JPH05201190A - Paper hold down mechanism in image forming device - Google Patents

Abstract

PURPOSE:To prevent a cut section of a form from being displaced by the weight of the form when the form is cut with a cutter. CONSTITUTION:When a cutter is moved in the direction that a form supporter 8 is crossed and a form on the form supporter 8 is cut, a paper hold-down member 50 is lowered from a position lifted from the form supporter 8 and pushed against the form on the form supporter 8, and is not displaced from the form supporter 8 during a time when the form is cut. The position of pushing against the form at the lower end of the paper hold-down member 50 is set on the reverse side to the form holding side by a driving roller 20 and a press roller 24 while using the cutting executing section of the form as a reference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper pressing mechanism in an image forming apparatus having a paper cutting mechanism.

[0002]

2. Description of the Related Art A paper-driven plotter or a raster plotter (RASTER PLO) for printing or drawing on roll paper.
In an image forming apparatus such as TTER), as shown in FIG. 5, the pull-out portion of the roll paper 4 on the paper support is held between the drive roller and the pressure roller 6, and the pull-out portion of the roll paper 4 is It is known that the cutter is provided with a cutter 2 that cuts along a cutting groove formed on a paper support.

[0003]

In the above-mentioned conventional apparatus, as shown in FIG. 5, the drive roller and the pressure roller 6 of the roll paper 4 are separated from each other by the portion to be cut by the cutter 2.
The sides clamped by and are firmly supported on the platen by these rollers. However, since the portion of the sheet 4 on the side opposite to the holding side hangs downward from the platen due to its own weight, when the sheet is cut, the cut portion is displaced downward due to the weight of the sheet 4, Could not be cut accurately. for that reason,
There was a defect that the paper 4 had to be pressed by hand during the cutting operation. The present invention aims to eliminate the above defects.

[0004]

In order to achieve the above object, the present invention holds a sheet guided by a sheet support by a pinch roller mechanism and rotates the drive roller of the pinch roller mechanism to rotate the sheet. While feeding the paper along the paper support in a predetermined direction,
Draw on the paper by drawing means, and after drawing,
In an image forming apparatus in which a cutter is moved in a direction traversing a paper support to cut the paper supported by the paper support, the paper support is placed at a position facing the paper support in a widthwise direction of the paper support. A paper pressing member extending over the entire area is arranged, and the paper pressing member is allowed to abut on the paper support on the side opposite to the paper holding side by the pinch roller mechanism with reference to the cut execution portion of the paper. It is a thing.

[0005]

When the paper is cut, the paper pressing member is lowered to the paper pressing position on the paper support, and the paper pressing member presses the paper on the paper support. In this state, the paper is cut by the cutter. During the cutting of the paper, the side of the paper hanging from the paper support is pressed by the paper pressing member 50, and the deviation of the paper is prevented.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. 8 is a paper drive type plotter 1
It is a platen (paper support) fixed to the machine frames 12 and 14 fixed to the machine frame 11 of No. 0, and a Y rail 16 is provided above the platen (paper support) and erected on the machine frames 12 and 14.

A drawing roller 18 is provided inside the platen 8.
And a driving roller 20 are rotatably arranged in association with an X-axis driving device, and the upper portions of the rollers 18 and 20 are arranged in a slit formed on the platen 8 in the Y-axis direction. The rollers 18 and 20 are rotatably supported by the machine body 11.

A pressure roller 24 is rotatably supported by an arm 22 mounted on the Y rail 16 so as to be movable up and down, and the pressure roller 22 can elastically contact the drive roller 20 by the elastic force of a spring. It has become a structure. The Y-rail 16 has a drawing head 28 holding a pen 26.
A casing 30 of the cutting unit is movably attached. A rubber roller 34 and a round blade cutter 36 are rotatably supported by an arm 32 fixed to the casing 30 of the cutting unit.

The lower part of the round blade cutter 36 elastically contacts the upper surface of the platen 8 in the vicinity of a cutter groove 38 formed in the platen 8 in the Y-axis direction (the direction perpendicular to the paper surface in FIG. 1).
With the movement of the casing 30 along the Y rail 16,
It is configured to rotate by friction with the platen 8 or the surface of the sheet 4 on the platen 8. The rubber roller 34
Is transmitted to the round blade cutter 36 via a gear speed increasing mechanism.

