JP2010038952A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus wherein a pressure at a fixation nip portion is more surely released in a jammed recording material removing work even when any portion of the recording material is held by the fixation nip portion, then, the breakage of the recording material is prevented, accordingly, the jammed recording material removing work can be carried out without damaging components of a fixing means. <P>SOLUTION: A front opening/closing part 32 and a rear opening/closing part 33 are separately disposed on the front and rear sides of the apparatus, and a detecting means for detecting the opening/closing state of the opening/closing part, a pressure releasing means for releasing the pressing force applied at the fixation nip portion, and a linking means for operatively linking the opening/closing part with the pressure releasing means are disposed in each of the opening/closing parts. When the opening operation of the opening/closing member of at least one of the front opening/closing part 32 and the rear opening/closing part 33 is carried out, the pressing force applied to the fixation nip portion is released cooperatively with the opening operation, and an image forming operation is restricted by a control part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus having a function of forming an image on a recording material such as a sheet, such as a copying machine, a printer, and a facsimile.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, or a facsimile, an unfixed visible image is formed on a recording material by an image forming process means such as electrophotography, electrostatic recording, and magnetic recording. Then, the unfixed visible image on the recording material is output as a permanently fixed image by the fixing means, and the recording material is output as an image formed product.

  As a fixing means, a recording material is sandwiched and conveyed by a fixing nip, and the recording material is heated and pressed to fix the visible image on the recording material, and a contact heating method fixing device such as a heat roller method or a film heating method is used. Is widely used.

  In the image forming apparatus using the contact heating type fixing device, when a jam of the recording material occurs in the fixing device, the image forming apparatus main body can be opened and closed to open the fixing device portion. The opening / closing part provided in the vicinity of the fixing device is opened to remove the jammed recording material.

  At this time, pressure is applied to the fixing nip, so if you try to remove the recording material carelessly, the recording material will be damaged, and the damaged recording material piece will remain in the device, causing it to become part of the fixing device. There was a possibility of doing damage.

In view of this, Patent Documents 1 and 2 disclose a mechanism that releases the pressure applied to the fixing nip portion in conjunction with the opening and closing operation of the opening and closing portion provided in the vicinity of the downstream side in the fixing device sheet conveyance direction. Patent Document 3 discloses a mechanism for releasing and setting the fixing nip pressure in conjunction with the attachment / detachment of the image forming process means when the access to the fixing device is limited from the front of the image forming apparatus. .
JP 2002-29648 A JP 2007-33897 A JP-A-8-129318

  However, in the conventional configuration as described above, it may be difficult to remove the recording material depending on the position of the jammed recording material.

  For example, if a jam is detected with the leading end of the recording material held in the fixing nip portion, the fixing nip pressure is released when attempting to remove the recording material from the opening / closing portion provided in the rear of the recording material conveyance direction. However, it is difficult to grasp the leading end of the recording material and pull it out in the recording material conveyance direction. This is because it is configured so that the operator cannot directly touch the vicinity of the fixing nip portion due to a safety problem.

  Therefore, the operator opens the opening / closing part at the rear, releases the pressure at the fixing nip part, opens the opening / closing part on the front side of the image forming apparatus, grasps the rear end of the recording material, and pulls out in the direction opposite to the recording material conveyance direction. The material needs to be removed.

Even when access to the fixing device is limited from the front side of the device, if a jam is detected with the trailing edge of the recording material held between the fixing nips, the recording material is pulled out as follows. There is a need. That is, it is necessary to open the opening / closing member in front of the image forming apparatus, remove the image forming process unit from the image forming apparatus, release the pressure in the fixing nip, and then pull out the recording material from the discharge port in the recording material conveyance direction.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide the following image forming apparatus. Even if any part of the recording material is clamped in the fixing nip portion, the pressure in the fixing nip portion is more reliably released during the jam processing operation, and the recording material is prevented from being damaged. Is an image forming apparatus that can perform jam processing without causing damage.

