JP6540987B2 - Image forming apparatus and fixing device - Google Patents

Description

  The present invention relates to an image forming apparatus and a fixing device.

  In a fixing device in which a recording material is sandwiched between a pair of fixing members opposed to each other and heat and pressure are applied to fix a toner image on the recording material, according to Patent Document 1, the fixing member is A pressing lever rotatable in a direction to press one of the fixing members toward the other fixing member, and the pressing lever rotates a pressing position at which the one fixing member presses the other fixing member; One fixing member can be switched to a pressure release position where it is separated from the other fixing member, and an end portion in the vicinity of the rotation shaft moves in the axial direction of the rotation shaft between displacement of the pressure position and the pressure release position. A fixing device is described which is regulated by first regulating means provided in the vicinity of the end portion.

  Patent Document 2 describes a fixing device that is detachable from an image forming apparatus main body, and has a positioning member that engages with a guide portion provided in the apparatus main body, wherein the positioning member is a sheet in the fixing device. A fixing device is described, which is characterized by being positioned and adjusted with respect to a rotating body having a conveying function.

In Patent Document 3, a guide groove or a long hole is provided on one side between a main body structure constituting a framework of an image forming apparatus main body and a first side plate of the main body structure, and the other side is a guide groove or a long side. In the width direction of the hole, there is formed a guide protrusion which engages with it without any space, and the guide protrusion and the guide groove or the long hole are engaged, and the length direction of the guide groove or the long hole in the first side plate A unit holding member attached to be freely adjustable in movement, and an attaching / detaching unit positioned and held by the unit holding member and supported between the first side plate and the second side plate of the main body structure opposed thereto.
The unit holding member includes a movement adjusting member for moving and adjusting the unit holding member in the longitudinal direction of the guide groove with respect to the main body structure, and the engaging position at which the movement adjusting member engages with the unit holding member An image forming apparatus is described, wherein the image forming apparatus is provided on a vertical line passing through the center of gravity of the mounting / demounting unit.

  In Patent Document 4, a heating rotator that heats a developer image formed on a recording medium, a pressing rotator that presses the recording medium with the heating rotator, and an axial direction of the pressing rotator. A pair of support plates rotatably supporting one end of the pressing rotating body and the heating rotating body with the thickness direction, and the support plate attached to the support plate from both sides in the thickness direction Mounting portion, and an operating portion on which an external force acts, and when an external force in a direction determined on the operating portion acts, the supporting plate is moved away from the other of the pressure rotating body and the heating rotating body A fixing member having a releasing member for moving one of the pressure rotating body and the heating rotating body to the other side by moving the pressure rotating body to the other of the pressure rotating body and the heating rotating body. .

JP, 2009-69701, A JP, 2011-53719, A JP, 2009-258457, A JP, 2013-61535, A

  An object of the present invention is to provide an image forming apparatus and a fixing device capable of improving the accuracy of alignment between the first rotating body and the second rotating body.

The present invention according to claim 1 is
An image forming unit that forms an image on a recording medium;
A first rotating body contacting a recording medium on which an image is formed by the image forming unit;
A plate-like member having a flat portion and a side portion, the first support member rotatably supporting the first rotating body;
A second rotating body contacting the first rotating body;
A second support member rotatably supporting the second rotary body, the second support member pivotally supported with respect to the first support member;
Have
The first support member is
A first fixed portion fixed to the image forming apparatus main body;
A second fixed portion fixed to the image forming apparatus main body;
A rotating body support unit for supporting the first rotating body;
A connecting portion pivotally connecting the second support member to the first support member;
With the side portion,
At least a part of each of the first fixed part, the second fixed part, the rotating body support part, and the connection part is located on the side part which is not bent from the flat part,
The portion of the image forming apparatus main body to which at least the first fixed portion is fixed is made of metal.
The first support member is an image forming apparatus fixed to the image forming apparatus main body via a nonconductive member .

