JP2014119518A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of avoiding an increase in size of the apparatus.
In an image forming apparatus including a drawer unit 76 configured to be drawable with respect to the apparatus main body and a lock unit for locking the drawer unit 76 to the apparatus main body, the lock unit is provided in the drawer unit 76. The lock mechanism 160 and the lock receiving member 180 provided in the apparatus main body are provided, and locking is performed between the lock mechanism 160 and the lock receiving member 180. The lock receiving member 180 is attached to the drawer unit 76. It was provided on the drawer unit side with respect to the main body rear plate 501 disposed on the back side in the drawer direction.
[Selection] Figure 30

Description

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

  In general, in an image forming apparatus using an electrophotographic process, a sheet as a recording medium accommodated in a sheet feeding unit is conveyed to an image forming unit through a sheet feeding conveyance path, and the image forming unit forms an image. The toner image thus transferred is transferred. The sheet on which the toner image is transferred is conveyed to a fixing device, and the toner image on the sheet is fixed. The sheet on which the toner image is fixed is conveyed to the sheet discharge tray through the sheet discharge path or is conveyed to the reverse conveyance path. The paper transported to the reverse transport path is reversed, transported again to the image forming unit, and the toner image is transferred to the back surface of the paper.

  Japanese Patent Application Laid-Open No. 2004-228688 contains an image forming apparatus including a paper feed conveyance path, a fixing device, a reverse conveyance path, a paper discharge path, and the like, and a drawer unit configured to be drawable with respect to the image forming apparatus main body. An apparatus is described. When a jam occurs in the conveyance path stored in the drawer unit, the paper can be easily removed by pulling the drawer unit out of the main body.

  Further, the drawer unit described in Patent Document 1 has a lock unit that pulls the drawer unit into the apparatus main body and locks the drawer unit so as not to be pulled out from the apparatus main body. The lock means has a unit side lock portion provided on the drawer unit side and a main body side lock portion provided on the main body side. When the unit-side lock portion comes into contact with the main body side lock portion from the back side in the pull-out direction, the pull-out unit is locked to the apparatus main body.

FIG. 32 is a perspective view of the drawer unit described in Patent Document 1. FIG.
As shown in FIG. 32, the drawer unit described in Patent Document 1 includes a pair of unit side plates 371 and 372 facing the front side and the back side in the drawer direction a of the drawer unit. A round bar-shaped lock shaft 375 is rotatably passed through the pair of unit side plates 371 and 372. An operation lever 376 is attached to the front side end of the lock shaft 375. A unit side lock portion 377 is provided at the back end of the lock shaft 375.

FIG. 33 is an enlarged view of the vicinity of the back end of the lock shaft 375.
As shown in FIG. 33, the unit side lock portion 377 provided at the back end portion of the lock shaft 375 has a prismatic fitting member 386 that fits into the back end portion of the lock shaft 375. . The unit-side lock portion 377 has a support shaft 388 standing on the fitting member 386 in a direction orthogonal to the lock shaft 375, and a roller 389 attached to the support shaft 388 so as to be rotatable about the support shaft 388.

  As shown in FIG. 34, the main body back side plate 310 on the back side of the image forming apparatus is formed with a rectangular passage hole 311 through which the unit lock portion 377 passes the main body back side plate 310. From the upper and lower hole edges of the passage hole 311, a device side lock portion 312 is formed by bending the back hole at a right angle. A cam end surface 313 and an abutting portion 314 are provided at the rear edge of both the main body side lock portions 312 on the rear side from the plate surface of the main body rear side plate 310 and the protrusion amount gradually increases.

  When the drawer unit 370 pulled out from the apparatus main body is pushed into the apparatus main body, the unit side lock portion 377 passes through the passage hole 111 opened in the main body back side plate 110 and is further to the back side than the main body back side plate 310. Protrusively. When the drawer unit 370 is completely pushed into the apparatus main body, the operation lever 376 is rotated. Then, the roller 389 comes into contact with the cam end surface 313 and rolls along the cam end surface 313, and the drawer unit 370 is gradually pulled into the apparatus main body. When the operation lever 376 is rotated and the roller 389 hits the abutting portion 314 as shown in FIG. 34, the operation lever 376 cannot be rotated and the locking operation is completed.

  As described above, by rotating the operation lever 376, the roller 389 of the unit side lock portion 377 comes into contact with the cam end surface 313 of the main body side lock portion 311 from the back side in the pull direction, so that the drawer unit 376 is attached to the apparatus main body. Locked.

  However, in the image forming apparatus described in Patent Document 1, the main body side lock portion 312 is provided on the far side in the pulling direction of the pulling unit 76 from the main body back side plate 310. For this reason, the lock position for locking the drawer unit 76 to the apparatus main body is located closer to the drawer unit than the main body back side plate 110. On the back side surface of the back plate 110 on the back side of the main body, a secondary transfer driving unit for rotating the secondary transfer roller, a secondary transfer power supply unit for applying a secondary transfer bias to the secondary transfer roller, and a heating member for the fixing device A heating power source unit for heating the fixing roller, a fixing driving unit for rotating the fixing roller, and the like are attached. As in the image forming apparatus described in Patent Document 1, when the main body side lock unit 312 is provided on the back side in the pulling direction of the drawer unit with respect to the main body back side plate 310, the units arranged around the unit are It is necessary to dispose the main body side lock portion 312 away. As a result, there arises a problem that the apparatus is increased in size by the main body side lock portion 312.

  The present invention has been made in view of the above problems, and an object thereof is to provide an image forming apparatus capable of avoiding an increase in size of the apparatus.

  To achieve the above object, an invention according to claim 1 is an image forming apparatus comprising: a drawer unit configured to be drawable with respect to the apparatus main body; and a lock unit that locks the drawer unit to the apparatus main body. The locking means includes a unit side lock portion provided in the drawer unit and a main body side lock portion provided in the apparatus main body, and locking is performed between the unit side lock portion and the main body side lock portion. According to another aspect of the present invention, the main body side lock portion is provided on the drawer unit side with respect to the back side plate of the apparatus main body disposed on the back side in the drawer direction of the drawer unit.

  According to the present invention, since the main body side lock portion is provided on the drawer unit side rather than the rear side plate in the drawer direction of the drawer unit of the apparatus main body, it is provided on the surface opposite to the drawer unit side of the rear side plate of the apparatus main body. The unit to be provided may not be arranged avoiding the main body side lock portion. Thereby, the enlargement of an apparatus can be avoided.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment. 1 is a perspective view of an image forming apparatus. Schematic diagram when the drawer unit is pulled out. The perspective view of a drawer unit. FIG. 4 is a diagram illustrating an example of an arrangement position of a sheet detection sensor. 1 is a schematic configuration diagram of an image forming apparatus in a state in which a drawer unit is pulled out. (A) is a disassembled perspective view of the carrier and front cover of the drawer unit. (B) is the perspective view which fixed the front cover to the carrier of the drawer unit. FIG. 3 is a perspective view of an image forming apparatus in which a front cover is separated from a drawer unit. The perspective view of the drawer unit which removed the front cover. The perspective view which shows the structure of a locking mechanism. The perspective view which shows the structure of a drive part. The front view of a drive part. FIG. 2 is a schematic configuration diagram of a secondary transfer roller contact / separation mechanism. The figure which shows the state which has located the secondary transfer roller in the separation position. The perspective view of the apparatus main body part rear side of the state in which the drawer unit was pulled out. The perspective view of the apparatus main body part rear side of the state in which the drawer unit was set to the apparatus main body part. The expansion block diagram of the set detection sensor vicinity. The expansion block diagram of the lock receiving member vicinity. The perspective view of a lock receiving member. FIG. 5 is a diagram illustrating an arrangement position of a secondary transfer driving unit. The figure which cut | disconnected the lock receiving member in the AA direction of FIG. The perspective view which shows a main body rear side board. The perspective view which shows a lock | rock detection mechanism. The functional block diagram which shows an example of the principal part structure of a control system. The figure explaining states, such as a set detection mechanism at the time of changing from a lock release state to a lock state, a lock detection mechanism. The operation | movement flowchart when making it into a locked state from unlocking. The front view of a drive part when a drawer unit is locked. The figure explaining the movement of a rotating roller when changing to a lock release from a locked state. The figure which shows the form which performed the lock release-> lock-> lock release by (1/2) rotation operation of the lock shaft. The figure explaining the positional relationship of the drawer direction of the lock receiving member and lock mechanism when it locks. The operation | movement flowchart at the time of jam occurrence. The perspective view of the conventional drawer unit. The enlarged view of the back end vicinity of the lock shaft in the conventional drawer unit. The figure explaining the lock | rock to the apparatus main body of the conventional drawer unit.