In order to achieve the above object, the present invention provides:
Image forming means for forming an unfixed image on a recording material;
A fixing unit for fixing the unfixed image to the recording material by sandwiching and conveying the recording material on which the unfixed image is formed at a nip portion to which pressure is applied by a pressure applying unit;
In an image forming apparatus comprising:
A first opening / closing member that is provided on one of the two side surfaces of the apparatus main body that intersects the conveyance direction of the recording material that is nipped and conveyed by the nip portion, and that can be opened and closed with respect to the apparatus main body;
A second opening / closing member provided on the other side surface of the two side surfaces and capable of opening and closing with respect to the apparatus main body;
First pressure release means for releasing the pressure applied to the nip portion;
A second pressure releasing means for releasing the applied pressure of the nip portion;
First interlocking means for interlocking the opening operation of the first opening and closing member and the pressure releasing operation of the first pressure releasing means;
Second interlocking means for interlocking the opening operation of the second opening / closing member and the pressure releasing operation of the second pressure releasing means;
First detecting means for detecting an open / closed state of the first opening / closing member;
Second detection means for detecting an open / closed state of the second opening / closing member;
At least one of the first detection means and the second detection means detects that at least one of the first opening / closing member and the second opening / closing member is in an open state. Control means for regulating the image forming operation by the image forming means,
With
When an opening operation of at least one of the first opening / closing member and the second opening / closing member is performed, the pressure applied to the nip portion is released in conjunction with the opening operation, and the control The image forming operation is restricted by the means.

  According to the present invention, even when any portion of the recording material is held by the fixing nip portion, the pressure of the fixing nip portion is more reliably released during the jam processing operation, and the recording material is prevented from being damaged. It is possible to perform a jam processing operation without damaging the constituent members.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

The present invention relates to a printer that forms an unfixed image on a recording material, and heats and presses the unfixed image by nipping and conveying the unfixed image at a nip portion of a fixing unit, thereby fixing the recording material and discharging it to the outside of the apparatus. The present invention relates to an image forming apparatus such as a copying machine or a facsimile.

  Embodiment 1 of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to Embodiment 1 of the present invention. The image forming apparatus of this embodiment is a transfer type electrophotographic laser beam printer.

  First, the overall configuration of the image forming apparatus of this embodiment will be described with reference to FIG.

  When a print start signal is input to the apparatus, the laser scanner 31 irradiates the surface of the photosensitive drum D rotating counterclockwise in FIG. An electrostatic latent image is formed on the surface. This electrostatic latent image is developed with toner by the developing unit 30. In the following description, in the cross-sectional state shown in FIG.

  When a print start signal is input to the image forming apparatus, the recording material S accommodated in a recording material stacking unit (not shown) is sequentially fed out from the uppermost recording material by a feeding roller R1 that rotates clockwise. .

  The fed recording material S is sent to a transfer portion between the photosensitive drum D and the transfer roller TR by the conveying roller pair R2, R3. A toner image formed on the surface of the photosensitive drum D is transferred to the recording material S passing through the transfer portion by the transfer roller. The recording material S on which an unfixed toner image (unfixed image) is formed by passing through the transfer portion is sent to a fixing device as fixing means. Here, the photosensitive drum D, the developing unit 30, and the transfer roller TR correspond to an image forming unit.

  In the fixing device, the recording material S is sandwiched by a fixing nip portion (nip portion) formed by the pressure roller 21 and the heating unit 22 and is heated and pressed to fix the transferred toner image on the surface of the recording material. The The recording material S that has passed through the fixing device is discharged from the discharge unit selected by the operator (operator).

  FIG. 2 shows an interlocking portion between the apparatus front side opening / closing section 32 provided on the apparatus front side of the image forming apparatus of this embodiment and the pressure releasing means of the fixing nip section. FIG. 3 shows the interlocking portion of the pressure release means in the open state of the apparatus front side opening / closing portion 32 in the present embodiment. Here, the apparatus front side opening / closing section 32 is provided on one of the two side faces of the apparatus main body that intersects the conveyance direction of the recording material nipped and conveyed by the fixing nip section, and can be opened and closed with respect to the apparatus main body. This corresponds to the first opening / closing member provided in.

