JPH03120147A - Skew correcting device for paper - Google Patents

Abstract

PURPOSE:To accurately convey paper with no position displacement by providing a detecting means, which detects the position displacement in a width direction of the roll paper, and a correcting means, which performs skew correction of the roll paper in accordance with the detected position displacement, when picture printing and winding back of the roll paper are performed. CONSTITUTION:An edge position of recording paper 21 by an edge sensor 28 and a paper edge detecting circuit is detected, and the edge position is judged for whether it is in a predetermined reference position or not. Here in the case of this edge position in a right side from the reference position, a position of the recording paper 21 is judged to be displaced to the right side, and by controlling a solenoid drive circuit to turn on a solenoid 29 to be extended for moving the recording paper 21 to the left side, a skew correction roll 33 and a guide roll 34 are placed in a non-parallel condition with tension applied to a right edge of the roll-shaped recording paper 21. The recording paper 21, when it is wound back by a supply roll 22, is moved to the left side following a turn-on of the solenoid 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper skew correction device that performs skinny correction for widthwise positional deviation of roll paper during conveyance.

[Conventional technology]

Conventionally, this type of apparatus has been used in an electrostatic color plotter as shown in FIG. 6, which does not include a recording paper cutting mechanism. In the electrostatic color plotter described above, when printing an image in multiple colors, the supply roll 12 for supplying paper, the take-up roll 13 for winding up paper, and the drive roll 14 for transporting paper are driven to form a roll. The conveyance and rewinding of the recording paper 11 must be performed alternately. For this purpose, registration marks are printed in advance at predetermined intervals on the edge of the recording paper 11 according to paper size information sent from a host computer (not shown), and the registration marks are printed on mark sensors attached to both sides of the recording head 18. 15 to adjust the print position, and also detect the edge position of the recording paper 11 by edge sensors 16 and 17 disposed near the supply roll 12 and take-up roll 13, and adjust the print position according to the detection. The above supply troll 12 and take-up roll 13
Skew correction during conveyance and rewinding of the recording paper 11 was performed by adjusting the alignment by sliding the recording paper 11 left and right.

FIG. 7 is a flowchart showing the operation of multicolor printing, and the skew correction is performed during image printing by the recording head 18 (steps 101, 103, 105, 107, and 109).
This is done by sliding the supply troll 12 left and right (see the arrows in Figure 6), and during rewind (step 10).
2.104.106.108), this was done by sliding the take-up roll 13 left and right (see the arrows in FIG. 6). In addition, 19 is a developing section having color toner for each color (black, cyan, magenta, and yellow in the embodiment), and a predetermined color toner is sprayed onto the electrostatic latent image generated by the recording head 18 to adhere to the electrostatic latent image. By doing so, a color visible image is developed and generated.

[Problem to be solved by the invention]

However, in the skew correction device used in the electrostatic color plotter, etc., when a cutter for cutting a roll of recording paper is installed, the recording paper is cut by the cutter before reaching the take-up roll. There is a problem in that skew correction cannot be performed by the take-up roll during rewinding, and this causes color shift in images during printing.

The present invention was made in view of the above-mentioned problems, and it is an object of the present invention to provide a skew correction device that can reliably perform skew correction when printing images on recording paper and during rewinding, and can prevent color misregistration of images. ;j.

[Means to solve the problem]

In the present invention, in a paper cutting device that performs image printing after adjusting the position of a roll paper, and cuts the roll paper on which the image has been printed at a predetermined position by a cutting means such as an auto cutter, the roll paper An edge sensor and C for detecting a positional deviation of the roll paper from a reference position in the width direction when printing an image on the paper and rewinding the paper.
The apparatus includes a detection means such as a PU, and correction means such as a correction solenoid, a supply troll, and a CPU that perform skinny correction of the roll paper according to the detected positional deviation.

[Effect]

When the detection means detects a positional deviation of the roll paper during image printing and rewinding of the paper, the correction means controls the movement of the paper according to the direction of the detected positional deviation, and moves the paper to a predetermined reference position. It works to correct.

Therefore, when the roll paper is rewound, the paper is wound up accurately without any misalignment, and when printing the next image, the image is printed at the correct paper position without causing any color misalignment. Ru.

〔Example〕

Embodiments of the present invention will be described in detail based on the drawings of FIGS. 1 to 5.

FIG. 1 is a perspective view of the configuration of an electrostatic color plotter using the skew correction device according to the present invention, in which the supply roll 22 and drive rolls 23 to 25 are driven when printing a multicolor color image. The roll-shaped recording paper 21 is conveyed and rewinded alternately. and,
When conveying the recording paper 21 when printing an image, the edge sensor 26 disposed near the supply trolley 22 detects the edge of the recording paper 11, and if a positional shift occurs, the supply trolley 22 is moved to the correct position. The positional deviation is corrected by controlling the movement from side to side in the figure according to the deviation. Also, when rewinding, cutter 27
The edge position of the recording paper 11 is detected by the edge sensor 28 disposed near the recording paper 11, and when a positional deviation occurs, a solenoid 2 disposed on the side of the recording paper 11 is activated.
9.30, the skew correction roll 33 (see FIG. 2) connected via the L-shaped arm 31.32 is moved, and the recording paper 21 is moved between it and the guide roll 34. The movement of the recording paper 21 is controlled by applying tension to one side. That is, the above solenoid 29.3
0 extends in the OFF state and contracts in the ON state, and the arm 31.
32 and each end of the skew correction roll 33 is connected to a shaft 31a.
, 32a. In addition, the arm 31.3
2 is the stopper 3 when the solenoid 29.30 is extended.
1b and 32b.