First, an image forming apparatus 1 according to an embodiment of the present invention will be described with reference to FIG. In the present embodiment, the image forming apparatus 1 is a tandem type color copying machine.
As shown in FIG. 1, the image forming apparatus 1 includes an automatic document feeder (hereinafter referred to as ADF) 10 and an image forming apparatus main body 11. The image forming apparatus main body 11 includes a paper feeding unit 3, an image reading unit 4, and an apparatus main body unit 5.

  The ADF 10 includes a document tray 20, a document feed roller 21, a document transport belt 22, a document discharge roller 23, and a document discharge tray 24. The ADF 10 is attached to the image reading unit 4 through an opening / closing mechanism (not shown) such as a hinge.

  The document feeding roller 21 separates a document (not shown) bundle placed on the document tray 20 one by one and conveys it toward the image reading unit 4. The document transport belt 22 transports the document separated by the document feed roller 21 to the image reading unit 4. The document discharge roller 23 discharges a document discharged from the image reading unit 4 by the document conveyance belt 22 to a document discharge tray 24 below the document tray 20.

The image reading unit 4 includes a housing 40, a scanning optical unit 41, a contact glass 42, and driving means (not shown).
The scanning optical unit 41 is provided inside the housing 40 and includes an LED unit. The scanning optical unit 41 emits light in the main scanning direction from the LED unit, and is scanned in the sub-scanning direction in the entire irradiation region by the driving unit. Thereby, the scanning optical unit 41 reads a two-dimensional color image of the document.

  The contact glass 42 is provided on the upper portion of the housing 40 of the image reading unit 4 and constitutes the upper surface portion of the housing 40. The drive means includes a wire (not shown) fixed to the scanning optical unit 41, a plurality of driven pulleys (not shown) and a drive pulley (not shown) bridged by the wires, and a motor for rotating the drive pulley. ing.

  The sheet feeding unit 3 includes a sheet feeding cassette 30 and a sheet feeding unit 31. The paper feed cassette 30 stores paper (not shown) as recording media having different paper sizes. The paper feed unit 31 transports the paper stored in the paper feed cassette 30 to the main transport path 70 of the apparatus main body 5.

  In addition, a manual feed tray 32 is disposed on the side surface of the apparatus main body 5 so as to be openable and closable with respect to the apparatus main body 5. The The uppermost paper in the manually fed paper bundle is sent out toward the main conveyance path 70 by the feed roller of the manual feed tray 32.

  In the main conveyance path 70, a registration roller pair 70a is disposed. The registration roller pair 70a sandwiches the sheet conveyed in the main conveyance path 70 between the rollers, and then feeds the sheet toward the secondary transfer nip at a predetermined timing.

  The apparatus main body 5 includes an exposure unit 51, a tandem image forming apparatus 50, an intermediate transfer belt 54, an intermediate transfer roller 55, a secondary transfer apparatus 52, a fixing unit 53, and the like. Further, it has a main transport path 70, a reverse transport path 73, a paper discharge path 60, and the like.

As shown in FIG. 1, the exposure unit 51 is disposed adjacent to the tandem image forming apparatus 50. The exposure unit 51 performs exposure on the photosensitive drum 74 provided for each color.
The tandem image forming apparatus 50 includes four image forming units 75 of yellow, cyan, magenta, and black on the intermediate transfer belt 54 along the rotation direction of the intermediate transfer belt 54. Although not shown in detail, each image forming unit 75 includes a charging device, a developing device, a photoconductor cleaning device, a static elimination device, and the like around the photoconductor drums 74 provided for the respective colors. Each photosensitive drum 74 and each of the devices provided around the photosensitive drum 74 are unitized to form one process cartridge.

  In the tandem image forming apparatus 50, a visible image (toner image) formed by toner is formed on each photosensitive drum 74 based on the image information read by the image reading unit 4 and separated by color. It has become. The visible image formed on each photosensitive drum 74 is transferred to the intermediate transfer belt 54 between each photosensitive drum 74 and the intermediate transfer roller 55.

  On the other hand, a secondary transfer device 52 is provided on the opposite side of the tandem image forming apparatus 50 with the intermediate transfer belt 54 interposed therebetween. The secondary transfer device 52 has a secondary transfer roller 521 as a transfer member. A secondary transfer nip is formed by pressing the secondary transfer roller 521 against the intermediate transfer belt 54. In the secondary transfer nip, a toner image formed on the intermediate transfer belt 54 is configured to be transferred to a sheet conveyed from the sheet feeding unit 3 via the main conveyance path 70.

  The sheet on which the toner image is transferred at the secondary transfer nip is sent to the fixing unit 53 by the sheet conveying belt 56 stretched around the two support rollers 57.

  The fixing unit 53 is configured by pressing a pressure roller 59 against a fixing belt 58 that is an endless belt. The fixing unit 53 applies heat and pressure to the paper by the pressure roller 59 to melt the toner of the toner image transferred onto the paper and fix it on the paper as a color image.

  The sheet on which the color image is fixed in this manner is stacked on a sheet discharge tray 61 outside the apparatus via a sheet discharge path 60 as a sheet discharge conveyance path.

  As shown in FIG. 1, a reverse conveyance path 73 is provided below the secondary transfer device 52 and the fixing unit 53. The reverse conveyance path 73 is used for reversing the front and back of the paper discharged from the fixing unit 53 and supplying it again to the secondary transfer device 52 via the main conveyance path 70 in order to form images on both sides of the paper. Is.

  In the main conveyance path 70 and the reverse conveyance path 73, a plurality of paper detection sensors as paper jam detection means are arranged along the conveyance path. Note that the number and location of the sheet detection sensors are set as appropriate. When each paper detection sensor does not detect the passage of paper within a predetermined time, it grasps that a paper jam has occurred, and detects that a jam has occurred in a display unit (not shown) of the image forming apparatus 1. Notice.

  The image forming apparatus 1 of the present embodiment holds the secondary transfer device 52, the fixing unit 53, the main transport path 70, the paper discharge path 60, and the reverse transport path 73 shown in FIG. 5 is provided with a drawer unit 76 that can be pulled out with respect to the unit 5.

FIG. 2 is a perspective view of the image forming apparatus 1.
The drawer unit 76 includes a carrier 71 that holds the secondary transfer device 52, the fixing unit 53, the main transport path 70, and the reverse transport path 73. A front cover 6 is attached to the carrier 71. The carrier 71 is supported by a rail 72 provided in the apparatus main body so as to be movable in the front-rear direction (arrow FR in FIG. 2) with respect to the apparatus main body 5. The user grips the handle 6a provided on the front cover 6 and moves the front cover 6 in the front-rear direction (arrow FR in FIG. 2) with respect to the apparatus main body 5. Can be pulled out against. Further, in this specification, the front side F of the image forming apparatus 1 means the front side of the image forming apparatus 1, and the rear side R means the back side of the image forming apparatus 1.

FIG. 3 is a schematic diagram when the drawer unit 76 is pulled out. In FIG. 3, the secondary transfer device 52, the fixing unit 53, the main conveyance path 70, and the reverse conveyance path 73 held by the carrier 71 are not shown. In the drawer unit 76 illustrated below, the secondary transfer device 52, the fixing unit 53, the main transport path 70, and the reverse transport path 73 held by the carrier 71 are not illustrated as appropriate.
As shown in FIG. 3, the electrical component board 120 is disposed in the drawer unit 76. The electrical board 120 has a CPU, a ROM, and the like. The ROM includes a control program for performing control of the secondary transfer device 52, control of the fixing unit 53, paper transport control in the main transport path 70, paper transport control in the reverse transport path 73, jam detection control, and the like. It is remembered. In the present embodiment, as shown in FIG. 3, even when the drawer unit 76 is pulled out, the electrical board 120 and the apparatus main body are connected using the bundled wire 105 as an electric wire, and the electrical connection is maintained. It is like that. Thus, by arranging the electrical board 120 that controls the device held by the carrier 71 in the drawer unit 76, the bundle line necessary for connection is one bundle line 105 that connects the electrical board 120 and the apparatus body. It is easy to secure the bundle path.

FIG. 4 is a perspective view of the drawer unit 76.
As shown in FIG. 4, the front cover 6 has an outer cover portion 602 exposed from the apparatus and a drawer unit 76 that is exposed from the apparatus body 5 when the drawer unit 76 is closed to the apparatus body. An exposed inner cover portion 601 is provided. On the upper surface of the inner cover 601, a plurality of drawer units LEDs 112 a to 112 c are provided as notification means for notifying the occurrence location of paper jam.