A detachable hook 38 is attached to the casing 30.
Is pivotally supported by a shaft 40, and a pin 42 slidably supported by the casing 30 is engaged with the hook 38 immediately above one end thereof. Machine frame 1 on one side of the platen 8
4, a solenoid 44 is fixedly installed. When the cutting unit has moved to a predetermined standby position at the end of the Y rail 16, the upper end of the pin 42 is located at the solenoid 4
It is configured to be located immediately below the output shaft 46 of No. 4.

The attachment / detachment hook 38 is biased counterclockwise in FIG. 3 by a spring 49. The drawing head 28 is provided with a hook receiver 48 for engaging with the detachable hook 38. Reference numeral 50 denotes a paper pressing member arranged in the upper direction of the platen 8, and guide members 52 and 54 are vertically fixed and fixed to both ends of the paper pressing member 52,
A rack is formed on one surface of each of 54.

The machine frame 12 includes gears 56 and 58 meshing with the rack of the guide member 52, and the guide member 52.
The guide rollers 60, 62 that come into contact with the other surface of the gear are rotatably supported by the guide rollers 60, 62 and the gear 5
Reference numerals 6 and 58 constitute a guide mechanism for guiding the guide member 52 in the vertical direction, and a guide mechanism having the same configuration as the guide mechanism is also provided on the guide member 54 side. The gear 58 is connected to an output shaft of a motor 64 fixed to the machine body 11.

Next, the operation of this embodiment will be described. When a sheet is placed on the platen 8 and the plotting operation of the plotter is started, the pressure roller 24 makes elastic contact with the drive roller 20 from above the sheet 4, and the sheet 4 on the platen 8 is pressed against the drive roller 20. The drive roller 20 is held by the roller 24.
By the forward and reverse rotation of, the sheet is fed on the platen 8 in the left-right direction (X-axis direction) in FIG. On the other hand, the pen 26 is controlled to move up and down with respect to the sheet 4 on the drawing roller 18 and is fed in a direction (Y-axis direction) across the sheet 4 along the Y rail 16 so that the pen 26 draws a predetermined sheet on the sheet 4. Is performed.

During drawing, the paper pressing member 50 is held above the platen 8. When drawing on the sheet 4 is completed, the sheet 4 is moved on the platen 8 by the driving roller 20,
Place the portion of the paper 4 to be cut on the cutter groove 38,
Move to paper cutting operation. First, the controller drives the motor 64 to rotate the gear 58 to move the guide member 5
2, 54 are lowered, the paper pressing member 50 is pressed against the upper surface of the platen 8 from above the paper 4, and the paper 4 is pressed in the entire area of the platen 8 in the width direction.

The paper pressing position of the paper pressing member 50 is in the vicinity of the cut groove 38 and with reference to the cut groove 38.
It is set on the side opposite to the side where the drive roller 20 is arranged. Next, the controller solenoid 44 is energized to push down the pin 42, swing the detachable hook 38 clockwise around the shaft 40 in FIG. 3, and lift the tip of the detachable hook 38.

Next, when the head 28 is moved toward the end of the Y rail 16 and the attachment / detachment hook receiver 48 is moved to the engagement position with the attachment / detachment hook 38, the movement of the head 28 is stopped and the solenoid 44 is moved. De-energize. The attachment / detachment hook 38 swings counterclockwise in FIG. 3 by the pulling force of the spring 49, and the hooking portion of the hook 38 and the hook receiver 48.
And are engaged. Next, when the head 28 is moved leftward in FIG. 3 along the Y rail 6, the cutting unit is
It moves along the Y rail 16 in conjunction with the head 28.

As the cut unit moves in the left direction along the Y rail 16 in FIG. 3, the rubber roller 34 rotates counterclockwise while pressing the sheet on the platen 8, and this rotation causes the gear speed increasing mechanism to operate. It is transmitted to the round blade cutter 36 through the round blade cutter 36, and the round blade cutter 36 cuts the paper in the moving direction of the head 28 while rotating in the same direction as the rotation direction of the rubber roller 34 along the cutter groove 38.

During paper cutting, the paper pressing member 50 supports the side of the already-cut portion of the paper opposite to the side supported by the drive roller 20 and the pressure roller 24 and hanging from the platen 8. Therefore, the cut portion of the paper 4 does not shift downward due to the weight of the paper during cutting, and the cutter 36
The sheet is accurately cut along the cutter groove 38 by.

Next, an embodiment in which the paper pressing member is moved up and down manually will be described. Reference numerals 66 and 68 denote guide members, which are supported by the machine frames 12 and 14 via guide rollers 70 so as to be vertically movable. A paper pressing member 72 is installed between the upper ends of the guide members 66 and 68, and the upper surface of the member 72 is composed of a magnetic surface.
Magnets 74 and 76 are fixedly mounted on the machine casings 12 and 14,
The magnets 74 and 76 are arranged at positions in close contact with the paper pressing member 72 when the paper pressing member 72 is moved to the highest position.

