JP2001083823A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming device provided with a fixing unit capable of easily dealing with paper jamming, and releasing pressure between a fixing roll and a pressure roll of necessary, thereby seeping them a separated state. SOLUTION: In this device, the upper surface of a main body part 111 housing the fixing roll 113 and the pressure roll 114 is made into a freely opened/closed lid 112, and a recording paper carrying path from the fixing roll 113 to a paper ejecting roll 119 is exposed by opening the lid 112 to easily deal with the paper jamming, also an approximately rectangular inserting part where a part 303b of a roll holding member 303 holding the press roll 114 and a part 11b of the main body part 111 are made into facing long sides is provided, an inserting part 311 of an approximately rectangular cross section of a release member 310 is inserted into the inserting part, the inserting part 311 is rotated by 90 deg., the long sides 303b and 111b are pushed and opened then the fixing roll 113 and the press roll 114 are made away from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a fixing unit for fixing toner on recording paper.

[0002]

2. Description of the Related Art In an electrostatic recording type image forming apparatus, a fixing unit is provided at a final exit of a conveying path for forming an image on a recording sheet. The fixing unit includes a fixing roller heated to a high temperature and a pressure roller pressed against the fixing roller. The toner is transferred to the recording paper before reaching the fixing unit, and the toner is fixed by the fixing unit. The recording paper entering the fixing unit from the entrance is drawn between the fixing roller and the pressure roller. Then, the toner is melted by the heat of the fixing roller, and the melted toner is fixed on the recording paper by the pressing force from the pressure roller. The recording paper on which the toner is fixed is discharged out of the fixing unit through the discharge port.

[0003] As described above, the fixing unit is conventionally provided with a high temperature for the fixing roller and its peripheral parts.
To prevent the high temperature part from being inadvertently exposed to the outside,
In this configuration, the user cannot easily open the fixing unit.

[0004]

However, in such a conventional configuration, since the inside of the fixing unit cannot be opened, if a paper jam occurs inside the fixing unit, it may not be possible to remove the paper jam. there were. In this case, since a service person had to be called each time, there was a problem that a quick response to a paper jam was not possible. To solve this problem, the fixing unit may be opened and closed. However, if the high-temperature fixing roller is exposed when the fixing unit is opened, the user may be in danger due to the high temperature. Alone is not a solution.

[0005] The fixing roller and the pressure roller provided in the fixing unit are pressed against each other by a spring. For this reason, the fixing roller and the pressure roller are pressed against each other in a non-rotating state from the time of production at the factory to the time of delivery to the user and start of use. When the surface of the fixing roller or the pressure roller is made of an elastic material, the fixing roller and the pressure roller are pressed against each other in a state where the fixing roller and the pressure roller are not rotated for a long period of time from factory production to delivery to the user as described above. In this state, the contact surface between the fixing roller and the pressure roller does not move, so that the contact surface is in a concave state and cannot be restored. If such a dent (permanent distortion) is formed on the fixing roller or the pressure roller, the fixing ability at that portion is significantly reduced, which causes a problem of deteriorating the image quality.

The present invention has been made in view of such a problem, and when a paper jam occurs during use, a user can easily and safely handle the paper jam, and can store and store the paper jam.
It is an object of the present invention to provide an image forming apparatus provided with a fixing unit configured to hold a fixing roller and a pressure roller separated from each other by a simple operation during transportation or the like and to prevent occurrence of dents on the surface. Aim.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has an opening / closing lid attached to a main body containing a fixing roller and a pressure roller of a fixing unit. The configuration is such that the transport path of the recording paper from the roller to the discharge port can be exposed, and an internal cover is attached at a position covering the fixing roller, and the transport path of the recording paper is formed on the outer surface side. With this configuration, when the lid is opened, the conveyance path from the nip point of the fixing roller and the pressure roller to the discharge port can be exposed. At this time, since the high-temperature fixing roller is covered with the internal cover, it is safe. Thus, the user can open the fixing unit and safely remove the paper jam.

