JPH0310861A - Paper feed mechanism of printer - Google Patents

Abstract

PURPOSE:To enable either of cutform paper or two kinds of continuous paper to be selected by a method wherein one side of two motive force routes of continuous paper feed mechanism is connected or otherwise both thereof are disconnected by moving each intermediate gear axially by rotation of a cam gear with a switching motor. CONSTITUTION:A cam gear 18 is equipped with a depressed part 18b on a shaft part, and a circular arc state projection part of over 240 deg. centering an axis and a flat part 18d of over 120 deg. on a cam surface 18a of a front surface, and both of the projection part and the flat part are continuous by a slope. When an imaginary line I extending radially outwards from a center of the cam gear 18 passes a center of the flat part 18d, a micro switch 29 falls in the depressed part 18d to turn OFF. It is ON at positions excepting that. Three states such as a state in which a front tractor 16 for continuous paper Pf operates, a state in which a rear tractor 17 for continuous paper Pr operates, and a state in which either tractor does not operate (a state of using cutform paper) can be produced by this cam gear 18.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a printer for a computer, and in particular to a method for selecting paper and setting it in a printing position in a printer equipped with two continuous paper feed mechanisms and a cut paper feed mechanism. Concerning mechanisms for automation.

(Prior Art) Conventionally, in printers equipped with a continuous paper feed mechanism and a cut paper feed mechanism, paper switching and opening/closing of a pail roller have been performed using a manual switching lever or the like.

(Problems to be Solved by the Invention) In the conventional system in which the selection of each paper feed mechanism and the opening and closing of the pail roller are performed by manually operating a switching lever, the operation is complicated and paper jams occur due to operational errors.

An object of the present invention is to provide a printer equipped with two continuous paper feed mechanisms and one single sheet feed mechanism,
An object of the present invention is to provide a paper feeding mechanism for a printer that automates the setting of paper in a printing position.

(Means for Solving the Problems) In order to achieve the above object, the invention according to claim 1 includes a cut sheet feeding mechanism including a platen and two continuous sheet feeding mechanisms, and prints by an operation switch or an external control signal. In a printer that operates, a paper feed motor and a single sheet feed mechanism are connected by a belt, and the paper feed gear of the paper feed motor can be connected to each continuous paper feed mechanism through each intermediate gear, and each intermediate gear is connected in the axial direction. The cam surface of the cam gear is in contact with the side surface of each intermediate gear, and each intermediate gear is moved in the axial direction by rotation of the cam gear by a switching motor, and one of the power paths of the two continuous paper feeding mechanisms is moved. The paper feed mechanism of the printer was configured to select either cut paper or two types of continuous paper by connecting or cutting both.

The invention as set forth in claim 2 is characterized in that the switching motor that rotates the cam gear is connected to the cam gear via a planetary gear, and the planetary gear is connected to a mechanism that opens and closes the pail roller by reversing the switching motor. Blink's paper feed mechanism was constructed.

(Operation and Effect) According to the invention described in claim 2, each paper feeding mechanism is operated by one paper feeding motor.

The paper feed motor is connected to the cut paper feed mechanism by a belt. The cut paper feed mechanism includes a platen, but the platen is also used when printing on continuous paper. Further, the paper feed gear of the paper feed motor can be connected to each continuous paper feed mechanism via a respective intermediate gear. Each intermediate gear is movable in the axial direction, and is moved in the axial direction by rotation of the cam gear. This movement allows each intermediate gear to disconnect and connect the power path of each continuous paper feed mechanism.

When any continuous paper feed mechanism operates, printing is performed on continuous paper. In a state where neither of them is engaged, neither continuous paper feed mechanism operates and single sheets can be fed.

According to the second aspect of the invention, the switching motor that rotates the cam gear is connected to the cam gear via the planetary gear, and the planetary gear is connected to the mechanism that opens and closes the pail roller by reversing the switching motor. The pail roller is opened and closed automatically.

Therefore, each continuous sheet feeding mechanism and cut sheet feeding mechanism can be selected by the operator's panel switch operations and external control signals, and the operator can easily select each sheet. Further, the operator is freed from complicated operations such as selecting and attaching paper, and it is also possible to prevent accidents such as paper jams due to operational errors.

(Example) Examples of the present invention will be described below.

FIG. 1 is a front view showing an embodiment of a paper feeding mechanism of a printer according to the present invention and its surrounding mechanisms, and FIG. 2 is a perspective view of the same mechanisms.

In each figure, 1 is a platen, a platen shaft 2 protrudes from one end of the platen 1, and a platen pulley 3 is fixed to the tip thereof. A timing belt 4 is wound around the platen pulley 3 and connected to a paper feed pulley 7 fixed to the tip of a shaft 6 of a paper feed motor 5.

