JP4399412B2 - Unit drawing mechanism and image recording apparatus - Google Patents

Description

  The present invention relates to a unit drawing mechanism that pulls out a unit from the inside of a main body apparatus, and an image recording apparatus that records an image on a sheet conveyed on a sheet conveyance path.

  An image recording apparatus such as an electrophotographic system transports paper stored in a paper feed tray or the like to an image recording unit to form an image, and then discharges the paper to a paper discharge tray or the like. At that time, the paper is transported on the paper transport path, but a transport jam may occur during the transport. In particular, it tends to occur when passing through the image recording unit. This is because each device such as a transfer device and a fixing device constituting the image recording unit performs a lot of processing such as transfer and fixing of the developer image on the paper, so that the paper is warped and other paper transports. This is because a paper jam is likely to occur compared to a road portion.

  Further, when an image is formed on both sides of a sheet, a conveyance jam is relatively likely to occur in a reversal conveyance path when the image is formed on one side and then the front and back are reversed and conveyed to the image recording unit again. This is because the frequency of the sheet passing through the branch point of the sheet conveyance path where the conveyance jam is likely to occur increases.

  When the conveyance jam occurs, the image recording apparatus interrupts image formation until all the sheets on the sheet conveyance path are removed. When a paper jam occurs in the image recording unit, for example, the image recording unit is pulled out from the inside of the image recording apparatus to the front side, and the paper is removed by opening a side wall or the like so as to expose the paper conveyance path (for example, Patent Documents). 1).

  However, in the configuration of Patent Document 1, even if the image recording unit is pulled out to the front side and the side wall is opened, the amount of exposure of the paper conveyance path in the image recording unit is small, so it is difficult to remove the paper and burden the user. It was over. In particular, recent image recording apparatuses have a complicated structure due to high functionality, and it is difficult to secure a wide working space for removing the paper on the paper transport path.

  In addition, when images are continuously formed, a plurality of sheets stay on the sheet conveyance path. Therefore, when the amount of exposure on the sheet conveyance path is small, the user does not have all sheets on the sheet conveyance path. It was necessary to check whether or not it was removed by opening a plurality of side walls.

  Therefore, the first unit has a first conveyance path that constitutes a part of the sheet conveyance path, and can be inserted into and removed from the front side from the inside of the main body apparatus, and another one different from the first conveyance path in the sheet conveyance path. A second transport path that constitutes a part, and is detachable from the first unit in a direction perpendicular to the insertion / removal direction when the first unit is pulled out in the insertion / removal direction from the inside of the main unit to the front side. A configuration of a unit drawing mechanism including a second unit is proposed.

  With the above configuration, the user uses the space for taking out the paper on which the image has been recorded as the space for drawing the second unit in the direction orthogonal to the insertion / removal direction of the first unit. Therefore, it is not necessary to secure a space only for the purpose, and since the second transport path is separated from the first transport path when the second unit is separated from the first unit, the first transport path and the second transport path are integrated. The amount by which each conveyance path is exposed when the side surfaces and the like of each unit are opened is improved as compared with the above-described configuration.

In this unit drawing mechanism, it is desirable to reduce the number of supporting members that support the first unit so as to be detachable in order to improve workability.
JP-A-9-134050

  However, in the configuration of the unit pull-out mechanism described above, since the change in the center of gravity of the first unit due to the insertion and removal of the second unit is large, if the second unit is repeatedly inserted into and pulled out from the first unit, There is a possibility that the positional accuracy between the main unit and the first unit and the second unit may be lowered due to deformation of the drawer shaft (support member) of one unit. Moreover, it is difficult to reduce the number of support members in order to ensure strength.

  An object of the present invention is to provide a unit drawing mechanism that can maintain the positional accuracy of the main unit, the first unit, and the second unit even with long-term use with a simple configuration.

  In order to solve the above problems, the present invention has the following configuration.