  The fixing unit heating unit 22 is pressed against the pressure roller 21 by a pressure plate 27 and a pressure spring 28 as pressure applying means, whereby pressure is applied to the fixing nip portion. The apparatus front side opening / closing part 32 is arranged to rotate counterclockwise around a fulcrum (support part) a with respect to the image forming apparatus, and includes a small link arm 11, a large link arm 12, and a link gear 23. The pressure release cam 26 is connected via an idler gear 24 and an idler gear 25. Here, the small link arm 11, the large link arm 12, the link gear 23, the idler gear 24, and the idler gear 25 serve as first interlocking means for interlocking the opening operation of the device front side opening / closing part 32 and the pressure releasing operation of the pressure releasing cam 26. Equivalent to. The pressure release cam 26 corresponds to first pressure release means.

The small link arm 11 is connected to the apparatus front side opening / closing part 32 and the connecting part b, and the large link arm 12 is connected to the connecting part c to be rotatable. The large link arm 12 is held by a holding member (not shown) so as to be able to reciprocate only in the horizontal direction.

  The link gear 23 is connected to the large link arm 12 by a connecting portion e so as to be rotatable about a fulcrum d. The fan-shaped portion of the link gear 23 has a gear tooth shape and transmits a rotational moment to the idler gear 24 and the idler gear 25. The sector of the pressure release cam 26 has a gear tooth shape and is connected to the idler gear 25.

  When the front opening / closing part 32 of the apparatus is rotated counterclockwise, the pressure release cam 26 is rotated counterclockwise via each transmission member to come into contact with the pressure plate 27 and further push up the pressure plate 27 (FIG. 3), the pressure in the fixing nip portion is released. Here, when the pressure release cam 26 pushes up the pressure plate 27 by the opening operation of the apparatus front side opening / closing part 32, the pressure applied to the fixing nip part by the pressure spring 28 is applied to the opened apparatus front side opening / closing part 32. It acts as a reaction force (resistance force) of the force (force acting on the fulcrum a).

  Between the apparatus front side opening / closing part 32 and the image forming apparatus main body, it is illustrated as a first detection means from the viewpoint of safety such as leakage of laser light from the laser scanner and prevention of user access to the driving gear during operation. A safety device for the interlock switch mechanism is provided.

  As a result, when the apparatus front side opening / closing part 32 is opened, the printing operation (image forming operation) is restricted (prohibited), and unless the apparatus front side opening / closing part 32 is closed, the print standby state and the printing operation are resumed. It is never done. For this reason, the printing operation does not start in a state where the pressure in the fixing nip portion is released.

  FIG. 4 shows an interlocking portion between the apparatus rear side opening / closing section 33 provided on the apparatus rear side of the image forming apparatus of the present embodiment and the pressure releasing means of the fixing nip section. FIG. 5 shows the interlocking portion of the pressure releasing means in the open state of the apparatus rear side opening / closing portion 33 in this embodiment. Here, the apparatus rear side opening / closing part 33 is provided on the other side of the two sides of the apparatus main body that intersects with the conveyance direction of the recording material nipped and conveyed by the fixing nip part, and opens / closes with respect to the apparatus main body. This corresponds to a second opening and closing member provided.

  The apparatus rear side opening / closing part 33 is arranged to rotate clockwise around the fulcrum f. The pressure release arm 29 is held by a holding member (not shown) so as to be able to reciprocate only in the h direction.

  When the apparatus rear side opening / closing part 33 is rotated clockwise, the cam shape g of the apparatus rear side opening / closing part 33 comes into contact with the pressure release arm 29 and pushes up the pressure release arm 29 in the h direction. The pushed-up pressure release arm 29 comes into contact with the pressure plate 27 and further pushes up the pressure plate 27 to release the pressure in the fixing nip portion. Here, when the pressure release arm 29 pushes up the pressure plate 27 by the opening operation of the apparatus rear side opening / closing part 33, the pressure applied to the fixing nip part by the pressure spring 28 is released from the apparatus rear side opening / closing part 33. It acts as a reaction force of the force applied to (the force acting on the fulcrum f). The cam shape g of the apparatus rear side opening / closing part 33 corresponds to second interlocking means for interlocking the opening operation of the apparatus rear side opening / closing part 33 and the pressure releasing operation of the pressure releasing arm 29. The pressure release arm 29 corresponds to a second pressure release means.