The present invention according to claim 2 is
A first rotating body contacting a recording medium on which an image is formed by the image forming unit;
A plate-like member having a flat portion and a side portion, the first support member rotatably supporting the first rotating body;
A second rotating body contacting the first rotating body;
A second support member rotatably supporting the second rotary body, the second support member pivotally supported with respect to the first support member;
Have
The first support member is
A first fixed portion fixed to the image forming apparatus main body;
A second fixed portion fixed to the image forming apparatus main body;
A rotating body support unit for supporting the first rotating body;
A connecting portion pivotally connecting the second support member to the first support member;
With the side portion,
At least a part of each of the first fixed part, the second fixed part, the rotating body support part, and the connection part is located on the side part which is not bent from the flat part,
The portion of the image forming apparatus main body to which at least the first fixed portion is fixed is made of metal.
The first support member is a fixing device fixed to the image forming apparatus main body via a non-conductive member.

According to the first aspect of the present invention, it is possible to improve the accuracy of alignment between the first rotating body and the second rotating body, to electrically insulate the fixing device, and to be nonconductive. It is possible to suppress image quality defects that may occur when the first support member is solidified on the image forming apparatus main body without the intervention of the member.

According to the second aspect of the present invention, it is possible to improve the accuracy of alignment between the first rotating body and the second rotating body, to electrically insulate the fixing device, and to be nonconductive. It is possible to suppress image quality defects that may occur when the first support member is solidified on the image forming apparatus main body without the intervention of the member.

FIG. 1 is a schematic view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a plan view showing a fixing device of the image forming apparatus shown in FIG. FIG. 3 is a cross-sectional view showing a fixing device shown in FIG. 2 and a cross section taken along line A-A shown in FIG. 2. FIG. 3 is a perspective view showing a state in which a pair of first support members included in the fixing device shown in FIG. 2 is fixed to an image forming apparatus main body. FIG. 7 is a perspective view showing a connecting portion that connects one of a pair of first support members included in the fixing device shown in FIG. 2 and the other of the pair of first support members. FIG. 5 is a view showing a state in which the first support member of the fixing device shown in FIG. 2 is fixed to the image forming apparatus main body, and showing a cross section on a virtual plane P shown in FIG. FIG. 5 schematically shows a state in which the first support member of the fixing device shown in FIG. 2 is fixed to the image forming apparatus main body, and schematically shows the first support member in the direction of arrow C shown in FIG. is there. FIG. 8 schematically shows a state in which the first support member of the fixing device shown in the comparative example is fixed to the image forming apparatus main body.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an image forming apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, the image forming apparatus 10 has an image forming apparatus main body 20, and the image forming apparatus main body 20 is formed with a discharge port 22 for discharging a sheet used as a recording medium. There is. In addition, the upper surface of the image forming apparatus main body 20 is used as a discharge unit 24 to which the recording medium on which the developer image is fixed is discharged.

  Further, the image forming apparatus main body 20 has a tie plate 30 used as a fixed portion to which a fixing device 200 described later is assembled and the fixing device 200 is fixed. The tie plate 30 is a side plate (not shown) located on the front side (the front side of the sheet in FIG. 1) of the image forming apparatus main body 20 and the rear side (the back side of the sheet of FIG. It is fixed with respect to the side plate (not shown) located in. Further, the tie plate 30 is made of metal.

  Further, in the image forming apparatus main body 20, an image forming unit 100 for forming an image (developer image) on a sheet is disposed. The image forming unit 100 includes a photosensitive drum 102 used as an image holder for holding an image, a charging device 104 for uniformly charging the surface of the photosensitive drum 102, and a photosensitive member uniformly charged by the charging device 104. The latent image forming device 106 for forming an electrostatic latent image on the surface of the body, the developing device 110 for developing the latent image formed by the latent image forming device 106 using a developer, and the latent image is developed by the developing device 110 The transfer device 122 for transferring the developer image formed on the surface of the photosensitive drum 102 onto a sheet of paper, and the developer image being transferred onto the sheet by the transfer device 122, remains on the surface of the photosensitive drum 102 And a cleaning device 124 for cleaning the developer and the like.

  Further, in the image forming apparatus main body 20, a fixing device 200 for fixing a developer image formed on a sheet by the image forming unit 100 on the sheet is disposed. The fixing device 200 is assembled to the tie plate 30 as described above, and is fixed to the tie plate 30. Details of the fixing device 200 will be described later.