(1) A first unit that is provided in an image recording apparatus that forms an image by an electrophotographic method in an image recording unit on a sheet that is being conveyed through a sheet conveyance path, and that is detachable from the inside of the image recording apparatus to the front side. A first unit that mounts a first sheet conveyance path that passes through the image recording unit together with a fixing device disposed at a downstream end of the first sheet conveyance path;
A second unit that is detachable from the first unit in a direction perpendicular to the insertion / removal direction in a horizontal plane in a state where the first unit is pulled out in the insertion / removal direction from the inside of the image forming apparatus to the front side. A second unit equipped with a second conveyance path that reversely conveys the sheet via a plurality of branch portions that continue downward from the downstream side with respect to the arrangement position of the fixing device in the first sheet conveyance path. When,
Two support members for detachably supporting the first unit in the insertion / removal direction, the two support members being arranged at different positions in the first unit in a direction orthogonal to the insertion / removal direction. A support member,
The arrangement position in the direction orthogonal to the insertion / removal direction is determined by the state in which the first unit into which the second unit is inserted is pulled out from the main body device in the insertion / removal direction, and the second unit is in the insertion / removal The position of the center of gravity of the first unit in a state where all of the plurality of branch portions are pulled out from the first unit to a position where the plurality of branch portions are exposed to the outside along a direction orthogonal to the direction is orthogonal to the insertion / removal direction. characterized in that set in the two support in each of the first unit so as to be between the members about the direction.

In this configuration, after the first unit is pulled out from the main unit, the state changes to a state in which the second unit is inserted into the first unit and a state in which the second unit is pulled out from the first unit. In these two states, the fixing unit is provided in the first unit so that the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members.

  Even if the state of the second unit in the first unit changes, the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members, so a plurality of support members are required in the two states of the first unit. Supporting force hardly changes.

  (2) The plurality of support members are arranged at positions including two diagonal positions in a minimum rectangle including a cross section orthogonal to the insertion / removal direction of the first unit.

  In this configuration, the support members are arranged on at least two positions on the diagonal line in the plane orthogonal to the insertion / removal direction of the first unit, that is, the direction in which the second unit is drawn from the first unit. Compared with the configuration in which the plurality of support members are arranged in the horizontal direction or the vertical direction, the moment acting on the first unit is small in one of the two support members arranged on the diagonal line. Therefore, the first unit is supported more stably.

(3) The fixing device is located on the side where the second unit is pulled out in the first unit,
The plurality of support members are characterized in that the strength of the support member located on the side where the second unit is pulled out in the first unit is stronger than the other support members.

In this configuration, the fixing device is located on the side where the second unit is pulled out from the first unit. Therefore, in the first unit, the center of gravity is located on the side where the second unit is pulled out, but among the plurality of supporting members, the supporting member located on the side where the second unit is pulled out from the first unit has higher strength. Therefore, the deterioration of the support member due to long-term use is reduced.

  (4) The plurality of support members are ball bearing precision slide rails.

  In this configuration, a ball bearing type precision slide rail is used as a support member. In the ball bearing type precision slide rail, the first unit is smoothly inserted and pulled out from the main body by the ball bearing, so that an excessive force is not applied to the support member and the first unit.

(5) An image recording apparatus for performing image formation by an electrophotographic method in an image recording unit on a sheet being conveyed in a sheet conveyance path
A first unit that can be inserted into and removed from the front side from the inside of the image recording apparatus, and a first sheet conveyance path that passes through the image recording unit is disposed at a downstream end of the first sheet conveyance path. A first unit mounted together with the fixing device;
A second unit that is detachable from the first unit in a direction perpendicular to the insertion / removal direction in a horizontal plane in a state where the first unit is pulled out in the insertion / removal direction from the inside of the image forming apparatus to the front side. A second unit equipped with a second conveyance path that reversely conveys the sheet via a plurality of branch portions that continue downward from the downstream side with respect to the arrangement position of the fixing device in the first sheet conveyance path. When,
Two support members for detachably supporting the first unit in the insertion / removal direction, the two support members being arranged at different positions in the first unit in a direction orthogonal to the insertion / removal direction. A support member,
The arrangement position in the direction orthogonal to the insertion / removal direction is determined by the state in which the first unit into which the second unit is inserted is pulled out from the main body device in the insertion / removal direction, and the second unit is in the insertion / removal the center of gravity of the first unit in each of the state where all of the plurality of branch portions along a direction perpendicular to the direction drawn from the first unit to a position to be exposed to the outside, perpendicular to the inserting and removing direction It is characterized in that it is set in the first unit so as to be between the respective arrangement positions of the two support members in the direction .