  6A and 6B are schematic views showing an interlocking portion between the apparatus rear side opening / closing part 33 and the apparatus rear side opening / closing detection means. FIG. 6A shows the closed state of the apparatus rear side opening / closing part 33, and FIG. The open state of the side opening / closing part 33 is shown.

In this embodiment, a discharge sensor disposed at the fixing unit outlet (downstream side) is used as the apparatus rear side opening / closing detection means (second detection means). The discharge sensor includes a photo interrupter 42, an oblique light flag 43, a fixing discharge guide 44a, and a sensor spring (not shown), and corresponds to a recording material detection unit that detects a recording material conveyed along the recording material conveyance path.

  The photo interrupter 42 is disposed below the fixing discharge guide 44a. The oblique flag 43 is held by the fixing discharge guide 44a so as to be rotatable about a shaft portion extending in the recording material width direction, and the oblique portion of the oblique flag 43 is photo interrupter during standby due to a pressing force of a spring (not shown). The light emitting unit 42 and the light receiving unit 42 are held in a posture to shield them. Here, the recording material width direction refers to the recording material width direction substantially orthogonal to the recording material conveyance direction.

  When the recording material passes through the fixing nip portion, the leading end of the recording material comes into contact with the oblique flag 43, the oblique flag 43 rotates clockwise around the axis engaged with the fixing discharge guide 44a, and the oblique portion of the oblique flag 43 Move. As a result, a signal is transferred between the light emitting unit and the light receiving unit of the photo interrupter 42, and the signal is input to a control unit as a control unit of the image forming apparatus.

  When a jam occurs for some reason and the recording material stays in the fixing unit, the oblique flag 43 is held at the rotated position, and a signal is continuously input from the photo interrupter 42 to the control unit. When this signal is output for a predetermined time or more, the control unit stops the printing operation.

  The sensor link 40 is rotatable about the fulcrum j with respect to the fixing discharge guide 44a, and a sensor link spring 41 having both ends engaged with a claw portion 44b provided on the fixing discharge guide 44a and a claw portion of the sensor link 40. It is held in a state of receiving a force in the pulling direction. Here, the sensor link 40 corresponds to third interlocking means for interlocking the opening operation of the apparatus rear side opening / closing part 33 and the detection operation of the discharge sensor.

  In the state where the apparatus rear side opening / closing part 33 is closed, as shown in FIG. 6A, the sensor link 40 and the apparatus rear side opening / closing part 33 are in contact with each other, and the oblique flag 43 passes through the fixing nip part. The material is held in a detectable posture.

  In the state where the apparatus rear side opening / closing part 33 is opened, the sensor link 40 is separated from the apparatus rear side opening / closing part 33 as shown in FIG. 6b, and rotates in the direction of the arrow shown in FIG.

  The oblique flag 43 receiving the rotational moment from the sensor link 40 rotates clockwise around the axis engaged with the fixing discharge guide 44a, so that the oblique portion of the oblique flag 43 moves and the photo interrupter 42 emits light. A signal is exchanged between the light receiving portion and the light receiving portion. When this signal is output for a predetermined time or more, the control unit stops the printing operation.

  With this configuration, even when the operator opens the rear opening / closing unit 33 of the apparatus and removes the recording material staying in the fixing unit, the image forming apparatus is maintained in the operation stop state. The printing operation is not resumed in the state where the pressure is released.

  Therefore, even when any part of the recording material is sandwiched by the fixing nip portion, the pressure of the fixing nip portion is surely released at the time of an operator's jam processing operation, and the damage of the recording material is prevented. Jam processing can be performed without damaging the members.

In recent years, the size of image forming apparatuses has been reduced, and the apparatus front side opening / closing section 32 is often composed of a plurality of members such as an apparatus exterior, a multi-size feeding unit, and a recording material conveyance guide. Therefore, there is a concern that a load is applied to the fulcrum a of the device front side opening / closing part 32 due to the weight of the parts. Here, the multi-size feeding unit corresponds to a feeding unit that is provided so as to be able to accommodate the recording material and feeds the recording material to the image forming means. The recording material conveyance guide corresponds to a recording material guide member that is provided along the recording material conveyance path and guides the recording material.

