JPH07214847A - Printer and method for changeover of paper of printer - Google Patents

Abstract

PURPOSE:To prevent paper from getting out of a press-in tractor, by checking up the position of a change lever when the paper is changed over, in a printer having a plurality of press-in tractors. CONSTITUTION:A printer 1 is provided with a rear press-in tractor 6 and a bottom press-in tractor 8. The two press-in tractors 6 and 8 rotate with a platen 2 and changeover thereof is conducted by a change lever 11. In the case when the changeover is made from paper 6 supplied by the rear press-in tractor 6 to paper 7 supplied by the bottom press-in tractor 8, the platen 2 is rotated in the normal direction (direction of discharge of paper), a change in a detecting lever 10 on the side of the press-in tractor 8 of which the paper is not at a printing position is viewed and it is judged therefrom that the change lever 11 is at a right position or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a plurality of pushing tractors, and more particularly to a method of switching continuous paper between a plurality of pushing tractors.

[0002]

2. Description of the Related Art Conventionally, in a serial printer or the like, a push-in type tractor (hereinafter referred to as a push-in tractor) that pushes continuous paper to a print position and a pull-type tractor that pulls continuous paper from the print position are used. . Among these, as the pushing tractor, in recent years, a printer provided with a plurality of pushing tractors has been proposed in accordance with the direction in which continuous paper is fed. FIG. 8 is an explanatory diagram showing a printer having a plurality of pushing tractors, which will be described below with reference to the drawings.

In FIG. 8, a printer 1 is provided with a cylindrical platen 2 rotatably, and a print head 3 is provided facing the platen 2. The print head 3 is mounted on a carriage 4 that is movable in the axial direction of the platen 2. A rear push-in tractor 6 that pushes the continuous paper 5 into a print position between the platen 2 and the print head 3 is disposed behind the platen 2 (on the side opposite to the print head 3 with respect to the platen 2). Below the platen 2, a bottom pushing tractor 8 for pushing the continuous paper 7 supplied from the lower side of the printer 1 to the printing position is arranged.

A detection lever 9 is arranged on the sheet conveying path from the rear pushing tractor 6 to the printing position, and a detecting lever 10 is arranged on the sheet conveying path from the bottom pushing tractor 8 to the printing position. , And paper 5 or 7 can be detected. Further, the printer 1 is provided with a change lever 11 so that driving of the rear pushing tractor 6 and the bottom pushing tractor 8 can be switched.

In the above printer 1, when the printing paper is switched or the printing paper is removed,
The operator reversely rotates the platen 2 and the pressing track 6 or 8 in use by depressing an operation switch or the like to reversely convey the sheet currently in use. When the detection lever 9 or 10 detects the sheet, the reverse conveyance is stopped, and the change lever 11 is switched to the pushing tractor 8 or 6 on which the sheet to be used next is set to be drivable, and thereafter, the printing is performed. Carry the paper to the print position.

[0006]

However, in the above-described conventional paper switching method, when the paper currently set at the printing position is to be retracted, the change lever is operated erroneously and the retracted paper is pushed in. When a push-in tractor other than the tractor is driven by being connected to the drive mechanism, there is a problem that the sheet set in the driven tractor is conveyed backward and comes out of the push-in tractor.

In order to prevent this, a detection switch for detecting the position of the change lever may be provided, but if the number of pushing tractors is further increased than two, a large number of detection switches are required, and the mounting structure thereof is complicated. The new problem of becoming.

[0008]

In order to solve the above-mentioned problems, a printer of the present invention has a plurality of push-in tractors for pushing paper into the platen, and paper is provided in each conveying path from each push-in tractor to the platen. When switching the paper to be printed, each of which has a paper detection unit for detecting the paper, the platen is rotated to retract the paper currently at the printing position to the front of the corresponding paper detection unit in the conveying direction, and the power transmission mechanism is switched by the switching mechanism. In the case where the pushing tractor equipped with the paper to be printed is driven to convey the paper to be printed to the printing position, when switching the paper to be printed,
By rotating the platen in the direction of ejecting the paper at the current print position and determining whether or not the paper detection unit other than the paper detection unit corresponding to the paper has detected the paper, the switching mechanism is operated in the normal mode. A control unit for determining whether or not the position is provided is provided.