  Further, in the image forming apparatus main body 20, a sheet feeding device 610 for feeding sheets to the image forming unit 100 and a sheet feeding device 620 are disposed. The sheet feeding device 610 has a sheet storage portion 612 for storing sheets in a stacked state, and a delivery device 614 for delivering the sheets stored in the sheet storage portion 612 to a conveyance path 500 described later. Further, the sheet feeding device 620 has a sheet storage portion 622 for storing sheets in a stacked state, and a delivery device 624 for delivering the sheets stored in the sheet storage portion 622 to a conveyance path 500 described later.

  Further, a conveyance path 500 for conveying a sheet is formed in the image forming apparatus main body 20, and the upstream side in the conveyance direction of the sheet by the conveyance path 500 is sequentially supplied from the side along the conveyance path 500. A paper device 620, the above-described sheet feeding device 610, a resist roll 510, the above-described transfer device 122 and the above-described photosensitive drum 102, the above-described fixing device 200, and the discharge roll 520 are disposed.

  The resist roll 510 temporarily stops the movement of the leading end of the sheet supplied from any of the sheet feeding device 610 and the sheet feeding device 620, and matches the timing when the toner image is formed on the surface of the photosensitive drum 102. As a result, the movement of the leading end of the sheet to the transfer portion formed by the photosensitive drum 102 and the transfer device 122 is resumed.

  The transfer device 122 electrostatically transfers the toner image formed on the surface of the photosensitive drum 102 to a sheet, to which a transfer bias is applied.

  The discharge roller 520 discharges the sheet on which the toner image is fixed by the fixing device 200 toward the discharge unit 24 while passing the discharge port 22.

  A fixing device 200 is shown in FIGS. 2 and 3. As shown in FIGS. 2 and 3, the fixing device 200 includes a fixing roll 210 used as a first rotation for contacting a sheet on which an image is formed by the image forming unit 100, and a fixing roll 210. The fixing side plate 220R and the fixing side plate 220F, which are used as a pair of first support members that support the roller so as to rotate, and the fixing belt 250 that is used as a second rotating body that contacts the fixing roll 210 And a rocking side plate 240R and a rocking side plate 240F capable of supporting and rocking the fixing belt 250 so that the fixing belt 250 can be rotated.

  Fixing roll 210 is supported such that the rear end side can be rotated relative to fixed side plate 220R via bearing 212R, and the front end side can be rotated relative to fixed side plate 220F via bearing 212F. It is supported to be able to do it. Further, a driving source 214 such as a motor is connected to the fixing roll 210, and the fixing roll 210 rotates in the direction of an arrow a shown in FIG. 4 in response to the drive transmission from the driving source 214. . Further, the fixing roll 210 has a cylindrical shape, and for example, two heat sources 216, which can use, for example, a halogen lamp, are disposed in the hollow portion of the fixing roll 210, for example.

  When the fixing roll 210 is supported by the fixed side plate 220R and the fixed side plate 220F, an auxiliary side plate (not shown) for pressing the rear end portion side of the fixing roll 210 from above is attached to the fixed side plate 220R. An auxiliary side plate (not shown) may be attached to the fixed side plate 220F for pressing the upper side from above.

  The fixing belt 250 is in contact with the fixing roll 210 and forms a nipping area N in which the sheet is nipped with the fixing roll 210. Further, the fixing belt 250 is a flexible, endless, strip-like member, and is supported so as to be rotatable by a belt support 252 disposed inside the fixing belt 250. . Further, the fixing belt 250 rotates in the direction of arrow b shown in FIG. 3 following the rotation of the fixing roll 210 in the direction of arrow a.

  The fixed side plate 220R is made of metal, for example, and is fixed to the tie plate 30 via the nonconductive member 222R and the nonconductive member 224R (see also FIG. 4). The fixed side plate 220F is made of, for example, a metal, like the fixed side plate 220F, and is fixed to the tie plate 30 via the nonconductive member 222F and the nonconductive member 224F (see FIG. 4).