The other structure is the same as that of the first embodiment. In the above-described configuration, the operator manually pulls up the paper pressing member 72, causes the magnets 74 and 76 to attract the paper pressing member 72, and holds the paper pressing member 72 at the raised position. When the paper is cut, the paper pressing member 72
Is pressed down by hand against the attraction force of the magnets 74 and 76, and the paper pressing member 72 is pressed against the paper on the platen 8. In each of the above-described embodiments, the movement of the cutting unit is performed by using the driving force of the drawing head, but the cutting unit may be self-propelled using a power source dedicated to the cutting unit.

In each of the above-mentioned embodiments, the paper pressing mechanism of the present invention is provided in the image forming apparatus for forming an image on a sheet with a pen. However, a known raster plotter or a known inject plotter or a known one is known. It can also be applied to plotters using serial heads. FIG. 6 shows an embodiment in which the present invention is applied to a raster plotter. In this embodiment, the cutter 36
The cutting unit provided with is connected to a dedicated drive device.

The paper 4 is the paper entrance 3 of the raster plotter.
It is inserted from 02. The paper 4 is the drive rollers 304, 3
06 and pressing rollers 308, 310 by a pinch roller mechanism, a known thermal head or a known L
The sheet 4 is delivered to the printing mechanism 312 including an ED head, and the sheet 4 is imaged here. When the drawing of the sheet 4 is completed, the controller lowers the guide member 52. As a result, the paper pressing member 50 moves the paper 4 into the guide plate 316.
Hold it on top.

Next, the controller drives the cutting unit in a direction traversing the sheet 4 and cuts the sheet 4 with the cutter 36. The paper pressing mechanism of this embodiment is the same as the paper pressing mechanism shown in FIG. The same components as those in FIG. 1 are designated by the same reference numerals to clarify the correspondence.

[0024]

As described above, according to the present invention, during the paper cutting operation, the side of the cut portion of the paper that hangs from the platen is pressed by the paper pressing member, so that accurate paper cutting can be performed.

[Brief description of drawings]

FIG. 1 is a side view of an image forming apparatus.

FIG. 2 is a front view of the image forming apparatus.

FIG. 3 is an enlarged front view of the image forming apparatus.

FIG. 4 is a front view of an image forming apparatus showing another embodiment.

FIG. 5 is an explanatory diagram of a conventional technique.

FIG. 6 is a side view of an image forming apparatus showing another embodiment.

[Explanation of symbols]

 2 Cutter 4 Roll paper 6 Pressure roller 8 Platen 10 Plotter 12 Machine frame 14 Machine frame 16 Y rail 18 Drawing roller 20 Driving roller 22 Arm 24 Pressure roller 26 Pen 28 Drawing line head 30 Casing 32 Arm 34 Rubber roller 36 Round blade cutter 38 Detachable Hook 40 Shaft 42 Pin 44 Solenoid 46 Output Shaft 48 Hook Receiver 50 Paper Holding Member 52 Guide Member 54 Guide Member 56 Gear 58 Gear 60 Guide Roller 62 Guide Roller 64 Motor 66 Guide Member 68 Guide Member 70 Guide Roller 72 Paper Holding Member 74 magnets 76 magnets

Claims (3)

[Claims] 1. A sheet guided by a sheet support is held by a pinch roller mechanism, and the sheet is sent in a predetermined direction along the sheet support by rotation of a drive roller of the pinch roller mechanism. Draw on the paper by the means, and after drawing, move the cutter across the paper support,
In an image forming apparatus configured to cut a sheet supported by a sheet support, a sheet pressing member is disposed at a position facing the sheet support and extending over substantially the entire widthwise direction of the sheet support. A paper pressing mechanism characterized in that a member can be brought into contact with the paper support on the side opposite to the paper holding side by the pinch roller mechanism, with reference to the cut portion of the paper. 2. The paper pressing member is linked to an elevating and lowering drive device, and by the driving device, a position in which the paper pressing member is raised with respect to the paper support and a paper pressing position in contact with the paper support are provided. The paper holding mechanism in the image forming apparatus according to claim 1, wherein the paper holding mechanism is controlled to move up and down. 3. The locking means for locking the paper pressing member at a position raised from the paper support, and the locking means can be manually released. A paper pressing mechanism in the described image forming apparatus.