In this configuration, a first unit and a second unit having a first transport path and a second transport path that are part of the paper transport path are provided. In addition, after the first unit is pulled out from the main body device, the state changes to a state where the second unit is inserted into the first unit and a state where the second unit is pulled out from the first unit. In these two states, the fixing unit is provided in the first unit so that the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members.

  Even if the state of the second unit in the first unit changes, the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members, so a plurality of support members are required in the two states of the first unit. Supporting force hardly changes.

  According to the present invention, the following effects can be obtained.

  (1) By providing a load member that applies a load to the first unit so that the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members, a plurality of supports are provided in the two states of the first unit. The supporting force required by each member hardly changes, can stably support the first unit, and maintain the positional accuracy of the main unit, the first unit and the second unit even after many years of use. can do.

  (2) Even if the number of support members is small, the support members are arranged in at least two places on the diagonal line in the direction perpendicular to the insertion / removal direction of the first unit, that is, the direction in which the second unit is pulled out from the first unit. Compared to the configuration in which the support members are arranged in a straight line, the first unit can be supported more stably, and the positional accuracy of the main unit, the first unit, and the second unit can be maintained even after many years of use. be able to. In particular, when the second unit is pulled out from the first unit, the pulling force is also applied to the first unit, which is effective.

  (3) Among the plurality of support members, the strength of the support member located on the side where the second unit is pulled out from the first unit can be increased, so that deterioration of the support member due to long-term use can be reduced. The positional accuracy between the first unit and the second unit can be maintained.

  (4) By using a ball bearing type precision slide rail as a support member, the first unit can be smoothly inserted and pulled out from the main unit by the ball bearing, so that an excessive force is applied to the support member and the first unit. Therefore, it is possible to reduce the deterioration of the support member due to long-term use, and to maintain the positional accuracy of the main body device, the first unit, and the second unit.

  (5) By providing a load member that applies a load to the first unit so that the position of the center of gravity of the first unit is between the arrangement positions of the plurality of support members, a plurality of supports are provided in the two states of the first unit. The supporting force required by each member hardly changes, and the first unit can be stably supported. As a result, the positional accuracy between the main body device and the first unit and the second unit can be maintained even after many years of use, so that the positional accuracy of the paper transport path can be maintained.

  (6) By using the fixing device as the load member, it is not necessary to use a new load member, and an increase in cost can be prevented.

  Hereinafter, an image recording apparatus to which a unit drawing mechanism according to the best embodiment of the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a schematic front sectional view showing the configuration of an image recording apparatus according to an embodiment of the present invention. The image recording apparatus 100 according to the present invention includes an image reading unit 200, an image forming unit 300, and a paper feeding unit 400.

  The image reading unit 200 includes an automatic document feeder (ADF) 201, a first document table 202, a second document table 203, a first mirror base 24, a second mirror base 205, a lens 206, and a solid-state image sensor ( A CCD (Charge Coupled Device) 207 is provided.

  The ADF 201 conveys documents one by one from the document tray 211 to the discharge tray 212 via the second document table 203. The ADF 201 is rotatable about the back side so that the top surface of the first document table 202 can be opened and closed. By rotating the ADF 201 so that the front side moves upward, the upper surface of the first document table 202 is exposed, so that the document can be placed on the first document table 202 by manual operation.

  Both the first platen 202 and the second platen 203 are made of hard glass plates.

  The first mirror base 204 and the second mirror base 205 are movable in the horizontal direction below the first document table 202 and the second document table 203. The moving speed of the second mirror base 205 is ½ of the moving speed of the first mirror base 204. The first mirror base 204 is equipped with a light source and a first mirror. The second mirror base 205 is equipped with a second mirror and a third mirror.