According to the present invention, one of the fixing roller and the pressure roller housed in the main body is held by the main body, and the other is held by a roller holding member rotatably connected to the main body so as to be movable. An elastic force is applied to the roller holding member by an elastic member to hold the fixing roller and the pressure roller in a state where they are pressed against each other, and a fixing roller and a pressing member are provided between the roller holding member and the main body. A release member for separating the pressure roller against the elastic force of the elastic member is provided. With this configuration, when it is necessary to release the pressure during storage and transportation of the image forming apparatus, the release member can hold the fixing roller and the pressure roller separated from each other, and the surface of the fixing roller and the pressure roller can be maintained. Even if is made of an elastic material, it is possible to prevent permanent deformation such as dents from occurring on the surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to a first embodiment of the present invention has a lid that can be opened and closed, holds a fixing roller and a pressure roller inside, holds one in a fixed position, and rotates the other. A main body portion configured to be held and accommodated by a possible roller holding member, and further, when the lid is opened, a conveying path of the recording paper from the fixing roller to the discharge port is exposed; An inner cover attached to a position that covers the roller, holding an oil application roller that applies oil to the surface of the fixing roller on the side facing the fixing roller, and forming a recording paper conveyance path on the opposite side; An elastic member that applies an elastic force to the main body and the roller holding member so as to hold the roller and the pressure roller in a pressed state; and a fixing roller and a pressure roller that are mounted between the main body and the roller holding member. The bullet It is obtained by a structure that comprises a fixing unit having a releasing member for separating against the elastic force by the member.

With this configuration, when a paper jam occurs in the fixing unit during use, the user can easily cope with the problem by exposing the recording paper transport path by opening the lid of the fixing unit. Since the fixing roller, which is hot, is covered by the internal cover even when the lid is opened,
The user does not directly touch the fixing roller, and the user can be protected from the heat of the fixing roller. In addition, during storage, transportation, and the like after manufacturing, the fixing roller and the pressure roller can be separated from each other by the release member, and can be held in that state. It is possible to prevent the fixing roller and the pressure roller from being continuously pressed in a state where the contact surface does not change, and even if the surface of the fixing roller or the pressure roller is formed of an elastic body, the surface is returned to the original surface. It is possible to prevent any permanent distortion from being applied, and to prevent the image quality from deteriorating.

In the image forming apparatus according to a second aspect of the present invention, in the fixing unit having the above-described configuration, the substantially rectangular insertion opening in which a part of each of the main body and the roller holding member has long sides parallel to each other is provided. On the other hand, the release member is provided with an insertion portion having a substantially rectangular cross section to be inserted into the insertion opening, and the insertion portion is inserted into the insertion opening with the long sides parallel, and then the insertion portion is inserted. By rotating a predetermined angle to the pressure release position, both long sides of the insertion port were pushed open by the short side of the insertion portion, and the fixing roller and the pressure roller were separated from each other against the elastic force of the elastic member. It is configured to hold the state.

With this configuration, the fixing roller and the pressure roller can be separated from each other by a simple operation of inserting the insertion portion of the release member into the insertion opening provided in the fixing unit and then rotating the fixing member. In addition, it is possible to prevent permanent deformation on the surface of the fixing roller or the pressure roller with a simple operation.

In the image forming apparatus according to a third aspect of the present invention, a lever portion extending in a lateral direction is provided at an upper end of the insertion portion of the release member, and an insertion opening for inserting the insertion portion of the release member is closed. The fixing unit is placed at a position covered by the lid of the fixing unit in a state in which the lever is released. When the release member is set at a position other than the pressure release position, a projection is provided to abut against the lever and prevent the lid from closing.

With this configuration, when the insertion portion of the release member is simply inserted into the insertion opening, the lid of the fixing unit hits the lever portion and does not close. To close the lid, the release member is inserted into the insertion opening. It is necessary to rotate the fixing roller and the pressure roller by a predetermined angle in the state to set the pressure release position where the fixing roller and the pressure roller are separated, so forget the operation to rotate the release member and contact the fixing roller and the pressure roller. Can be prevented, and the structure of the release member itself that separates the fixing roller and the pressure roller can function to prevent forgetting the rotation operation of the release member itself. There is no need to separately provide a mechanism, and the apparatus can be simplified.

