JPH07271234A - Fixing device - Google Patents

Abstract

PURPOSE:To open/close a sheet guide accompanying the shifting of a separating pawl between positions where it is used with the separating pawl kept in slidable contact with a fixing roller as it is and where it is unused by a small turn. CONSTITUTION:On of upper and lower carrying guide members 3 and 4 is pivotally supported on the axis line 2a of one fixing roller 2 on the same side as one carrying guide member 4 out of upper and lower fixing rollers 1 and 2, one carrying guide member 4 comes into contact/uncontact with the other carrying guide member 3 by the turning centering the axis line 2a, to open/close a sheet path 5 between both guide members 3 and 4 and the separating pawl 7 coming into contact with the surface on a sheet feeding side of one fixing roller 2 is provided so as to move between a sheet separating position and a retreat position where the pawl 7 is retreated from the sheet separating position, accompanied with the turning of one carrying guide member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device, and more particularly, to a fixing device provided with a pair of rollers which rotate in pressure contact with each other, and a pair of upper and lower conveyance guide members for guiding a sheet fed from the pair of fixing rollers. It is about.

[0002]

2. Description of the Related Art In order to process a jammed sheet generated in a fixing section, it is necessary to open a sheet passage on the delivery side of the fixing section. As a structure around the fixing unit that satisfies this, the structure shown in FIGS. 5A and 5B and the structure disclosed in Japanese Patent Publication No. 4-7512 shown in FIGS. 6A and 6B. There is.

FIG. 5 shows an upper guide 51, an upper separation claw 52, a lower guide 53, a lower separation claw 54, and upper and lower sheet discharge guides 55 and 56, a first sheet discharge roller and roller 57,
58, the second paper discharge rollers and rollers 59, 60, and the paper discharge tray 61 are mounted on a single support bracket 62 to form a unit structure capable of handling all of them as a single assembly. By rotating around a fulcrum shaft P provided separately from the sheet passage 63 on the sheet feeding side of the pair of upper and lower fixing rollers 64 and 65 and the upper and lower fixing rollers 64 and 65,
As the upper and lower separation claws 52 and 54 are brought into contact with and separated from the fixing rollers 64 and 65 and moved between the sheet separation position shown in FIG. 5A and the retracted position shown in FIG. The upper and lower guides 51 and 53, the upper and lower paper ejection guides 55 and 56, and the paper ejection tray 61 can be moved between a use position and a retracted position retracted from the use position. In the state of the retracted position shown in FIG. 5B, the separation claw is moved to the retracted position, and the sheet passage 63 is opened so that the jam processing can be performed.

In FIG. 6, the sheet path 63 on the sheet feeding side of the upper and lower fixing rollers 64 and 65 and the fulcrum shaft P provided outside the axes of the upper and lower fixing rollers 64 and 65 are rotated. A movable support member 71 is provided, and the upper guide 51 is directly attached to the support member 71.
The separation claw 52, which is in sliding contact with the upper and lower fixing rollers 64, is provided via another support member 72, and the fulcrum shaft P of the support member 71 is provided.
As the separation claw 52 is brought into contact with and separated from the upper fixing roller pair 64 by the rotation around the center, the upper guide 51 is moved to the use position shown in FIG. It is designed to be moved to and from the retracted position shown in (b). In the state shown in FIG. 6B, the separation claw can be moved to the retracted position and the sheet passage 63 can be opened to perform jam processing and the like.

[0005]

However, in any of the above-mentioned prior arts, the separation claw is separated from the fixing roller or pressed against the fixing roller as the sheet guide is opened or closed. Therefore, the surface of the fixing roller is easily scratched. Further, since opening and closing of the sheet guide for jamming and the like is performed by rotating the sheet passage on the sheet feeding side of the fixing roller pair and the fulcrum shaft at a position deviated from the fixing roller, a relatively large operation is performed. Will be needed.
For example, in the one shown in FIG. 5, the opening / closing operation angle of the paper discharge unit is about 40 degrees, but a large paper discharge unit has a large swing diameter, and the work is not easy to rotate by the angle. Since the required space is large, other members are likely to be affected, and it is necessary to open and close the main body of the clamshell type, which makes the work even more troublesome. Although the seat guide shown in FIG. 6 has a small swing diameter, the seat passage cannot be sufficiently opened and closed unless the seat guide is rotated in a substantially inverted state of about 180 degrees, and therefore, the same operation as that shown in FIG. There is a space problem.

