JPH04232080A - Method for sending carriage of serial printer - Google Patents

Abstract

PURPOSE:To impart efficient printing action by excluding the wastefulness within the approach region until the carriage of a serial printer reaches a constant speed in the feed of the carriage. CONSTITUTION:The start position of a carriage is arbitrarily altered corresponding to the printing condition of a printer. As a result, the carriage is efficiently fed so that a printing region can be just started when the approach run of the carriage is completed, that is, the speed of the carriage reaches a predetermined definite value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carriage feeding method for a serial printer, and more particularly to an improved carriage feeding method that eliminates wasteful carriage feeding and enables efficient printing.

0002

[Prior Art] Serial printers are well known in which a carriage carrying a print head such as a dot matrix head or a thermal head is driven along a platen around which paper is wound, and sequentially prints on the paper. It is used as an output device for information processing equipment.

[0003] In such a serial printer,
The carriage carrying the print head is continuously fed and driven by a DC servo motor, a stepping motor, or the like. The print head position at this time is managed by electrically detecting character pulses or dot pulses using an encoder rotated by the motor, or by counting drive pulses sent out by the motor control circuit. ing. Therefore,
If the print head is excited in synchronization with such a print position, printing can be performed at a desired position.

[0004] Generally, in a serial printer, a carriage is driven back and forth along a platen, and printing is performed by the print head during movement in either one direction or both directions. However, since the carriage is driven back and forth, the carriage speed is unstable until it reaches a predetermined constant speed from the carriage start position at both ends, so it cannot be used for printing. This is actually a wasted time as it is a run-up area in which printing is not performed until the constant speed is reached. Then, when the carriage moves at a constant speed past this run-up area, the printing operation by the print head described above is performed, and this constant speed movement area of the carriage is used as the printing area.

[0005]

[Problems to be Solved by the Invention] Conventionally, the carriage start position is usually known as the home position, and the home position in the printer is determined mechanically to a constant value in each printer from a home position sensor such as a limit switch. This fixed home position has conventionally been fixed as a reference position for carriage feeding.

However, in recent years, various printing conditions are required of printers, including, for example, high-speed mode and low-speed mode.

[0007] That is, when printing characters of relatively simple shapes such as alphabets, numbers, or kana, a sufficiently distinguishable printing effect can be obtained even when the carriage is moved at high speed. , high-speed printing is used.

On the other hand, when printing Chinese characters with complex strokes or high-quality printing, such as what is known as letter quality, the carriage feed speed is reduced to enable the print head operation to follow the carriage feed. mode is used.

[0009] In addition, the normal mode and the silent mode are often used as printing conditions, and control is performed to suppress the increase in speed of the carriage feed motor when it starts up.

Furthermore, when the carriage feeding speed is increased, the excitation current of the print head must be increased or the duty ratio of the excitation pulse must be increased in order to cause the print head operation to follow this increase. In such a case, the print head is likely to become overheated, and conventionally, the carriage feeding speed was adjusted while monitoring the temperature of the print head.

As described above, conventionally, the carriage feeding speed changes depending on the printing conditions, but as mentioned above, the starting position of the carriage is fixed as the home position, so a considerable amount of wasted feeding time of the carriage occurs. This is a factor that reduces the printing efficiency of printers.

FIG. 5 shows wasted time in the conventional high-speed printing mode and low-speed printing mode. A printing operation is performed when the carriage moves rightward from the home position (HP).

The vertical axis in FIG. 5 indicates the carriage speed, and a predetermined constant speed is obtained between the home position (HP) and the run-up region indicated by the symbol L.

In the figure, 80 digits are printed in the printing area, and, for example, relatively coarse printing is performed in the high-speed printing mode, and dense, high-quality printing is performed in the low-speed printing mode.

As is well known, in the low-speed printing mode, this constant speed can be obtained earlier than in the high-speed printing mode, but as is clear from FIG. 5, in the conventional carriage feeding method, even in this low-speed printing mode, Since L is constant, a wasteful run-up must be performed.

Therefore, in the past, the run-up area L was determined in accordance with the highest speed mode, and at a printing speed lower than this, there was a drawback that non-negligible waste occurred in the run-up area.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to control the run-up area to an optimal value as necessary, thereby increasing the efficiency of the entire printing operation. The object of the present invention is to provide an improved carriage feeding method that can be used.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is characterized in that the carriage start position, which was conventionally fixed as a home position, is changed in accordance with various printing conditions.

