair of torsion coil springs 95.
(8) Further, according to the printer 1, as shown in FIG. 3, forward rotation of each of the pair of arms 80 is restricted by each of the pair of rotation restricting portions 69.

Therefore, each of the pair of arms 80 can be rotated within an appropriate range.
6). Printer of Second Embodiment A modification of the printer will be described with reference to FIG. In the following modification, the same reference numerals are given to the same members as those in the first embodiment, and the description thereof is omitted.

  In the first embodiment, the transfer roller 13 is rotatably supported by each of the pair of arms 80 and is movably supported with respect to the opening / closing cover 21.

  On the other hand, in the second embodiment, as shown in FIG. 7, the transfer roller 13 is supported by each of a pair of torsion coil springs 95.

  The distal end portion of each second engagement portion 98 of the pair of torsion coil springs 95 has a substantially annular shape in side view. In each of the pair of torsion coil springs 95, both end portions of the shaft portion 90 of the transfer roller 13 are inserted into the distal end portion of the second engaging portion 98.

  Accordingly, the transfer roller 13 is rotatably supported by each of the pair of torsion coil springs 95 and is movable so as to rotate with respect to the opening / closing cover 21 by each of the pair of torsion coil springs 95. is there.

According to such a configuration, since the transfer roller 13 is rotatably supported by each of the pair of torsion coil springs 95, the number of parts can be reduced. The printer 1 can be configured easily.
7). Other Modifications In the first embodiment, the transfer roller 13 is biased in a direction away from the opening / closing cover 21 by each of the pair of torsion coil springs 95.

  However, the transfer roller 13 only needs to be biased in a direction away from the opening / closing cover 21, and the member for biasing is not limited to the pair of torsion coil springs 95. For example, the transfer roller 13 and the opening / closing cover 21 may be biased in a direction away from each other by a compression spring.

  According to such a configuration, it is not necessary to rotatably support the compression spring, so that the printer 1 can be simply configured.

  In the first embodiment, each of the pair of arms 80 is rotatably supported by the opening / closing cover 21.

  However, each of the pair of arms 80 may be rotatably supported on each of the pair of side walls 41. The transfer roller 13 may be rotatably supported by each of the pair of arms 80 and may be movable with respect to each of the pair of side walls 41.

  According to such a configuration, the opening / closing cover 21 can be simplified.

DESCRIPTION OF SYMBOLS 1 Printer 2 Main body casing 12 Photosensitive drum 13 Transfer roller 20 Opening part 21 Opening / closing cover 41 Side wall 50 Engagement part 51 Inclination part 54 Guide part 68 Engagement part 69 Rotation restriction part 80 Arm 95 Torsion coil spring 96 Winding part 97 1 engaging portion 98 second engaging portion

Claims (9)

An apparatus main body having an opening, and comprising a pair of side walls spaced apart in the first direction across the opening;
An opening / closing member that is pivotable about a first axis extending in the first direction, and that opens and closes the opening by pivoting;
A rotating body supported rotatably about an axis extending in the first direction;
A contact body that contacts the rotating body when the opening and closing member is in a closed state;
An urging member for urging the opening / closing member in a direction of separating the rotating body;
The opening / closing member includes an engaging portion,
At least one of the pair of side walls includes an engaged portion with which the engaging portion is engaged,
The biasing member is
One end part engages with the engaging part,
The other end engages with the rotating body,
When the opening / closing member is in a closed state, the rotating body is biased toward the contact body,
The image forming apparatus, wherein the engaged portion is located on the opposite side of the rotating body with respect to the engaging portion when the opening / closing member is in a closed state.   2. The image formation according to claim 1, wherein at least one of the pair of side walls includes a first guide portion that guides the rotating body along a biasing direction of the biasing member. apparatus. The biasing member is
A torsion coil spring,
Comprising a winding part configured by winding a wire,
The one end extends in a tangential direction from the winding portion;
The image according to claim 1, wherein the other end portion extends in a tangential direction from the winding portion and extends in a direction different from a direction in which the one end portion extends. Forming equipment.   The image forming apparatus according to claim 3, wherein the first axis is located inward of the winding portion.   5. The at least one of the pair of side walls includes a second guide part that guides the engaging part to the engaged part. 6. Image forming apparatus. The engaging portion is
When the opening / closing member is in a closed state, the opening / closing member is movable to a first position for engaging with the engaged portion and a second position for releasing the engagement with the engaged portion. The image forming apparatus according to claim 1. The other end portion further includes a support portion that rotatably supports the rotating body,
One end portion of the support portion is rotatably supported by the opening / closing member with a second axis extending in the first direction as a fulcrum.
The image forming apparatus according to claim 3, wherein the second axis is located inward of the winding portion.   The image forming apparatus according to claim 7, wherein the opening / closing member includes a restricting portion that restricts a rotation range of the support portion with respect to the opening / closing member. The contact body is a photosensitive drum on which a developer image is formed on the outer peripheral surface,
The image forming apparatus according to claim 1, wherein the rotating body is a transfer roller that transfers a developer image formed on the photosensitive drum to a recording medium.

Images