Further, in the paper switching method of the present invention,
When switching the paper to be printed, by rotating the platen in the direction to eject the paper at the current print position, it is determined whether or not the paper detection unit other than the paper detection unit corresponding to the paper detects the paper. The judgment is made as to whether or not the switching mechanism is in the normal position.

[0010]

According to the printer of the present invention having the above structure,
When switching the paper to be printed, the control unit rotates the platen in the direction to eject the paper at the current print position, and this rotation causes the paper detection units other than the paper detection unit corresponding to the paper at the current print position. It is determined whether the paper is detected. If the switching mechanism is in the normal position, the paper detection unit corresponding to the paper currently in the print position will detect the paper, so if the other paper detection units detect the paper, the control unit It can be judged that the switching mechanism is not in the normal position.

Further, according to the paper switching method of the present invention having the above-mentioned structure, when the paper to be printed is switched, the platen is first rotated in the paper ejecting direction. Next, it is determined whether or not a sheet detection unit other than the sheet detection unit corresponding to the sheet currently at the print position has detected the sheet. Then, when a sheet detection unit other than the sheet detection unit corresponding to the sheet currently at the print position detects the sheet, the switching mechanism determines that the sheet is not in the normal position.

In either case, it is possible to determine whether or not the switching mechanism is in the proper position, so that it is possible to solve the problem caused by the setting error of the change lever.

[0013]

Embodiments of the present invention will be described in detail below with reference to the drawings. Note that elements common to the drawings are given the same reference numerals. FIG. 1 is an explanatory view showing a printer of an embodiment according to the present invention, and FIG. 2 is an exploded perspective view showing the printer of the embodiment.

In FIG. 1, the printer 1 of this embodiment is
The configuration is similar to that shown in the figure. A transport path 23 is formed between the rear pushing tractor 6 and the platen 2 by the paper chute 21 and the paper guide 22. The detection lever 9 is rotatably attached so as to cross the transport path 23. A conveyance path 26 is formed between the bottom pushing tractor 8 and the platen 2 by the paper guide 24 and the paper guide 25. The detection lever 10 is rotatably attached so as to cross the transport path 26.

In FIG. 1, the paper 5 supplied from the rear push-in tractor 6 is set at the printing position,
The tip 5a thereof projects above the platen 2, and the detection lever 9 detects the presence of paper. Further, the leading edge 7a of the paper 7 supplied from the bottom pushing tractor 8 is located closer to the bottom pushing tractor 8 than the detection lever 10, and the detection lever 10 naturally detects the absence of paper.

FIG. 2 shows a state in which the bottom pushing tractor is removed. The bottom pushing tractor 8 has a tractor idle gear 17 to which the drive is transmitted from the printer 1 side.
Is installed. The bottom pushing tractor 8 is attached to the bottom of the printer 1 by a support 12. Further, the printer 1 is provided with an operation unit 27, and the operation unit 27
Is provided with a changeover switch 27a for changing over the printing paper. A change lever 11 for switching the drive transmission of the push-in tractor is provided on the upper portion of the printer 1.

Next, the drive switching of the pushing tractor will be described with reference to FIG. FIG. 3 is an explanatory view showing a drive switching mechanism of the pushing tractor.

In FIG. 3, the drive source for rotating the platen 2 is provided on the opposite side of the gear 13. The gear 13 attached to the shaft of the platen 2 meshes with the idle gear 14, and the idle gear 14 is attached rotatably and slidably in the axial direction. Idle gear 14
The aforementioned tractor idle gear 17 and change gear 1
It is possible to mesh with 5. The change gear 15 is rotatable and axially slidable, and can mesh with the tractor idle gear 16. The tractor idle gear 16 is attached to the rear push-in tractor 6 and transmits drive to the rear push-in tractor 6.