  When reading an image of a document conveyed by the ADF 201, the first mirror base 204 is stopped below the second document table 203. The light from the light source is emitted toward the image surface of the document passing over the second document table 203, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  When reading an image of a document placed on the first document table 202, the first mirror base 204 and the second mirror base 205 move horizontally below the first document table 202. The light from the light source is emitted toward the image surface of the document placed on the first document table 202, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  Regardless of whether or not the ADF 201 is used, the reflected light on the image surface of the document is incident on the CCD 207 via the lens 206 by the second mirror and the third mirror with a constant optical path length.

  The CCD 207 outputs an electrical signal corresponding to the amount of reflected light on the image surface of the document. This electrical signal is input to the image forming unit 300 as image data.

  The image forming unit 300 includes a photosensitive drum 31, a charger 32, an exposure device 33, a developing device 34, a transfer belt 35, a cleaner 36, and a fixing device 37 that constitute the image recording unit 30.

  The photosensitive drum 31 has a photosensitive layer formed on the surface thereof, and rotates in the direction of the arrow. The charger 32 uniformly charges the surface of the photosensitive drum 31 to a predetermined potential. The charger 32 may use either a non-contact method using a charger or a contact method using a roller or a brush.

  The exposure device 33 irradiates the surface of the photosensitive drum 31 with light based on the image data. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31 by the photoconductive action in the photosensitive layer. The exposure device 33 scans the laser beam modulated based on the image data in the axial direction of the photosensitive drum 31 via a polygon mirror. Alternatively, an exposure apparatus in which light emitting elements such as EL and LEDs are arranged in an array can be used.

  The developing device 34 supplies toner to the surface of the photosensitive drum 31 and visualizes the electrostatic latent image into a toner image.

The transfer belt 35 is looped between a plurality of rollers below the photosensitive drum 31, and has a resistance value of about 1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm. Inside the loop-shaped movement path of the transfer belt 35, there is provided a transfer roller 35A that presses against the photosensitive drum 31 with the transfer belt interposed therebetween. A predetermined transfer voltage is applied to the transfer roller 35 </ b> A, and a toner image carried by the photosensitive drum 31 is transferred onto a sheet passing between the transfer belt 35 and the photosensitive drum 31.

  The cleaner 36 removes residual toner from the surface of the photosensitive drum 31 after the transfer of the toner image to the paper.

  The fixing device 37 includes a heating roller 37A and a pressure roller 37B. The heating roller 37A is heated by an internal heater to a temperature at which the toner can be melted. The pressure roller 37B is in pressure contact with the heating roller 37A with a predetermined pressure. The fixing device 37 firmly fixes the toner image to the paper by heating and pressurizing the paper passing between the heating roller 37A and the pressure roller 37B. The paper that has passed through the fixing device 37 is discharged to a paper discharge tray 38 (corresponding to a paper discharge portion of the present invention) mounted on one side surface of the image recording apparatus 100.

  In the paper feeding unit 400, a plurality of sheets of the same size are stored in each of the paper feeding cassettes 401, 402, 403, and 404 including the paper feeding cassettes 401, 402, 403, and 404 and the manual feed tray 405. . On the manual feed tray 405, paper of a size or quality that is not frequently used is placed.

  The paper feed unit 400 feeds paper one by one from one of the paper feed cassettes 401, 402, 403, 404 or the manual feed tray 405. A sheet fed from the sheet feeding unit 400 is conveyed to the image recording unit 30 via a sheet conveyance path 10 described later.

  FIG. 2 is a diagram illustrating a configuration of the sheet conveyance path 10 in the image recording apparatus 100. Inside the image forming unit 300, a paper transport path 10 is configured. The paper transport path 10 includes a first transport path 11, a second transport path 12, a third transport path 13, a fourth transport path 14, and a fifth transport path 15.

  The first transport path 11 reaches the paper discharge tray 38 via the first unit 21, the image recording unit 30, the first branch unit 24, and the second unit 22 in this order from the paper feed unit 400. In the first conveyance path 11, conveyance rollers 61, 62, and 63, a registration roller 51, and a paper discharge roller 52 are arranged. The conveyance rollers 61, 62, 63, the registration roller 51, and the paper discharge roller 52 are supplied with rotation from a first motor (not shown).

