JPS62117756A - Medium feed system - Google Patents

Abstract

PURPOSE:To enhance the accuracy of a line feed position by preventing the excessive feed of a platen due to inertia, by reading a change-over line feed program from a memory part and performing line feed by predetermined quantity in the same direction as the line feed direction so far on the basis of the program before driving ordered line feed quantity in several steps. CONSTITUTION:An LF signal (a) is fed to a line feed direction change-over discriminating part 27a from an interface circuit 19 to discriminate the presence of the positive and reverse change-over order in a line feed direction. When no change-over is performed as the result of discrimination, a signal a1 is sent to an LF control circuit 26 which in turn drives an LF motor 25 to the same direction as that theretofore to perform a predetermined quantity of line feed. When change-over is performed as the result of discrimination, a signal a2 is sent to a program control circuit 29 which is turn reads a program concerned from a program memory 28a on the basis of 'positive reverse' or 'reverse positive' of the signal a2 to send the same to the LF control circuit 26. The LF control circuit 26 performs the line feed correspondingly to the program, that is, performs a predetermined quantity of line feed to the same direction as the line feed direction up to that time and drives ordered line feed quantity in several steps to perform line feed.

Description

[Detailed Description of the Invention] [Summary] This is a medium feeding method when switching between forward and reverse line feed feed for a print medium of a printer that performs printing including graph ink printing, etc., which divides a predetermined line feed amount into multiple times at the time of switching. By providing a feeding drive control means, the accuracy of the line feed position can be improved.

[Industrial application field]

The present invention relates to a medium feeding system for a don't printer that can perform graph ink printing, and more particularly to a medium feeding system that can improve line feed position accuracy when switching between forward and reverse directions for line feed feeding.

Recently, it has been used as office equipment such as various computer terminals and word processors! A twirled dot printer is developed and put into practical use.

In addition, printers that print graphics such as figures in addition to character printing have become widespread, and in such printers, printing is performed while switching the line feed of printing paper in the forward and reverse directions.

There is a need for a method of improving line feed position accuracy when switching between the forward and reverse directions of line feed.

[Conventional technology]

Figure 5 is a plan view showing the outline of the wire tod printer;
FIG. 6 is a side view of FIG. 5, and FIGS. 7(a) and 7(b) are illustrations of the conventional method. The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 5, the side frame 1 includes a platen 2.
is rotatably supported. A printing paper 3 is wound around the platen 2, and the printing paper 3 is sent in the directions of arrows A and B in the figure by a paper transport section 4, which will be described later.

At the bottom of the front view of the platen 2, a carrier 5 is slidably fitted into a guide shaft 6 provided parallel to the platen 2; It is screwed together with the feed screw 7. The feed screw 7 is connected to a space (hereinafter referred to as SP) motor 9 via a belt 8 and the like, and the carrier 5 can be moved in the directions of arrows C and D in the figure by forward and reverse rotation of the SP motor 9.

The gear rear 5 is equipped with an ink ribbon cassette 10,
An ink ribbon 10a is built in with a portion thereof exposed to the platen 2 side.

Further, a printing head 11 is mounted on the carrier 5 so as to face the platen 2 with a gap in between, and the printing head 11 has a plurality of printing marks having printing wires (not shown) in order to form printing by dots. Built-in magnet.

Further, as shown in FIG. 6, the platen 2 is located below,
A paper guide 12 is provided from the bottom to the rear.

The paper transport section 4 is connected to sprockets 41 of tractors 4a and 4b.
．． 42 is the square shaft 13. and a guide shaft 14 in a slidable manner, and the square shaft 13 is connected to a drive source (not shown). The distance between the tractors 4a and 4b is adjusted according to the size of the printing paper 3, and an eccentric cam lever 43
Fixed by

On the outer periphery of the sprocket wheels 1-41 and 42, an endless heald 44 shown by a broken line in the figure is hung, and a sprocket bin 45 is formed on the outside. The printing paper 3 has its feed hole centered in a sprocket bin 45 and is held down by pressers 46 and 47.

Therefore, the rotation of the square shaft 13 causes the sprocket 41 to rotate, and the platen 2 is interlocked and rotated in the same direction by a transmission mechanism (not shown).