In the image forming apparatus according to a fourth aspect of the present invention, in addition to the features of the third aspect, a lever provided on the release member is inserted into the insertion port by inserting the release member into the insertion port.
When rotated to the pressure release position, the inner cover is prevented from being attached to the main body.

With this configuration, when the release member inserted into the insertion port is at the pressure release position, that is, when the fixing roller and the pressure roller are separated from each other, even if the inner cover is erroneously mounted in the main body, the lever portion is moved. I couldn't put it in the way,
For this reason, it is possible to avoid an erroneous operation in which the internal cover is mounted at a predetermined position with the fixing roller and the pressure roller being separated from each other and a normal recording operation is started. When the release member, which was in the pressure release position, is rotated and returned to the original insertion position, the inner cover can be attached, but the lever unit is obstructed even if the lid of the fixing unit is closed. It cannot be closed and the release member must be removed from the insertion slot to close the lid. For this reason, if the internal cover is attached to the fixing unit, it is understood that the releasing member must be removed from the fixing unit due to the configuration of the releasing member itself, and even with the simple configuration, even after the internal cover is attached to the fixing unit. It is possible to prevent an erroneous operation of leaving the release member attached.

In the image forming apparatus according to a fifth aspect of the present invention, the lever provided at the upper end of the insertion portion of the release member is provided with the long side parallel to the insertion opening with the inner cover attached to the main body. When it is attempted to rotate the release member inserted by a predetermined angle in order to push open both long sides of the insertion slot, the release member hits the inner cover and prevents the rotation.

With this configuration, it is possible to mount the inner cover when the insertion portion of the release member is inserted into the insertion opening of the fixing unit with the long sides parallel to each other, but after the inner cover is mounted, Even if the release member is erroneously rotated to the pressure release position at which the fixing roller and the pressure roller are separated from each other, the lever portion collides with the inner cover in the middle and does not rotate any more. After being mounted at a predetermined position, it is possible to avoid an erroneous operation in which the fixing roller and the pressure roller are separated from each other and a normal recording operation is started, and since the release member does not rotate by a predetermined angle, the lever can be closed even when the lid is closed. The lid cannot be closed because the part is in the way, and the release member must be removed from the insertion port to close the lid. The release member after mounting the inner cover can be prevented an erroneous operation that left at Tsukeppanashi knit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic side view showing the structure of an image forming apparatus provided with a fixing unit according to an embodiment of the present invention. As shown in FIG. 1, the present image forming apparatus 100
A paper feed cassette 101 is provided at the bottom. The recording paper on the uppermost surface of the recording paper bundle 102 is taken out of the paper feed cassette 101 by the pickup roller 103. The recording paper taken out of the paper feed cassette 101 is transferred to a registration roller 104. Beyond the registration roller 104,
A transfer unit 105 is provided.

The transfer unit 105 has a transfer film 106 on which images of four colors are superimposed. A process unit 108 is provided adjacent to the transfer unit 105. The process unit 108 includes four color process cartridges. An image of a color corresponding to the photoconductor 109 provided for each cartridge is formed. The four color images produced by the four color process cartridges are superimposed on the transfer film 106 at the same position. Transfer unit 1
In the step 05, the image formed on the transfer film 106 is transferred to the recording paper by the transfer roller 107. At this time, the position adjustment between the transfer film 106 and the leading end of the recording paper is controlled by the registration roller 104. The recording paper on which the image has been transferred is transferred from the transfer unit 105 to the fixing unit 110.
Passed to

The fixing unit 110 has a case-shaped main body 111 and an openable / closable lid 112 for covering the upper surface thereof. The recording paper on which the image has been transferred by the transfer unit 105 enters the lower surface of the main body 111. Entrance 122
The fixing roller 113 and the pressure roller 114 are provided at the end of the entrance, and the discharge port 123 is provided at the upper side. The fixing roller 113 applies heat to the recording surface of the recording paper, and the pressure roller 114 applies the recording paper to the fixing roller 11.
The image is fixed on the recording paper by pressing the recording paper 3. The holding, pressing mechanism, and pressure releasing mechanism of the fixing roller 113 and the pressing roller 114 will be described later.