  Accordingly, the pressure release cam 26 is set so that the fixing nip pressure release amount P1 when the apparatus front side opening / closing part 32 is opened and the fixing nip pressure release amount P2 when the apparatus rear side opening / closing part 33 is opened satisfy P1> P2. And the amount of movement of the pressure release arm 29 may be set.

  By setting in this way, the pressure applied to the fixing nip portion is related to the fulcrum a of the apparatus front side opening / closing part 32 when the apparatus front side opening / closing part 32 is opened, regardless of which of the front and rear opening / closing parts is opened first. It becomes a reaction force of the rotational moment, and a damper effect can be obtained.

  Thus, the rotation amount (pressure release amount) of the pressure release cam 26 and the movement amount (pressure release amount) of the pressure release arm 29 are the pressure release amount of the pressure release means corresponding to the opening / closing member as shown below. It is good that it is set to be larger. That is, the force applied to the device front side opening / closing portion 32 when the device front side opening / closing portion 32 is opened (the force acting on the fulcrum a) and the force applied to the device rear side opening / closing portion 33 when the device rear side opening / closing portion 33 is opened. It is an opening / closing member to which a large force is applied among (the force acting on the fulcrum f).

  In this embodiment, the safety state of the interlock switch mechanism is provided between the apparatus front opening / closing part 32 and the image forming apparatus main body, so that the opening / closing state of the apparatus front opening / closing part 32 is detected. However, it is not limited to this. That is, the recording material detecting means for detecting the recording material conveyed through the recording material conveyance path may be used (used or shared) as in the case of opening / closing detection of the apparatus rear side opening / closing unit 33.

  Next, a second embodiment of the present invention will be described.

FIG. 7 is a view showing an interlocking portion between the apparatus front side opening / closing part 32 and the apparatus rear side opening / closing part 33 and the pressure releasing means of the fixing nip part in this embodiment.
The FIG. 8 is a view for explaining a configuration for interrupting the transmission of the rotational moment generated when the apparatus rear side opening / closing part is opened to the interlocking part with the apparatus front side opening / closing part. It is a figure for demonstrating schematic structure of the side transmission gear 24b. 8A is a perspective view seen from the front transmission gear 24a side (the front side of the drawing shown in FIG. 7), and FIG. 8B is a perspective view seen from the compression spring 24c side. The basic configuration of the image forming apparatus according to the present exemplary embodiment is the same as that of the first exemplary embodiment. Therefore, in the present exemplary embodiment, only components that are different from the first exemplary embodiment will be described. The description of is omitted.

  The apparatus front side opening / closing part 32 is arranged to rotate counterclockwise around the fulcrum a with respect to the image forming apparatus. The apparatus front side opening / closing part 32 is connected to the pressure release cam 26 via the link arm small 11, the link arm large 12, the link gear 23, the front transmission gear 24a, the rear transmission gear 24b, and the idler gear 25. Here, the small link arm 11, the large link arm 12, the link gear 23, the front transmission gear 24 a, the rear transmission gear 24 b, and the idler gear 25 open the device front side opening / closing part 32 and the pressure release operation of the pressure release cam 26. Corresponds to a first interlocking means for interlocking with.

  The small link arm 11 is connected to the apparatus front side opening / closing part 32 and the connecting part b, and the large link arm 12 is connected to the connecting part c so as to be rotatable. The large link arm 12 is held by a holding member (not shown) so as to be able to reciprocate only in the horizontal direction.

The link gear 23 is connected to the large link arm 12 by a connecting portion e so as to be rotatable about a fulcrum d. The fan-shaped portion of the link gear 23 has a gear tooth shape and transmits a rotational moment to the front transmission gear 24a.

  The front transmission gear 24a and the rear transmission gear 24b are such that only a counterclockwise rotational moment is transmitted from the front transmission gear 24a to the rear transmission gear 24b on the contact surfaces (surfaces substantially orthogonal to the axial direction) in contact with each other. Are provided with an engaging recess 24a1 and an engaging protrusion 24b1, respectively.