Therefore, according to the present invention, the sheet guide is sufficiently moved by the movement of the separation claw between the sheet separation position while slidingly contacting the fixing roller and the retracted position retracted from the separation position with a small rotation. It is an object of the present invention to provide a fixing device which can be opened and closed to solve the above-mentioned conventional problems.

[0007]

In order to achieve the above object, the present invention provides a pair of upper and lower fixing rollers that rotate in pressure contact with each other, and a pair of upper and lower conveyance guide members that guide the sheet sent from the pair of fixing rollers. In the fixing device, one of the upper and lower conveying guide members is pivotally supported on the axis of one fixing roller on the same side as the one conveying guide of the upper and lower fixing rollers, One of the conveyance guide members is rotated around this axis to separate from and contact the other conveyance guide member so that the passage between the two can be opened and closed, and the surface of the one fixing roller on the sheet delivery side. The separation claw that comes into contact with is provided so as to move between the sheet separation position and the retracted position retracted from the sheet separation position by being driven by the rotation of the one conveyance guide member. It is an butterfly.

[0008]

According to the above-mentioned structure of the present invention, one of the pair of upper and lower conveyance guide members separates from and comes into contact with the other conveyance guide member by pivoting about the pivot portion, and opens and closes the sheet passage between them. This pivotal support portion is on the same side as the one conveyance guide member of the pair of upper and lower fixing rollers, and on the axis line of the one fixing roller, the sheet passage on the sheet feeding side of the pair of upper and lower fixing rollers, and the fixing roller. Since it is located in the immediate vicinity of the sheet conveyance path, a small rotation of the one conveyance guide member causes the sheet passage to be sufficiently opened and closed with respect to the other conveyance guide member, so that the sheet passage can be sufficiently opened, which facilitates the work. However, since it does not easily interfere with others, it is possible to eliminate the inconvenience that the opening and closing of the clamshell is a condition by adopting a clamshell type main body. In addition, the separation claw that comes into contact with the one fixing roller is provided between the sheet separation position and the retracted position retracted from the sheet separation position without the need for any other special operation or work when the conveyance guide member is opened or closed. It is moved between the two to exert the separation function in a timely manner.
The sheet is retracted from the sheet path so that it does not interfere with the jam processing. The movement of the separation claw at this time is caused by the rotation of the one conveyance guide member around the axis of the one fixing roller on which the separation claw operates. The separation claw is in sliding contact with the surface of the one fixing roller from the beginning to the end, and is not in contact with or separated from the fixing roller, and the separation claw may damage the surface of the fixing roller. Can be resolved.

[0009]

EXAMPLES The fixing device of the present invention will be specifically described below with reference to some examples.

1 and 2 show a first embodiment of a fixing device of the present invention. This embodiment includes a pair of upper and lower fixing rollers 1 and 2 which rotate in pressure contact with each other, and a pair of upper and lower conveyance guide members 3 and 4 which guide the sheet S fed from the upper and lower fixing rollers 1 and 2. Assuming a fixing device, one of the upper and lower conveyance guide members 3 and 4, that is, the lower conveyance guide member 4 in this embodiment, is fixed to the upper and lower fixing rollers 1 and 2.
One of the fixing rollers, which is on the same side as the one lower conveyance guide member 4, of the present embodiment, is pivotally supported on the axis of the lower fixing roller 2, and the one conveyance guide 4 is centered on this axis. With this rotation, the other conveying guide member 3 is brought into contact with and separated from the other conveying guide member 3 so that the sheet passage 5 therebetween can be opened and closed.
The separation claw 7 that comes into contact with the surface of the lower fixing roller 2 on the sheet delivery side is moved in synchronism with the rotation of the one lower conveyance guide member 4 to a sheet separation position, and a retracted position retracted from this sheet separation position. It is provided to move between.