  When a jam is detected in the secondary transfer device 52, the fixing unit 53, the main conveyance path 70, the paper discharge path 60, and the reverse conveyance path 73 held by the drawer unit 76, a drawer unit LED 112a corresponding to the location where the jam has occurred. ~ 112c emit light. In the present embodiment, as shown in FIG. 4, even when the drawer unit 76 is pulled out from the apparatus main body, it is electrically connected by the bundle wire 105. Therefore, even when the user pulls out the drawer unit 76 for the jam processing, the drawer unit LEDs 112a to 112c corresponding to the location where the jam has occurred can be turned on. Each drawer unit LED112a-112c is arrange | positioned in the location corresponding to the location where jam occurred. For example, the first drawer unit LED 112a is provided at a position corresponding to an operation member (not shown) that is operated when removing paper jammed in the conveyance path from the paper feed unit 3 to the secondary transfer nip of the drawer unit 76. Yes. The second drawer unit LED 112b is provided at a position corresponding to an operation member (not shown) that is operated when removing paper jammed in the conveyance path from the secondary transfer nip to the fixing unit 53. The third drawer unit LED 112c is provided at a position corresponding to an operation member (not shown) that is operated when removing paper jammed in the paper discharge path 60 from the fixing unit 53 to the paper discharge tray 61. Although not shown, the drawer unit LED is also provided at a position corresponding to an operation member (not shown) provided on the front surface of the outer cover portion 602 that is operated when removing the jammed paper in the reverse conveyance path 73. Is provided.

  FIG. 5 is a diagram illustrating an example of an arrangement position of a paper detection sensor as a paper jam detection unit. As shown in FIG. 5, it has a pre-secondary transfer sheet detection sensor 201a for detecting a sheet passing through the registration roller pair 70a, and a post-secondary transfer sheet detection sensor 201b for detecting a sheet passing through the sheet transport belt 56. Yes. Further, a pre-fixing sheet detection sensor 201c that is disposed in front of the fixing unit 53 and detects a sheet conveyed to the fixing unit 53, and a post-fixing sheet that is disposed after the fixing unit 53 and detects the sheet that has passed through the fixing unit 53. It also has a detection sensor 201d.

  For example, when a jam occurs, if the pre-secondary transfer sheet detection sensor 201a detects a sheet, the first drawer unit LED 112a is turned on. When the jam occurs, if the post-secondary transfer sheet detection sensor 201b or the pre-fixing sheet detection sensor 201c detects the sheet, the second drawer unit LED 112b is turned on. If the post-fixing paper detection sensor 201d detects a paper when a jam occurs, the third drawer unit LED 112c is turned on.

  Thereby, the user can easily grasp which operation member should be operated in order to perform jam processing from the lighted drawer unit LED, and can perform accurate jam processing. . When the user removes the jammed paper and the paper detection sensor stops detecting the paper, the corresponding drawer unit LED is turned off. When the user visually confirms that all the drawer unit LEDs are not lit, the drawer unit 76 is returned to the apparatus main body, and the jam processing is terminated. This can also prevent the user from forgetting to perform jam processing.

  It is preferable that the drawer unit 76 be pulled out beyond the length of the apparatus main body in the drawer unit pull-out direction. With this configuration, the secondary transfer device 52, the fixing unit 53, the main transport path 70, the paper discharge path 60, and the reverse transport path 73 held by the drawer unit 76 can be completely pulled out from the apparatus main body. . Thereby, the jam processing can be easily performed.

  With respect to the arrangement of the drawer units LED 112a to 112c as the notification means, it is desirable to provide the drawer units LED 112a to 112c in a place where the drawer unit 76 is easily visible from the front side. In the present embodiment, the drawer unit 76 is installed on the upper surface of the inner cover portion 601 of the front cover 6 that is considered to be easily visible when pulled out from the apparatus main body.

  When a jam occurs and the conveyance of the paper stops, the paper may straddle and stop between the conveyance path of the drawer unit 76 and the conveyance path other than the drawer unit. In the present embodiment, as shown in FIG. 5, there is a paper feed path straddling portion A that the paper straddles when being transported from the paper feed portion 3 to the drawer unit. Further, there is also a manual path straddling portion B where the sheet straddles when being conveyed from the manual feed tray 32 to the drawer unit. Further, there is a discharge path straddling portion C where the sheet straddles when the sheet is discharged from the drawer unit 76 to the discharge tray 61.

  FIG. 6 is a schematic configuration diagram of the image forming apparatus 1 when the drawer unit 76 is pulled out. As shown in FIG. 6, when the drawer unit 76 is pulled out, the paper feed unit 3, the manual feed tray 32, and the paper discharge tray 61 are located on the apparatus main body side.

  During jam processing, when the drawer unit 76 is pulled out with the paper straddling at one of these straddling parts, the part located on the paper drawer unit side approaches the apparatus main body side while being crumpled. To go. Further, the portion of the paper located on the apparatus main body 5 or the paper feed unit 3 side is approaching the drawing direction of the drawer unit 76 while being crumpled. When the drawer unit 76 is completely pulled out from the apparatus main body, the so-called tearing of the paper that tears the paper occurs. The paper that has been pulled away from the apparatus main body side of the drawer unit 76 that has been pulled out from the apparatus main body section 5 enters into the gap on the apparatus main body side of the drawer unit 76 in a complicated manner. Become. Similarly, paper that has been torn off in the direction of pulling out the main body of the apparatus or paper feed section also enters into the gap on the side of the pull out direction of the main body of the apparatus or paper feed section. Become. As described above, when trying to forcefully exchange the paper that has entered the gap and the like in one direction by squeezing in one direction of the drawer unit 76 and the apparatus main body unit 5 or the paper feeding unit 3, the paper is torn and the piece of paper is pulled out. 76 or the apparatus main body 5 (paper feeding unit 3). As a result, a paper piece may be caught in the conveyance roller provided in the drawer unit 76, the conveyance roller provided in the apparatus main body or the paper feeding unit, and the conveyance failure may occur. Further, if a piece of paper stays on the paper detection sensor provided in the drawer unit 76 or the like, there is a possibility that good jam detection cannot be performed.

  Therefore, in the present embodiment, during jam processing, when the paper is straddling at any of the straddling portions, the drawer unit 76 cannot be pulled out from the apparatus main body, and when the straddling paper is removed, the drawer unit is removed. 76 can be pulled out from the apparatus main body.

  As shown in FIG. 5, in the present embodiment, a paper feed conveyance sensor 207 a is provided in the vicinity of the paper feed path straddling section A as a straddle detection unit that detects a paper straddle in the paper feed path straddling section A. ing. In addition, a manual paper feed sensor 207b is provided in the vicinity of the manual path crossing portion B as a crossing detection means for detecting the paper crossing in the manual path crossing portion B. In addition, a paper discharge sensor 207c serving as a crossing detection unit that detects a paper crossing at the paper discharge path crossing portion C is provided in the vicinity of the paper discharge path crossing portion C. The paper feed / conveyance sensor 207 a and the manual paper feed sensor 207 b are installed in the apparatus main body 5, and the paper discharge sensor 207 c is installed in the drawer unit 76. Hereinafter, the paper feed and transport sensor 207a, the manual paper feed sensor 207b, and the paper discharge sensor 207c that detect the paper stride will be collectively referred to as a stride sensor 207 unless they are distinguished. When the stride sensor 207 detects a jam, the drawer unit 76 is locked to the apparatus main body by a lock mechanism described later.

  Also, as shown in FIG. 5, the right cover member of the apparatus main body is provided with an upper right cover LED 208b as a notification means. In addition, a lower right cover LED 208 a is provided on the right cover member of the paper feeding unit 3. These cover LEDs 208a and 208b are also used for notifying which part is operated when the user performs jam processing.

FIG. 7A is an exploded perspective view of the carrier 71 of the drawer unit 76 and the front cover 6, and FIG. 7B is a perspective view of the front cover 6 fixed to the carrier 71 of the drawer unit 76.
The front cover 6 is screwed to the drawer unit front side plate 150 and is configured to be removed without using a tool. Thus, in this embodiment, by fixing the front cover 6 to the drawer unit 76, the drawer unit 76 can be pulled out only by pulling out the front cover 6. Thereby, the operation of pulling out the drawer unit 76 becomes one action, and the work efficiency of the jam processing can be improved as compared with the configuration in which the front cover 6 is opened and closed and the drawer unit 76 is pulled out as shown in FIG.

