JPH08165049A - Curl correcting device for sheet - Google Patents

Abstract

PURPOSE: To provide a curl correcting device which can stably convey a sheet and correct its curl in both directions regardless of a kind and ream weight of paper. CONSTITUTION: A pair of variable rollers 1 are mounted in a moving mechanism. In this way, a pair of the variable rollers 1, left as interposing conveying belts 5, 6, are moved vertically relating to a conveying direction of a sheet 12. Since the sheet 12, left a interposed by the conveying belts 5, 6, is fed to run, the sheet is conveyed along the shape of the belts. The conveying belts 5, 6 are driven by a motor through a timing belt. By tension rollers 9, 10 mounted in springs 7, 8, fixed tension is always obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet curl correction device used in printers, copying machines and the like.

[0002]

2. Description of the Related Art In printers and copiers of computer peripherals, printed sheets are discharged to a stacker.
At this time, the curl of the sheet may deteriorate the alignment of the sheet, and it is necessary to correct the curl.

Conventionally, as shown in FIG. 5, a belt and a roller are installed so as to face each other, and a sheet is passed between them, so that the correction can be made in only one direction.

Further, as shown in FIG. 6, a device is known in which a path is divided into three parts according to the curl direction of the sheet and the curling correction is performed in both directions by utilizing the ironing action.

[0005]

The curl direction of a sheet after printing is not constant depending on the sheet setting direction before printing, and it is difficult to correct all curl corrections in only one direction. For this reason, conventionally, the operator had to set the paper in the direction in which the curl can be corrected, which is troublesome. Even if the path is divided into several parts and correction in both directions is possible, it is difficult to stably feed the sheet.

In order to solve the above problems, an object of the present invention is to provide a sheet curl correction device capable of correcting in both directions by conveying a sheet by a belt and changing the shape of the belt by a roller. To do.

Another object of the present invention is to provide a curl correction device capable of correcting in both directions.

Another object of the present invention is to provide a curl correction device in which a sheet is sandwiched by a belt so that stable feeding is performed.

Still another object of the present invention is to provide a curl correction device capable of arbitrarily changing the correction amount within the correction range.

[0010]

[Means for Solving the Problems] The above-mentioned object is that the curl of the paper can be corrected by squeezing it in the opposite direction to the curl direction, and that the paper is pinched by a continuous belt so that the curl can be corrected even during the curl correction. This is achieved by moving a pair of rollers via a belt in the direction opposite to the paper curl direction, paying attention to the fact that stable feeding performance can be ensured.

[0011]

According to the present invention, the shape of the belt which conveys the sheet can be corrected in both directions by deforming the belt by moving the variable roller up and down in the feeding direction by a motor or the like.

Further, the curl correction amount can be adjusted by providing a means for adjusting the movement amount.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a sheet curl correction device according to an embodiment of the present invention.

The sheet 12 after fixing is sent to the first carrying path 4 by the carrying roller 13 and the pressure roller 15 while curling upward or downward. When the leading edge of the sheet 12 exits the first transport path 4, the sheet 12 is firmly nipped by the transport belts 5 and 6 driven by the drive roller 2 and the transport roller 3, and is transported. The conveyor belts 5 and 6 are sandwiched by a pair of variable rollers 1 and driven by a driving roller 2, conveyor rollers 3, 17, and 18, tension rollers 9 and 10.

The drive roller 2 uses a motor 19 as a drive source and is driven via a timing belt 20. Here, the pair of variable rollers 1 is moved up and down in the direction opposite to the curling direction of the sheet 12 with respect to the feeding direction of the sheet 12. The vertical movement of the pair of variable rollers 1 is performed by the moving mechanism 21.
Performed by. When the curl direction of the sheet is upward, the center position of the pair of variable rollers 1 is above the first conveyance path 4 and the second conveyance path 11 (FIG. 2). When the curl direction of the sheet is downward, the pair of variable rollers 1
The center position of is lower than the first transport path 4 and the second transport path 11 (FIG. 3), and its displacement amount can be adjusted arbitrarily. When the pair of variable rollers 1 move up and down, the tension of the conveyor belts 5 and 6 is reduced by the tension rollers 9 and 10.
It is kept constant by springs 7 and 8 mounted on.

The sheet 12 sandwiched by the conveyor belt 5 and the conveyor belt 6 is forcibly bent in a direction opposite to the curl direction by the pair of variable rollers 1 to remove the curl.