Presser rollers 16 and 17 press the printing paper 3 on the left and right sides of the upper part of the platen 2.

With such a configuration, the platen 2 shown in FIG.
The printing wire of the printing magnet collides with the upper printing paper 3 via the ink ribbon 10a to print, and the printing head 11 prints while moving in the direction of arrow C together with the gear rear 5.

- When printing for a line is completed, paper transport section 4 shown in FIG. 6 is used for line feed. The platen 2 is driven to transport the print paper 3 by a predetermined feed amount in the direction of arrow A, and the print head 11
continues printing while moving in the direction of the arrow.

When drawing and printing figures, graphs, etc., they are printed with finer line breaks than normal character line breaks, and in addition, the paper transport section 4. Then, the driving of the platen 2 is switched in both the front and rear directions, and the printing paper 3 is reciprocated up and down during printing, and line feed printing is performed.

As shown in Figure 7(a), when printing with continuous line feeds in the forward direction, the printing section a and the line feed section 2 become like an upward staircase, and similarly, when printing with continuous line feeds in the opposite direction, they form a downward staircase. It becomes step-like.

Case 9: For example, as shown in FIG. 7(b), in the case of direction switching in which a line feed is printed in the forward direction to a line feed position d after printing a line feed in the forward direction, a predetermined line feed is printed. Method I is to move directly to position d, and method 2 is to perform excessive reverse line feeds and then move to a predetermined line feed position d.

[Problem that the invention seeks to solve]

According to the conventional method described above, when printing line feeds by switching between the forward and reverse directions, the method ``directly moving to a predetermined line feed amount id'' causes an insufficient feed amount due to hacking and lashing of the gears of the drive mechanism, and the predetermined line feed amount is It stops before position d, resulting in a large error due to insufficient line feed.

■Method ■ is often used to compensate for the shortcomings of Method I, but in Method ■, overshoot occurs due to the inertia of platen 2, and the line feed position d goes too far forward. ■Although the error is smaller than
For example, there is a problem that an error of about 0.5 to 0.6 mm occurs.

[Means for solving problems]

FIG. 1 is a block diagram of the principle of the present invention.

In the figure, when 24 is commanded to switch the line feed of the printing medium between the forward and reverse directions, the line feed is performed by a predetermined amount in the same direction as the previous line feed direction, and then the commanded line feed amount is driven in multiple steps. It is a drive control means for controlling, and includes a determining section 27 that determines a line feed direction switching command, and a storage section 28 that stores a switching line feed feed program. This program is a sequence program that causes a predetermined amount of line feed in the same direction as the previous line feed direction, and then drives the commanded line feed amount in multiple steps. Therefore, based on the switching command determination by the determining section 27, the switching line feed program is read out from the storage section 28 and the line feed drive is controlled.

[Effect]

When a command is given to switch the line feed of the printing medium between the forward and reverse directions, the command is sent to the drive control means 24, and the discriminator 27 determines that it is a switching command, and based on this determination, the storage unit 2
The switching line feed feed program is read from 8, and after the program causes a predetermined line feed in the same direction as the previous line feed direction, by driving the commanded line feed amount in multiple steps, the inertia of the platen etc. It is possible to prevent over-feeding and improve the accuracy of line feed positions.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4. FIG. 2 is a block diagram showing an embodiment according to the present invention, FIG. 3 is a flowchart of FIG. 2, and FIG. 4 is an explanatory diagram of FIG. The same reference numerals indicate the same objects throughout the figures. In FIG. 2, parts corresponding to those in FIG. 1 are shown surrounded by a dashed line.

In FIG. 2, the main control section 18 has a function of controlling each section to transport the printing paper 3 and perform printing operations based on input printing information.

The interface circuit 19 receives the print information, sends the command information therein to the command decode circuit 20, and sends the print information to each section based on the command.

The command decoding circuit 20 determines the input command, sends a line feed (hereinafter referred to as LF) signal a to the line feed direction switching determining section 27a, and sends the sp signal to the SP control circuit 21.
, and issues a command to send the print data to the line buffer 22.

The line buffer 22 is a memory that temporarily stores print data for -lines.

