JPH0768910A - Serial dot printer - Google Patents

Abstract

PURPOSE:To provide a serial dot printer capable of uniformizing the consumption of the ink in an ink ribbon regardless of the setting of a printing mode. CONSTITUTION:A ribbon feed motor 24 feeding an ink ribbon and a ribbon feed motor control part 22 controlling the driving of the ribbon feed motor 24 are provided and the ribbon feed control part 22 drives the ribbon feed motor 24 by constant quantity at each time when a printing head 4 is once driven by a printing head control part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial dot printer for printing by driving a print head mounted on a carriage while reciprocating the carriage by driving a carriage motor.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional serial dot printer. In the figure, a CPU 1 controls a print mode by receiving a command from a host computer (not shown). This is to control the output timing of drive signals from each control unit according to a control program written in a memory (not shown). Control.

In the CPU 1, the print head control unit 2 controls the drive of the print head 4 via the print head drive circuit 3. In addition, the carriage motor control unit 5
The drive of the carriage motor 7 is controlled via the carriage motor drive circuit 6. On the other hand, the line feed motor control unit 8 controls the drive of the line feed motor 10 via the line feed motor drive circuit 9.

FIG. 5 is a schematic diagram showing the structure of a conventional serial dot printer. In the figure, a print head 4 and an ink ribbon 13 housed in a ribbon cassette 12 are mounted on a carriage 11. A carriage belt 14 is connected to the carriage 11, and the driving force of the carriage motor 7 is transmitted to the carriage 11 via the carriage belt 14.

On the other hand, below the carriage 11, the wire 1
5 is stretched by the pulling force of the spring S, and a part of this wire 15 is wound once around a pulley 16 rotatably attached to the carriage 11. Also, the drive gear 1 fixed coaxially with the pulley 16
7 is meshed with a planetary gear 18, and this planetary gear 18
Is engaged with either one of the pair of idle gears 19 and 20 depending on the rotation direction of the carriage motor 7. Further, one idle gear 20 is a pair of ribbon feed rollers 2 built in the ribbon cassette 12.
It is connected to 1a and 21b.

Here, in FIG. 5, the carriage motor 7
When the carriage motor 7 is rotated clockwise, the carriage 11 moves from the right direction to the left direction in the drawing in accordance with the rotation amount. Conversely, when the carriage motor 7 is rotated counterclockwise, the carriage 11 moves to the left direction in the drawing. To the right. Also,
When the carriage 11 moves in this way, the pulley 16 rotates together with the drive gear 17 according to the amount of movement. The rotational force of the drive gear 17 is transmitted through the planetary gear 18 and the idle gears 19 and 20 to the ribbon feed rollers 21a and 2a.
1b, whereby the ink ribbon 13 is fed. At that time, the feed direction of the ink ribbon 13 is appropriately moved according to the rotation direction of the carriage motor 7, and the planetary gear 18 is moved to a position shown by a broken line and a position shown by a solid line in FIG. By engaging one of them, it is always controlled in one direction.

Next, the operation of the conventional serial dot printer will be described. The carriage motor drive circuit 6 operates by receiving the rotation command pulse output from the carriage motor control unit 5 to drive the carriage motor 7. At this time, the carriage motor 7 rotates the rotation command pulse at 1 / per pulse. At the same time that the carriage 11 is moved by 360 inches, the ink ribbon 13 is fed by 1/360 inch per pulse.
The print modes to be described are the normal print mode in which print control is performed every 1/180 inch, the draft print mode in which print control is performed every 1/90 inch, and 1/3.
There are three double-density printing modes in which printing is controlled every 60 inches.

First, when a host computer (not shown) outputs a draft print mode command signal to the CPU 1, the CPU 1 which receives the command signal outputs four rotation command pulses from the carriage motor control unit 5 and at the same time. The print head controller 2 outputs a control signal for printing. As a result, the print head controller 2 drives the print head 4 once every time the carriage motor 7 moves the carriage 11 by 1/90 inch, and the carriage motor controller 5 causes the print head controller 2 to print the print head 4. Each time 4 is driven once, the ink ribbon 13 is moved to 1/90
Feed in inches.

On the other hand, when a host computer (not shown) outputs a command signal in the normal print mode to the CPU 1, the CPU 1 which receives the command signal outputs two rotation command pulses from the carriage motor control unit 5 and at the same time. The control signal is output from the print head controller 2. As a result, the print head controller 2 controls the carriage motor 7
Drives the print head 4 once each time the carriage 11 moves 1/180 inch, and the carriage motor controller 5 drives the ink ribbon 13 one time each time the print head controller 2 drives the print head 4 once. Feed every 180 inches.

When a double-density print mode command signal is output from the host computer (not shown) to the CPU 1, the CPU 1 that receives the command signal outputs one rotation command pulse from the carriage motor controller 5. At the same time, the print head controller 2 outputs a control signal. As a result, the print head controller 2 controls the carriage motor 7
Drives the print head 4 once each time the carriage 11 moves 1/360 inch, and the carriage motor control unit 5 drives the ink ribbon 13 one time each time the print head control unit 2 drives the print head 4 once. Feed every 360 inches. By the way, such switching of the printing mode is performed in units of lines.