A paper feed gear 8 is fixed to the shaft 6 of the paper feed motor 5. As will be described later, the paper feed gear 8 meshes with two intermediate gears, a front switching gear 9 and a rear switching gear 10. Each switching gear 9 , 10 is supported so as to be movable in the axial direction, and is biased toward the frame 12 by a spring 11 .

Each switching gear 9.10 is located in the lower position, i.e. in the frame 1
When it moves to a position close to frame 12, it is connected to the continuous paper feed mechanism, and when it moves to a high position, that is, a position far from the frame 12, it is disconnected from the continuous paper feed mechanism. When in the lower position, the front switching gear 9 is connected to the front tractor gear 13, and the rear switching gear 10 is connected to the idler gear 14.
It is connected to the rear tractor gear 15 via. The front tractor gear 13 drives the front tractor 16 to feed the front continuous paper Pf, and the rear tractor gear 15 drives the rear tractor 17 to feed the rear continuous paper Pr.

Each switching gear 9,10 is moved in the axial direction by rotation of the cam gear 18. A cam surface 18a is provided on the surface of the cam gear 18, and is configured to move one of the switching gears 9, 10 to a lower position, or to move both to a higher position. This mechanism will be described later.

Cam gear 18 is driven via idler gear 19 by planetary gear 21 of switching motor 20 when rotating in the direction of arrow a.

When the switching motor 20 rotates in the direction of the arrow, the planetary gear 21 rotates at the position of the imaginary line and drives the idler gear 22. Furthermore, the opening/closing gear 23 is controlled by the idler gear 22.
rotates, pulls the link 24 rotatably attached to the opening/closing gear 23, and the arm 25 rotatably attached to the other end of the link 24, and moves it to the position shown by the imaginary line.
Open and close the pail roller 26. The arm 25 is rotatably attached to the frame 12 at a fulcrum 25a, and is biased by a spring 27 in a direction to close the pail roller 26, thereby functioning as a paper presser during printing.

28 is a print head, and 29 is a microswitch.

Next, the operation of the present invention will be explained with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram showing the control structure of the present invention, and FIG. 4 is a flow chart of paper switching control of the present invention.

(Step 1) First, an operation instruction is given to the CPU 32 inside the printer by the operator's operation switch 30 or the external control signal 31. Here, it is assumed that an instruction is given to change the paper to be used. The type of paper currently used is ROM.

It is stored in RAM33.

(Step 2) According to the operation instruction, the drive circuit 34 causes the paper feed motor 5 to rotate clockwise (rotate in the direction of arrow a) to automatically evacuate the continuous paper. That is, the platen 1 and any of the tractors 16, 17 that were being used are reversed and evacuated to a position where they do not interfere with feeding other sheets.

This is not necessarily necessary when changing from single-sheet paper to continuous paper.

The paper feed motor 5 stops when the continuous paper has retreated to an appropriate position.

(Step 3) Next, the switching motor 20 is rotated in the a direction by the drive circuit 36, the planetary gear 21 is moved in the a direction, and the idler gear 19
The cam gear 18 is rotated through , and the type of paper feeding mechanism is selected.

The cam gear 18 has a shape as shown in FIG. 5(a),
It has a cam surface on its surface and a recess 18b in its shaft. The cam surface 18a has an arcuate protrusion 18c extending about 240° about the axis and a flat part 18d extending about 120°, both of which are continuous by a slope.

FIG. 5(b) is a side view showing the positional relationship among the cam gear 18, rear switching gear 10, idler gear 14, and paper feed gear 8. At the position shown by the solid line, the lower surface of the rear switching gear 10 contacts the protrusion 18c of the cam surface 18, and the rear switching gear lO
is pushed up to a higher position. At this time, the rear switching gear 10 is separated from the idler gear 14. When the cam gear 18 rotates to the position shown by the imaginary line, the rear switching gear 10
is pressed down by the spring 11 and is in contact with the flat portion 18d. At this time, the rear switching gear 10 is in a low position and meshes with the idler gear 14.

Note that the rear switching gear lO is in meshing engagement with the paper feed gear 8 no matter which position it is in.

FIG. 5(C) shows the positional relationship of members around the cam gear 18 when viewed from the front.

When the virtual line I extending radially outward from the center of the cam gear 18 passes through the center of the flat portion 18d, the microswitch 29 falls into the recess 18d, and the microswitch 29 is turned off. It is ON at other positions.

This microswitch 29 is provided to detect and control the stop position of the cam gear 18. That is, first, the cam gear 18 is rotated in the direction of the arrow, the micro switch 29 is turned OFF, and then turned OFF again.
The CPU 32 detects the number of pulses required to reach F, and stores the number of pulses required for one revolution.