Suitable printing conditions include, for example, the feed speed required for the carriage, the speed increase value in the run-up region, or the temperature of the print head.

[0020]

[Operation] Therefore, according to the present invention, the carriage start position can be controlled to an optimal value according to various printing conditions, so that it is possible to reliably eliminate waste in the run-up area and improve the overall printing efficiency. becomes.

That is, by optimally selecting the carriage start position, the position where the carriage reaches a predetermined constant speed can be determined as the start position of the printing area, and the conventional waste can be reliably eliminated.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the main parts of a serial printer to which the present invention is applied.
1 is wound around the paper 11, and a desired printing operation is performed on this paper 11.

A carriage guide 12 is fixed to a machine frame (not shown) parallel to the platen 10, and a carriage 13 is supported on the carriage guide 12 so as to be able to reciprocate. A print head 14 such as a dot matrix head or a thermal head is supported on the carriage 13, and a desired printing operation is performed on the paper 11 in synchronization with the movement of the carriage 13.

A carriage feed motor 15 is provided to reciprocate the carriage 13 along the platen 10, and the carriage is moved by a feed belt 18 hooked around a pulley 16 fixed to its main shaft 15a and an idle pulley 17. 13 is movement controlled.

In order to detect the home position of the carriage 13, a home position sensor 19 consisting of a limit switch is fixed to the machine frame, and as is clear from FIG. The area from HP) to the printing start position forms a basic run-up area L.

The characteristic feature of the present invention is that since the run-up area L in FIG. 1 is variable, the start position of the carriage 13 can be arbitrarily adjusted without being fixed at the home position (HP).

FIG. 2 shows a control circuit block for realizing the carriage feeding method according to the present invention.

In FIG. 2, the entire printer is controlled by a processor 20, a control signal is sent from a motor control circuit 21 to a carriage feed motor 15 that feeds and drives the carriage 13, and the printing operation of the print head 14 is controlled by a processor 20. This is performed using a control signal from the head control circuit 22.

In the embodiment, the above-mentioned carriage 13
The home position sensor 19 provides a detection signal to the interface control circuit 23, and the temperature of the print head 14 is detected by the thermistor 24, which is sent as a control signal to the processor 20 via the interface control circuit 23.

[0031] The device includes a RAM 25 and a ROM 26;
In the embodiment, various printing conditions are written in the RAM 25, and a plurality of predetermined approach area values and the like are read out from the ROM 26.

Printing commands that define printing conditions of the printer and mode designations such as speed and normal/quiet are performed via the input port 27 or panel switch 28, and the processor 20 adjusts the carriage according to these commands and the various printing conditions. In the present invention, the feed control in No. 13 includes selection of the carriage start position.

FIG. 3 shows a preferred control example of the carriage feeding method according to the present invention, which corresponds to the conventional control shown in FIG.

In the present invention, as described above, the starting position of the carriage 13 can be changed arbitrarily, and this change is performed every reciprocating cycle of the carriage 13.

In the embodiment, the home position (H
The starting position of the carriage 13 is changed based on P).

In FIG. 3, the solid line indicates the high-speed printing mode as in the conventional case, and in the conventional case, the low-speed printing mode indicated by the broken line was adopted, which caused wasted time within the run-up area L. .

On the other hand, according to the present invention, in the low-speed printing mode, the carriage start position is moved to P0, and as a result, the approach area in the low-speed printing mode in this embodiment is set to L'.

Therefore, according to this embodiment, the carriage 1
By changing the carriage start position when the printing speed of No. 3 is changed, it is possible to reliably reduce wasted time in the run-up area.

In this embodiment, the carriage start position is determined based on the home position (HP), but in the present invention, this carriage start position can be independently set using a plurality of limit switches.

FIG. 4 shows a flowchart for adjusting the carriage start position in the embodiment of the invention described above. When the printer is powered on and control is started (101), the carriage 13 normally moves to the left and starts a home position detection operation (102), regardless of its current position.

As mentioned above, the home position detection in the embodiment is performed by turning on the sensor 19 (
103), When the sensor 19 is activated, the carriage 13 temporarily stops at the home position and uses this as the reference position (
104).

