JPH05155086A - Recording paper skewing correcting method - Google Patents

Abstract

PURPOSE:To always perform a favorable recording paper skewing correction. CONSTITUTION:When a paper feeding is performed, a paper feeding roller 70 and separating roller 71 are normally rotated, and an inserter driving roller 72' is reversed. When the leading end of a recording paper (e.g. a thick envelope E1 or thin envelope E2) is positioned on a sensor 75, a control circuit detects that the output of the sensor 75 has become ON, and a further paper feeding by the distance between the sensor 75 and the inserter driving roller 72' and an excessive feeding quantity is performed, and then, the inserter driving roller 72' is rotated forward, and the paper feeding roller 70 and separating roller 71 are placed under an idle condition. Also, the excessive feeding quantity is a large value when the thickness of the recording paper is large, and a small value when the thickness of the recording paper is small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skewed sheet correcting method in a printer. In the printer, after the leading edge of the paper hits the reversing inserter roller, overfeeding is further performed to correct the skew of the paper by bending the paper, and after performing skew correction of the paper, the inserter roller is corrected. Is rotated normally and the paper is inserted between the print head and the platen.

FIG. 5 is a diagram for explaining a conventional skewed sheet correction. In the figure, 1 is a print head, 2 is a platen,
70 is a paper feed roller, 71 is a separation roller, 72 'is an inserter drive roller, 72 is an inserter driven roller, 73 is a separation pad, 74 is a guide, 75 is a sensor, 76 is a hopper, E1 is a thick envelope, E2 is a thin envelope. Are shown respectively.

In the hopper 76, a plurality of sheets (thick envelope E1 or thin envelope E2 in the case shown) are stacked. When printing characters on paper, use hopper 7
6, the paper feed roller 70 and the separation roller 71 rotate in the normal direction, and the inserter drive roller 72 'rotates in the reverse direction. The rotation of the roller that conveys the paper toward the print head is called normal rotation, and the rotation in the opposite direction is called reverse rotation. The paper is taken out from the hopper 76 by the paper feed roller 70, and one paper is placed on the guide 74 by the separation roller 71 and the separation pad 73 and fed leftward. The separation pad 73 is made of urethane rubber, for example.

When the leading edge of the paper reaches the position of the sensor 75, the sensor 75 detects this. After the sensor 75 detects the leading edge of the sheet, the rollers 70 and 71 are further rotated by a fixed angle, and then the inserter drive roller 72 'is rotated in the normal direction. Although not shown, the motor shaft and the paper feed roller 7
0, the separation roller 71 is connected via a one-way clutch, and the motor shaft and the inserter driving roller 72 'are connected via a gear. Then, when the motor is rotating in the clockwise direction, the paper feed roller 70 and the separation roller 71 rotate in the normal direction, and the inserter drive roller 72 'rotates in the reverse direction. When the motor is rotating in the counterclockwise direction, the paper feeding roller 70 and the separating roller 71 lose their driving force, and the inserter driving roller 72 'rotates normally.

FIG. 6 is a diagram showing a flow chart of conventional paper feeding. In step S1, it is checked whether or not the sensor 75 has detected a sheet. In the case of Yes, it progresses to step S2. In step S2, the rollers 70 and 71 are normally rotated by an angle corresponding to the distance between the sensor 75 and the inserter drive roller 72 '+ a constant overfeed amount. In step S3, the inserter drive roller 72 'is rotated normally.

[0006]

As described above, when correcting the skew of the print medium fed from the hopper 76,
Although the skew feeding is corrected by abutting the print medium on the rollers 72, 72 'which are rotating in the reverse direction and applying the overfeed, it is necessary to increase the overfeed for the thick envelope E1 which is stiff and difficult to correct the skew feeding. However, in the case of the thin envelope E2, the bending becomes too large as shown in FIG. 5 (b) when the overfeed is set, and the leading end of the medium is returned by the reverse rotation of the rollers 72 and 72 ', which causes the problem of skewing. there were. The present invention was created in view of this point, and an object of the present invention is to always be able to perform good sheet skew correction regardless of the thickness of the print medium.

[0007]

Therefore, therefore, the skewed sheet correcting method according to claim 1 of the present invention comprises a print head (1),
A platen (2), an inserter roller pair consisting of an inserter drive roller (72 ') and an inserter driven roller (72),
A method for correcting skewed sheets in a printer device, which comprises roller means (70, 71) for transporting a sheet toward an inserter / roller pair, in which the roller means (70, 71) is normally rotated to transport the sheet. At the same time, the inserter drive roller (72 ') is reversed, and after the leading edge of the paper hits the inserter roller pair, the value is large when the paper thickness is large, and when the paper thickness is small. After feeding a small amount of overfeed, after the overfeed is completed, the inserter drive roller (72 ') is rotated forward and the paper is inserted between the print head (1) and the platen (2). To do. The skewed sheet correcting method according to the second aspect of the present invention measures the thickness of the sheet by utilizing the automatic gap adjusting function of the printer.