  The engaging recess 24a1 includes a flat portion 24a2 that is substantially perpendicular to the circumferential direction, and an inclined portion 24a3 that extends from the flat portion 24a2 in the circumferential direction and is inclined to the contact surface.

  The engaging convex portion 24b1 includes a flat portion 24b2 that is substantially perpendicular to the circumferential direction, and an inclined portion 24b3 that extends in the circumferential direction from the flat portion 24b2 and is inclined to the contact surface.

  The front transmission gear 24a and the rear transmission gear 24b are pressed by the compression spring 24c in a direction in which the engagement recess 24a1 and the engagement projection 24b1 are engaged with each other.

  When a counterclockwise rotational moment is applied to the front transmission gear 24a, the planar portion 24a2 of the engagement recess 24a1 and the planar portion 24b2 of the engagement projection 24b1 are engaged (engaged), whereby the front transmission gear 24a. To the rear transmission gear 24b.

  Here, when a clockwise rotational moment acts on the front transmission gear 24a, or when a counterclockwise rotational moment acts on the rear transmission gear 24b, the engagement concave portion 24a1 and the engagement convex portion 24b1 are: They will slide against each other and repeat contact and separation while one of them rotates. In this case, the front transmission gear 24a or the rear transmission gear 24b moves (slides) in a direction in which the engagement state is released against the pressing force of the compression spring 24c, that is, in the direction of the rotation axis and away from each other. To do. For this reason, no rotational moment is transmitted between the front transmission gear 24a and the rear transmission gear 24b.

  The sector of the pressure release cam 26 has a gear tooth shape and is connected to the idler gear 25. When the front opening / closing part 32 of the apparatus is rotated counterclockwise, the pressure release cam 26 is rotated counterclockwise via each transmission member to come into contact with the pressure plate 27, and further, the pressure plate 27 is pushed up to fix. The pressure at the nip is released.

  The apparatus rear side opening / closing part 33 is arranged to rotate clockwise around the fulcrum f, and the sector part has a gear tooth shape.

  When the apparatus rear side opening / closing part 33 is rotated clockwise, both the gear tooth mold parts of the apparatus rear side opening / closing part 33 rotate around the fulcrum f and mesh with the rear transmission gear 24b.

  As a result, a counterclockwise rotational moment is applied to the rear transmission gear 24b, and the pressure release cam 26 rotates counterclockwise via the idler gear 25 to contact the pressure plate 27. Further, the pressure plate 27 By pushing up, the pressure in the fixing nip is released.

  At this time, the slopes of the transmission surfaces of the front transmission gear 24a and the rear transmission gear 24b, that is, the engagement recess 24a1 and the engagement projection 24b1, slide on each other as described above. In this case, since the rear transmission gear 24b moves in the direction in which the engagement state is released against the pressing force of the compression spring 24c, that is, in the rotation axis direction, no rotational moment is applied to the front transmission gear 24a.

  Here, the rear transmission gear 24 b and the idler gear 25 correspond to second interlocking means for interlocking the opening operation of the apparatus rear opening / closing part 33 and the pressure releasing operation of the pressure releasing cam 26.

  In the present embodiment, as described above, the first interlocking means for linking the opening operation of the apparatus front side opening / closing part 32 and the pressure releasing operation links the opening operation of the apparatus rear side opening / closing part 33 and the pressure releasing operation. 2 Interlocking means are included. Such a configuration can be easily realized by disposing the apparatus rear side opening / closing part 33 closer to the fixing device than the apparatus front side opening / closing part 32.

  With this configuration, the pressure applied to the fixing nip portion can be released by a single (same) pressure release means in conjunction with the opening operation of both the front and rear opening / closing members.