FIG. 2 is an enlarged schematic sectional view showing the fixing unit 110, FIG. 3 is a schematic perspective view showing the fixing unit 110 in an exploded manner, and FIGS. It is an outline sectional view showing the procedure of attaching a cover. In the following description, the fixing unit 1
10, the surface connecting the lid 112 is the rear surface, and the opposite surface is the front surface. 1 to 6, a lid 11 is provided.
Reference numeral 2 is connected to an upper portion of the rear surface of the main body 111 so as to be rotatable about a shaft 125. By opening the main body 111 as shown in FIG. 4, the upper surface of the main body 111 can be largely opened.

Inside the main body 111, an inner cover 115 for covering the fixing roller 113 from above is detachably attached. The inner cover 115 has the fixing roller 1
Cleaning roller 1 for removing toner remaining on toner 13
16 and an oil application roller 117 that applies oil for improving the releasability of the toner remaining on the fixing roller 113. When the inner cover 115 is mounted at a predetermined position in the main body 111, the peripheral surfaces of the cleaning roller 116 and the oil application roller 117 are fixed.
3 so as to be pressed against the peripheral surface.
That is, as can be seen clearly from FIG.
Reference numeral 5 has side portions 203 at both ends, and the shafts of the cleaning roller 116 and the oil application roller 117 are movably held in grooves formed in the side portions 203 and urged toward the front side by a spring (not shown). As shown in FIG. 6, when the inner cover 115 is mounted at a predetermined position in the main body 111, the cleaning roller 11 is
6 and the oil application roller 117 are lightly pressed against the fixing roller 113.

In FIG. 1 to FIG. 3, on the upper surface of the inner cover 115, there is provided a conveyance guide comprising a plurality of ribs 202 for guiding the lower surface of the recording paper passing through the fixing roller 113 and the pressure roller 114. On the lower surface of the lid 112, a conveyance guide including a plurality of ribs 208 for guiding the upper surface of the recording paper is provided. Further, at a position away from the lower surface of the lid 112 by a predetermined distance and downstream of the rib 202 of the internal cover 115,
A conveyance guide including a guide plate 209 for guiding the lower surface of the recording paper is provided. With this configuration, the inner cover 1
15 in a predetermined position in the main body 111, and the lid 11
When the cover 2 is closed, the recording paper transport path 118 is formed between the rib 202 on the upper surface of the inner cover 115 and the guide plate 209 of the lid 112 and the rib 208 on the lower surface of the lid 112. A discharge roller 119, 1
20 are installed.

Since the fixing unit 110 has the above-described configuration, as shown in FIG. 2, with the cover 112 closed, recording paper is fed from the entrance 122 on the lower surface, and the fixing roller 1
13. When the toner passes between the pressure rollers 114, the toner is fixed. After that, the toner is discharged to the outside by the discharge rollers 119 and 120 via the transport path 118 between the inner cover 115 and the lid 112. During this fixing operation, the oil application roller 117 applies oil to the fixing roller 113 so that the toner hardly adheres to the fixing roller 113, and the cleaning roller 116
Removes dirt such as toner adhered to the fixing roller 113. Accordingly, the fixing roller 113 can be used for a long time without cleaning. During the fixing operation, a paper jam may occur. In this case, by opening the lid 112, the nip portion between the fixing roller 113 and the pressure roller 114,
And the transport path 118 above it can be exposed,
In addition, at this time, the fixing roller 113 heated to a high temperature
Since there is no danger because is covered with the internal cover 115, the user can easily and safely perform paper jam processing.