  The fixed side plate 220R and the fixed side plate 220F are, for example, a flat portion 220a which is a substantially horizontal surface, and a side portion 220b which is a surface which is substantially perpendicular to the flat portion 220a and which is a substantially vertical surface. Have. Here, in the stationary side plate 220R, the side surface portion 220b is not only substantially perpendicular to the surface forming the edge in the thickness direction of the stationary side plate 220R, but also the outer peripheral portion of the through hole into which the shaft member 242R described later is inserted. It is also almost perpendicular to the part that forms. Further, in the stationary side plate 220F, the side surface portion 220b is not only substantially perpendicular to the surface forming the edge in the thickness direction of the stationary side plate 220F, but also the outer peripheral portion of the through hole into which the shaft member 242F described later is inserted. The portion to be formed is also substantially perpendicular.

  The swing side plate 240R can be rotated relative to the fixed side plate 220R using the shaft member 242R, and can be swinged relative to the fixed side plate 220R, as shown by arrow c in FIG. It is possible to rotate around the shaft member 242R in the direction of the arrow d shown in FIG. Further, the swing side plate 240F can be rotated relative to the fixed side plate 220F using the shaft member 242F, and is mounted so as to be able to swing relative to the fixed side plate 220F. It can be rotated about the shaft member 242F in the c direction and the arrow d direction shown in FIG.

  The swing side plate 240R and the swing side plate 240F are, for example, a flat portion 240a which is a substantially horizontal surface, and a side portion 240b which is a surface which is substantially perpendicular to the flat portion 240a and which is a substantially vertical surface. Each has it. Here, in the swing side plate 240R, the side surface portion 240b is not only substantially perpendicular to the plane forming the edge in the thickness direction of the swing side plate 240R, but also the outer peripheral portion of the through hole into which the shaft member 242R is inserted. It is also almost perpendicular to the part that forms. Further, in the swing side plate 240F, the side surface portion 240b is not only substantially perpendicular to the plane forming the edge in the thickness direction of the swing side plate 240F, but also the outer peripheral portion of the through hole into which the shaft member 242F is inserted. The portion to be formed is also substantially perpendicular.

  The belt support portion 252 has its rear end fixed to the swing side plate 240R and its front end fixed to the swing side plate 240F. Therefore, the belt support portion 252, the swing side plate 240R, the swing side plate 240F, and the fixing belt 250 integrally swing with respect to the fixed side plate 220R and the fixed side plate 220F.

  The fixing device 200 further includes a pressing mechanism 260 that presses the fixing roll 210 and the fixing belt 250 to each other, and the pressing mechanism 260 includes a biasing member 262R. The biasing member 262R has one end connected to the swing side plate 240R and the other end connected to the fixed side plate 220R, and biases the swing side plate 240R to rotate in the direction of arrow d shown in FIG. The pressing mechanism 260 has a biasing member 262F (not shown) similar to the biasing member 262R. The biasing member 262F has one end connected to the swing side plate 240F and the other end connected to the fixed side plate 220F, and biases the swing side plate 240F to rotate in the direction of arrow d shown in FIG. As the biasing member 262R and the biasing member 262F, for example, an elastic body such as a coil spring can be used.

  The biasing member 262R biases the swinging side plate 240R to rotate in the direction of arrow d, and the biasing member 262F biases the swinging side plate 240F to rotate in the direction of arrow d. The rocking side plate 240F, the belt support portion 252, and the fixing belt 250 are integrally urged in the direction of the arrow d, whereby the fixing belt 250 and the fixing roll 210 are pressed against each other.

  FIG. 4 is a perspective view showing a state in which the fixed side plate 220R and the fixed side plate 220F are fixed to the tie plate 30, respectively. As described above, the fixed side plate 220R is fixed to the tie plate 30 via the nonconductive member 222R and the nonconductive member 224R. Further, as described above, the fixed side plate 220F is fixed to the tie plate 30 via the nonconductive member 222F and the nonconductive member 224F.