Furthermore, for printing multicolor images of the electrostatic color plotter, 35 is an encoder shaft, 36 is a recording head, and 37 is a developing section, and the operation of printing multicolor images is the same as the flowchart in FIG. The explanation will be omitted here.

FIG. 3 is a block diagram showing a schematic configuration of the skew correction device. In the figure, when a plotter control circuit 40 takes in image information and size information of paper on which the image is printed from a host computer (not shown), it controls a paper drive motor drive circuit 41 to rotate the supply troll 22. The drive motor 42 is driven, and the developer pump drive circuit 43 is controlled to drive the pump 44 that sprays the color toner from the developer section 37 onto the recording paper 21.

The edge sensor 26 sends position information (edge position information) in the width direction of the recording paper 21, which is conveyed as the rolls rotate, to the paper edge detection circuit 45 when the recording head 36 prints an image.

The paper edge detection circuit 45 detects the recording paper 2 based on the edge position information taken in at predetermined intervals.
1 is detected, and the position of the recording paper 21 is notified to the plotter control circuit 40. When the block control circuit 40 receives the edge position of the recording paper 21, it compares it with a predetermined reference position to detect positional deviation. Then, according to the positional deviation, the correction motor drive circuit 46
is controlled to drive a correction motor 47 that moves the supply roller 22 in the left-right direction shown in FIG. 1, thereby correcting the positional deviation of the recording paper 21.

The plotter control circuit 40 also sends a synchronization signal to the control circuit 50 of the paper cutting device to synchronize the paper drive motor 42 and a paper transport motor 52, which will be described later, and a rotation signal to control forward/reverse rotation of the paper drive motor 42. It outputs various signals such as.

When the paper cutting control circuit 50 receives the synchronization signal and the rotation signal, the paper cutting control circuit 50 controls the paper transport motor drive circuit 51 to rotate the drive roll drive motor 52 that rotates the drive rolls 23 to 25, and the paper drive motor 42. drive in synchronization with. Thereby, the supply roll 22 and each of the drive rolls 23 to 25 are rotated in synchronization.

When rewinding the paper, the edge sensor 28 sends position information in the width direction of the recording paper 21 conveyed as the rolls rotate to the paper edge detection circuit 53. The edge position of the recording paper 21 is detected based on the edge position information taken in at intervals of , and the edge position of the recording paper 21 is notified to the paper cutting control circuit 50. When the paper cutting control circuit 50 receives the position of the recording paper 21, it compares it with a predetermined reference position to detect a positional deviation, and controls the solenoid drive circuit 54 according to the positional deviation to cut the recording paper 21 to the right or left side. The solenoids 29 and 30 of are driven to extend, and the recording paper 2
Correct the positional deviation in step 1. Further, when the paper cutting control circuit 50 receives a paper cutting instruction from the plotter control circuit 40, the solenoid drive circuit 55 for the cutter 27
is controlled to drive the solenoid 56, and the cutter 27 cuts the recording paper 21.

Next, the skew correction operation during image printing on paper and rewinding will be explained based on the flowcharts of FIGS. 4 and 5.

FIG. 4 is a flowchart showing the skew correction operation when printing an image on paper. First, the plotter control circuit 40
When the printing position is confirmed by detecting the registration mark with the encoder shaft 15 and printing is started (step 101), the edge position of the recording paper 21 is detected by the edge sensor 26 and the paper edge detection circuit 45 (step 102). , it is determined whether the edge position is a predetermined reference position set in advance (step 103
).

Here, if the detected edge position is the predetermined reference position, the process returns to step 102 to detect the next edge position,
If the detected edge position is not a predetermined reference position, it is determined whether the edge position is to the right of the reference position (step 104).

Here, if the edge position is to the right of the reference position, it is determined that the position of the recording paper 21 has shifted to the right (see Figure 1), and the correction motor is activated to move the supply troll 22 to the left. The drive circuit 46 is controlled to drive the skew correction motor, and the roll-shaped recording paper 21 is moved to the left (see FIG. 1) along with the movement of the supply roll 22 (step 105). And step 10
Returning to step 2, the next edge position is detected. If the edge position is not to the right of the reference position, it is determined that the position of the recording paper 21 has shifted to the left (see Figure 1), and the correction motor is activated to move the supply roll 22 to the right. The drive circuit 46 is controlled to drive the skew correction motor, and the roll-shaped recording paper 21 is moved to the right (see FIG. 1) along with the movement of the supply roll 22 (step 105). And step 102
Returning to step 1, the edge sensor 26 and paper edge detection circuit 45 detect the next edge position. As a result, skew correction can be performed accurately during image printing, and misalignment of paper can be prevented.