Next, a mechanism for attaching and detaching the inner cover 115 will be described. 3 to 6, the inner cover 115 has side portions 203 at both ends, and a guide guide 206 is provided along the rear edge. This guide 206
Has a pair of upper and lower shafts 206a and 206b.
On the other hand, a pair of upper and lower entrance guides 207 is provided on the inner surface of the side wall of the main body 111 opposed to the side surface 203 of the inner cover 115.
a and an end guide 207b are provided to accommodate the pair of shafts 206a and 206b. The guide guide 206, the entrance guide 207a, and the end guide 207b allow the oil application roller 117 to be used even when the inner cover 115 is installed in an oblique state as shown in FIG. 4 from the state shown in FIG. The fixing roller 113 can be attached to a predetermined position as shown in FIG. 6 by being brought into contact with the fixing roller 113 and pushed along the fixing roller 113 or by rotating the fixing roller 113. In addition, a knob 204 is provided on the front side of the side surface 203 of the inner cover 115 so that it can be easily grasped and put in and out. Thus, the user can open the lid 112 widely, grasp the knob 204, and easily attach or detach the inner cover 115 at a predetermined position in the main body 111. Further, even if the inner cover 115 becomes hot when it is removed after use, the work can be performed safely because the temperature of the knob 204 is not so high.

Fixing roller 113 and oil application roller 1
Although the surface material of 17 is not particularly limited, it is preferable that both are made of an elastic body, and in this embodiment, they are made of an elastic body. As shown in FIG. 5, when the inner cover 115 is inserted, the oil applying roller 117 is brought into contact with the fixing roller 113 when the inner cover 115 is inserted, and when the oil applying roller 117 is pushed along the fixing roller 113 as shown in FIG. This has the advantage of acting to prevent breakage of the member.

Next, the fixing roller 113 and the pressure roller 1
The holding, pressurizing mechanism and pressurizing release mechanism of 14 will be described. FIG. 7 is a schematic sectional view of the main body 111, and FIG. 8 is a schematic plan view thereof. The main body 111 holds the fixing roller 113 so as to rotate at a fixed position. In the main body 111,
The main body 1 holds the pressure roller 114 so that the pressure roller 114 can be pressed against the fixing roller 113.
11 is provided with a roller holding member 303 rotatably connected via a pin 304. Roller holding member 30
A hook 303a is provided in the upper end portion of the main body 3 in the lateral direction, while a hook 111a is provided in the main body 111 at a position appropriately separated from the hook 303a and substantially in parallel. An elastic member (a coil spring in this embodiment) 306 that applies elastic force to press the pressure roller 114 against the fixing roller 113 is hung between the hook 303a and the hook 111a. Thus, the elastic member 306 always keeps the roller holding member 303 fixed.
13, and the pressure roller 114 is in contact with the fixing roller 113 with a suitable pressing force for the fixing operation.

The cover 11 is located near both sides of the front surface of the main body 111 and
A substantially rectangular insertion port 308 is formed at a position covered by the lid 112 when the cover 2 is closed. The insertion port 308 is disposed so that its long axis is parallel to the fixing roller 113 and the pressure roller 114, and one long side 111 b is formed as a part of the main body 111, and the other long side 303 b Is constituted by a part of the roller holding member 303. When the pressure roller 114 and the fixing roller 113 are in contact with each other, the insertion port 308 has a rectangular shape shown in FIG. With this configuration, the parallel long sides 111b, 3
By pushing and opening the gap 03b, the roller holding member 303 is rotated against the elastic force of the elastic member 306, and the fixing roller 113 and the pressing roller 114 can be separated. As means for pushing and opening the parallel long sides 111b and 303b, a release member 310 shown in FIG. 9 is used.

The release member 310 has an insertion portion 311 having a substantially rectangular cross section for insertion into the insertion opening 308, and a lever portion 312 provided at the upper end thereof so as to extend in the lateral direction.
It has. Here, as shown in FIG. 10, the insertion section 311 makes the long sides parallel to the insertion port 308 when the fixing roller 113 and the pressure roller 114 are in contact with each other (the long axis of the rectangle is parallel). After the insertion, the insertion portion 311 is rotated 90 degrees as shown in FIGS. 11 and 12 so that the short side 311a of the insertion portion 311 and the long side of the insertion port 308 can be inserted. 111b, 303b
, So that the fixing roller and the pressure roller can be separated from each other against the elastic force of the elastic member. The short side 311a of the insertion portion 311 is formed flat so that the insertion portion 311 can be rotated to the position shown in FIG. 11 and can stably stop with the long sides 111b and 303b of the insertion port 308 pushed open. I have. On the other hand, the insertion portion 31
One long side 311b is formed in an arc shape so that it can be easily rotated from the insertion position shown in FIG.

