JP2003252506A - Image recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording device having a fixing unit allowing easy removal of jammed paper from the outside without requiring removal or the like of covers even when the paper jam occurs in the fixing unit. <P>SOLUTION: A delivery roller is constituted integrally turnably by a connecting frame, and a delivery opening can be opened by an operation from the outside. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image recording apparatus represented by a copying machine, a printer and a facsimile apparatus, and more particularly to a fixing unit for fixing a toner image transferred on a sheet. is there.

[0002]

2. Description of the Related Art Conventionally, in an image recording apparatus such as a copying machine, a printer or a facsimile machine, a toner image transferred onto a sheet in a recording section is fixed by a fixing unit to be a permanent image. In this fixing unit, a heat roller for melting the resin component of the toner is rotatably arranged, and a temperature sensor for detecting the temperature of the heat roller is provided. The temperature sensor is arranged above a guide plate that guides a sheet to a fixing unit, and a detection unit formed in a leaf spring shape is brought into sliding contact with the heat roller to detect the temperature of the heat roller. The detection unit is biased toward the heat roller and is in pressure contact with the heat roller.

The fixing unit is composed of a heat roller and a pressure roller which are in pressure contact with each other, a discharge roller, and a separation claw for preventing the recording sheet from winding around the heat roller. The recording paper on which the image has been transferred passes through a nip portion between the heat roller and the pressure roller to be heated and pressed, whereby the image is fixed and is discharged from the paper discharge roller to a paper discharge portion outside the apparatus.

[0004]

However, in the fixing unit constructed as described above, after the recording paper passes through the fixing portion where the heat roller and the pressure roller are in pressure contact with each other, the recording paper is not normally discharged and is wound around the heat roller. As a result, the paper may get jammed between the detection portion of the temperature sensor and the outer peripheral surface of the heat roller to cause a paper jam. In addition, the paper may not be properly fed into the nip portion of the paper discharge roller, and may form a bellows-shaped jam (paper jammed with paper in a bellows shape).

When a paper jam occurs in the fixing unit,
Since the paper discharge roller arranged immediately after the fixing unit is fixed to the fixing unit, the jammed paper cannot be removed from the paper discharge unit as it is. Therefore, by opening the upper cover of the image recording device, taking out the fixing unit, and further removing the fixing unit covers,
The paper feed path is opened, jammed paper is removed, and jams are being removed.

It is an object of the present invention to fix a jammed paper easily from the outside of the apparatus even if a paper jam occurs in the fixing unit without requiring a work such as removing covers. An image recording apparatus having a unit is provided.

[0007]

In order to achieve the above object, the invention according to claim 1 is characterized in that a paper discharge roller mechanism is arranged at a paper discharge port of a fixing unit, and the paper discharge roller mechanism is the above-mentioned It is characterized in that it is configured to be displaceable or detachable so as to open the discharge port portion largely.

According to the first aspect of the present invention having the above structure, even if a paper jam occurs in the fixing unit, the paper discharge port can be largely opened by displacing or removing the paper discharge roller mechanism. Since a space for inserting hands and fingers can be secured, the jammed paper inside the fixing unit can be removed without removing covers.

The invention according to claim 2 is characterized in that the paper discharge roller mechanism is provided with a driving roller, a driven roller, and a connecting frame for rotatably supporting these.

According to the second aspect of the present invention having the above-mentioned structure, even if a paper jam occurs in the fixing unit, the driving roller and the driven roller forming the paper discharging roller mechanism are simultaneously supported. By displacing or removing the frame, the paper discharge port can be largely opened, so that the jammed paper in the fixing unit can be removed without removing the covers.

According to a third aspect of the present invention, the connecting frame is a frame that supports both ends of the drive shaft of the drive roller and the rotating shaft of the driven roller, and the end of the drive shaft penetrates the connecting frame. The connecting frame is connected to the drive means of the fixing unit, and the connecting frame is rotatable about the drive shaft.

According to the third aspect of the present invention having the above-mentioned structure, the discharge roller mechanism including the driving roller, the driven roller and the connecting frame is configured such that the connecting frame is rotatable, so that the driving roller is rotatable. Since it rotates about the drive shaft as the center of rotation, it is possible to obtain an opening through which the jammed paper can be removed without changing the positional relationship with the drive means.

According to a fourth aspect of the present invention, an operating portion for rotating the connecting frame is provided so as to be operable from the outside, and the operation is performed from the outside while maintaining the fixing unit mounted on the image recording apparatus. It is characterized in that the sheet discharge port can be opened by operating the section.