FIG. 5 is a flowchart showing the skew correction operation when rewinding paper. First, the paper cutting control circuit 50
controls the drive rolls 23 to 25 in response to a rewind start instruction from the plotter control circuit 40;
When rewinding is started (step 201), the edge position of the recording paper 21 is detected by the edge sensor 28 and paper edge detection circuit 53 (step 202),
It is determined whether the edge position is a predetermined reference position set in advance (step 203).

Here, if the detected edge position is a predetermined reference position, both the left and right solenoids 30.29 are turned off (the skew correction roll 33 and the guide roll 34 are in a parallel state) (step 204). , step 20
2, the next edge position is detected, and if the detected edge position is not the predetermined reference position, it is determined whether the edge position is to the right of the reference position (step 205).

Here, if the edge position is to the right of the reference position, it is determined that the position of the recording paper 21 has shifted to the right (see Figure 1), and the solenoid drive circuit is activated to move the recording paper 21 to the left. 54 to turn on the solenoid 29 and extend it, making the skinny correction roll 33 and guide roll 34 non-parallel! ! ! (closed to the right in FIG. 1) and tension is applied to the right edge of the roll-shaped recording paper 21. Then, when the recording paper 21 is rewound by the supply troll 22, the recording paper 21 is
When the solenoid 29 is turned on, the left side (see Figure 1)
(step 206).

Then, the process returns to step 202 to detect the next edge position. If the edge position is not to the right of the reference position, it is determined that the position of the recording paper 21 has shifted to the left (see Figure 1), and the solenoid is driven to move the recording paper 21 to the right. By controlling the circuit 54, the solenoid 30 is turned on and extended, and the skew correction roll 33 and the guide roll 34 are placed in a non-parallel state (closed to the left in FIG. 1!Iff'') to form a roll of recording paper. Tension is applied to the left edge of the solenoid 30 when the recording paper 21 is rewound by the supply roll 22.
is moved to the right (see FIG. 1) as the switch is turned on (step 207). Then, the process returns to step 202 to cause the edge sensor 28 and paper edge detection circuit 53 to detect the next edge position. As a result, skew correction can be performed accurately when rewinding the paper, and misalignment of the paper can be prevented.

Therefore, in the present invention, when a misalignment of the recording paper is detected, the misalignment of the recording paper is corrected by moving the supply roll left and right when printing an image on the paper, and the winding of the paper is corrected. When returning the paper, it is possible to correct the skew of the recording paper by turning on one of the left and right solenoids, so the recording paper is transported in the correct position, and the paper is transported in the correct position, making it easier to print images and rewind. It is possible to reliably perform time skew correction.

In the embodiment, a case has been described in which the skew correction device is used in an electrostatic color plotter, but the second invention is not limited to this, but can also be applied to copying machines such as printers. Furthermore, in the embodiment, the skew correction during rewinding is performed by the paper cutting control circuit, but the present invention is not limited to this, and it is also possible to have the plotter control circuit perform the skew correction.

〔Effect of the invention〕

As explained above, in the present invention, when printing an image on the paper and rewinding the paper, the movement of the paper is controlled according to the direction of the detected paper misalignment, so that the paper does not become misaligned. The sheet is conveyed accurately, and when the next image is printed, there will be no color shift, and the image can be printed at the correct position on the paper, thereby making it possible to obtain a high-quality printed image.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the configuration of an electrostatic color plotter using the skinny correction device according to the present invention, FIG. 2 is an enlarged perspective view of the skew correction device shown in FIG. 1, and FIG. 3 is the structure shown in FIG. 1. FIGS. 4 and 5 are a block diagram of a conventional electrostatic color plotter, and FIGS. 4 and 5 are flowcharts showing an embodiment of the skew correction operation according to the present invention. FIG. FIG. 7 is a flowchart showing the operation of multicolor printing. 11.21...Recording paper, 12.22...Supply roll, 14.23-25...Drive roll, 1
5...Mark sensor 16,17.26,28...
・Edge sensor, 27...Cutter 29.30°5
6...Solenoid, 31.32...Arm, 33.
... Skew correction roll, 34 ... Guide roll, 3
5... Encoder shaft, 40.50... Control circuit, 41.46.51... Motor drive circuit, 42.4
7゜52...Motor, 45.53...Paper edge detection circuit, 54.55...Solenoid drive circuit. Figure 7

Claims (1)

[Scope of Claims] A paper cutting device that adjusts the position of a roll paper to print an image, and cuts the roll paper on which the image has been printed at a predetermined position by a cutting means, comprising: printing an image on the roll paper; and a detection means for detecting a positional shift in the width direction of the roll paper when rewinding, and a correction means for correcting the skew of the roll paper according to the detected positional shift. Paper skew correction device.