[0008]

The operation of the skewed sheet correcting method of claim 1 will be described. The present invention is premised on the technology of correcting the skew of the sheet by further feeding the sheet after the leading edge of the sheet hits the inserter roller pair. If the sheet is thin, the bending of the sheet becomes too large, and good skew feeding cannot be performed when the sheet is thin. Therefore,
If the paper is thin, reduce the overfeed amount,
If the paper is thick, increase the overfeed amount. In the skewed sheet correcting method according to the second aspect, the thickness of the sheet is measured by using the automatic gap adjusting function of the printer device. According to the invention of claim 2, it is possible to obtain the effect that it is not necessary to install a dedicated paper thickness measuring mechanism.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining the skewed sheet correction of the present invention. In the figure, 1 is a print head, 2 is a platen,
70 is a paper feed roller, 71 is a separation roller, 72 'is an inserter drive roller, 72 is an inserter driven roller, 73 is a separation pad, 74 is a guide, 75 is a sensor, 76 is a hopper, E1 is a thick envelope, E2 is a thin envelope. Are shown respectively.

The printer device of the present invention comprises means for measuring the thickness of the print medium. As a means for measuring the thickness of the print medium, a known automatic gap adjusting means can be used, or a dedicated automatic paper thickness measuring means can be used. In summary, the present invention determines whether the print medium is thin or thick, sets the overfeed amount according to the thickness, and performs optimum skew feeding correction. In Fig. 1 (a), the print medium is thick envelope E1.
1B, the print medium is a thin envelope E2. The overfeed amount of the thin envelope E2 is made smaller than the overfeed amount of the thick envelope E1.

FIG. 2 is a diagram showing an example of a printer device capable of adjusting the head gap. In the figure, 1 is a print head, 2 is a platen, 3 is paper, 4 is a carriage, 5
Is a first guide shaft, 6 is a second guide shaft, 7 is an end shaft, 8 is a frame, 9 is a drive device, 10 and 11 are pins, 12 is a roller, 13 is an arm, 14 is a roller, 15 is a winding spring, 16
Is a photoelectric sensor, 17 is a bracket, 18 is a shielding plate, 19
Indicates detection slits, respectively.

A print head 1 is mounted on the carriage 4. The carriage 4 can rotate around the first guide shaft 5 and can slide on the first guide shaft 5. The second guide shaft 6 is parallel to the first guide shaft 5. The second guide shaft 6 is axially supported by the frame 8 by eccentric end shafts 7 at both ends thereof, and a drive device 9 (for example, a pulse motor) for rotating the second guide shaft 6 around the end shaft 7 is provided. It is provided.

The pins 10 and 11 are provided vertically on the upper end of the carriage 4, and a roller 12 facing the second guide shaft 6 is pivotally attached to the pin 10. Arm 13
Is swingable around a pin 11, and a roller 14 is pivotally attached to the tip of an arm 13. The winding spring 15 urges the roller 14 toward the second guide shaft 6 that faces the roller 14. The second guide shaft 6 is sandwiched between the roller 12 and the roller 14 by the urging force of the winding spring 15.

The photoelectric sensor 16 is fixed to the upper end of the carriage 4 via a bracket 17. The shield plate 18 is fixed to the arm 13. In the state where the roller 12 and the roller 14 sandwich the second guide shaft 6, the tip of the shielding plate 18 is located in the detection slit 19 of the photoelectric sensor 16 and blocks the light detected by the photoelectric sensor 16.

The head gap setting operation will be described. At the time of inserting the paper 3, the second guide shaft 6 is rotated in the head retreating direction to separate the tip of the print head 1 from the platen 2, the paper 3 is inserted between the print head 1 and the platen 2, and then the paper 3 is inserted. 2 The guide shaft 6 is rotated in the head advancing direction. As the second guide shaft 6 rotates, the tip of the print head 1 advances toward the platen 2 and contacts the paper 3.

Although the second guide shaft 6 continues to rotate further, the carriage 4 cannot rotate any more due to the collision between the print head 1 and the platen 2, so that the second guide shaft 6 cannot rotate further.
The advancing of the guide shaft 6 is absorbed by the arm 13 rotating around the pin 11 and retracting. As the arm 13 retreats, the shield plate 18 also retreats, and the tip of the shield plate 18 is exposed to the photoelectric sensor 16
Is removed from the detection slit 19.

This detachment timing is detected by the photoelectric sensor 16, and the interval L formed between the roller 12 and the second guide shaft 6 at this time is always constant. The rotation of the second guide shaft 6 is stopped by the detection signal, and then the second guide shaft 6 is retracted by an amount corresponding to the amount obtained by adding the interval L and the set gap M. As a result, the tip of the print head 1 and the paper 3
The interval between is always set to a constant value. At this time, the fixed roller 12 and the second guide shaft 6 are in contact with each other.