According to the fourth aspect of the present invention having the above-mentioned structure, even if a paper jam occurs in the fixing unit, the jammed paper can be removed by opening the paper discharge port by an external operation. You can

According to a fifth aspect of the present invention, a member disposed at or near the sheet discharge port of the fixing unit can be operated from the outside while maintaining the fixing unit mounted on the image recording apparatus. Further, it is characterized in that the member is configured to be displaceable or detachable. According to the invention having the above-mentioned configuration, even if a paper jam occurs in the fixing unit, the member operable from the outside is displaced without removing the fixing unit mounted in the image recording apparatus. The paper exit port can be opened by removing the jammed paper, and the jammed paper can be removed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image recording apparatus according to the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view showing a fixing unit according to an embodiment of the present invention. FIG. 2 is a front view showing a paper discharge roller mechanism according to an embodiment of the present invention, and FIG. 2A shows a paper discharge roller in which each roller is divided into a plurality (three in the drawing),
(B) shows a discharge roller in which each roller is a single roller. FIG. 3 is an overall sectional view showing the inside of the image recording apparatus in which the fixing unit according to the present invention is mounted. FIG. 4 is a schematic explanatory view showing the layout of each unit of the image recording apparatus. FIG. 5 is an overall perspective view showing the appearance of the image recording apparatus.

An image recording apparatus according to an embodiment of the present invention will be described with reference to FIGS. The image recording apparatus A includes a developing unit 10, a drum unit 20, and a fixing unit 3.
0, etc., and especially the developing unit 10
The drum unit 20 and the drum unit 20 are integrally detachably configured as a process unit. At the lower part of the main body of the image recording apparatus A, a paper storage unit 60 for storing the recording paper P is arranged. An ADF (automatic document feeder) 40 is provided on the upper part of the main body of the recording device A, and has a fax function and a copy function. To record an image on the recording paper P, one sheet of the recording paper P is picked up by the separating and feeding means, conveyed toward the developing unit 10, the image is transferred by the drum unit 20, and fixed by the fixing unit 30, The recording paper P on which an image is recorded is conveyed in the B direction and sent to the paper discharge unit 50.

Integrated as respective units,
The developing unit 10, the drum unit 20, and the fixing unit 30 are configured to be attachable to and detachable from the apparatus main body for maintenance or replacement of parts. In addition, each unit 10, 20, 30 is configured such that the upper part of the apparatus main body is opened for easy operability and the unit can be inserted and removed from the opened upper part.

The developing unit 10 includes a toner 15, a toner supply roller 12, the supply roller 12 and the photosensitive drum 2.
1 and a toner regulating blade 14 which is elastically contacted with the peripheral surface of the developing roller 11 on the downstream side in the toner 15 conveyance direction.

The toner supply roller 12 is the developing roller 11
And the roller portions are arranged so as to come into pressure contact with each other, and rotate in the same direction as the developing roller 11 as indicated by an arrow in the figure. Due to this rotational movement, the toner supply roller 12 moves the toner 1
5 is supplied to the developing roller 11, the toner is frictionally charged at the contact portion with the developing roller 11, and the developing roller 11
It works to scrape off the unused toner above.

The drum unit 20 includes a photosensitive drum 21,
The transfer roller 22, the charging brush 23, and the memory removal brush 24 are provided to form a unit. A recording head (LED head) 25 is disposed around the photosensitive drum 21, and the recording head 25 causes the photosensitive drum 21 to move.
The image written on the photosensitive drum 21 is transferred and recorded on the recording paper P conveyed by the conveying roller 13.

A fixing unit 30 for fixing the toner image transferred to the recording paper P is disposed downstream of the drum unit 20. The fixing unit 30 includes a heat roller 31 and a pressure roller 32 that are in pressure contact with each other, a discharge roller 33 that discharges the fixed recording sheet P, and a separation unit that prevents the recording sheet P from winding around the heat roller 31. And a claw 34.

The recording paper P to which the image has been transferred passes through the nip portion between the heat roller 31 and the pressure roller 32, is heated and pressed, and fixes the image to form a permanent image. The recording paper P on which the image has been fixed is ejected by a paper ejection roller 33 to a paper ejection unit 50 outside the apparatus.

The fixing unit 30 will be described with reference to FIG. The fixing unit 30 includes a unit frame 30a (see FIG. 2) made of resin or the like, and a heat roller 31 and a pressure roller 32 which are opposed to each other, and guides the recording paper P to a nip portion between the rollers 31 and 32. Guide plate 37
Is provided to fix the toner image transferred to the paper. The pressure roller 32 is urged toward the heat roller 31 and is in pressure contact with the heat roller 31. The detection portion 35a of the temperature sensor 35 is in sliding contact with the outer peripheral surface of the heat roller 31 to detect the temperature of the surface of the heat roller 31. Further, the heat roller 31 rotates in the direction of the arrow 31a, a cleaning member 38 is arranged above the heat roller 31, and the lower end of the cleaning member 38 is brought into sliding contact with the outer peripheral surface of the heat roller 31 to heat it. The outer peripheral surface of the roller 31 is cleaned.