[0011]

However, in the above-mentioned conventional serial dot printer, due to its mechanism, the drive gear 17 for feeding the ink ribbon 13 is configured to rotate in association with the movement of the carriage 11. Therefore, when the setting of the print mode is switched, the ink ribbon 1 when the print head 4 is driven once according to the change
The feed amount of 3 also changes. For this reason, if the setting of the print mode is switched line by line during the printing process, the ink consumption amount in the ink ribbon 13 becomes uneven, which causes a difference in shade in the print result, resulting in deterioration of print quality. There was a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a serial dot printer capable of making the ink consumption amount in the ink ribbon uniform regardless of the setting of the print mode.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and includes a carriage that reciprocates by driving a carriage motor, a print head and an ink ribbon mounted on the carriage, A carriage motor control unit for controlling the drive of the carriage motor,
A serial dot printer having a print head control unit for controlling the drive of a print head, comprising a ribbon feed motor for feeding an ink ribbon and a ribbon feed motor control unit for controlling the drive of the ribbon feed motor. The feed motor control unit drives the ribbon feed motor by a constant amount each time the print head control unit drives the print head once.

[0014]

In the serial dot printer of the present invention,
Each time the print head controller drives the print head once, the ribbon feed motor controller drives the ribbon feed motor by a constant amount, so that the printing interval of the print head on the ink ribbon is always constant. Ink consumption in the ink ribbon becomes uniform regardless of the setting.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. In this embodiment, the same components as those in the conventional example will be designated by the same reference numerals. FIG. 1 is a block diagram showing an embodiment of a serial dot printer according to the present invention. In the figure, CPU1
Controls the printing mode by receiving a command from a host computer (not shown), which controls the output timing of the drive signal from each control unit in accordance with a control program written in a memory (not shown).

In the CPU 1, the print head control unit 2 controls the drive of the print head 4 via the print head drive circuit 3, and the print head 4 is controlled from the print head control unit 2 to the print head drive circuit 3. The head pin is selectively driven according to the control signal output to the printer to print. The carriage motor control unit 5 controls the drive of the carriage motor 7 via the carriage motor drive circuit 6, and the carriage motor 7 outputs the rotation direction output from the carriage motor control unit 5 to the carriage motor drive circuit 6. It is rotationally driven according to the instruction signal and the rotation command pulse. On the other hand, the line feed motor control unit 8 controls the drive of the line feed motor 10 via the line feed motor drive circuit 9, and the line feed motor 10 outputs a rotation command output from the line feed motor control unit 8 to the line feed motor drive circuit 9. It is rotated according to the pulse.

Further, in this embodiment, a ribbon feed motor control section 22 is provided in the CPU 1. The ribbon feed motor control unit 22 controls the drive of the ribbon feed motor 24 via the ribbon feed motor drive circuit 23. The ribbon feed motor 24 transfers from the ribbon feed motor control unit 22 to the ribbon feed motor drive circuit 23. It is rotationally driven according to the output rotation command pulse.

FIG. 2 is a schematic diagram showing the structure of the serial dot printer in this embodiment. In the figure, a print head 4 and an ink ribbon 13 housed in a ribbon cassette 12 are mounted on a carriage 11. A carriage belt 14 is connected to the carriage 11, and the driving force of the carriage motor 7 is transmitted to the carriage 11 via the carriage belt 14.

Further, in this embodiment, a ribbon feed motor 24 for feeding the ink ribbon 13 is mounted on the carriage 11. In this ribbon feed motor 24, its motor gear 25 is an idle gear 26.
Further, the idle gear 26 is connected to the pair of ribbon feed rollers 21a and 21b. Therefore, when the ribbon feed motor 24 is rotated clockwise as shown in the drawing, the rotational force is transmitted to the ribbon feed rollers 21a and 21b via the idle gear 26, whereby the ribbon feed rollers 21a and 2b are rotated.
1b rotates and the ink ribbon 13 is fed in one direction.

Next, the operation of the serial dot printer in this embodiment will be described. In this embodiment, the carriage motor 7 driven according to the rotation command pulse from the carriage motor control unit 5 moves the carriage 11 by 1/360 inch per pulse, and the rotation from the ribbon feed motor control unit 22. The ribbon feed motor 24, which is driven according to the command pulse,
1/360 inch ink ribbon per pulse 13
Shall be fed.

First, when a command signal in the draft print mode is output from the host computer (not shown) to the CPU 1, the CPU 1 which receives the command signal outputs four rotation command pulses from the carriage motor control unit 5 and at the same time. , The print head control unit 2 outputs a control signal for printing, and the ribbon feed motor control unit 2
Two rotation command pulses are output from 2. As a result, the print head controller 2 causes the print head 4 to move each time the carriage motor 7 moves the carriage 11 by 1/90 inch.
The ribbon feed motor control unit 22 drives the ribbon feed motor 24 by a fixed amount each time the print head control unit 2 drives the print head 4 once, and the ribbon feed motor control unit 22 drives the ink ribbon 13 to 1/180. Feed by inch.