  The portion of the first conveyance path 11 that passes through the image recording unit 30 stably transfers the toner image from the photosensitive drum 31 to the surface of the paper, and stabilizes the paper on which the toner image before fixing is electrostatically adsorbed. Thus, the transfer belt 35 is disposed for conveyance and is substantially horizontal.

  The second transport path 12 passes the second branch section 25 and the third branch section 26 below the first branch section 24 disposed between the image recording section 30 and the paper discharge tray 38 in the first transport path 11. It goes to 12A of 1st switchback parts in order. The first switchback unit 12A is substantially parallel to a range passing through the image recording unit 30 in the first conveyance path 11, and conveys the paper in the reciprocating direction. Reversing rollers 53 and 58 are disposed in the second transport path 12. Rotation is selectively supplied to the reverse rollers 53 and 58 from a second motor (not shown) via a first clutch (not shown) in the forward direction or the reverse direction.

  The third conveyance path 13 passes from the third branching section 26 via the third merging section 23 to the first merging section 21 disposed between the paper feeding unit 400 and the image recording section 30 in the first conveyance path 11. It reaches. Conveying rollers 54, 55, 56, and 57 are disposed in the third conveying path 13. Rotation is selectively supplied to the transport rollers 54, 55, 56, 57 from a third motor (not shown) via a second clutch (not shown) in the forward direction or the reverse direction.

  The fourth conveyance path 14 connects the second branch portion 25 and the third junction portion 23. The fifth conveyance path 15 connects between the second branch portion 25 and the second junction portion 22.

  The first switchback portion 12A of the second transport path 12 is disposed up and down so as to be substantially parallel to the range passing through the image recording section 30 disposed in the substantially horizontal direction in the first transport path 11. A third conveyance path 13 is disposed between the range passing through the image recording unit 30 in the first conveyance path 11 and the first switchback portion 12A of the second conveyance path 12.

  FIG. 3 is a diagram illustrating the configuration of the first branching section 24, the second branching section 25, and the third branching section 26 in the paper conveyance path 10 of the image recording apparatus 100. A branch claw 41 is disposed in the first branch portion 24. The branching claw 41 swings between a position indicated by a solid line in FIG. 3 and a position indicated by a two-dot chain line in FIG. 3 by the operation of a first solenoid (not shown). Switch to either the path 11 or the second transport path 12.

  A branch claw 42 and a branch claw 43 are arranged in the second branch portion 25. The branching claw 42 is in a position indicated by a solid line in FIG. 3 in a state where no external force is applied, and guides the sheet conveyed upward from the second conveying path 12 or the fourth conveying path 14 to the fifth conveying path 15. The sheet conveyed upward from the second conveyance path 12 or the third conveyance path 13 is restricted from entering the second conveyance path 12 by the branching claw 42.

  The branching claw 43 swings between a position indicated by a solid line and a position indicated by a two-dot chain line in FIG. 3 by the operation of a second solenoid (not shown). Either the conveyance path 15 or the second conveyance path 12 and the fifth conveyance path 15 is opened.

  Note that the branching claw 42 swings to a position indicated by a broken line in FIG. 3 by contact with the sheet conveyed downward from the first branching section 24 in the second conveyance path 12.

  A branch claw 44 is disposed in the third branch portion 26. The sheet whose front and rear ends are reversed in the switchback transport path 12A is not discharged from the second transport path 12 to the paper discharge tray 38 via the fifth transport path 15. For this reason, the conveyance roller 58 rotates only in one direction, and the branch claw 44 is urged to a position indicated by a solid line in FIG. 3 by an elastic member. This elastic member has such an elasticity that the branching claw 44 easily swings to the position indicated by the broken line in FIG. 3 by the sheet from the first conveying path 11 through the second conveying path 12 to the switchback conveying path 12A. A force is applied to the branch claw 44. Thereby, the branching claw 44 selectively opens the second conveyance path 12 between the second conveyance path 12 and the third conveyance path in the third branch portion 26.