The guide plate 37 is mounted so as to be inclined so as to be located at a high position in the sheet conveying direction.
The leading end of the guide plate 37 in the paper transport direction is located near the nip portion between the heat roller 31 and the pressure roller 32, and guides the transported recording paper P to the nip portion in a proper posture and at a proper position. Is configured to. Further, at the downstream side of the nip portion between the heat roller 31 and the pressure roller 32, the separation claw 34 is attached to the heat roller 3
It is in sliding contact with the outer peripheral surface of the recording sheet 1 and prevents the recording sheet P passing through the nip portion from winding around the heat roller 31. Then, the recording paper P on which the toner image has been fixed by the heat roller 31 and the pressure roller 32 is the paper discharge roller 3
3 is discharged to the outside of the apparatus.

The temperature sensor 35 has a detecting portion 35a attached downward from the lower end of the main body 35b, and the detecting portion 35a is composed of an elastic plate-like thermistor or the like. The temperature sensor 35 is arranged in the unit frame 30a on the guide plate 37 side of the heat roller 31, and the detection portion 35a is connected to the heat roller 3.
The temperature of the outer peripheral surface of the heat roller 31 is detected by sliding and press contacting the outer peripheral surface of the first guide plate 37 side.

A protective cover 39 is arranged above the guide plate 37 to separate the inside of the unit frame 30a in which the temperature sensor 35 and the like are arranged from the paper conveyance path through which the recording paper P passes. There is. On the upper surface of the protective cover 39, a protrusion 36, which is a support member of the detection unit 35a, is projected. The protrusion 36 is formed in a rib shape, and the detection unit 35a is in sliding contact with the heat roller 31. It is arranged so as to abut on the opposite side to. A thermostat (not shown) is provided in the unit frame 30a,
When the temperature detected by the temperature sensor 35 is abnormal, the heating of the heat roller 31 is stopped.

The paper discharge roller 33 is composed of a pair of rollers mounted on the connecting frame 1a so that the driving roller 3 and the driven roller 2 are pressed against each other. In this embodiment, the drive shaft 3a, which is the rotation shaft of the drive roller 3, is used as the center of rotation.
The connection frame 1a is configured to be rotatable. Since the drive roller 3 and the driven roller 2 are integrally mounted on the connection frame 1a, even if the connection frame 1a is rotated about the drive shaft 3a of the drive roller 3,
The positional relationship between the rollers 2 and 3 does not change, and the rollers 2 and 3 rotate while maintaining a constant pressure contact state, and the sheet discharge port D is opened.

When the recording paper P is not properly conveyed to the nip portion between the drive roller 3 and the driven roller 2 and a paper jam occurs, the leading end portion of the recording paper P in the conveying direction is stopped near the nip portion and the heat roller Since the trailing end of the recording paper P in the transport direction is continuously fed by the feeding of the pressure roller 31 and the pressure roller 32, a bellows-shaped jam (paper jam) P1 is formed.

In the conventional apparatus in which the peripheral members such as the paper discharge roller 33 and the cover are fixed, the bellows-shaped jam P is used.
When 1 occurs, it is impossible to remove the jammed paper as it is. Therefore, the fixing unit 30 is taken out by removing the upper cover of the recording apparatus main body, the frame of the fixing unit 30 is removed, and the fixing unit is removed. The inside was opened to remove the bellows-shaped jam P1.

In the present invention, the paper discharge roller mechanism 1 is
A paper discharge roller 33 including a driving roller 3 and a driven roller 2 is integrally arranged on the connecting frame 1a. The rotation shaft 2a of the driven roller 2 is fixed to the connecting frame 1a, but the driven roller 2 is rotatable with respect to the rotation shaft 2a, and the driven roller 2 comes into contact with the driving roller 3 and is driven to rotate. The paper discharge roller 33 of FIG. The drive shaft 3a of the drive roller 3 is rotatably mounted on the connecting frame 1a via a bush 7. Therefore, the connecting frame 1a is rotatable about the drive shaft 3a of the drive roller 3, and the discharge port D is opened to form an opening.