FIG. 9 is a perspective view of the drawer unit 76 with the front cover 6 removed.
FIG. 9 shows a state in which the drawer unit is stored in the apparatus main body.
As shown in FIG. 9, a bundled wire 105 is disposed at the right end (the main conveyance path 70 side end) of the drawer unit 76 in the drawing, and the bundled wire 105 is held by the code guide 130. . The bundled wire 105 is a so-called curl cord in which a cord is wound spirally. By using the curled cord as the bundled wire 105, the bundled wire 105 can be expanded and contracted in the pull-out direction. Thereby, the bending of the bundled wire 105 can be suppressed compared with the case where the bundled wire 105 is not expanded and contracted. Thereby, when viewed from the pulling-out direction of the drawer unit 76, it is possible to suppress the bundled wire 105 from protruding from the drawer unit 76 and bend it, and to suppress the bundled wire 105 from being caught by the components in the apparatus main body. Can do. The code guide 130 is attached to a main body rear plate 501 (see FIG. 15) of the apparatus main body 5 described later. As shown in FIG. 9, when the drawer unit is housed in the apparatus body 5, the code guide 130 is housed in the drawer unit 76. When the drawer unit 76 is pulled out from the apparatus main body, the code guide 130 is pulled out from the drawer unit 76 together with the bundled wire 105 relatively from the drawer unit rear side plate 151. Thereby, the bundled wire 105 drawn relatively from the drawer unit 76 is guided by the code guide 130 and can be prevented from bending (see FIG. 15).

  A lock shaft 703 is rotatably supported by the drawer unit front plate 150 and the rear plate 151. A lock mechanism 160 as a unit-side lock portion is provided at the rear end portion of the lock shaft 703.

FIG. 10 is a perspective view showing the configuration of the lock mechanism 160.
As shown in FIG. 10, the rear end portion of the lock shaft 703 protrudes from the drawer unit rear plate 151, and the lock mechanism 160 is attached to the end portion. The lock mechanism 160 has a prismatic fitting member 163 fixed to the lock shaft 703. Further, the lock mechanism 160 has a roller shaft 161 fixed to the fitting member 163 so as to penetrate in a direction orthogonal to the axial direction of the lock shaft 703. In the vicinity of both ends of the roller shaft 161, there is a rotating roller 162 that is rotatably attached to the roller shaft 161.

  Further, as shown in FIG. 10, the lock shaft 703 is attached to the drawer unit rear plate 151 via a sintered bearing 721. Further, an E ring 722 is fixed to a groove provided in the lock shaft 703 so as to contact the front side surface of the drawer unit rear plate 151.

  Further, as shown in FIG. 9, the drawer unit front side plate 150 is provided with a drive unit 700 that rotationally drives the lock mechanism 160 via the lock shaft 703.

FIG. 11 is a perspective view showing the configuration of the drive unit 700.
As shown in FIG. 11, the drive unit 700 includes a drive motor 701. The drive motor 701 is fixed to the drawer unit front plate 150 so that the motor shaft is parallel to the drawer unit front plate 150. By fixing the drive motor 701 in this way, the drawer unit 76 becomes larger in the pull-out direction than when the motor shaft of the drive motor 701 is fixed so as to be orthogonal to the drawer unit front plate 150. Can be suppressed.

  A screw gear 704 a of the worm gear 704 is fixed to the motor shaft of the drive motor 701. The driving force of the drive motor 701 is transmitted from the helical gear 704b of the worm gear 704 meshing with the screw gear 704a to the driven gear 706 fixed to the lock shaft 703 via a gear train 705 including a plurality of idler gears. Is driven to rotate.

FIG. 12 is a front view of the drive unit 700.
As shown in FIG. 12, a worm gear 704, a plurality of idler gears constituting the gear train 705, and a driven gear 706 fixed to the lock shaft 703 are housed in a case 702.
A link mechanism 710 that transmits driving to a contact / separation mechanism that contacts and separates a secondary transfer roller 521 (described later) with respect to the intermediate transfer belt 54 is connected to a front end portion of the lock shaft 703.

  The link mechanism 710 includes an output link member 711, a connection link member 712, and an input link member 713. One end of the output link member 711 is fixed to the lock shaft 703, and the other end is provided with an output protrusion 711a. The front end portion of the lock shaft 703 has a D-shaped cross section, and a D-shaped fitting hole is formed at one end of the output link member 711 and is fitted into the front end portion of the lock shaft 703. The E ring 714 is attached to the lock shaft 703 so that the output link member 711 does not come out of the lock shaft 703. Thereby, the output link member 711 is fixed to the lock shaft 703.

  One end of a connecting link member 712 is rotatably attached to the output projection 711a of the output link member 711. An elongated hole 712a is formed at the other end of the connecting link member 712, and an input projection 713a provided at one end of the input link member 713 is fitted into the elongated hole 712a. An end portion of the input shaft 361 for inputting a driving force to the contact / separation mechanism described later has a D-shaped cross section, and a D-shaped fitting hole formed at the other end of the input link member 713 is input. The shaft 361 is fitted into one end. The E-ring 714 is attached to the input shaft 361 so that the input link member 713 does not come out of the input shaft 361.

  By using the link mechanism 710 to transmit the drive from the lock shaft 703 to the input shaft 361, a plate material can be used as each link member, and the drawer unit 76 is larger in the pull-out direction than when the drive is transmitted by gears. Can be suppressed.

Here, a contact / separation mechanism that contacts and separates the secondary transfer roller 521 from the intermediate transfer belt 54 will be described. The contact / separation mechanism is provided at both axial ends (front side and rear side) of the secondary transfer roller, and has the same configuration.
FIG. 13 is a schematic configuration diagram of a contact / separation mechanism provided at one axial end of the secondary transfer roller 521.
The secondary transfer roller 521 is rotatably supported by the holding member 354. The holding member 354 is rotatably supported by a support shaft 359 attached to the frame 350 of the secondary transfer device. A spring receiver 354 a is provided at the end of the holding member 354 opposite to the support shaft 359 side and the secondary transfer roller 521. One end of a spring 351 is attached to the spring receiver 354a, and the holding member 354 is urged upward in the drawing (on the intermediate transfer belt 54 side) by the spring 351. In addition, a long hole 354c is provided on the opposite side of the holding member 354 from the support shaft 359 side with respect to the secondary transfer roller 521, and the above-described input shaft 361 passes through the long hole 354c. A release cam 362 is attached to the input shaft 361. The holding member 354 is provided with an abutting portion 354b against which the release cam 362 abuts.

As shown in FIG. 13, when the release cam 362 is separated from the abutting portion 354b, the secondary transfer roller 521 contacts the intermediate transfer belt 54 with a predetermined pressure by the biasing force of the spring 351. ing. When pulling out the drawer unit 76, the input shaft 361 is rotated, and the release cam 362 is rotated clockwise in the drawing. Then, the release cam 362 abuts against the abutting portion 354b. When the input shaft 361 further rotates, the release cam 362 causes the holding member 354 to rotate clockwise with respect to the support shaft 359 as a fulcrum against the urging force of the spring 351 as shown in FIG. . As a result, the secondary transfer roller 521 is separated from the intermediate transfer belt 54. That is, in the present embodiment, the holding member 354, the spring 351, the release cam 362, and the like constitute a contact / separation mechanism that contacts and separates the secondary transfer roller 521 from the intermediate transfer belt 54.
In the present embodiment, the secondary transfer roller 521 is configured to move about 5 to 7 mm from the pressure position shown in FIG. 13 to the retracted position shown in FIG.

15 is a perspective view of the rear side of the apparatus main body with the drawer unit 76 pulled out, and FIG. 16 is a perspective view of the rear side of the apparatus main body with the drawer unit 76 set in the apparatus main body 5. It is.
A positioning hole 502 into which a positioning pin 152 provided at the left end portion of the drawer unit 76 in the drawing is inserted near the left end portion of the main body rear side plate 501 in the drawing. The positioning pin 152 includes a fitting portion 152b that fits into the positioning hole 502, and a tapered guide portion 152a that guides the fitting portion 152b to the positioning hole. In addition, when the drawer unit is locked to the apparatus main body portion 5 by a lock mechanism 160 described later, the seat surface portion 152c has a larger diameter than the fitting portion 152b pressed against the main body rear side plate 501.

  Further, the main body rear plate 501 is provided with a set detection sensor 172 for detecting that the drawer unit 76 is set in the apparatus main body 5. The drawer unit rear side plate 151 is provided with a filler 171 as a set detection portion detected by the set detection sensor 172. That is, in the present embodiment, the set detection sensor 172, the filler 171 and the like constitute a set detection mechanism as set detection means for detecting the set of the apparatus main body 5 of the drawer unit 76.

FIG. 17 is an enlarged configuration diagram near the set detection sensor 172.
As shown in FIG. 17, as the set detection sensor 172, a photo interrupter (transmission type optical sensor) is used. When the drawer unit 76 is set in the apparatus body 5, the set detection filler 171 provided on the drawer unit rear side plate 151 enters between the light receiving part 172b and the light emitting part 172a of the set detection sensor 172, and emits light. Blocks light from the portion 172a. Thereby, the light receiving unit 172b does not detect the light from the light emitting unit 172a, and it can be detected that the drawer unit 76 is set in the apparatus main body 5.