  The connection part 270 which connects the stationary side plate 220R and the stationary side plate 220F is shown by FIG. The connecting portion 270 is located between the fixed side plate 220R and the fixed side plate 220F, one end thereof is fixed to the fixed side plate 220R, the other end is fixed to the fixed side plate 220F, and further to the tie plate 30. It is fixed. It is desirable that the stationary side plate 220R and the stationary side plate 220F be connected by the connecting portion 270 as shown in FIG. By providing the connecting portion 270, the stationary side plate 220R and the stationary side plate 220F are less likely to move as compared with those without the connecting portion 270.

  FIG. 6 shows a state in which the fixed side plate 220R is fixed to the tie plate 30, and is a view showing a cross section in the virtual plane P shown in FIG. 4 from the arrow B direction shown in FIG. Here, the virtual plane P is a vertical plane.

  The fixed side plate 220R is fixed to the tie plate 30 via the nonconductive member 222R and the nonconductive member 224R as described above. Further, as shown in FIG. 6, the stationary side plate 220R is not in direct contact with the tie plate 30 by the nonconductive member 222R and the nonconductive member 224R. In addition, the fixed side plate 220F is also fixed to the tie plate 30 via the non-conductive member 222F and the non-conductive member 224F, so as not to be in direct contact with the tie plate 30 (see FIG. See 4).

  Therefore, fixing device 200 can be electrically insulated even when fixing side plate 220R, fixing side plate 220F and tie plate 30 are all made of a conductive member such as metal. The fixed side plate 220R is fixed to the tie plate 30 without the nonconductive member 222R and the nonconductive member 224R, and the fixed side plate 220F is fixed without the nonconductive member 222F and the nonconductive member 224F. It is possible to suppress image quality defects due to discharge that may occur when fixed to the tie plate 30.

  The nonconductive member 222R, the nonconductive member 224R, the nonconductive member 222F, and the nonconductive member 224F can be made of, for example, a resin, and the resistance value can be, for example, 50 MΩ to 20 GΩ.

  FIG. 7 schematically shows a state in which the fixed side plate 220R is fixed to the tie plate 30, and schematically shows the fixed side plate 220R in the direction of arrow C shown in FIG. Although FIG. 4 shows the tie plate 30 in a state in which the bearing 212R and the shaft member 242R are not attached, in FIG. 7, the bearing 212R and the shaft member 242R are attached. A tie plate 30 is shown.

  Here, the position fixed to the tie plate 30 via the non-conductive member 222R of the fixed side plate 220R is taken as a first fixed portion 232, and is separated from the first fixed portion 232 of the fixed side plate 220R. A position which is at a fixed position relative to the tie plate 30 via the non-conductive member 224R as a second fixed portion 234 and which supports the fixing roll 210 via the bearing 212R of the fixed side plate 220R. 7 shows a fixing roll supporting portion 236 and a position where the swinging side plate 240R (see, for example, FIG. 3) is swingably connected using the shaft member 242R of the fixed side plate 220R as a connecting portion 238, as shown in FIG. The first fixed portion 232, the second fixed portion 234, the fixing roll supporting portion 236, and the connecting portion 238 are virtual planes in which at least a portion of each is the same plane. It is located at the top. In other words, at least a portion of each of the first fixed portion 232, the second fixed portion 234, the fixing roll supporting portion 236, and the connecting portion 238 is the side surface portion 220b of the fixed side plate 220R, and is a flat portion It is located in the side part 220b which does not bend from 220a.

  Further, in the fixed side plate 220F, similarly to the fixed side plate 220R, the position fixed to the tie plate 30 via the non-conductive member 222F and the tie plate 30 via the non-conductive member 224F. The fixed position, the position supporting the fixing roll 210 via the bearing 212F, and the position connecting the swinging side plate 240F so as to allow the swing side plate 240F to pivot using the shaft member 242F are at least partially coplanar. Located on the top. Further, the position fixed to the tie plate 30 via the nonconductive member 222F, the position fixed to the tie plate 30 via the nonconductive member 224F, and the fixing roll via the bearing 212F At least a part of each of the position for supporting the swing side plate 240F and the position for supporting the swing side plate 240F by using the shaft member 242F is a side surface portion 220b of the fixed side plate 220F, and a flat portion It is located in the side part 220b which does not bend from 220a.