  Therefore, the image forming apparatus of the present embodiment can obtain the same effects as those of the first embodiment with a simpler configuration than that of the image forming apparatus of the first embodiment.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to Embodiment 1. FIG. Schematic which shows the interlocking | linkage part of the apparatus front side opening / closing part and pressure release means in Example 1. FIG. In Example 1, it is the schematic which shows the interlocking | linkage part of the pressure release means in the open state of an apparatus front side opening / closing part. Schematic which shows the interlocking | linkage part of the apparatus rear side opening / closing part and pressure release means in Example 1. FIG. In Example 1, it is the schematic which shows the interlocking | linkage part of the pressure release means in the open state of an apparatus back side opening / closing part. Schematic which shows the interlocking | linkage part of the apparatus rear side opening / closing part and opening / closing detection means in Example 1. FIG. Schematic which shows the interlock | cooperating part of the apparatus front side opening / closing part in Example 2, the apparatus rear side opening / closing part, and a pressure release means. The figure for demonstrating schematic structure of the front side transmission gear in Example 2, and a rear side transmission gear.

Explanation of symbols

11 Link arm small 12 Link arm large 21 Pressure roller 22 Heating unit 23 Link gear,
24 idler gear 25 idler gear 26 pressure release cam 28 pressure plate 27 and pressure spring 29 pressure release arm 30 developing unit 32 device front side opening / closing unit 33 device rear side opening / closing unit 42 photointerrupter 43 oblique light flag 44a fixing discharge guide g cam shape D photosensitive drum S Recording material TR Transfer roller

Claims (6)

Image forming means for forming an unfixed image on a recording material;
A fixing unit for fixing the unfixed image to the recording material by sandwiching and conveying the recording material on which the unfixed image is formed at a nip portion to which pressure is applied by a pressure applying unit;
In an image forming apparatus comprising:
A first opening / closing member that is provided on one of the two side surfaces of the apparatus main body that intersects the conveyance direction of the recording material that is nipped and conveyed by the nip portion, and that can be opened and closed with respect to the apparatus main body;
A second opening / closing member provided on the other side surface of the two side surfaces and capable of opening and closing with respect to the apparatus main body;
First pressure release means for releasing the pressure applied to the nip portion;
A second pressure releasing means for releasing the applied pressure of the nip portion;
First interlocking means for interlocking the opening operation of the first opening and closing member and the pressure releasing operation of the first pressure releasing means;
Second interlocking means for interlocking the opening operation of the second opening / closing member and the pressure releasing operation of the second pressure releasing means;
First detecting means for detecting an open / closed state of the first opening / closing member;
Second detection means for detecting an open / closed state of the second opening / closing member;
At least one of the first detection means and the second detection means detects that at least one of the first opening / closing member and the second opening / closing member is in an open state. Control means for regulating the image forming operation by the image forming means,
With
When an opening operation of at least one of the first opening / closing member and the second opening / closing member is performed, the pressure applied to the nip portion is released in conjunction with the opening operation, and the control An image forming apparatus, wherein the image forming operation is restricted by means.   At least one of the first detection means and the second detection means corresponds to the recording material detection means for detecting the recording material conveyed along the recording material conveyance path and the one detection means. The image forming apparatus according to claim 1, further comprising a third interlocking unit that interlocks an opening operation of the opening / closing member and a detection operation of the recording material detection unit.   The applied pressure applied to the nip portion by the pressure applying means is a reaction of a force applied to the opened opening / closing member when at least one of the first opening / closing member and the second opening / closing member is opened. The image forming apparatus according to claim 1, wherein the image forming apparatus acts as a force.   The pressure release amount of the first pressure release means and the pressure release amount of the second pressure release means are the force applied to the first opening / closing member when the first opening / closing member is opened, and the second opening / closing member. The pressure release amount of the pressure release means corresponding to the open / close member to which a large force is applied is larger than the force applied to the second open / close member when the is opened. Item 4. The image forming apparatus according to any one of Items 1 to 3. The first opening / closing member is provided along the recording material conveyance path, and is provided along the recording material conveyance path, the exterior of the apparatus main body, a feeding unit that is capable of accommodating the recording material and feeds the recording material to the image forming unit. A recording material guide member to be
The second opening / closing member includes an exterior of the apparatus main body, and a recording material guide member that is provided along the recording material conveyance path and guides the recording material,
5. The pressure release amount of the first pressure release means is provided to be larger than the pressure release amount of the second pressure release means. 2. The image forming apparatus according to item 1. The first pressure releasing means and the second pressure releasing means are the same means,
6. The image forming apparatus according to claim 1, wherein the first interlocking unit includes the second interlocking unit.

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