  Further, as shown in FIGS. 15 and 16, there is provided a lock receiving member 180 against which the rotary roller 162 of the lock mechanism 160 is pressed when the drawer unit 76 is locked to the apparatus main body 5. .

FIG. 18 is an enlarged configuration diagram in the vicinity of the lock receiving member 180, and FIG. 19 is a perspective view of the lock receiving member 180.
The lock receiving member 180 is provided with a lock through hole 184 into which the lock mechanism 160 is inserted. A secondary transfer through hole 185 into which a joint member 353 b fixed to the shaft of the secondary transfer roller 521 is inserted is provided above the lock through hole 184. As shown in FIG. 19, the secondary transfer through hole 185 and the lock through hole 184 of the lock receiving member 180 have a cylindrical shape.

  When the drawer unit 76 is set in the apparatus main body 5, the joint member 353 b passes through the secondary transfer through hole 185 and is assembled to a joint member (not shown) of the secondary transfer driving unit 800 shown in FIG. 20. It is done. Thereby, the secondary transfer roller 521 is rotationally driven by the driving force of the secondary transfer motor.

  As shown in FIG. 18, lock receiving surfaces 182 a and 182 b for locking the drawer unit 76 to the apparatus main body 5 by contacting the rotary roller 162 of the lock mechanism 160 with the inner peripheral surface of the lock through hole 184. Is formed. Further, guide surfaces 183a and 183b for guiding the rotary roller 162 of the lock mechanism 160 to the lock receiving surfaces 182a and 182b are connected to the end portions of the lock receiving surfaces 182a and 182b in the clockwise direction in the drawing, respectively. Yes.

21 is a view in which the lock receiving member 180 is cut in the AA direction of FIG. 19, (a) is a cross-sectional view of the lock receiving member 180 viewed from the side, and (b) is a lock receiving member. It is a cross-sectional perspective view of a member.
As shown in FIG. 21, the guide surfaces 183a and 183b are tapered surfaces that are inclined toward the drawer unit side (front side) as they are separated from the lock receiving surfaces 182a and 182b.

  Further, as shown in FIG. 18, notches 181a and 181b for inserting the rotary roller 162 of the lock mechanism 160 are formed on the guide surfaces 183a and 183b in the clockwise end portions in the drawing. ing.

  In addition, inclined surfaces 186a and 186b that are inclined forward are also formed on the counterclockwise ends of the lock receiving surfaces 182a and 182b in the drawing.

  As shown in FIG. 22, the cylindrical secondary transfer through hole 185 and the lock through hole 184 of the lock receiving member 180 protrude from the main body rear side plate 501 to the drawer unit 76 side. In this way, the lock receiving member 180 is prevented from protruding from the surface of the main body rear side plate 501 opposite to the drawer unit side. As shown in FIG. 20, the secondary transfer driving unit 800 is screwed to the rear surface of the main body rear side plate 501 with a screw 801 so as to face the lock receiving member 180. When the lock receiving member 180 protrudes from the surface opposite to the drawer unit side of the main body rear side plate 501, the secondary transfer driving unit 800 is separated from the rear surface of the main body rear side plate 501 by the protrusion of the lock receiving member 180. Must be provided. As a result, there is a possibility that the apparatus becomes large in the pull-out direction.

  The main body rear side plate 501 positions a process cartridge including a photoconductor, a transfer unit including an intermediate transfer belt 54, a drawer unit 76 storing a fixing unit, a secondary transfer device, and the like within the apparatus main body 5. It is a member for. For this reason, the main body rear side plate 501 is fixed to the rear side surface of the housing 40 (see FIG. 1) of the image reading unit 4. Thus, by fixing the main body rear side plate 501 to the rear side surface of the housing 40 (see FIG. 1) of the image reading unit 4, the main body rear side plate 501 does not tilt in the pull-out direction in the apparatus main body unit 5. Can be fixed to. Thereby, the process cartridge, the transfer unit, the drawer unit 76 and the like can be accurately positioned in the apparatus main body. Generally, the length in the front-rear direction of the image reading unit 4 is longer than the length in the width direction of an image on which the image forming apparatus can form an image. On the other hand, the length in the front-rear direction of the drawer unit 76 and the like is slightly longer than the length in the width direction of an image that can be formed. Therefore, when the drawer unit 76 is attached to the apparatus main body 5, there is a certain gap between the drawer unit rear side plate 151 and the main body rear side plate 501. Therefore, even if the lock receiving member 180 is protruded to the drawer unit side (front side) of the main body rear side plate 501, the drawer unit rear side plate 151 does not get in the way. Therefore, by causing the lock receiving member 180 to protrude toward the drawer unit side of the main body rear side plate 501, it is possible to suppress the apparatus from becoming large in the drawer direction.

Next, a lock detection mechanism as lock detection means for detecting whether the drawer unit 76 is in the locked state or the unlocked state will be described.
FIG. 23 is a perspective view showing a lock detection mechanism.
As shown in FIG. 23, the lock detection mechanism includes a disk-shaped lock detection filler 192 attached to a lock shaft 703 and a part of which is missing, and a lock detection sensor 191 of a photo interrupter (transmission type optical sensor). doing. The lock detection filler 192 enters between the light receiving unit 191b and the light emitting unit 191a of the lock detection sensor 191, and blocks the light from the light emitting unit 191a. Thereby, the light receiving unit 191b does not detect the light from the light emitting unit 191a, and the signal from the light receiving unit 191b becomes “OFF: shielding state”. On the other hand, when the lock detection filler 192 is not between the light emitting unit 191a and the light receiving unit 191b, the light receiving unit 191b receives light from the light emitting unit 191a. Thereby, the signal from the light receiving unit 191b becomes “ON: non-shielding state”. Based on the ON / OFF signal from the light receiving unit 191a, the control unit 121 (see FIG. 24) grasps whether the drawer unit 76 is in the locked state or the unlocked state.

FIG. 24 is a functional block diagram illustrating an example of a main configuration of the control system according to the present embodiment.
As shown in FIG. 24, a drive motor 701, paper detection sensors 201a to 201d, drawer LEDs 112a to 112c, and the like are connected to the control unit 121 as control means. Further, the straddle detection sensors 207a to 207c, the lock detection sensor 191, the set detection sensor 172, the right cover LEDs 208a and 208b, and the like are connected. For example, the control unit 121 controls the drive motor 701 to control the lock of the drawer unit 76 or turn on the drawer LEDs 112a to 112c and the right cover LEDs 208a and 208b by executing a control program incorporated in advance. Or

Next, the lock operation of the drawer unit 76 will be described.
FIG. 25 is a diagram for explaining states of the set detection mechanism, the lock detection mechanism, and the like when transitioning from the unlocked state to the locked state, and FIG. 26 is an operation flow diagram when changing from the unlocked state to the locked state. .
As shown in FIG. 25 (a), when the drawer unit 76 is unlocked and in a drawable state (S1), the rotating roller 162 of the lock mechanism 160 corresponds to the notches 181a and 181b of the lock receiving member 180. It is in place to do. Further, in the unlocked state, the lock detection filler 192 of the lock detection mechanism is located just at a position where the lock detection sensor 191 is removed from the facing portion between the light receiving portion 191b and the light emitting portion 191a. Therefore, at this time, the light receiving unit 191b of the lock detection sensor detects the light of the light emitting unit 191a, and is “ON: non-shielding state”. At this time, the secondary transfer roller 521 is located at a separated position away from the intermediate transfer belt 54, and the link mechanism 710 is in the state shown in FIG.

  When the drawer unit 76 is set in the apparatus main body 5 from this state (S2), the lock mechanism 160 is inserted into the lock through hole 184 of the lock receiving member 180. When the rotary roller 162 moves to the rear side of the guide unit 183a, 183b end on the drawer unit side, the set detection filler 171 enters between the light receiving unit 172b and the light emitting unit 172a of the set detection sensor 172, The light from the light emitting unit 172a is blocked. As a result, the set detection unit detects the setting of the drawer unit 76 (S3), starts driving the drive motor 701 shown in FIG. 11 (S4), and rotates the lock shaft 703.