Further, the rotating operation of the connecting frame 1a can be performed by putting a hand from the outside (in the direction of the paper discharge section 50) and operating the horizontal portion 1aa of the connecting frame 1a with a finger or the like. It can be done easily without removing the covers. When the connecting frame 1a is rotated by approximately 90 degrees in the direction of arrow C as shown in the drawing, the tip of the bellows-shaped jam P1 is near the opening of the paper discharge port D, and a finger should be inserted into the opening. The bellows-shaped jam P1 can be removed with.

As shown in FIG. 2B, the connecting frame 1a is a U-shaped frame having a horizontal portion 1aa and a side surface portion 1ab, and the side surface portion 1ab has a driving roller 3 formed thereon.
The rotary shafts of the driven roller 2 and the driven roller 2 are mounted and integrated to form the paper discharge roller mechanism 1. The drive shaft 3a, which is the rotation shaft of the drive roller 3, penetrates the connecting frame 1a and is connected to the drive means 5 mounted on the unit frame 30a of the fixing unit 30. As the connection method at this time, there are known connection methods such as a connection by a coupling, a connection by a gear and a connection through a belt. Which of these is adopted depends on the structure of the image recording apparatus A or the fixing unit 30 and It is decided by the mechanism. The drive shaft 3a is supported by the unit frame 30a and bearings 6 at both ends thereof.
It is rotatable with respect to a and is rotatably attached to the connecting frame 1a via a bush 7.

Further, as shown in FIG. 2 (a), the driving roller 3 is divided into a plurality of parts such as 3-1, 3-2 and 3-3, and the driven roller is provided for each driving roller. In the paper discharge roller having the driven rollers 2-1, 2-1 and 2-3 which are separately in contact with each other, the connection frames 1-1 and 1
The sheet discharge roller mechanism 1 ′ may be formed by separately providing −2 and 1-3 and forming a connection frame 1 a that integrally connects them.

Due to the above structure, the connecting frame 1a is rotatable with respect to the drive shaft 3a,
As shown in FIG. 1A, it is rotatable between a solid line portion showing a regular paper discharge position and a position shown by a broken line which is rotated approximately 90 degrees counterclockwise. Further, at the regular paper discharge position, the fixing member 4
With this configuration, the side surface portion 1ab of the connection frame 1a is fixed. The fixing member 4 is a leaf spring-like member, and the side surface portion 1ab is fitted and fixed, but other means such as a magnet may be used.

Since the horizontal portion 1aa of the connecting frame 1a is used as the operating portion to rotate the sheet discharge roller mechanism 1, the projection roller or the like is not formed in a flat plate structure as in the present embodiment, but a projection or the like is provided so that a finger can easily hang it. The shape may be provided.

When the connecting frame 1a is rotated, the drive shaft 3a of the drive roller 3 is fixed, and the driven roller 2 rolls on the roller surface of the drive roller 3 to rotate. Therefore, even if there is the recording paper P nipped by both rollers, it will not be pulled out and will not be torn. FIG. 1B shows a state in which the connection frame 1 is pivotally operated to open the discharge port portion D. Since the bellows-shaped jam P1 is located near the opening portion, It is possible to take out the bellows-shaped jam P1, which has been difficult in the past, just by inserting the hand from the (paper discharge portion 50) and covering the paper discharge portion D opened by the finger.

Further, depending on the shape of the fixing unit 30, it seems that the bellows-shaped jam P1 can be removed only by opening a member such as a cover around the discharge roller 33. In this case, the peripheral members such as the cover are operated from outside the image recording apparatus A while the fixing unit 30 is mounted, and are rotated or moved so as to be displaced or removed. It can be carried out.

In this embodiment, the paper discharge roller mechanism 1 disposed immediately after the fixing unit is displaced by rotating the drive shaft 3a of the paper discharge roller 33 as a rotation center, and the paper discharge port portion D is moved. Although it is configured to be opened, the drive shaft 3a may be configured to be movable in and out of contact with the drive means 5, and the rotation center may be provided at another position. Further, the paper discharge roller mechanism 1 may be configured to be movable or detachable as a whole. Alternatively, only the driven roller 2 may be movable or detachable. However, there is no room to remove the driven roller 2 and the discharge roller mechanism 1,
For the compact and small-sized image recording apparatus A, there is a bellows-shaped jam processing method in which a finger is inserted from the paper discharge unit 50 originally having an opening for taking out a recording sheet and the connecting frame 1a is rotated. It is valid.

[0041]

According to the first aspect of the present invention, the paper discharge roller mechanism is arranged at the paper discharge opening of the fixing unit, and the paper discharge roller mechanism opens the paper discharge opening greatly. In addition, since it is configured to be displaceable or removable, even if a paper jam occurs in the fixing unit, the discharge roller mechanism can be displaced (rotated or moved) or removed to remove the paper discharge port. Since it can be opened widely and a space for inserting hands and fingers can be secured, the jammed paper in the fixing unit can be removed without removing covers.