  FIG. 8 schematically shows a state in which the fixed side plate 220R of the image forming apparatus according to the comparative example is fixed to the tie plate 30. In this comparative example, although the first fixed portion 232, the fixing roll supporting portion 236, and the connecting portion 238 are located on the virtual plane P, at least a portion of each of which is the same plane, the second target The fixing portion 234 is not located on the virtual plane P. Further, in this comparative example, at least a portion of each of the first fixed portion 232, the second fixed portion 234, the fixing roll supporting portion 236, and the connecting portion 238 is the side surface portion 220b of the fixed side plate 220R. It is not arranged to be located from the flat portion 220a to the side portion 220b without bending.

  More specifically, in the comparative example, the fixed side plate 220R is bent at two points of the first bent portion 226 and the second bent portion 228, respectively. Therefore, the side surface portion 220b is at a position where it is bent from the flat surface portion 220a, and the side surface portion 220b is not at a position where there is no bending from the flat surface portion 220a. Further, in this comparative example, the second fixed portion 234 positioned closer to the end than the second bent portion 228 is fixed to the tie plate 30 by the screw 34, and the second fixed portion 234 is at a position deviated from the virtual plane P. Therefore, the fixed side plate 220R may be inclined in the direction indicated by the arrow f in FIG. 8, and when the fixed side plate 220R is inclined, the alignment accuracy of the fixing roll 210 and the fixing belt 250 may be reduced.

  As described above, the present invention can be applied to, for example, an image forming apparatus such as a copying machine, a facsimile machine, or a printer, and a fixing device used in such an image forming apparatus.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 20 ... Image forming apparatus main body 30 ... Typeplate 100 ... Image formation part 200 ... Fixing apparatus 210 ... Fixing roll 220F, 220R ... Fixed side plate 220a · · · · Flat portion 220b · · · Side portion 222F, 222R, 224F, 224R · · · non-conductive member · · · first fixed portion 234 · · · second fixed portion 236 · · · · fixing roll Support portion 238 ··· Linking portion 240F, 240R · · · Swinging side plate 250 ··· Fixing belt 270 ··· Connection

Claims (2)

An image forming unit that forms an image on a recording medium;
A first rotating body contacting a recording medium on which an image is formed by the image forming unit;
A plate-like member having a flat portion and a side portion, the first support member rotatably supporting the first rotating body;
A second rotating body contacting the first rotating body;
A second support member rotatably supporting the second rotary body, the second support member pivotally supported with respect to the first support member;
Have
The first support member is
A first fixed portion fixed to the image forming apparatus main body;
A second fixed portion fixed to the image forming apparatus main body;
A rotating body support unit for supporting the first rotating body;
A connecting portion pivotally connecting the second support member to the first support member;
With the side portion,
At least a part of each of the first fixed part, the second fixed part, the rotating body support part, and the connection part is located on the side part which is not bent from the flat part,
The portion of the image forming apparatus main body to which at least the first fixed portion is fixed is made of metal.
The image forming apparatus, wherein the first support member is fixed to the image forming apparatus main body via a nonconductive member. A first rotating body contacting a recording medium on which an image is formed by the image forming unit;
A plate-like member having a flat portion and a side portion, the first support member rotatably supporting the first rotating body;
A second rotating body contacting the first rotating body;
A second support member rotatably supporting the second rotary body, the second support member pivotally supported with respect to the first support member;
Have
The first support member is
A first fixed portion fixed to the image forming apparatus main body;
A second fixed portion fixed to the image forming apparatus main body;
A rotating body support unit for supporting the first rotating body;
A connecting portion pivotally connecting the second support member to the first support member;
With the side portion,
At least a part of each of the first fixed part, the second fixed part, the rotating body support part, and the connection part is located on the side part which is not bent from the flat part,
The portion of the image forming apparatus main body to which at least the first fixed portion is fixed is made of metal.
A fixing device in which the first support member is fixed to the image forming apparatus main body via a nonconductive member.

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