  When the lock shaft 703 rotates, as shown in FIG. 25 (b), the rotary roller 162 of the lock mechanism 160 contacts the guide surfaces 183a and 183b and is guided by the guide surfaces 183a and 183b. Move to 182a, 182b. In this way, the rotary shaft 162 moves rearward while being guided by the guide surfaces 183a and 183b, whereby the lock shaft 703 is pulled back. As shown in FIG. 10, the E-ring 722 is fixed to the groove of the lock shaft 703 so as to contact the front side surface of the drawer unit rear side plate 151. Therefore, when the lock shaft 703 tries to move to the rear side, the drawer unit rear plate 151 is pushed rearward by the E ring 722, and the drawer unit 76 is pulled into the apparatus main body 5.

  Further, the contact / separation mechanism described above is driven via the lock shaft 703 and the link mechanism 710, and the secondary transfer roller 521 moves from the separation position to the contact position.

  Since the rotating roller 162 is rotatably attached to the roller shaft 161, the rotating roller 162 moves on the guide surfaces 183a and 183b while rotating. Thereby, an increase in frictional resistance with the guide surfaces 183a and 183b can be suppressed, and the drawer unit can be smoothly pulled back.

  In the present embodiment, the positioning pin 152 is fitted into the positioning hole 502 after the drawing by the lock mechanism 160 is started, and the positioning is performed. In the case where the fitting portion 152b of the positioning pin 152 is fitted into the positioning hole 502 before the drawing is started (the set detection sensor 172 detects the set detection filler 171), the drawer unit 76 is manually pushed in. The fitting portion 152b fits into the positioning hole 502. As a result, the resistance when pushing in manually is increased. As a result, it is misunderstood that the user has pushed in to the pull-in start position, and there is a possibility that the push-in of the drawer unit is stopped.

  On the other hand, in this embodiment, after the drawing by the lock mechanism 160 is started, the positioning pins 152 are fitted into the positioning holes 502 to perform positioning. Therefore, it is possible to prevent the push-in resistance from rapidly increasing until the pull-out unit 76 is pushed into the pull-in start position by the lock mechanism 160 (the position where the set detection sensor 172 detects the set detection filler 171). Thereby, the drawer unit can be manually pushed into the retracting start position by the lock mechanism 160 with certainty.

  When the drawer unit 76 and the apparatus main body are provided with connectors, and the drawer unit is set in the apparatus main body, the connectors of the drawer unit are fitted to the connectors of the apparatus main body and energized. The drive motor 701 cannot be driven unless it is fitted. When the connectors are fitted together, the push-in resistance of the drawer unit increases. Therefore, there is a possibility that the user pushes the drawer unit into the pull-in start position and stops pushing the drawer unit.

  However, in this embodiment, even when the drawer unit 76 is pulled out by the bundled wire 105, the drawer unit 76 is in an energized state and can drive the drive motor 701. Therefore, the drawer unit can be manually pushed into the pull-in start position more reliably than in the case where the connector of the drawer unit is engaged with the connector of the apparatus main body and energized.

  Even after the positioning pin 152 is fitted in the positioning hole 502, the drawer unit 76 is pulled back by the guide surfaces 183a and 183b, and the seating surface portion 152c of the positioning pin 152 provided on the drawer unit rear plate 151 is provided. Butt against the rear plate 501 of the main body. Then, as shown in FIG. 25 (c), when the rotating roller 162 of the lock mechanism 160 reaches the lock receiving surfaces 182a and 182b, a lock detection filler is provided between the light receiving unit 191b and the light emitting unit 191a of the lock detection sensor. 192 enters and becomes “OFF: shielding state”. Thereby, it is detected by the lock detection mechanism that the drawer unit 76 is locked to the apparatus main body 5 (S5), and the drive of the drive motor 701 is stopped (S6). At this time, the secondary transfer roller contacts the intermediate transfer belt 54 with a predetermined pressure. The link mechanism 710 at this time is in the state shown in FIG.

  In the present embodiment, after the seating surface portion 152c of the positioning pin 152 provided on the drawer unit rear side plate 151 abuts against the main body rear side plate 501, the drawer unit 76 is pulled rearward by pulling the drawer unit 76 to the rear side. 76 is locked to the apparatus main body. Thereby, the drawer unit 76 can be locked to the apparatus main body 5 without backlash in the front-rear direction. As a result, it is possible to prevent the image from being disturbed due to vibration during image formation. In addition, the drawer unit rear side plate 151 and the main body rear side plate 501 which are long in the horizontal direction are bent, or a member made of resin among the members that abut against the main unit rear side plate 501 of the drawer unit 76 is elastically deformed. Then, after the seating surface portion 152c of the positioning pin 152 abuts against the main body rear side plate 501, the 0 to 1 mm drawer unit 76 can be pulled back.

  As will be described later, when a jam or the like occurs and it becomes necessary to pull out the drawer unit 76, the drive motor 701 is rotated and the lock mechanism 160 is rotated counterclockwise in the drawing. Then, the rotating roller 162 moves from the lock receiving surfaces 182a and 182b to the inclined surfaces 186a and 186b. Then, as shown in FIG. 25 (d), the rotating roller 162 that has been in contact with the lock receiving surface 182a reaches the position of the notch 181a, and the rotating roller 162 that has been in contact with the lock receiving surface 182b is When the position of the notch 181b is reached, the lock detection filler 192 does not exist between the light receiving unit 191b and the light emitting unit 191a of the lock detection sensor. Thereby, it switches from "OFF: shielding state" to "ON: non-shielding state", and it can detect that the lock | rock of the drawer unit 76 was cancelled | released by the lock | rock detection mechanism.

  27, when the lock shaft 703 rotates clockwise in FIG. 27, the input shaft 361 rotates slightly in the counterclockwise direction in FIG. The direction is switched to the clockwise direction in FIG. As a result, the secondary transfer roller 521 switches from a direction close to the intermediate transfer belt 54 to a direction away from the intermediate transfer belt 54. When the lock is released, the link mechanism 710 is in the state shown in FIG. 12 and reaches the position where the secondary transfer roller 521 is separated from the intermediate transfer belt 54.

  Thus, in this embodiment, the drawer unit can be automatically locked and unlocked. Therefore, the jam handling operation can be simplified as compared with the case where a lever or the like is provided in the drawer unit and the drawer unit is manually locked and unlocked. As a result, the efficiency of the jam handling work can be improved.

  Further, the secondary transfer roller 521 is brought into contact with and separated from the intermediate transfer belt 54 in conjunction with the locking operation of the drawer unit 76. As a result, the secondary transfer roller 521 can always be separated from the intermediate transfer belt 54 when the drawer unit 76 is in a drawable state. Therefore, the secondary transfer roller 521 can be prevented from rubbing against the intermediate transfer belt 54 when the drawer unit 76 is pulled out from the apparatus main body, and the surface of the secondary transfer roller 521 and the surface of the intermediate transfer belt 54 are damaged. Can be suppressed. In addition, the contact of the secondary transfer roller 521 with the intermediate transfer belt 54 is not forgotten.

  Further, since the unlocking of the drawer unit 76 is automatically performed by driving the drive motor 701, the work of releasing the lock becomes unnecessary. Thereby, compared with the structure which cancels | releases a lock | rock manually, the drawer operation | work of the drawer unit 76 can be performed easily.

  In the present embodiment, as shown in FIG. 2, the front cover 6 is fixed to the drawer unit 76, and the front cover 6 is pulled out together with the drawer unit 76. In such a configuration, when the drawer unit 76 is manually locked and unlocked, the operation unit needs to be provided at a location exposed from the apparatus. Therefore, the malfunction that the appearance of an apparatus worsens arises. Therefore, for example, it is considered that an operation unit for unlocking the drawer unit is provided in the handle portion 6a. Specifically, when the user grips the handle portion 6a, the operation portion is pushed and unlocked. However, in the present embodiment, as described above, after the seating surface portion 152c of the positioning pin 152 abuts against the main body rear side plate 501, the 0 to 1 mm drawer unit 76 is pulled back and locked. For this reason, a large force is required when the rotary roller 162 is moved from the lock receiving surfaces 182a and 182b to be unlocked or the guide surfaces 183a and 183b are moved and locked. Thus, in order to make the drawer unit 76 that is firmly locked to the apparatus main body 5 easily lockable and unlockable by the operation of the operation unit of the user, it is necessary to increase the operation amount of the operation unit. . Therefore, when the structure is such that the drawer unit 76 that is firmly locked to the apparatus main body 5 is locked and unlocked by the operation amount when grasping the handle portion 6a, a considerably large force is required for the operation. Can not be moved easily.

  On the other hand, in this embodiment, it is possible to prevent the appearance of the apparatus from being impaired by automatically locking and unlocking the drawer unit.