[0042] Through the above operations, the printer enters a standby state and waits for a print command to be supplied from the outside through the input port 27. In Figure 4, when a print command is input (
105), data such as character type or print position included in this print command is usually edited for one line (106)
).

A feature of the present invention is that after the print command is edited by the processor 20, a home page that is initialized using the print command and the current printer status, such as the temperature of the print head, etc. The purpose is to calculate a necessary start position for each row of the carriage 13 from the position.

In the embodiment, this calculation is divided into three stages, and in FIG.
07), selection by quiet/normal mode (108), and selection by print head temperature (109).

That is, when the carriage 13 is fed at a high speed, it is necessary to set the run-up area long, and on the other hand, when the carriage 13 is fed at a low speed, it is desirable to set it short.

In either case, the carriage 13
Based on the feed speed required for
110).

Next, for the silent/normal mode, the optimum carriage start position is similarly calculated using the rising acceleration of the carriage 13. In an embodiment, position changes in quiet/normal mode will be performed with priority over carriage speed.

Similarly, when the temperature of the print head exceeds a predetermined value, the carriage feeding speed is controlled to be low for each print line, thereby cooling the print head.

In particular, if the run-up area L is set long, the period during which the carriage 13 is apparently moving becomes longer, the cooling effect of the print head 14 is also promoted, and the decrease in the feed speed causes the print head 14 to The duty ratio of the applied excitation current is also significantly reduced, which enables a sufficient cooling effect, prevents the print head 14 from overheating, and allows the print head 14 to quickly return to its normal high-speed printing state.

The selection based on the silent/normal mode and the selection based on print head detection are realized by the calculations in steps 111 and 112, respectively, and the selection of the carriage start position due to the increase in print head temperature is given priority over other conditions. It will be done.

In this embodiment, when the carriage start position calculation is performed in the above three stages, the determined start position is set (113), and if the current start position needs to be changed (114). ), the carriage start position is corrected (115).

This correction of the carriage start position is performed by the processor 20 rotating the feed motor 15 by a predetermined amount via the motor control circuit 21.

As a result of the above, the preparation for transporting the carriage 13 is completed, and the carriage transport operation is started (116).

The processor 20 constantly monitors the position of the carriage 13, and when it passes a predetermined run-up area, it detects a print area (117), and prints the print head 14 in this print area.
A predetermined excitation current is supplied to perform the printing operation (11
8).

As a result of the above, when printing of one predetermined line is completed (119), the carriage 13 stops at the set carriage start position (120).

As described above, according to the present embodiment, it is possible to set the desired carriage start position for each line based on the predetermined home position, and it is possible to set the desired carriage start position for each line, which is suitable for the various printing conditions of the printer. A suitable carriage start position is selected.

In the present invention, a plurality of carriage start positions are set in advance at predetermined intervals, and these are stored in the ROM 26, and the processor 20 performs the following based on predetermined printing conditions.
It is also possible to select one of these preset carriage start positions.

[0058]

[Effects of the Invention] As explained above, according to the present invention,
Since the carriage start position can be changed based on predetermined printing conditions, waste in the run-up area can be eliminated and efficient printing can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part of a serial printer to which a carriage feeding method according to the present invention is applied.

FIG. 2 is a diagram showing a control circuit block of the serial printer shown in FIG. 1;

FIG. 3 is an explanatory diagram of carriage feeding according to the present invention.

FIG. 4 is a flowchart showing carriage feeding in this embodiment.

FIG. 5 is a diagram illustrating conventional carriage feeding.

[Explanation of symbols]

10 Platen 11 Paper 13 Carriage 14 Print head 15 Carriage feed motor L Run-up area

Claims (3)

[Claims] Claim 1: A carriage carrying a print head is fed and driven along a platen, and the carriage is moved from a carriage start position to a run-up area and at a constant speed until it reaches a predetermined constant speed so that the print head can operate. In the carriage feeding method of a serial printer including the printing area,
A method for feeding a carriage in a serial printer, characterized in that the carriage start position is changed according to printing conditions. 2. A carriage feeding method for a serial printer according to claim 1, wherein said printing condition comprises a carriage feeding speed. 3. A method of transporting a carriage for a serial printer according to claim 1, wherein said printing condition comprises a temperature of a print head.