Lever 31 provided on release member 310
Reference numeral 2 functions not only as a knob for operation but also as a means for avoiding various erroneous operations described later, and is formed in a shape capable of fulfilling the function. Hereinafter, avoidance of an erroneous operation by the lever unit will be described.

The lever 312 is provided in parallel with the long axis of the cross-section rectangle of the insertion portion 311. For this reason, as shown in FIG.
When it is inserted in the fixing roller 08, the fixing roller 113 and the pressure roller 114 are parallel to the axis. This position is called an initial position. Then, the fixing roller 113 and the pressure roller 114 can be kept separated by rotating the lever portion 312 of the release member 310 90 degrees from the initial position to the rear side to the position shown in FIG. This position is called a pressure release position. As shown in FIGS. 12 and 13, the lid 112 is provided on the lower surface near both ends with a concave portion 112a capable of accommodating the lever portion 312 at the pressure release position, and closes properly when the lever portion 312 is at the pressure release position. Things are possible. Further, as shown in FIGS.
12 at a position adjacent to the recess capable of accommodating
When the lever portion 312 is out of the pressure release position, the lever portion 312 abuts on the first protrusion 312a formed on the upper surface of the lever portion 312, and the lid 112 cannot be closed properly. Thus, the release member 310
Is rotated only to hold the fixing roller 113 and the pressure roller 114 apart from each other.
2 can be closed, and forgetting to rotate the release member 310 can be prevented.

The lever 312 of the release member 310 is
6, as shown in FIG. 17, when the pressure release position is set,
The inner cover 115 to be attached to the main body 111
A second protrusion 312b is provided at a tip end of the second protrusion 312b, which extends to a position overlapping the knob 204. Thus, in a state where the fixing roller 113 and the pressure roller 114 are separated from each other with the release member 310 being in the pressure release position, even if the inner cover 115 is to be mounted on the main body 111, the lever portion 312 becomes an obstacle, and Can not.

On the other hand, when the release member 310 is returned to the initial position shown in FIG. 18, the lever 312 is retracted near the front surface of the main body 111, so that the inner cover 115 can be mounted. The lever portion 312 has a knob portion 204 of the inner cover 115 attached to a predetermined position in the main body portion 111 on a lower surface thereof.
A third protrusion 312c (see FIGS. 9, 16 and the like) is provided at a position where the third protrusion 312 hits. Therefore, as shown in FIGS. 18 and 19, after the inner cover 115 is attached, the release member 310
When the lever 312 is rotated from the initial position to the pressure release position, the lever 312 hits the knob 204 in the middle and does not rotate any more.
After the fixing roller 113 is mounted at a predetermined position, the fixing roller 113 and the pressing roller 114 cannot be separated from each other.

Next, how to use the release member 310 will be described. After the image forming apparatus 100 provided with the fixing unit 110 is manufactured in a factory, the fixing unit 1 is prepared for packing for storage, transportation, and the like until delivery to a user.
Remove the inner cover 115 from the main body 111 of the ten,
Pack separately. This is to prevent oil leakage from the oil application roller 117. Next, the release member 310 is inserted into the insertion port 308 and rotated to the pressure release position shown in FIGS.
14 and then, as shown in FIG.
Close. As a result, the fixing unit 110 is normally prepared for packing and stored for transportation, and thereafter, is packed and stored, transported, and the like. By packing in this manner, even if storage, transportation, and the like take a long time, the fixing roller 113 and the pressure roller 114 are kept apart from each other. It is possible to prevent permanent deformation due to long-term contact on the surface. Further, there is no problem of contamination of the fixing unit 110 due to oil leakage from the oil application roller 117.

During this operation, the operator mistakenly releases the release member 3
There is a case where the lid 112 is to be closed without rotating the cover 10 to the pressure release position. In this case, as shown in FIG. 14, the protrusion 112b on the back surface of the lid 112 hits the first protrusion 312a of the lever 312 and cannot be closed properly, whereby the operator notices a mistake. In some cases, the worker attaches the release member 310 without removing the inner cover 115 by mistake and rotates the release member 310 to the pressure release position. In this case, as shown in FIG. 19, the lever portion 312 hits the knob portion 204 of the inner cover 115 and cannot be rotated. Further, even when the lid 112 is to be closed, the lever portion 312 is in the 112 cannot be closed. This makes the worker notice the mistake. Thus, the operator can prepare for packing correctly without erroneous operation.