The sheet 12 whose curl has been removed by the pair of variable rollers 1 is guided to the second transport path 11 and is transported to the next unit by the transport roller 14 and the pressure roller 16.

The volume resistivity values of the conveyor belts 5 and 6 are
100 to prevent electrostatic charging due to contact with paper
It is made below MΩcm.

FIG. 4 shows an example of a vertical movement mechanism for the pair of variable rollers 1. Regarding mounting of the pair of variable rollers 1, the variable upper roller 1a and the variable lower roller 1b are
It is fixed to the plates 22 and 23 via bearings 32, 33, 34 and 35. However, since the bearings 32 and 34 of the variable upper roller 1a can move up and down, the gap adjustment with the variable lower roller 1b can be easily performed.

The end faces of the plates 22 and 23 are partly racks, and mesh with gears 27, 28, 30, 31 fixed to the shafts 26 and 29. Shaft 2
6 is fixed to the motor 24 via a tight ring 25. Therefore, when the motor 24 rotates, the shaft 26 rotates via the tight ring 25, so that the gear 27
The rotation of plates 28 and 28 causes plates 22 and 23 to rotate.
Moves up and down. As a result, the pair of variable rollers 1 moves up and down while the belts 5 and 6 are sandwiched.

By providing the projection 36 on a part of the plate 22, the upper and lower limits are detected by the upper sensor 37 and the lower sensor 38. During this time, the pair of variable rollers 1 can be stopped at an arbitrary position, whereby
The mechanism is such that the amount of curl correction on the sheet can be changed.

[0022]

[Application example]

(1) The pair of variable rollers 1 has a movable mechanism for adjusting the amount of curl correction. However, when only a certain amount of correction is required, the pair of variable rollers 1 is fixed at a certain place. However, the same effect as the present invention can be obtained.

(2) The position of the pair of variable rollers 1 is set by a drive source such as a motor, but the same effect as the present invention can be obtained even when the positions are set manually.

(3) Even if the conveyor rollers 17 and 18 can be moved instead of the tension rollers 9 and 10 in order to obtain the tension of the conveyor belts 5 and 6, the same effect as the present invention can be obtained.

[0025]

As described above, according to the present invention, the curl of the sheet can be corrected in both directions by moving the belt for conveying the sheet up and down with respect to the sheet feeding direction.

Further, by using the belt system, it is possible to secure stable feeding performance while performing curl correction.

Further, since the pair of variable rollers is moved so that the correction amount can be arbitrarily changed, it is possible to deal with the case where the amount and direction of curl are different depending on the type of sheet and the continuous amount.

Therefore, it can be used as a curl correction device in a printer or a copying machine of computer peripherals.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a sheet curl correction device.

FIG. 2 is an explanatory diagram showing correction of upward curl.

FIG. 3 is an explanatory diagram showing correction of a downward curl.

FIG. 4 is an explanatory view showing an example of a vertical movement mechanism of a roller.

FIG. 5 is a curl correction device according to the related art (one-way correction)
It is explanatory drawing which showed an example.

FIG. 6 A curl correction device according to the related art (bidirectional correction)
It is explanatory drawing which showed an example.

[Explanation of symbols]

1 is a pair of variable rollers, 5 and 6 are conveyor belts, 7 and 8 are springs, 9 and 10 are tension rollers, 21 is a motor, 22 is a timing belt, and 23 is a variable roller moving mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Seino 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Hitachi Koki Co., Ltd.

Claims (5)

[Claims] 1. A sheet conveying apparatus comprising a belt for conveying a sheet, a roller for driving the belt, and a pair of rollers mounted so as to sandwich the belt, wherein the pair of rollers are displaced by a predetermined amount with respect to a feeding surface. A sheet curl correcting device, which is provided as a sheet curl correction device. 2. A pair of rollers that sandwich the belt,
The sheet curl correcting device according to claim 1, wherein the curl of the sheet is corrected in both directions so as to be vertically movable with respect to the sheet feeding surface. 3. The pair of vertically movable rollers are located above the sheet feeding surface when the sheet is curled upward, and below the sheet feeding surface when the sheet is curled downward. 3. The sheet curl correction device according to claim 2, wherein the sheet curl direction and the pair of rollers have a positional relationship. 4. The sheet curl correcting device according to claim 1, wherein the belt has a volume resistivity of 100 MΩcm or less. 5. The sheet curl correction device according to claim 2, wherein the position of the roller is adjustable within the moving range of the roller moving up and down, and an arbitrary correction amount can be set.