FIG. 3 is a diagram showing an example of an electric circuit of the printer device. In the figure, 50 is a microprocessor,
51 is a RAM, 52 is a control memory having a ROM configuration, and 53 is E
² PROM, 54 is an interface control circuit, 55 is a console panel, 56 is a driver & mechanism section, 57 is an output port, 58 is an input port, 59 is an address decoder, and 60 to 62 are bidirectional drivers / receivers, respectively. ing.

The microprocessor 50 has a control memory 52.
Execute the program stored in. RAM51
Has a buffer for temporarily holding data and a work area. The E ² PROM 53 stores data to be saved. Interface control circuit 54
Is for controlling data transfer to and from the main computer.

The microprocessor 50 has an output port 5
It is possible to send data to the console panel 55 and the driver & mechanism section 56 via 7, and read the data of the console panel 55 and the driver & mechanism section 56 via the input port 58. The bidirectional driver / receiver 60 amplifies the address signal, and the bidirectional drivers / sillers 61, 62 amplify the data signal.

The address decoder 59 decodes an address signal. Data is written / read to / from a register or the like defined by the decoding result. In the driver & mechanism unit 56, the print head,
There are various motors and drivers.

FIG. 4 is a diagram showing a flow chart of the present invention. The processing shown in this flowchart is realized by executing the paper feed start program stored in the control storage 52 by the microprocessor. In step S1, it is checked whether or not the sensor 75 detects the paper. In the case of Yes, it progresses to step S2. Step S2
Then, the paper is further fed by the distance between the sensor 75 and the inserter driving roller 72 '+ the constant overfeed amount.

In step S3, the inserter drive roller 72 'is rotated in the forward direction. In step S4, automatic gap adjustment of the print head is performed. In step S5, it is checked whether or not the print head is farther from the platen than the set position. If Yes, the process proceeds to step S6, and if No, the process proceeds to step S8.

In step S6, it is determined that the paper is thick. In step S7, the overfeed amount from the next sheet feeding is set to the thick overfeed amount. In step S8, it is determined that the paper is thin. In step S9, the overfeed amount from the next sheet feeding is set to the thin overfeed amount.

According to the embodiment of the present invention, as in the above flow chart, the automatic gap adjustment function of the printer is used to determine whether the paper is thin or thick and set the overfeed amount for each. , It is possible to perform optimal skew feed correction.
Further, when the automatic gap adjusting function of the printer is used as described above, the optimum overfeed cannot be applied to the first sheet, but a sheet thickness measuring means is separately provided in front of the rollers 72 and 72 '. By providing it, it is possible to apply optimum overfeeding from the first sheet.

[0026]

As is apparent from the above description, according to the present invention, the skew feeding correction effect can be improved by the optimum overfeed. The printer device can be made compact without requiring a large space for bending. It has a remarkable effect.

[Brief description of drawings]

FIG. 1 is a diagram showing sheet skew correction according to the present invention.

FIG. 2 is a diagram showing an example of a printer device capable of adjusting a head gap.

FIG. 3 is a diagram illustrating an example of an electric circuit of the printer device.

FIG. 4 is a diagram showing a flowchart of the present invention.

FIG. 5 is a diagram illustrating conventional skewed sheet correction.

FIG. 6 is a diagram showing a conventional flowchart.

[Explanation of symbols]

 1 Print Head 2 Platen 70 Paper Feed Roller 71 Separation Roller 72 'Inserter Drive Roller 72 Inserter Driven Roller 73 Separation Pad 74 Guide 75 Sensor 76 Hopper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Kakuhashi Nouki-nu, Unoku-cho, Kawakita-gun, Ishikawa Prefecture 2 No. 98, PUEU Co., Ltd. (72) Masashi Matsumoto Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa Prefecture No. 98 2 PFU Co., Ltd.

Claims (2)

[Claims] 1. A print head (1), a platen (2), an inserter drive roller (72 ') and an inserter driven roller (72).
A method of correcting skewed sheets in a printer device, comprising: an inserter roller pair consisting of: and roller means (70, 71) for conveying a sheet toward the inserter roller pair. When the paper is fed in the forward direction, the inserter drive roller (72 ') is rotated in the reverse direction, and when the leading edge of the paper hits the inserter roller pair, when the paper thickness is large, If the thickness is too small, carry out a small value of overfeed, and after the overfeed is completed, rotate the inserter drive roller (72 ') forward to feed the paper between the print head (1) and platen (2). A method for correcting skewed sheets, which is characterized in that the sheet is inserted between them. 2. The printer device has an automatic gap adjusting function for making the gap between the paper placed on the platen (2) and the print head (1) a constant value, and utilizing the automatic gap adjusting function. The sheet skew correction method according to claim 1, wherein the thickness of the sheet is measured.