According to the second aspect of the present invention, since the paper discharge roller mechanism is provided with the drive roller, the driven roller, and the connecting frame that rotatably supports these, the paper is set in the fixing unit. Even if a paper jam occurs, by simultaneously displacing the drive roller and driven roller that make up the paper ejection roller mechanism, the paper ejection opening can be opened widely, and the jammed paper inside the fixing unit can be removed without removing covers. Can be removed.

According to the third aspect of the present invention, the connecting frame is a frame that supports both ends of the drive shaft of the drive roller and the rotating shaft of the driven roller, and the end portion of the drive shaft is the connecting frame. Is connected to the drive means of the fixing unit and is rotatable around the drive shaft as a rotation center. Since the paper roller mechanism rotates about the drive shaft of the drive roller as the center of rotation, it is possible to obtain an opening through which the jammed paper can be removed without changing the positional relationship with the drive means. .

According to the fourth aspect of the present invention, an operating portion for rotating the connecting frame is provided so as to be operable from the outside, and the fixing unit is attached to the image recording apparatus while keeping the fixing unit mounted from the outside. Since the paper discharge port can be opened by operating the operation unit, even if a bellows-shaped paper jam occurs in the fixing unit, the paper discharge port can be opened by an external operation. You can remove jammed paper.

According to the fifth aspect of the present invention, the member provided at or near the sheet discharge port of the fixing unit can be operated from the outside while keeping the fixing unit mounted on the image recording apparatus. Further, since the member is configured to be displaceable or detachable, even if a paper jam occurs in the fixing unit, a member that can be operated from the outside without removing the fixing unit mounted in the image recording apparatus The paper discharge port can be opened by displacing or removing the paper, and the jammed paper can be removed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a fixing unit according to an exemplary embodiment of the present invention, in which FIG. 1A shows the discharge roller mechanism in a regular position. (B) shows where the paper discharge roller mechanism is opened and the opening is exposed.

FIG. 2 is a front view showing a paper discharge roller mechanism according to the embodiment of the present invention, in which (a) is an example in which the paper discharge roller is divided into a plurality of rollers. (B) is an example in which the paper discharge roller is composed of a single roller pair.

FIG. 3 is an overall sectional view showing the inside of an image recording apparatus to which a fixing unit according to the present invention is attached.

FIG. 4 is a schematic explanatory diagram showing a layout of each unit of the image recording apparatus.

FIG. 5 is an overall perspective view showing an overview of an image recording apparatus.

[Explanation of symbols]

1 Paper ejection roller mechanism 1a connection frame 1aa Horizontal part (operation part) 1ab side part 2 driven roller 2a Rotating shaft (driven roller) 3 drive roller 3a drive shaft 4 fixing members 5 Drive means 10 Development unit 20 drum unit 30 fixing unit 33 paper ejection roller 50 paper output section A image recording device D Paper exit P recording paper P1 bellows jam

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H033 AA37 BA06 BA10                 2H071 BA03 BA13 BA24 BA27 BA29                       DA12 DA24                 2H072 CA01 EA16 FB01 JA02                 3F049 AA04 CA31 DA12 DB02 LA02                       LA05 LA07 LB03

Claims (5)

[Claims] 1. A paper discharge roller mechanism is provided at a paper discharge opening of a fixing unit, and the paper discharge roller mechanism is configured to be displaceable or detachable so as to open the paper discharge opening largely. An image recording device characterized in that 2. The image recording apparatus according to claim 1, wherein the paper discharge roller mechanism includes a driving roller, a driven roller, and a connecting frame that rotatably supports the driving roller and the driven roller. 3. The fixing unit is a frame that supports both ends of a drive shaft of the drive roller and a rotation shaft of a driven roller, and an end portion of the drive shaft penetrates the connection frame to form the fixing unit. Connected to the driving means of
The image recording apparatus according to claim 2, wherein the connection frame is rotatable about the drive shaft. 4. An operating unit for rotating the connecting frame is provided so as to be operable from the outside, and the operating unit is operated from the outside while maintaining the state in which the fixing unit is attached to the image recording apparatus. The image recording apparatus according to claim 2 or 3, wherein the sheet discharge port can be opened. 5. A member disposed at or near the sheet discharge port of the fixing unit can be operated from the outside while maintaining the state in which the fixing unit is attached to the image recording apparatus,
Further, the image recording apparatus is characterized in that the member is configured to be displaceable or detachable.