According to this structure, the lower transport guide member 4, which is one of the pair of upper and lower transport guide members 3 and 4, is
The other transport guide member 3 is rotated by the pivotal support.
The sheet passage 5 between the two is opened and closed by contacting and separating with the axis of the lower fixing roller 2 on the same side as the lower conveyance guide member 4 of the pair of upper and lower fixing rollers 1 and 2. Since the sheet passage 5 on the sheet delivery side of the pair of upper and lower fixing rollers 1 and 2 and the fixing rollers 1 and 2 are positioned in the immediate vicinity, the small rotation of the one lower conveyance guide member 4 causes Since the sheet passage 5 can be opened sufficiently by being brought into and out of contact with the other upper conveyance guide member 3 easily, the work is easy and does not easily interfere with others, and a clamshell type main body is adopted. The inconvenience that the opening and closing of the clam shell is a condition can be eliminated. Further, the lower separation claw 7 that contacts the one lower fixing roller 2
However, when the lower conveyance guide member 4 is opened / closed, it is moved between the sheet separating position and the retracted position retracted from the sheet separating position without any other special operation or work, and the separating function is timely. In addition, the lower separation claw 7 moves in the axial direction of the one lower fixing roller 2 on which the separation claw 7 operates, while the sheet is retracted from the sheet path 5 so as not to interfere with the jam processing. The lower separation claw 7 is in sliding contact with the surface of the one lower fixing roller 2 from beginning to end.
It is possible to eliminate the inconvenience of scratching the surface of the lower fixing roller 2 by separating or contacting without contacting and separating.

In this embodiment, the lower conveyance guide member 4 and the lower separation claw 7 are fitted to the rotary shaft 2a of the lower fixing roller 2 and are pivotally supported as shown in FIGS. And a lower guide assembly 11 that can be integrally rotated around the rotation shaft 2a. On the other hand, the upper conveyance guide member 3 and the upper separation claw 6 are provided with a fixed support member 12
The upper guide assembly 13 is also supported by the first paper discharge roller 18 provided immediately after the upper transport guide member 3. On the other hand, the transport guide members 3, 4
Immediately after, a paper discharge unit 15 is provided. The paper discharge unit 15 includes a first paper discharge roller 19, which is opposed to a first paper discharge roller 18 which is sequentially arranged in the paper discharge direction from the fixing rollers 1 and 2 in the paper discharge frame 17, and a pair of upper and lower paper discharge rollers. Guide pair 21, 22 and second paper ejection roller 2
3 and the second discharge roller 24 are supported, and the discharge frame 1
By pivoting about a shaft 25 that pivotally supports a part of the lower part of 7, it is necessary to move it between the use position of FIG. 1 (a) and the retracted position shown in FIG. 1 (b). Accordingly, by setting the retracted position of FIG. 1B, the lower separation claw 7 is set to the retracted position and the sheet passage 5 is opened, so that the jam processing and the like can be dealt with.

Here, the upper fixing roller 1 is a heating roller having a built-in heater, and the lower fixing roller 2 is a pressure contact roller which is in pressure contact with the upper fixing roller 1, and the sheet S passing between the both is subjected to a fixing process by heating and pressing. It's done. However, there are various fixing methods using the upper and lower fixing rollers, and the present invention is not limited to the method. The upper and lower conveyance guide members 3 and 4 are plate members, one of which has a flat surface as a guide surface, and the other of which has an edge as a guide surface. However, the guide surface may be any portion, and a portion other than the plate member may be a conveyance guide. It can also be adopted as a member.

The support frame 17 of the paper discharge unit 15 is provided with a paper discharge tray 26 for receiving the discharged sheets. In addition to this, when the paper discharge unit 15 is in the use position, the lower guide assembly 11 is provided. A spring member 27 is also provided, which elastically holds it in use position.

The spring member 27 is a leaf spring in this embodiment, but is not limited to this. The spring member 27 is provided in an inclined posture from the lower portion of the support frame 17 to the rearward and obliquely downward direction, and when the support frame 17 is retracted to the retracted position shown in FIG. 1B, the spring member 27 is moved to the lower guide assembly. Apart from 11, the lower guide assembly 11 can be automatically moved to the non-use position by the rotation around the shaft 2a by its own weight.

When the support frame 17 is pushed back to the use position, the spring member 27 is pressed against the lower guide assembly 11 from below, and the lower guide assembly 11 is elastically pushed back upward to return it to the use position. At the same time, it is pressed and held in this use position to be stabilized.

The lower guide assembly 11 has a stopper 28 which regulates the position returned by this pressing. As shown in FIG. 2, the stopper 28 supports the support member 9
The upper and lower transport guides 3 and 4 are prevented from approaching each other by a predetermined distance or more by being integrally molded with the upper transport guide member 3.

