JPH0977295A - Endless belt drive - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an endless belt drive device capable of performing quicker and more reliable return control with respect to rapid movement of the endless belt in the depth direction. [Structure] An endless belt 1 is suspended between a drive roller 2 and a tension roller (following roller) 3 whose one end is movably supported up and down, and the endless belt 1 is rotated by driving the drive roller 2. In an endless belt driving device that rotates and conveys, a belt pressing member to which the inner peripheral surface of the endless belt 1 should be abutted and pressed by the vertical movement of one end of the driven roller 3 when the endless belt 1 is displaced from the neutral position. (Belt pressing means) 4 and 5 are provided. According to the present invention, when the endless belt 1 is disengaged from the neutral position, the endless belt 1 is pressed against the belt pressing members 4 and 5, so that wrinkles do not occur in the endless belt 1 and therefore the tension roller 3 The vertical movement amount can be set larger than in the conventional case, and quicker and more reliable return control can be performed for a sudden movement of the endless belt 1 in the depth direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless belt drive device for rotating and conveying an endless belt.

[0002]

2. Description of the Related Art As such an endless belt drive device, as shown in FIG. 8, an endless belt 1 is stretched over a drive roller 2, a tension roller 3, etc.
It is known that the endless belt 1 is driven and conveyed in the direction of the arrow B in the drawing by the rotation of. In this type of endless belt drive, the endless belt 1 is shown in FIG.
Is moved in the depth direction (front side or back side), and the conveyance of the endless belt 1 is likely to be unstable.

Therefore, one end of the tension roller 3 is fixed, and the other end is indicated by an arrow A in FIG.
Endless belt 1 by moving up and down in the direction
There is known a method of stabilizing the conveyance of the endless belt 1 by controlling the movement of the endless belt 1 in the depth direction. In this method, when the moving end side of the tension roller 3 is moved upward, the endless belt 1 shifts toward the moving end side of the tension roller 3, and when moved downward, the endless belt 1 is fixed at the fixed end of the tension roller 3. Get closer to you.

[0004]

However, in the conventional endless belt driving device, if the vertical movement amount of the tension roller 3 is set excessively in order to rapidly move the position of the endless belt 1 in the depth direction, the endless belt 1 Since the endless belt 1 may be wrinkled due to a noticeable difference in circumferential length between the two ends of the tension roller 3, the vertical movement amount of the tension roller 3 is limited, and the latitude of the position control of the endless belt 1 is limited. It is a cause that can not be taken widely.

The present invention has been made in view of the above problems, and its object is to prevent wrinkles from occurring in the endless belt even if the vertical movement amount of the driven roller is excessively set to some extent. An object of the present invention is to provide an endless belt drive device capable of performing quicker and more reliable return control with respect to a sudden movement in the depth direction.

[0006]

To achieve the above object, the invention according to claim 1 suspends an endless belt between a drive roller and a driven roller whose one end is movably supported up and down. In an endless belt drive device that rotationally conveys the endless belt by rotationally driving a drive roller, the inner peripheral surface of the endless belt is abutted by the vertical movement of one end of the driven roller when the endless belt is displaced from the neutral position. It is characterized in that a belt pressing means to be pressed against is provided.

According to a second aspect of the invention, in the first aspect of the invention, the belt pressing means is formed in an arc shape in which the belt pressing means is arranged in parallel with the driving roller and the driven roller on the inner peripheral side of the endless belt. It is characterized by comprising the belt pressing member of.

According to a third aspect of the present invention, in the first aspect of the invention, the belt pressing means is disposed on the inner peripheral side of the endless belt so as to be rotatable parallel to the driving roller and the driven roller. It is characterized by comprising a belt pressing roller.

Therefore, according to the present invention, when the endless belt is disengaged from the neutral position, one end of the driven roller is vertically moved to press the endless belt against the belt pressing means. Since wrinkles and slacks do not occur, the amount of vertical movement of the driven roller can be set to a larger value than without the belt pressing means, and it is quicker and more reliable against sudden movement of the endless belt in the depth direction. Recovery control can be performed.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIGS. 1 to 3 are side sectional views of a heating and fixing device including an endless belt driving device according to a first embodiment of the present invention, and FIG. 4 is a plan view of the endless belt driving device. .

In FIG. 1, reference numeral 1 denotes an endless heat-resistant thin film endless belt wound around a driving roller 2, a tension roller 3 and a heating element 7. The heating element 7 is applied with the endless belt 1 interposed therebetween. The pressure roller 8 is pressed with a predetermined pressure.

By the way, as shown in FIG. 4, the tension roller 3, which is the driven roller, is rotatably supported at both axial ends by bearings 11 and 12, and one axial end (D side) thereof is supported. It is a fixed end, and the other end (C side) is supported so as to be vertically movable. And the bearings 11, 12
Are urged in the direction of the arrow E in FIG. 4 by the tension coil springs 9 and 10, respectively.
The tension roller 3 supported by is pulled in the same direction (the direction away from the belt driving roller 2), whereby a required tension is applied to the endless belt 6.

The bearing 12 on the C side is supported by a swing arm 14. The bearing 12 and the C side of the tension roller 3 supported by the bearing 12 are driven by a driving means (not shown) about a shaft 15 as a rotation center. It is configured to be movable in the vertical direction (F direction in FIG. 2 and G direction in FIG. 3).

Thus, in the present embodiment, the arc-shaped belt pressing members 4, 5 are provided on the inner peripheral side of the endless belt 6.
Are arranged above and below the driving roller 2 and the tension roller 2 in parallel, and when the C-side end of the tension roller 3 is in the neutral position as shown in FIG. 1, both belt pressing members 4 and 5 are endless. It is in a position where it does not come into contact with the belt 1.