  Further, when the lock shaft 703 is configured to rotate easily, the lock shaft 703 may rotate when the drawer unit 76 is mounted. When the lock shaft 703 rotates when the drawer unit 76 is mounted, the rotary roller 162 of the lock mechanism 160 is not inserted into the notches 181a and 181b, but abuts against the guide surfaces 183a and 183b, and the drawer unit 76 can be mounted. There is a risk of disappearing. Further, when the drawer unit 76 is attached to the apparatus main body 5, the lock shaft 703 may rotate due to vibration or the like, and the drawer unit may be unlocked. Therefore, in this embodiment, the worm gear 704 having a large reduction ratio and a high torque is used for driving transmission from the drive motor 701 to the lock shaft 703. By using the worm gear 704, the lock shaft 703 can be prevented from rotating easily. As a result, it is possible to prevent problems such that the drawer unit 76 cannot be mounted on the apparatus main body or the lock is released due to vibration or the like.

  In the present embodiment, as shown in FIG. 17, the set detection sensor 172 is disposed in the vicinity of the lock receiving member 180. When the set detection sensor 172 is disposed at a position away from the lock receiving member 180, the following problem occurs. That is, the set detection sensor 172 detects the filler 171 before the rotating roller 162 is positioned behind the guide surfaces 183a and 183b due to the influence of the deformation of the drawer unit rear plate 151 and the deformation of the main body rear plate 501. It is a malfunction that there is a risk of doing.

  On the other hand, by arranging the set detection sensor 172 in the vicinity of the lock receiving member 180 as in the present embodiment, the influence of the deformation of the drawer unit rear plate 151 and the deformation of the main body rear plate 501 can be suppressed. Thereby, the malfunction that the set detection sensor 172 detects the filler 171 before the rotating roller 162 is located behind the guide surfaces 183a and 183b can be suppressed.

  In the present embodiment, when the lock is released, each rotary roller 162 is guided from the lock receiving surfaces 182a and 182b to the inclined surfaces 186a and 186b and moved to the notches 181a and 181b. As described above, by providing the inclined surfaces 186a and 186b, it is possible to suppress a sudden change in torque and to suppress a load on the drive motor 701 and the like.

  In this embodiment, as shown in FIG. 28, the lock release → lock → lock release is performed by one rotation of the lock shaft 703. As described above with reference to FIGS. 12 and 27, the secondary transfer roller 521 is intermediately transferred by using the link mechanism 710 and switching the rotation direction of the input shaft 361 in one rotation of the lock shaft 703. This is because it is in contact with and away from the belt 54. Therefore, when the lock of the drawer unit 76 and the contact and separation of the secondary transfer roller 521 are performed separately, the configuration shown in FIG. 29 may be used.

  In the configuration shown in FIG. 29, as shown in the figure, the lock release → lock → lock release is performed by the (1/2) rotation operation of the lock shaft 703. For this reason, the lock detection filler 192 of the lock detection mechanism has a fan shape and is provided at two locations in the circumferential direction of the lock shaft 703 with an interval of 180 °. With such a configuration, when the rotary roller 162 that has been in contact with the lock receiving surface 182a reaches the notch 181b, the lock detection sensor 191 changes from “OFF: shielded state” to “ON: non-shielded state”. It is detected that the lock has been released. By adopting such a configuration, it is possible to shorten the time until the transition from the locked state to the unlocked state.

  Further, in the present embodiment, as shown in FIG. 30, in the state where the drawer unit 76 is locked, the rear end of the lock mechanism 160 is the front side by a distance D from the rear surface of the main body rear plate 501. Is located. In this way, when locked to the apparatus main body, the lock mechanism 160 does not protrude from the rear surface of the main body rear side plate 501. Therefore, the secondary transfer driving unit 800 provided to face the lock receiving member 180 shown in FIG. 20 can be provided in contact with the rear surface of the main body rear side plate 501. As a result, the size of the image forming apparatus in the front-rear direction can be reduced.

FIG. 31 is an operation flowchart when a jam occurs.
When the image forming operation is performed, the drawer unit 76 is locked to the apparatus main body 5 (S11).
When it is detected that a paper jam has occurred by a plurality of paper detection sensors arranged along the conveyance path such as the main conveyance path 70 and the reverse conveyance path 73 (S12), the driving of each conveyance roller is stopped. Next, the control unit 121 checks whether the paper feed conveyance sensor 207a, which is a straddle detection sensor, has detected a sheet (S13).

  When the paper feeding / conveying sensor 207a detects the paper (No in S13), the paper is present in the paper feeding path straddling portion A shown in FIG. Therefore, at this time, the lower right cover LED 208a provided on the right cover member of the paper feeding unit 3 is turned on, and the operation display unit (not shown) indicates that there is paper in the paper feeding path straddling part A, and jam processing. The work location, jam processing method, etc. are displayed and notified to the user (S15). The user visually confirms the operation display unit (not shown) and the lit lower right cover LED 208a, opens the right cover member of the paper feeding unit 3, and removes the paper in the paper feeding path straddling part A. When the jam processing of the user is finished and the paper feed sensor 207a no longer detects paper (Yes in S16), the lower right cover LED 208a is turned off and the display on the operation display unit is turned off.

  When the paper feed sensor 207a has not detected the paper (No in S13), the control unit 121 checks whether the manual paper feed sensor 207b has detected the paper (S17). When the manual paper feed sensor 207b detects the paper (No in S17), the paper exists in the manual path crossing portion B shown in FIG. Therefore, at this time, the upper right cover LED 208b provided on the right cover member of the apparatus main body 5 is turned on. Further, the fact that there is a sheet in the manual path crossing section B, the jam processing work location, the jam processing method, and the like are displayed on the operation display section (not shown) (S19). The user follows the contents of the operation display unit (not shown), visually confirms that the lower right cover LED 208a is turned on, and removes the paper straddling the manual path crossing portion B. When the paper is straddling the manual path crossing portion B, the rear end of the paper is on the manual feed tray 32. Therefore, the user can perform jam processing by grasping and pulling out the rear end of the sheet on the manual feed tray. When the paper in the manual path straddling section B is removed and the manual paper feed sensor 207b no longer detects the paper (Yes in S20), the upper right cover LED 208b is turned off and the operation display section is turned off.

  When the paper feed sensor 207a and the manual paper feed sensor 207b have not detected the paper (Yes in S13, Yes in S17), it is checked whether or not the paper discharge sensor 207c has detected the paper (S21). . When the paper discharge sensor 207c detects the paper (No in S21), the paper is present in the paper discharge path straddling portion C shown in FIG. Therefore, at this time, the fact that paper is present in the discharge path straddling part C, the jam processing work location, the jam processing method, etc. are displayed on the operation display section (not shown), and the user is notified (S22). Then, according to the instruction of the operation display unit (not shown), the paper in the discharge path straddling part C is removed. When the sheet straddles the sheet discharge path straddling portion C, the leading edge of the sheet is on the sheet discharge tray 61. Therefore, the user can perform jam processing by grasping and pulling out the leading edge of the paper on the paper discharge tray. When the paper in the paper discharge path straddling portion C is removed and the paper discharge sensor 207c no longer detects the paper (Yes in S23), the display on the operation display unit is turned off. Further, an LED is provided on the left cover member of the apparatus main body 5 so that when the paper discharge sensor 207c detects paper, the LED is turned on to display a work location when removing the paper in the paper discharge path straddling portion C. You may do it.

  When none of the paper feed conveyance sensor 207a, the manual paper feed sensor 207b, and the paper discharge sensor 207c detects a sheet (Yes in S13, Yes in S17, S21 Yes), the paper is conveyed along the conveyance path of the drawer unit 76. It is checked whether any of the plurality of paper detection sensors detects the paper (S24). If the paper detection sensor of the drawer unit has not detected the paper (Yes in S24), the jam processing is terminated (S25).

  On the other hand, when the paper detection sensor of the drawer unit detects paper (No in S24), the unlocking operation of the drawer unit 76 is executed. That is, as described above, the drive motor 701 is driven to move the rotary roller 162 that has been in contact with the lock receiving surfaces 182a and 182b to the positions of the notches 181a and 181b. Then, the rotating roller 162 reaches the positions of the notches 181a and 181b, and the lock detection sensor 191 switches from “OFF: shielded state” to “ON: non-shielded state” to detect that the lock is released ( When S27), the drive motor 701 is stopped (S28), and the drawer unit 76 can be pulled out (S29).

  Next, the drawer unit LEDs 112a to 112c shown in FIG. 4 are turned on based on the detection result of the paper detection sensor arranged in the conveyance path of the drawer unit 76 (S30). Further, a jam processing work location, a jam processing method, and the like are displayed on an operation display unit (not shown) to notify the user (S31). For example, when the set detection sensor 172 detects that the drawer unit 76 is set, the operation display unit displays an instruction to pull out the drawer unit 76. Further, an LED may be provided on the upper portion of the handle portion 6a of the front cover 6, and the LED may be turned on to display the work location to the user. When the user pulls out the drawer unit 76 and the set detection sensor 172 stops detecting the setting of the drawer unit 76, a procedure for removing the paper in the drawer unit is displayed on the operation display unit.