On the other hand, the actual stopping position of the cam gear 18 is on the virtual line I
, ■, and ■ are positions passing through the center of the flat portion 18d (hereinafter referred to as positions 1r, ■, and ■, respectively). Each line I, n, Iff
are at an angle of 120° to each other. Rear switching gear 10
is on the linework, and the front switching gear 9 is on the line ■.

Therefore, to stop at position I, the switching motor 20 is stopped when the microswitch is OFF. To stop at position H, turn the microswitch OFF, then
The switching motor 20 is stopped with a pulse number that is 1/3 of the initially stored pulse number. Similarly, to stop at position (2), the switching motor 20 is stopped with 2/3 the number of pulses.

When the cam gear 18 is in position I, the rear switching gear 10 is in a low position, contacting the flat portion 18d, and the front switching gear 9 is in a high position, contacting the protrusion 18c. Therefore, the rear tractor 17 is connected to the paper feed motor 5, and the front tractor 1
6 is disconnected.

When the cam gear 18 is in position H, the switching gears 9 and 10 are both pushed up by the protrusion 18c, so that both continuous paper feed mechanisms are disconnected from the paper feed motor 5.

When the cam gear 18 is in position III, the front switching gear 9 is in a low position and is transmitted to the front tractor 16,
The rear switching gear 10 is located at a high position and the idler gear 14
It's off.

As described above, the cam gear 18 can create three states: a state in which the front tractor 16 operates, a state in which the rear tractor 17 operates, and a state in which neither tractor operates (a state in which slip paper is used). .

(Step 4) The drive circuit 36 rotates the switching motor 20 to the left (in the direction of the arrow) to open the pail roller 26.

When the switching motor 20 is rotated to the left, the planetary gear 21 rotates at the position shown by the imaginary line, the link 24 is pulled in the direction of the arrow to the position shown by the imaginary line, and the pail roller 26 is opened. The switching motor 20 stops in the open state.

(Step 5) The drive circuit 34 causes the paper feed motor 5 to rotate in the direction of the arrow to feed the selected paper to the printing position.

One of the sheets selected in step 3 is set at the printing position by the paper feed mechanism. In either case, the platen 1 rotates.

Note that setting to the print position is detected by a sensor (not shown) provided in the print head 28, and paper feeding is stopped.

(Step 6) The switching motor 20 further rotates to the left, closes and stops the pail roller 20 at the position shown by the solid line, and presses the paper.

(Step 7) The printing preparation is completed as described above, and the drive circuit 35.37
As a result, the carriage drive motor 38 and the print head 28 are operated and the printing operation begins.

In this manner, according to this embodiment, it is possible to automate the switching of paper sheets, which was conventionally performed manually. Therefore, it is possible to prevent operational errors from occurring, and accidents such as paper jams can be prevented.

Further, in this embodiment, the opening and closing of the pail roller is also automated, so manual operation is not required, and the operator is freed from complicated operations. Furthermore, it is possible to suppress the occurrence of paper jams and the like due to operational errors.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments (it goes without saying that modifications can be made as appropriate within the scope of the gist of the present invention).

[Brief explanation of the drawing]

FIG. 1 is a front view showing the printer paper feeding mechanism and peripheral mechanisms of the present invention, FIG. 2 is a perspective view of the same embodiment, and FIG.
The figure is a circuit block diagram showing the control structure of the printer, FIG. 4 is a flowchart showing the control of the printer, and FIG. 5(a)
5(b) and 5(C) are perspective views of the cam gear, and FIGS. 5(b) and 5(C) are diagrams illustrating the operation of the cam gear. Tractor gear, 16...Front tractor, 17...
- Rear tractor, 18... Cam gear, 20... Switching motor, 21... Planetary gear, 23... Opening/closing gear, 2
6... Pail roller, 28... Print head, 29.
...Micro switch, 32...cpu.

Claims (2)

[Claims] (1) In a printer that is equipped with a cut paper feed mechanism including a platen and two continuous paper feed mechanisms and performs printing operations in response to an operation switch or an external control signal, the paper feed motor and the cut paper feed mechanism are connected by a belt, and the The paper feed gear of the paper feed motor can be connected to each of the continuous paper feed mechanisms through respective intermediate gears, each of the intermediate gears is supported to be movable in the axial direction, and a cam of a cam gear is attached to a side surface of each of the intermediate gears. The sheets are brought into contact with each other, and each of the intermediate gears is moved in the axial direction by the rotation of the cam gear by the switching motor to connect one of the power paths of the two continuous sheet feeding mechanisms, or to disconnect both. A paper feed mechanism for a printer, characterized in that it selects one of two types of continuous paper. (2) The printer according to claim 1, wherein the switching motor that rotates the cam gear is connected to the cam gear via a planetary gear, and the planetary gear is connected to a mechanism that opens and closes the pail roller by reversing the switching motor. Paper feed mechanism.