By the way, in this embodiment, the paper discharge unit 1
Utilizing that 5 is located on the outermost side,
The lower guide assembly 11 can be automatically opened and closed with the opening and closing of the lower guide assembly. However, the lower guide assembly 11 may be directly operated to be opened and closed independently. In this case, the lower guide assembly 11
Since the opening / closing operation of the item is small, it is less likely to interfere with other items, and the simultaneous opening / closing of other items does not become a condition, which facilitates work.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the vine winding portion 31 is provided between the lower guide assembly 11 and the bottom of the support frame 17 of the paper discharge unit 15.
A torsion coil spring 31 in which a is pivotally supported by a shaft 32 is provided, and the lower guide assembly 11 is moved by a movement between the use position and the retracted position of the paper discharge unit 14 via the torsion coil spring 31. It can be moved between the use position and the retracted position, and this point is different from the first embodiment. When the torsion coil spring 31 is employed as in this embodiment, the position of the fulcrum pivotally supported by the shaft 32 can be freely set, which increases the degree of freedom in design and facilitates design.

For smooth interlocking, a cam portion 17a is provided by obliquely cutting a portion of the support frame 17 that abuts the vine spring 31.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, one upper conveyance guide member 3 of the conveyance guide member pairs 3 and 4 is rotated about the axis of the one upper fixing roller 1 on the same side as the upper conveyance guide member 3 so that the upper conveyance guide member 4 is rotated.
The upper separation claw 9 that is in contact with the surface of the upper fixing roller 1 on the sheet feeding side is slidably contacted with the surface of the upper fixing roller 1 while being brought into contact with the surface of the upper fixing roller 1 so as to be opened and closed. And a retracted position retracted from the use position. Such a configuration also belongs to the category of the present invention, and it is possible to exhibit the same action and effect as in the case of the first and second embodiments described above. The upper guide assembly 31 of this embodiment shows a case where the upper guide assembly 31 is manually operated to open and close.

In this embodiment, the support member 12 for supporting the upper conveyance guide member 3 for rotating the upper conveyance guide member 3 is
The upper fixing roller 1 is pivotally supported by a rotation shaft 1a.

[0023]

According to the present invention, from the above configuration and operation, a small rotation of one of the transport guide members causes the other transport guide member to be brought into large contact with and separated from the other transport guide member to sufficiently open the sheet passage. It can be done easily, does not interfere with others, and adopts a clamshell type main body, so that the inconvenience of opening and closing the clamshell can be eliminated. In addition, the movement of the separation claw, which is in contact with the one fixing roller, between the sheet separation position that exhibits the separation function when the conveyance guide member is opened and closed and the retracted position that does not interfere with the jam processing, is caused by the movement of the one fixing roller. It is achieved by merely sliding the surface of the fixing roller from beginning to end and does not come into contact with or separate from the surface of the fixing roller.

[Brief description of drawings]

FIG. 1 is a side view showing separately a sheet discharge state and a jam processing state of a fixing device according to a first exemplary embodiment of the present invention.

FIG. 2 is a perspective view showing the relationship between the lower fixing roller and the lower separation claw of FIG.

FIG. 3 is a side view separately showing a sheet discharge state and a jam processing state of the fixing device according to the second exemplary embodiment of the present invention.

FIG. 4 is a side view showing a paper discharge state and a jam processing state of a fixing device showing a third embodiment of the present invention with solid lines and broken lines.

FIG. 5 is a side view separately showing a sheet discharge state and a jam processing state of the fixing device showing the first conventional example.

FIG. 6 is a side view showing separately a paper discharge state and a jam processing state of a fixing device showing a second conventional example.

[Explanation of symbols]

 1, 2 Vertical fixing rollers 1a, 2a Rotating shafts 3, 4 Vertical transport guide members 5 Sheet passages 6, 7 Vertical separation claws 9, 12 Support members S sheets

Claims (1)

[Claims] 1. A fixing device comprising: a pair of upper and lower fixing rollers that rotate in pressure contact with each other; and a pair of upper and lower conveyance guide members that guide a sheet sent from the pair of fixing rollers. One of the members is pivotally supported on the axis line of one fixing roller on the same side as the one conveyance guide member of the upper and lower fixing rollers, and the one conveyance guide member is centered on this axis line. When rotated, it separates from and comes into contact with the other conveyance guide member so that the sheet path between them can be opened and closed, and the separation claw that comes into contact with the surface of the one fixing roller on the sheet feeding side is provided with the one conveyance guide member. The fixing device is provided so as to move between a sheet separating position and a retracted position retracted from the sheet separating position in response to the rotation of the fixing device.