On the other hand, when a host computer (not shown) outputs a command signal in the normal print mode to the CPU 1, the CPU 1 which receives the command signal outputs two rotation command pulses from the carriage motor controller 5 and at the same time. The print head control unit 2 outputs a control signal and the ribbon feed motor control unit 22 outputs two rotation command pulses. As a result, in the print head control unit 2, the carriage motor 7 moves the carriage 11 to 1/1.
The print head 4 is driven once every 80 inches of movement, and the ribbon feed motor controller 22 drives the ribbon feed motor 24 by a constant amount each time the print head controller 2 drives the print head 4 once. Then, the ink ribbon 13 is fed 1/180 inch at a time.

When a host computer (not shown) outputs a command signal in the double-density printing mode to the CPU 1, the CPU 1 which receives the command signal outputs one rotation command pulse from the carriage motor controller 5. At the same time, the print head controller 2 outputs a control signal and the ribbon feed motor controller 22 outputs two rotation command pulses. As a result, in the print head controller 2, the carriage motor 7 moves the carriage 11 to 1 /
The print head 4 is driven once every 360 inches, and the ribbon feed motor controller 22 drives the ribbon feed motor 24 by a constant amount each time the print head controller 2 drives the print head 4. Then, the ink ribbon 13 is fed 1/180 inch at a time.

FIG. 3 is a schematic diagram showing the consumption state of the ink ribbon for each printing mode. First, in FIG. 3, the upper part shows the ribbon consumption state of the draft printing mode, the middle part shows the normal printing mode, and the lower part shows the ribbon consumption state of the double-density printing mode. Also, the left side of the figure shows the conventional example, and the right side of the figure shows the ribbon consumption state of the embodiment. It shows the state. Here, in order to make it easier to understand the difference between the conventional example and the example, a rotation command pulse output from the carriage motor control unit 5 and the ribbon feed motor control unit 22, a movement amount of the carriage 11 per pulse, and an ink amount. The feed amount of the ribbon 13 is shown as 1/360 inch.

As is apparent from the figure, first, in the conventional example,
The embossing dot interval in the draft print mode is 1/90 inch, and the embossing dot interval in the normal print mode is 1/180
Inch and dot spacing in double density print mode is 1/3
It is 60 inches, and the embossing dot interval by the print head 4 (adopting vertical 6-dot row head pins) differs depending on the print mode. On the other hand, in the embodiment, the embossing dot interval in the draft print mode is 1/180 inch, the embossing dot interval in the normal print mode is 1/180 inch, and the embossing dot interval in the double density print mode is also Also 1
Even if the setting of the print mode is different, such as / 180 inch, the interval of the dots printed by the print head 4 is constant.

As described above, in the serial dot printer of this embodiment, the ribbon feed motor 24 for feeding the ink ribbon 13 and the ribbon feed motor control for controlling the drive of the ribbon feed motor 24 via the ribbon feed motor drive circuit 23. And the ribbon feed motor controller 22 drives the ribbon feed motor 24 each time the print head controller 2 drives the print head 4 once.
Since the printing head 4 is driven by a constant amount, the printing dot interval of the print head 4 with respect to the ink ribbon 13 is always constant (1/180 inch) no matter which printing mode is used.
Becomes

In this embodiment, the rotation command pulse from the ribbon feed motor control unit 22 and the ribbon feed amount per pulse are set to 1/360 inch, and the ribbon when the print head 4 is driven once is set. Although the feed amount is set to 1/180 inch, the feed amount of the ink ribbon 13 can be freely set by changing the outer diameters of the motor gear 25 and the idle gear 26.

[0028]

As described above, according to the serial dot printer of the present invention, the ribbon feed motor control unit drives the ribbon feed motor by a constant amount each time the print head control unit drives the print head once. Therefore, the printing interval of the print head with respect to the ink ribbon is always constant, which makes it possible to make the ink consumption amount in the ink ribbon uniform regardless of the setting of the print mode. As a result, the unevenness of the ink consumption amount in the ink ribbon is eliminated, and the generation of light and shade in the print result is prevented, whereby the print quality is improved.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing a structure of a serial dot printer according to an embodiment.

FIG. 3 is a schematic diagram showing a consumption state of an ink ribbon for each print mode.

FIG. 4 is a block diagram showing a conventional serial dot printer.

FIG. 5 is a schematic diagram showing the structure of a conventional serial dot printer.

[Explanation of symbols]

 2 print head control unit 4 print head 5 carriage motor control unit 7 carriage motor 11 carriage 13 ink ribbon 22 ribbon feed motor control unit 24 ribbon feed motor

Claims (1)

[Claims] 1. A carriage that reciprocates by driving a carriage motor, a print head and an ink ribbon mounted on the carriage, a carriage motor control unit that controls the drive of the carriage motor, and a drive of the print head. A serial dot printer including a control unit for controlling a print head, comprising: a ribbon feed motor that feeds the ink ribbon; and a ribbon feed motor control unit that controls driving of the ribbon feed motor. A serial dot printer, wherein the print head controller drives the ribbon feed motor by a constant amount each time the print head controller drives the print head once.