In the heat fixing device having the above-described structure, the driving roller 2 and the pressure roller 8 are rotationally driven in the directions of the arrows in FIG. 1 by the driving means (not shown), whereby the endless belt 1 and the tension roller are driven. 3 are rotated in the directions of the arrows in FIG.

Then, the transfer sheet P carrying the toner image is conveyed in the direction of the arrow in FIG. 1 along the conveying guide 18, and the transfer sheet P passes through the fixing nip portion between the endless belt 1 and the pressure roller 8. In the process of passing, the toner image is fixed on the transfer paper P by heat and pressure. The amount and direction of movement of the endless belt 6 in the depth direction (H direction in FIG. 4) at the time of driving are detected by a belt position detection means (not shown).

When the belt position detecting means determines that the endless belt 1 has moved from the neutral position to the D side, the swing arm 14 swings upward so that the endless belt 1 returns to the neutral position. 2, the end portion of the tension roller 3 on the C side is moved in the upward direction (F direction), so that the endless belt 1 is pressed against the lower belt pressing member 5 as illustrated.

When it is determined by the belt position detecting means that the endless belt 1 has moved from the neutral position to the C side, the swing arm 14 swings downward so that the endless belt 1 returns to the neutral position. As shown in FIG. 3, the end portion of the tension roller 3 on the C side is moved upward (direction G), so that the endless belt 1 is pressed against the upper belt pressing member 4 as shown in the drawing.

As described above, when the endless belt 1 is disengaged from the neutral position, the end portion of the tension roller 3 on the C side is moved up and down as shown in FIGS. 2 and 3, and the endless belt 1 is pushed by the belt pressing member 5. , 4 are abutted and pressed, no wrinkles or slack is generated in the endless belt 1. As a result, the vertical movement amount of the tension roller 3 can be set to be larger than that without the belt pressing members 4 and 5, and the sudden movement of the endless belt 1 in the depth direction (H direction in FIG. 4) can be prevented. Therefore, quicker and more reliable return control can be performed.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6 are side sectional views of a heating and fixing device including an endless belt driving device according to the second embodiment of the present invention, and FIG. 7 is a plan view of the endless belt driving device. The same elements as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted below.

In this embodiment, instead of the belt pressing members 4 and 5 in the first embodiment, a belt pressing roller 16,
17 is provided, and the other structure is the same as that of the first embodiment.

Thus, also in the present embodiment, when the endless belt 1 is out of the neutral position, the end portion of the tension roller 3 on the C side is moved up and down as shown in FIGS. 1 is the belt pressing roller 1
The endless belt 1 is not wrinkled or loosened because the endless belt 1 is abutted against and pressed by the rollers 6 and 17. As a result, the vertical movement amount of the tension roller 3 can be set to be larger than that without the belt pressing rollers 16 and 17, and the sudden movement of the endless belt 1 in the depth direction (H direction in FIG. 7) can be prevented. Therefore, quicker and more reliable return control can be performed. In addition, in the present embodiment, the rotatable belt pressing roller 1
Since Nos. 6 and 17 are used, the rotational drive load of the endless belt 1 can be further reduced, and sliding wear of the inner peripheral surface of the endless belt 1 can be prevented to improve the durability of the endless belt 1. be able to.

[0024]

As is apparent from the above description, according to the present invention, the endless belt is suspended by the drive roller and the driven roller whose one end is movably supported up and down to rotate the drive roller. In an endless belt drive device that rotates and conveys the endless belt by driving, the inner peripheral surface of the endless belt is abutted and pressed by the vertical movement of one end portion of the driven roller when the endless belt deviates from the neutral position. When the endless belt comes out of the neutral position, one end of the driven roller is moved up and down, and the endless belt is pressed against the belt pressing means, causing wrinkles and slack in the endless belt. Therefore, the vertical movement amount of the driven roller can be set larger than that without the belt pressing means. It can be, the effect is obtained that it is possible to perform more rapid and reliable recovery control for rapid movement in the depth direction of the endless belt.

[Brief description of drawings]

FIG. 1 is a side sectional view of a heat fixing device including an endless belt driving device according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of a heat fixing device including the endless belt drive device according to the first embodiment of the present invention.

FIG. 3 is a side sectional view of a heating and fixing device including the endless belt driving device according to the first embodiment of the present invention.

FIG. 4 is a plan view of the endless belt drive device according to the first embodiment of the present invention.

FIG. 5 is a side sectional view of a heat fixing device including an endless belt drive device according to a second embodiment of the present invention.

FIG. 6 is a side sectional view of a heating and fixing device including an endless belt drive device according to a second embodiment of the present invention.

FIG. 7 is a plan view of an endless belt drive device according to a second embodiment of the present invention.

FIG. 8 is a side sectional view of a heating and fixing device including a conventional endless belt driving device.

[Explanation of symbols]

 1 Endless Belt 2 Drive Roller 3 Tension Roller (Following Roller) 4,5 Belt Pressing Member (Belt Pressing Means) 16,17 Belt Pressing Roller (Belt Pressing Means)

Claims (3)

[Claims] 1. An endless belt is suspended from a drive roller and a driven roller whose one end is movably supported up and down.
In an endless belt drive device that rotationally conveys the endless belt by rotationally driving the drive roller, an inner peripheral surface of the endless belt is formed by vertical movement of one end of the driven roller when the endless belt deviates from a neutral position. An endless belt drive device comprising a belt pressing means to be contacted and pressed. 2. The belt pressing means comprises an arcuate belt pressing member which is arranged on the inner peripheral side of the endless belt in parallel with the driving roller and the driven roller. The endless belt drive described. 3. The belt pressing means is composed of a belt pressing roller arranged on the inner peripheral side of the endless belt so as to be rotatable in parallel to a driving roller and a driven roller. The endless belt drive described.