The user receiving the image forming apparatus 110 having the fixing unit 110 opens the lid 112 and
The release member 310 is rotated to the original initial position shown in FIG. 10, and the release member 310 is pulled out. Thus, the pressing roller 114 is pressed against the fixing roller 113. Thereafter, the inner cover 115 is attached to a predetermined position in the main body 111 according to the procedure shown in FIGS. 4 to 6, and the lid 112 is closed. Preparation for use is now complete.

By the way, on the user side, the release member 3
There is a case where the user tries to mount the inner cover 115 by mistake while the 10 is inserted in the pressure release position. In this case, as shown in FIG. 16, since the lever portion 312 hinders the mounting of the inner cover 115, the inner cover 115 cannot be mounted, whereby the fixing roller 113 and the pressing roller 114 are separated from each other. An erroneous operation of mounting the inner cover at a predetermined position and starting a normal recording operation can be avoided. After returning the release member 310 to the initial position, the user forgets to remove the release member 310, and
15 may be put on and ready to use.
Also in this case, when the lid 112 is to be closed,
The user notices a mistake because the collides with the lever portion 312 and cannot be closed properly. Further, the lid 112
There is a case where the release member 310 is erroneously rotated to the pressure release position in order to close the lever, but in this case, the lever portion 312 hits the knob portion 204 of the inner cover 115 and cannot be further rotated, so that The lid 112 cannot be closed. Thus, the user notices the erroneous operation and surely rotates the release member 310 from the pressure release position to the initial position, removes the cover 112, closes the lid 112, and uses the fixing unit 110. In this way, the user can prepare for use correctly without erroneous operation, and can use it satisfactorily.

[0040]

As is apparent from the above description, according to the present invention, an openable / closable lid is attached to the main body of the fixing unit accommodating the fixing roller and the pressure roller, and by opening the lid, the discharge port from the fixing roller is opened. The cover is opened by adopting a configuration in which the transport path of the recording paper toward the head is exposed, and furthermore, an internal cover is attached to a position covering the fixing roller and the transport path of the recording paper is formed on the outer surface side. In addition, it is possible to expose the transport path from the nip point of the fixing roller and the pressure roller to the discharge port. At this time, since the high-temperature fixing roller is covered with the internal cover, it is safe and easy for the user. There is an effect that the paper jam can be safely removed by opening the fixing unit.

Further, according to the present invention, one of the fixing roller and the pressure roller accommodated in the main body is held by the main body, and the other is held by a roller holding member rotatably connected to the main body. The fixing roller and the pressure roller are held in a state where they are pressed against each other by applying elastic force to the roller holding member by an elastic member, and a fixing roller is provided between the roller holding member and the main body. And a release member that separates the pressure roller against the elastic force of the elastic member, so that the fixing member and the pressure roller are separated by the release member during storage, transportation, and the like of the image forming apparatus. Can be held in state,
Even when the surface of the fixing roller or the pressure roller is made of an elastic material, there is an effect that permanent deformation such as dents can be prevented from being generated on the surface.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus including a fixing unit according to an embodiment of the present disclosure.

FIG. 2 is an enlarged schematic cross-sectional view illustrating a fixing unit used in the image forming apparatus of FIG. 1;

FIG. 3 is an exploded schematic perspective view showing the fixing unit shown in FIG. 2;

FIG. 4 is a schematic sectional view showing a state in which the inner cover is being mounted on the fixing unit of FIG. 2;

FIG. 5 is a schematic sectional view showing a state in which the inner cover is being mounted on the fixing unit of FIG. 2;

FIG. 6 is a schematic sectional view showing a state in which an inner cover is attached to the fixing unit of FIG. 2;

FIG. 7 is a schematic sectional view of a main body of the fixing unit shown in FIG. 2 and components housed therein.

8 is a schematic plan view of the portion shown in FIG.