  The image recording apparatus 100 according to the present embodiment is configured to perform normal sheet conveyance for discharging from the sheet discharge tray 38 after the image is recorded on one side after being conveyed through the first conveyance path 11 and the sheet recording surface is not visible. It is possible to perform face-down conveyance that enables the image forming surface to face the discharge tray 38 and reverse conveyance that enables image recording on both sides.

  In face-down conveyance, the paper recorded by the image recording unit 30 is transferred from the first branch unit 24 to the second conveyance path 12, the switchback unit 12A, the second conveyance path 12, the second branch unit 25, the fifth conveyance path 15, The paper is conveyed in the order of the second junction 22 and discharged from the paper discharge tray 38. In face-down conveyance, the sheet recorded by the image recording unit 30 is transferred from the first branch claw 24 to the second conveyance path 12, the second branch section 25, the fourth conveyance path 14, the third conveyance path 13, and the fourth conveyance. It can also be performed by transporting the path 14, the second branching section 25, the fifth transport path 15, and the second joining section 22 in this order.

  In the reverse conveyance, the sheet recorded by the image recording unit 30 is fed from the first branching unit 24 to the second conveying path 12, the first switchback unit 12A, the second conveying path 12, the third branching unit 26, and the first joining unit 21. Then, the sheet is conveyed in the order of the first conveyance path 11, and after the image is recorded on the surface not recorded in the image recording unit 30, the sheet is discharged from the discharge tray 38.

  In addition, the 2nd conveyance path 12 and the conveyance path from the 3rd conveyance path 13 to the 1st junction part 21 through the 2nd conveyance path 12 at the time of the above-mentioned reversal conveyance operation become the reversal conveyance path of the present invention. Corresponds to the transport path.

  FIG. 4 is an external view when the first unit 1 and the second unit 2 are pulled out from the inside of the image recording apparatus 100 to the front side. The image recording apparatus 100 includes a first unit 1 and a second unit 2. In the first unit 1, a transfer belt 35, a transfer roller 35A, and a fixing device 37 are arranged, and the slide rails 3A and 3B are arranged in an arrow Y direction that is an insertion / removal direction from the inside of the image recording apparatus 100 toward the front side (outside). It is supported so that it can be pulled out (inserted / removed).

  As shown in FIG. 6, the first unit 1 includes a portion of the first transport path 11 that passes through the image recording unit 30 and a part of the third transport path 13. When the first unit 1 is pulled out from the inside of the image recording apparatus 100 to the front side, a portion passing through the image recording unit 30 in the first conveyance path 11 is exposed as shown in FIG. As a result, the paper staying in the first conveyance path 11 in the image recording unit 30 can be easily removed simply by pulling out the first unit when a conveyance jam occurs. In addition, it is possible to easily confirm the presence or absence of the paper staying on the first transport path 11.

  The slide rails 3A and 3B are arranged on a diagonal line in a plane (arrow Z direction) orthogonal to the arrow Y direction. Ball slide precision slide rails are used as the slide rails 3A and 3B. In the ball bearing type precision slide rail, since the first unit 1 is smoothly inserted and pulled out from the main body device by the ball bearing, excessive force is not applied to the slide rails 3A and 3B and the first unit 10.

  As shown in FIG. 6, the second unit 2 includes a part of the first transport path 11, a second transport path 12, a part of the third transport path 13, a fourth transport path 14, and a fifth transport path 15. In the state shown in FIG. 4 in which the first unit 1 is pulled out from the inside of the image recording apparatus 100, the slide unit 4A, 4B can be pulled out in the arrow Z direction, which is a direction orthogonal to the arrow Y direction, as shown in FIG. It is supported (insertable / removable). Ball slide precision slide rails are also used for the slide rails 4A and 4B.

  Further, as shown in FIG. 7, the second unit 2 is rotated from the position indicated by the solid line from the position indicated by the solid line to the position indicated by the dotted line while being pulled out (detached) from the first unit 1. A part of the second transport path 12 and a part of the third transport path 13 can be exposed by rotation.