  The user removes the paper in the transport path of the drawer unit 76 based on the instruction on the operation display unit or the lighting display of the drawer units LEDs 112a to 112c, and any of a plurality of paper detection sensors arranged in the transport path of the drawer unit 76. If paper is no longer detected, a message to close the drawer unit 76 is displayed on the operation display section. Then, the lock operation flow shown in FIG. 26 is performed (S33), the drawer unit 76 is locked, and the jam processing is finished (S34).

  As described above, in this embodiment, when any of the paper feed sensor 207a, the manual paper feed sensor 207b, and the paper discharge sensor 207c detects paper, the drawer unit 76 is in a locked state. Accordingly, the drawer unit 76 is not pulled out in a state in which paper is present in any one of the paper feed path straddling portion A, the manual feed straddling portion B, and the paper discharge path straddling portion C. Thereby, it is possible to prevent the tearing of the paper from occurring. Furthermore, in the present embodiment, the drawer unit 76 is unlocked and can be pulled out only when the paper is jammed in the conveyance path in the drawer unit 76. Thereby, it can suppress that the drawer | drawing-out unit 76 is drawn out without darkness and the components in the drawer | drawing-out unit 76 are damaged.

  Further, in the present embodiment, it is possible to appropriately perform the jam processing work by displaying the operation portion of the paper jam processing by the operation display unit or the LED. Thereby, it can suppress that a user tries to pull out drawer unit 76 in a locked state.

  In the above description, the embodiment in which the present invention is applied to the image forming apparatus in which the front cover 6 is attached to the drawer unit 76 and the drawer unit 76 is pulled out integrally with the front cover 6 has been described. However, the present invention is also applied to an image forming apparatus in which the front cover 6 and the drawer unit 76 shown in FIG. 8 are separate bodies and the drawer unit 76 is pulled out after the front cover 6 is opened. Can do. Further, only the portion of the front cover 6 that covers the drawer unit 76 may be attached to the drawer unit 76 and only that portion may be pulled out integrally with the drawer unit 76. The present invention can also be applied to an image forming apparatus that manually locks and unlocks the drawer unit.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
In an image forming apparatus including a drawer unit 76 configured to be drawable with respect to the apparatus main body and a lock unit that locks the drawer unit 76 to the apparatus main body, the lock unit is a lock mechanism 160 provided in the drawer unit 76. Etc. and main body side lock parts such as lock receiving surfaces 182a and 182b provided on the apparatus main body, and the lock is performed between the unit side lock part and the main body side lock part. The main body side lock portion is provided closer to the drawer unit than the rear side plate of the apparatus main body such as the main body rear side plate 501 disposed on the rear side in the pulling direction of the drawer unit 76.
By providing such a configuration, when the drawer unit is locked, it is possible to prevent the unit side lock portion such as the lock mechanism 160 from protruding from the back side plate such as the main body rear side plate 501 to the back side. Accordingly, there is no restriction on the arrangement of the secondary transfer driving unit 800 provided on the back side of the back side plate. Components provided on the back side of the back side plate such as the secondary transfer driving unit 800 can be provided facing the main body side lock portions such as the lock receiving surfaces 182a and 182b, and the back side of the secondary transfer driving unit 800 and the like can be provided. The freedom degree of arrangement | positioning of the components provided in the back | inner side rather than a side side board can be raised. In addition, the apparatus can be reduced in size.

(Aspect 2)
Further, in (Aspect 1), the lock is performed by the unit side lock portion such as the lock mechanism 160 coming into contact with the main body side lock portion such as the lock receiving member 180 from the back side in the pulling direction.
With this configuration, the drawer unit 76 can be locked to the apparatus main body as described in the embodiment.

(Aspect 3)
Further, in the image forming apparatus of (Aspect 1) or (Aspect 2), when the drawer unit is locked to the apparatus main body, the unit side lock portion such as the lock mechanism 160 does not protrude from the rear side plate such as the main body rear side plate 501. It was configured as follows.
With this configuration, as described in the embodiment, there is no restriction on the arrangement of the secondary transfer driving unit 800 and the like provided on the back side of the back side plate such as the main body rear side plate 501. As a result, components provided on the back side of the back side plate such as the secondary transfer driving unit 800 can be provided facing the main body side lock portions such as the lock receiving surfaces 182a and 182b, and the secondary transfer driving unit 800. The degree of freedom of arrangement of components provided on the back side of the back side plate such as can be increased. In addition, the apparatus can be reduced in size.

(Aspect 4)
Further, in any one of (Aspect 1) to (Aspect 3), at least a part covering the drawer unit of the exterior cover of the apparatus main body such as the front cover 6 disposed on the front side in the drawer direction of the drawer unit 76 is used as the drawer unit. Attached and integrated with the drawer unit so that it can be pulled out.
With this configuration, as described in the embodiment, the drawer unit 76 can be pulled out by pulling out an exterior cover such as the front cover 6. Thereby, the drawer operation of the drawer unit can be simplified.

(Aspect 5)
Further, in any one of (Aspect 1) to (Aspect 4), the main body side lock portion such as the lock receiving member 180 pulls the unit side lock portion such as the lock mechanism 160 into the back side in the pull-out direction of the pull-out unit 76. It has drawing-in means such as surfaces 183a and 183b.
With this configuration, as described in the embodiment, the drawer unit 76 can be attached to the apparatus main body without rattling in the drawer direction.

1: Image forming apparatus 3: Paper feeding section 4: Image reading section 5: Apparatus main body section 6: Front cover 6a: Handle section 11: Image forming apparatus main body 32: Manual feed tray 50: Tandem image forming apparatus 52: Secondary transfer apparatus 53: fixing unit 54: intermediate transfer belt 56: paper transport belt 60: paper discharge path 61: paper discharge tray 70: main transport path 70a: registration roller pair 73: reverse transport path 74: photosensitive drum 75: image forming means 76 : Drawer unit 112: Drawer unit LED
105: Bundled wire 121: Control unit 130: Code guide 150: Drawer unit front plate 151: Drawer unit rear plate 152: Positioning pin 152a: Guide unit 152b: Fitting unit 152c: Seat surface unit 160: Lock mechanism 161: Roller shaft 162 : Rotating roller 163: fitting member 171: set detection filler 172: set detection sensor 180: lock receiving members 181 a and 181 b: notches 182 a and 182 b: lock receiving surfaces 183 a and 183 b: guide surface 184: lock through hole 185 : Secondary transfer through-holes 186a and 186b: Inclined surface 191: Lock detection sensor 192: Lock detection filler 201a: Pre-secondary transfer paper detection sensor 201b: Post-secondary transfer paper detection sensor 201c: Pre-fixing paper detection sensor 201d : Paper detection sensor 207a after fixing: Paper feed Sensor 207b: manual feed sensor 207c: discharge sensor 208a: lower right cover LED
208b: Upper right cover LED
501: Main body rear plate 502: Positioning hole 521: Secondary transfer roller 601: Inner cover portion 602: Outer cover portion 700: Drive portion 701: Drive motor 702: Case 703: Lock shaft 704: Worm gear 704a: Screw gear 704b: Lotus Toothed gear 705: Gear train 706: Driven gear 710: Link mechanism 711: Output link member 712: Connection link member 713: Input link member 800: Secondary transfer drive unit

Japanese Patent No. 4484210

Claims (5)

A drawer unit configured to be drawable from the apparatus main body;
In an image forming apparatus provided with a locking means for locking the drawer unit to the apparatus main body,
The locking means includes a unit side lock portion provided in the drawer unit and a main body side lock portion provided in the apparatus main body, and locking is performed between the unit side lock portion and the main body side lock portion. Is,
An image forming apparatus, wherein the main body side lock portion is provided closer to the drawer unit than a back side plate of the apparatus main body disposed on the back side in the pulling direction of the drawer unit. The image forming apparatus according to claim 1.
2. The image forming apparatus according to claim 1, wherein the unit side lock portion is locked by contacting the main body side lock portion from the back side in the pulling direction. The image forming apparatus according to claim 1 or 2,
An image forming apparatus, wherein the unit-side locking portion is configured not to protrude from the back side plate when the drawer unit is locked to the apparatus main body. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus characterized in that at least a portion of the exterior cover of the apparatus main body arranged on the front side of the drawer unit in the drawer direction is attached to the drawer unit and can be pulled out integrally with the drawer unit. . The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the main body side lock unit includes a pulling unit that pulls the unit side lock unit into a back side in a pulling direction of the pulling unit.

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