9 (a), (b), (c) and (d) are respectively
Schematic plan view, schematic end view, schematic side view, schematic bottom view of release member

FIG. 10 is a schematic plan view showing a fixing member with a cover removed, a release member attached thereto, and the release member as an initial position.

FIG. 11 is a schematic plan view showing a release member attached to the fixing unit with the lid removed, and showing the release member as a pressure release position.

FIG. 12 is a schematic cross-sectional view showing a state in which a release member is attached to the fixing unit, the release member is in a pressure release position, and the lid is correctly closed.

13 is a schematic plan view of the fixing unit in the state shown in FIG.

FIG. 14 is a schematic cross-sectional view illustrating a state where a release member is attached to the fixing unit and the lid is to be closed while the release member is in the initial position.

FIG. 15 is a schematic plan view of the fixing unit in the state shown in FIG.

FIG. 16 is a schematic cross-sectional view showing a state in which a release member is attached to a fixing unit, the release member is set to a pressure release position, and then an inner cover is to be attached.

17 is a schematic plan view of the fixing unit in the state shown in FIG.

FIG. 18 is a schematic plan view showing a state in which a release member is attached to the fixing unit, the release member is in an initial position, and an inner cover is attached.

FIG. 19 is a schematic plan view showing a state where the release member is attached to the fixing unit, and after the inner cover is attached, the release member is about to be rotated to the pressure release position.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Paper feed cassette 105 Transfer unit 108 Process unit 110 Fixing unit 111 Main body 111b Long side 112 Lid 113 Fixing roller 114 Pressure roller 115 Inner cover 116 Cleaning roller 117 Oil application roller 118 Transport path 119, 120 Discharge roller 303 Roller holding member 303a Hook 303b Long side 306 Elastic member 310 Release member 311 Insertion part 311a Short side 311b Long side 312 Lever part

Claims (5)

[Claims] 1. A fixing roller and a pressure roller having an openable and closable lid are housed therein, one of which is held at a fixed position and the other is held by a rotatable roller holding member. A main body configured to expose a recording paper transport path from the fixing roller to the discharge port when opened, and a detachably attached to the main body at a position covering the fixing roller, and fixing to a side facing the fixing roller. An inner cover that holds an oil application roller that applies oil to the surface of the roller, and an opposite side that forms the recording paper conveyance path; and the main body and the roller that hold the fixing roller and the pressure roller in a pressed state. An elastic member that applies an elastic force to the holding member, and a release member that is mounted between the main body and the roller holding member and separates the fixing roller and the pressure roller against the elastic force of the elastic member. An image forming apparatus comprising a fixing unit having the same. 2. The fixing unit according to claim 1, further comprising a substantially rectangular-shaped insertion opening having long sides parallel to each other formed by a part of the main body and the roller holding member, and a release member inserted into the insertion opening. The cross section has a substantially rectangular insertion portion,
The insertion portion is inserted into the insertion opening with the long sides thereof parallel to each other, and then the insertion portion is rotated by a predetermined angle to the pressure release position, so that the short side of the insertion portion has both long sides of the insertion opening. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to push open the fixing roller and hold the fixing roller and the pressure roller in a state of being separated from each other against the elastic force of the elastic member. 3. The release member has a lever portion extending in the lateral direction at an upper end of the insertion portion, and an insertion opening for inserting the insertion portion of the release member is disposed at a position covered by a lid of the fixing unit in a closed state. When the lid of the fixing unit is inserted into a lever portion of a release member at a pressure release position, a concave portion that allows the lid to be closed to the end, and when the release member is at a position other than the pressure release position, The image forming apparatus according to claim 2, further comprising a protrusion that abuts on the lever to prevent the lid from closing. 4. The image forming apparatus according to claim 3, wherein the lever portion of the release member is configured to prevent the inner cover from being attached to the main body when the lever is at the pressure release position. 5. A lever portion of the release member is provided so that the release member inserted into the insertion port with the long sides parallel to each other in a state where the inner cover is attached to the main body section and pushes open both long sides of the insertion port. The image forming apparatus according to claim 3, wherein the image forming apparatus is configured to impinge on the inner cover to prevent rotation when the image is rotated by an angle.