  In particular, the opening of the opening / closing plate 6 causes the first branch of the paper transport path 10 that is relatively easy to cause a paper transport failure (transport jam) arranged side by side along a part of the second transport path 12. All of the section 24, the second branching section 25, and the third branching section 26 are exposed to the outside, and it is possible to simplify the operation of removing the accumulated paper.

  FIG. 8 is a front view showing the position of the center of gravity of the first unit 1. FIG. 8A shows a state where the first unit 1 is pulled out from the main unit, and FIG. 8B shows a state where the second unit 2 is pulled out from the first unit 1. As shown in FIG. 8A, when the second unit 2 is inserted into the first unit 1, the position of the center of gravity of the first unit 1 in the arrow Z direction is slightly closer to the center than the arrangement position of the fixing device 37. There is G.

  On the other hand, as shown in FIG. 8B, when the second unit 2 is pulled out from the first unit 1, it is located between the arrangement positions of the fixing device 37 and the slide rail 3A. In this state, the center of gravity position G is not located on the left side of FIG. 8 with respect to the arrangement position of the slide rail 3A because the first unit 1 is relatively heavy among the devices arranged on the paper conveyance path 10 and the like. This is because the fixing unit 37 and the like are provided, so that the second unit 2 constituting a part of the sheet transport path 10 is lighter than the first unit excluding the second unit 2.

  Therefore, in the two states described above, the center of gravity G of the first unit 1 is between the arrangement positions of the slide rails 3A and 3B in the arrow Z direction. For this reason, the supporting force required by the slide rails 3A and 3B hardly changes compared to the case where the center of gravity position G of the first unit deviates from the position between the slide rails 3A and 3B due to a change in state. Thereby, the 1st unit 1 can be supported stably and the positional accuracy of a main body apparatus, the 1st unit 1, and the 2nd unit 2 can be maintained even if it uses for many years.

  Note that the center-of-gravity position G is at the same position in the state in which the first unit 1 is inserted into the main apparatus and the state in which the first unit 1 is pulled out. Further, the position of the center of gravity of the first unit 1 in the arrow Y direction does not change even if the second unit 2 is inserted from the first unit 1 or pulled out.

  In the present embodiment, since the slide rails 3A and 3B are arranged on the diagonal line in the smallest rectangle including the cross section orthogonal to the arrow Y direction, the plurality of slide rails are arranged in the horizontal direction or the vertical direction. In comparison, the moment acting on the first unit 1 is small in one of the two slide rails 3A and 3B arranged on the diagonal line. Therefore, the first unit 1 can be supported more stably.

  Thereby, if it is the structure which has arrange | positioned the supporting member in two places on a diagonal line, the positional accuracy with a main body apparatus, the 1st unit 1, and the 2nd unit 2 can be maintained even if it uses for many years. In particular, when the second unit 2 is pulled out from the first unit 1, the pulling force is also applied to the first unit 1, which is effective. In the present embodiment, the two slide rails 3A and 3B are provided at two locations on the diagonal line, but it is sufficient that support members are disposed at least at two locations, and the four slide rails 3A and 3B may be provided. .

  In the present embodiment, the slide rail 3A has higher strength than the slide rail 3B. The fixing device 37 as a load member is located on the side where the second unit 2 is pulled out from the first unit 1. Therefore, in the first unit 1, the center of gravity is located on the side where the second unit 2 is pulled out from the center, but the second unit 2 is located on the side where the second unit 2 is pulled out from the first unit 1 in the slide rails 3A and 3B. Since the slide rail 3A has higher strength, deterioration of the slide rails 3A and 3B due to long-term use can be reduced.

  In the present embodiment, the fixing device 37 is used as a load member. Since the fixing device 37 is configured on the paper conveyance path 10 and is heavier than an apparatus or the like located on the paper conveyance path 10, it is not necessary to provide a new load member, thereby preventing an increase in cost. it can.