When the change lever 11 is tilted in the direction of arrow A, the change gear 15 moves in the direction of arrow, and the change gear 15 meshes with the idle gear 14 and the tractor idle gear 16. As a result, the rotation of the platen 2 is transmitted to the tractor idle gear 16. At this time, the idle gear 14 and the tractor idle gear 17 do not mesh. When the change lever 11 is tilted in the direction of arrow B, the idle gear 14 meshes with the tractor idle gear 17, and the rotation of the platen 2 is transmitted to the tractor idle gear 17. At this time, the idle gear 14 and the change gear 15 do not mesh.

FIG. 4 is a control block diagram of the printer of this embodiment. Next, the control system of the embodiment will be described. CPU31
Controls the entire operation of the printer 1 and is connected to the ROM 32, the RAM 33 and the I / O port 34 by a bus. The ROM 32 stores a control program and the like, and the RAM 33 temporarily stores data and the like for control.

The I / O port 34 has an operating section 27, a head drive circuit 35, a motor drive circuit 36, and a detection sensor 3.
7, 38 are respectively connected. Head drive circuit 3
Reference numeral 5 drives the print head 3, and the motor drive circuit 36 drives a platen motor 39 that rotates the platen 2.
The detection sensor 37 detects the displacement of the detection lever 9 shown in FIG.
Detects the displacement of.

Next, the sheet switching operation of this embodiment will be described mainly with reference to the flow chart shown in FIG. FIG. 5 is a flow chart showing the paper switching operation of the embodiment. The paper switching operation starts from the state shown in FIG. 1, that is, the paper 5 supplied from the rear push-in tractor 6 is set at the printing position, and the paper 7 supplied from the bottom push-in tractor 8 is retracted.

First, when the changeover switch 27a of the operation unit 27 is pressed (step 1), the CPU 31 receives this input signal and drives the motor drive circuit 36 to rotate the platen motor 39 in the positive direction by a predetermined amount (step). 2). As a result, the platen 2 rotates a fixed amount in the clockwise direction in FIG. At this time, when the trailing edge of the sheet 5 passes the detection lever 9, the detection sensor 37 is turned off (step 3), and in this case, the platen motor 39 is further rotated in the forward direction to eject the sheet 5. (Step 4).

At the time of rotation of the platen 2 in step 2, if the change lever 11 is tilted in the direction of arrow A shown in FIG. 3, that is, if the change lever 11 is in the normal position, the rear of the platen 2 and the rear is achieved. The pushing tractor 6 is driven, and the bottom pushing tractor 8 is not driven.
However, when the change lever 11 is tilted in the direction of arrow B, the bottom pushing tractor 8 is driven.
Therefore, in step 2, the change lever 11
When the sheet is tilted in the direction of arrow B, the sheet 7 is conveyed in the direction of the platen 2, and the detection lever 10 detects this.

When it is detected in step 5 that the detection sensor 38 is turned on, the detection lever 10 detects the sheet 7, so the CPU 31 causes the change lever 1 to operate.
Assuming that 1 is in an irregular position, the state is returned to the initial state before the start of the paper switching operation (step 6). That is, the platen 2 is rotated in the opposite direction by a certain amount. Then, an alarm is displayed on the operation unit 27 (step 7).

When it is detected in step 5 that the detection sensor 38 is off, the detection lever 10 does not detect the sheet 7, so the CPU 31 determines that the change lever 11 is in the normal position, Next, the platen 2 is rotated in the opposite direction (step 8). By this reverse rotation, the sheet 5 once conveyed in the discharge direction is sent in the reverse direction, that is, the retracted direction. This reverse rotation is performed until the leading edge 5a of the sheet 5 passes the detection lever 9. When the detection sensor 37 confirms that the sheet 5 has passed through the detection lever 9 (step 9), the platen 2 is further rotated in the reverse direction from this point (step 10). As a result, the leading edge 5 of the paper 5
Position a at the regular retracted position.