Based on the print data input from the line buffer 22, the print head drive control circuit 23 controls the SP control '<ff11.
In synchronization with the control of the circuit 21, the print head 1
Controls the printing operation of step 1.

The LF control circuit 26 drives the LF motor 25 to rotate in both forward and reverse directions based on the LF signal a sent from the discrimination section 27 or the program sent from the program control section 29.

The line feed direction switching determination unit 27a determines whether there is a forward/reverse switching command for the line feed direction of the input LF signal a, and when not switching, sends the signal a to the LF control circuit 26, and when switching, sends the signal a2. It is sent to the program control circuit 29.

The program memory 28a is composed of, for example, a ROM,
This memory stores a sequence program that causes a line feed to be performed by a predetermined amount in the same direction as the previous line feed direction, and then to drive the line feed amount to a commanded position g in multiple steps. For example, as shown in Fig. 4, when switching from reverse line feed printing to forward line feed printing, this program first performs a reverse line feed e, and then moves to a specified position g in the forward direction.
Forward-reverse, in which the line feed amount f is divided into multiple times and sent stepwise with minute line feeds, and when the line feed is switched from the forward direction to the reverse direction, the direction is reversed but controlled in the same way.

and reverse-forward programs.

The program control circuit 29 reads the sequence program from the program memory 28a based on the input LF signal a2 and sends it to the LF control circuit 26.

Since it has such a configuration and function, the operation of the line feed operation will be explained with reference to the flowchart in FIG. Determine whether there is a switching command.

(2) As a result of the determination, if there is no switching, the signal a1 is sent to the LFF control circuit 26.

(2) The Ll1%lI control circuit 26 drives the LF motor 25 in the same direction as before to perform line feed by a predetermined amount.

(2) As a result of the determination, when switching is to be performed, a signal a2 is sent to the program control circuit 29.

(2) The program control circuit 29 reads out a corresponding program from the program memory 28a depending on whether the signal a2 is positive-reverse or reverse-positive, and sends it to the LFF control circuit 26.

■The LF control circuit 26 feeds a line feed according to the program.

That is, as explained in FIG. 4, after a predetermined line feed is performed in the same direction as the previous line feed direction, the line feed is performed by driving the commanded line feed amount in multiple steps.

In this way, the inertia of the platen 2, etc., which is a drawback of the conventional method (2), can be braked by feeding the printing paper 3 by setting the movement amount as one control wheel position which is sufficiently smaller than the normal movement amount of one control wheel position. For example, 0.1 to 0.2
The precision of the line feed position can be increased to about mm.

In the above example, we explained the case where the line feed amount up to the commanded position is divided into several equal parts. An effect can also be obtained by dividing the material into parts and sending them in steps.

(Effects of the Invention) As described above, according to the present invention, there is an effect that the precision of the line feed position when switching between the forward and reverse line feed directions of a print medium in a printer that performs graphic printing can be improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram showing an embodiment according to the invention, Fig. 3 is a flowchart of Fig. 2, Fig. 4 is an explanatory diagram of Fig. 2, and Fig. 5 is a block diagram showing an embodiment of the invention. FIG. 6 is a side view of FIG. 5, and FIG. 7 is an explanatory diagram of a conventional method. In the figure, 3 is the printing paper, 4 is the paper transport unit, 9 is the SP motor, 11 is the print head, 1 is the main control unit,
19 is an interface circuit, 20 is a command decode circuit, 21 is an SP control circuit, 22 is a liner sofa, 23
is a print head drive circuit, 24 is a drive control means, 25 is an LF motor, and 26 is an L
F control circuit; 27 is a determining section; 27a is a line feed direction switching determining section; 28, 288 is a program memory; and 29 is a program control circuit. AA figure

Claims (2)

[Claims] (1) In a printer device in which a printing medium set between a platen member and a printing section is transferred in forward and reverse directions by a medium transfer section and printing is performed on the printing medium by the printing section, line feed of the printing medium is performed. When switching between forward and reverse directions is commanded, a drive control means (24 ). (2) The drive control means (24) includes a determination unit (27) that determines a line feed direction switching command, and a memory that stores a switching line feed program that is read out based on the switching command determination of the determination unit (27). The medium feeding system according to claim 1, further comprising a section (28).