1 is a schematic front sectional view showing a configuration of an image recording apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a sheet conveyance path in an image recording apparatus. It is a figure which shows the structure of the 1st branch part in the paper conveyance path of an image recording device, a 2nd branch part, and a 3rd branch part. FIG. 3 is an external view when the first unit and the second unit are pulled out from the inside of the image recording apparatus to the front side. It is an external view when the 2nd unit is pulled out from the 1st unit. It is an enlarged view which shows a part of structure of an image recording device. It is sectional drawing which shows the structure of a 2nd unit. It is the front view which showed the gravity center position of the 1st unit.

Explanation of symbols

1-first unit 2-second unit 3A, 3B-slide rail 10-paper transport path 11-first transport path 12-second transport path 13-third transport path 37-fixing device 100-image recording apparatus

Claims (5)

A first unit that is provided in an image recording apparatus that forms an image by an electrophotographic method in an image recording unit on a sheet that is being conveyed in a sheet conveyance path, and is detachable from the inside of the image recording apparatus to the front side; A first unit that mounts a first paper transport path that passes through the image recording unit together with a fixing device disposed at a downstream end of the first paper transport path;
A second unit that is detachable from the first unit in a direction perpendicular to the insertion / removal direction in a horizontal plane in a state where the first unit is pulled out in the insertion / removal direction from the inside of the image forming apparatus to the front side. A second unit equipped with a second conveyance path that reversely conveys the sheet via a plurality of branch portions that continue downward from the downstream side with respect to the arrangement position of the fixing device in the first sheet conveyance path. When,
Two support members for detachably supporting the first unit in the insertion / removal direction, the two support members being arranged at different positions in the first unit in a direction orthogonal to the insertion / removal direction. A support member,
The arrangement position in the direction orthogonal to the insertion / removal direction is determined by the state in which the first unit into which the second unit is inserted is pulled out from the main body device in the insertion / removal direction, and the second unit is in the insertion / removal The position of the center of gravity of the first unit in a state where all of the plurality of branch portions are pulled out from the first unit to a position where the plurality of branch portions are exposed to the outside along a direction orthogonal to the direction is orthogonal to the insertion / removal direction. units out mechanism, characterized in that set in the first unit so as to be between each of the two support members about the direction.   The plurality of support members are arranged at positions including two locations on a diagonal line in a minimum rectangle including a cross section perpendicular to the insertion / removal direction of the first unit. Unit drawer mechanism. The fixing device is located on a side where the second unit is pulled out in the first unit;
2. The unit drawer according to claim 1, wherein the plurality of support members have a strength of a support member positioned on a side where the second unit is pulled out in the first unit as compared with other support members. mechanism.   The unit drawing mechanism according to claim 1, wherein the plurality of support members are ball bearing precision slide rails. An image recording apparatus that forms an image by an electrophotographic method in an image recording unit on a sheet being conveyed in a sheet conveyance path,
A first unit that can be inserted into and removed from the front side from the inside of the image recording apparatus, and a first sheet conveyance path that passes through the image recording unit is disposed at a downstream end of the first sheet conveyance path. A first unit mounted together with the fixing device;
A second unit that is detachable from the first unit in a direction perpendicular to the insertion / removal direction in a horizontal plane in a state where the first unit is pulled out in the insertion / removal direction from the inside of the image forming apparatus to the front side. A second unit equipped with a second conveyance path that reversely conveys the sheet via a plurality of branch portions that continue downward from the downstream side with respect to the arrangement position of the fixing device in the first sheet conveyance path. When,
Two support members for detachably supporting the first unit in the insertion / removal direction, the two support members being arranged at different positions in the first unit in a direction orthogonal to the insertion / removal direction. A support member,
The arrangement position in a direction orthogonal to the insertion / removal direction is determined by referring to a state in which the first unit in which the second unit is inserted is pulled out from the main body device in the insertion / removal direction, and the second unit is in the insertion / removal direction. The position of the center of gravity of the first unit in a state where all of the plurality of branch portions are pulled out from the first unit to a position where the plurality of branch portions are exposed to the outside along a direction orthogonal to the direction is orthogonal to the insertion / removal direction. The image recording apparatus according to claim 1, wherein the image recording apparatus is set in the first unit so as to be between the respective arrangement positions of the two support members in the direction .

Images