6 and 7 are time charts of the paper switching operation of this embodiment. FIG. 6 shows the case where the change lever 11 is in the normal position, and FIG. 7 shows the case where the change lever 11 is not in the normal position.

As can be seen from both figures, the change lever 1
When 1 is in the normal position, the detection sensor 38 does not turn on when the platen 2 is rotating normally. However, when the change lever 11 is not in the normal position, the detection sensor 38 is turned on when the platen 2 rotates forward. By transmitting this ON signal to the CPU 31, it is determined that the change lever 11 is not in the normal position.

As described above, according to this embodiment,
When switching the paper, the platen 2 is temporarily rotated in the direction of ejecting the paper and the detection lever of each conveyance path is checked to detect the position of the change lever 11 that is currently set. Even if you make a mistake, the paper will not come off.

In the above embodiment, the case where there are two pushing tractors has been described, but it goes without saying that the present invention can be applied even when there are three or more pushing tractors.

In the above embodiment, the detection lever is used as a means for detecting the presence / absence of the sheet, but an optical sensor may be provided in each conveying path to detect the sheet.

[0032]

As described in detail above, according to the present invention, when the sheets are switched in the apparatus having a plurality of pushing tractors, the platen is once rotated in the forward direction, and the change lever is output by the output of the sheet detection sensor during the period. Since the position of is checked, it is possible to prevent the paper from coming off the pushing tractor without providing a switch for detecting the position of the change lever, and to provide a printer which is easy for the operator to use.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a printer according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the printer of the embodiment.

FIG. 3 is a perspective view showing a drive switching mechanism.

FIG. 4 is a control block diagram of the printer of the embodiment.

FIG. 5 is a flowchart showing a sheet switching operation of the embodiment.

FIG. 6 is a time chart of the paper switching operation of the embodiment.

FIG. 7 is a time chart of the paper switching operation of the embodiment.

FIG. 8 is an explanatory diagram showing a printer including a plurality of pushing tractors.

[Explanation of symbols] 1 printer 2 platen 5, 7 paper 6 rear pushing tractor 8 bottom pushing tractor 9, 10 detection lever 11 change lever 27a changeover switch 31 CPU 37, 38 detection sensor

Claims (3)

[Claims] 1. When switching a paper to be printed by having a plurality of push-in tractors for pushing the paper against the platen, and a paper detecting unit for detecting the paper in each conveying path from each push-in tractor to the platen. Rotates the platen to retract the paper at the current print position to the front of the corresponding paper detection unit in the transport direction, switches the power transmission mechanism by the switching mechanism, and drives the push-in tractor equipped with the paper for printing. In a printer that conveys paper to be printed to the print position, when switching the paper to be printed, rotate the platen in the direction to eject the paper at the current print position, and the paper detection units other than the paper detection unit corresponding to the paper A control unit is provided for determining whether or not the switching mechanism is in a normal position by determining whether or not a sheet is detected. Printer. 2. A case where a plurality of pushing tractors for pushing a sheet against a platen are provided, and a sheet detecting unit for detecting the sheet is provided on each conveying path from each pushing tractor to the platen, and a sheet to be printed is switched. Rotates the platen to retract the paper at the current print position to the front of the corresponding paper detection unit in the transport direction, switches the power transmission mechanism by the switching mechanism, and drives the push-in tractor equipped with the paper for printing. In the paper switching method of the printer that conveys the paper to be printed to the printing position, when switching the paper to be printed, rotate the platen in the direction to eject the paper at the current printing position, and remove the paper other than the paper detection unit corresponding to the paper. By determining whether or not the sheet detection unit has detected the sheet, it is determined whether or not the switching mechanism is in the regular position. Printer paper switching method of that. 3. If the switching mechanism is not in the normal position, the platen is rotated in the opposite direction by the amount of rotation in the direction in which the paper at the current printing position is discharged.
Paper switching method for the described printer.