JPH06255195A - Serial printer - Google Patents

Abstract

PURPOSE:To provide means which is capable of correctly detecting the home position in a serial printer by making a carriage hit a stopping part of a mechanical part of the printer at the initialization of the printer by means of a detector and a linear scale mounted to the carriage. CONSTITUTION:A carriage 2 stopped at an A point when the printer is initialized is driven in a direction of a stopper 5. After stopping of the carriage is detected, the carriage is moved a distance corresponding to the maximum printable area of the printer from an origin as a starting point. When the carriage can be moved the distance of the maximum printable area, the carriage is moved and stopped at a preliminarily set home position. Therefore, it becomes possible to specify the home position and detect by the movement from the home position in the direction of printing lines whether the detection of the home position is correct.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home position detecting method which is a starting point of a printing position of a serial printer.

[0002]

2. Description of the Related Art Serial printers for printing characters and bit images by dot matrix are widely used because of their excellent cost performance. In most of these dot matrix printers,
In order to specify the print position in the print line direction, position detection is generally performed by an optical transmission type detector.

First, a general printing method will be described with reference to FIG. 5 showing the appearance of an impact type serial printer. Reference numeral 1 is a print head, 2 is a carriage, 3 is a carriage guide shaft, 4 is a platen, and 8 is a side frame. A shield plate 10 is provided on the carriage 2. The ribbon cartridge and printing paper are not shown in the figure.

The starting point of the printing position is determined as the position where the shield plate 10 has passed the detector 9 when the printer is powered on or reset. During the printing operation, the starting point or a position distant from the starting point by an arbitrary distance is set as a home position, and the printing position of each character is managed with the home position as a reference, whereby printing in the line direction is performed.

Further, in the serial printer having the structure shown in FIG. 5, when high positional accuracy is required for a character to be printed, a detector 6 mounted on the carriage and a high resolution installed parallel to a guide shaft for supporting the carriage. The linear scale 7 is used to control the printing position. The detector 6 is generally of two types, an optical type and a magnetic type.

[0006]

However, in the conventional origin position setting method in which the linear scale 7 is provided, the position is managed by the detector 2 for detecting the origin position and the detector 6 of the linear scale 7. Therefore, there is a drawback that the origin position and the detection position of the linear scale position do not coincide with each other and the accuracy of the printing set from the origin position with respect to the home position is poor. In addition, since two detectors are also used for position management, there is a drawback that the cost ratio with respect to the function is high. Further, in the origin position setting method using only the detector 6 with the linear scale 7, since the origin position is determined by stopping the movement of the carriage, the original position may be determined by a jam of the printing paper during the movement toward the origin position. When it stops at the origin position, it becomes impossible to distinguish, and there is a problem that the setting error of the origin position is detected after printing data is received from an external device and printing is started.

[0007]

[Means for Solving the Problems] Solving such problems
For this reason, the serial printer of the present invention does not move the print head.
The serial type printer installed in the printer
Power source in the direction of the origin position that is virtually set beforehand.
The carriage is moved when entering, and the carriage stops.
Carriage stop detecting means for detecting that
Starting from the virtual origin position obtained by the ridge stop detection means
The key in the direction opposite to the carriage movement direction.
Move the carriage to set the preset movable distance.
A movement end determining means for determining whether or not the
As a result of the determination by the motion end determination means,
If the carriage cannot move, an error signal will be sent.
Equipped with at least error signal generating means
It is characterized by

[0008]

According to the serial printer of the present invention, the detector and the linear scale mounted on the carriage specify the home position by the carriage hitting a stop part of the printer mechanical portion at the time of printer initialization such as power-on or reset. Therefore, the quality of the home position detection can be determined by the movement operation from the home position in the print line direction.

[0009]

EXAMPLES The present invention will be described according to one example.

FIG. 1 shows the appearance of an impact type serial printer. Reference numeral 1 is a print head, 2 is a carriage, 3 is a carriage guide shaft, 4 is a platen, and 8 is a side frame. The ribbon cartridge and the printing paper are not shown in the figure for the sake of clarity. A high-resolution linear scale 7 is installed in parallel with the carriage guide shaft 3, and the position is detected by a detector 6 mounted on the carriage. 5
Is a stopper for stopping the carriage.

FIG. 2 shows an outline of the position detecting operation. The carriage 2 stopped at the point A when the printer is initialized is first driven in the direction of the stopper 5 (operation A). After the carriage stop is detected, the carriage moves from the origin position by a distance corresponding to the maximum printable area of the printer (operation a). When the carriage is moved by the distance of the maximum print area, the carriage is moved to the preset home position and stopped (operation c).

FIG. 4 shows an explanatory view of the carriage stop determination. The carriage movement speed profile shows how the speed changes from the carriage stop to the set speed v1.
Encoder A generated by linear scale and detector
The signal is output corresponding to the carriage moving speed, and the cycle of the encoder A signal becomes shorter as the acceleration is started from the stopped state. Here, the carriage stop detection means sets the timer value Td every time the edge of the encoder A signal is inverted, and performs the time counting operation. In the normal state, the timer value Td
Is set to be longer than the inversion cycle of the encoder A signal in the carriage acceleration or deceleration state, so that the encoder A signal is always inverted before the timer finishes counting.

The control method will be described with reference to the flowchart of FIG.

By the initial operation such as power-on of the printer,
First, the moving speed 1 for moving the carriage is set, and the carriage starts moving toward the origin position (steps 1 and 2).

An encoder A signal is generated with the start of movement. The carriage stop detecting means stores the signal level every time the level of the encoder A signal is inverted, sets the timer value Td in the timer 1 and starts the timer (steps 3 and 4).

It is judged whether or not the level of the encoder A signal has changed from the stored level (step 5). If the level change of the encoder A signal is earlier than the end of the time measurement of the timer 1 which is measuring time, When the encoder A signal level change is detected, the timer stops counting (step 18) and returns to the encoder A signal level storing step again.

If the timer 1 finishes timing earlier than the level change of the encoder A signal, it is determined that the carriage has stopped, timer 1 timing is stopped, and carriage movement is stopped (steps 6, 7, 8). ).

Here, the count value of the encoder A signal at the time of stop is temporarily stored as the origin position (step 9).

Next, the moving speed 2 for moving the carriage
Is set, and the carriage is driven in the direction opposite to the origin (steps 10 and 11).

Here, it is judged by the movement end judging means whether or not the movement is completed with respect to the movable distance preset in the carriage moving means (step 1).
2).

When the movement is completed, the temporarily stored origin position is permanently stored as the origin position. Then, the moving speed 3 for moving the carriage is set, the carriage is moved toward the home position which is the starting point of the printing start, and after the home position is confirmed, the motor drive is stopped and the carriage is stopped (step 1
3,14,15,16).

If the movement of the movable distance cannot be performed in step 12, the detected origin position is inaccurate. Therefore, the error signal generating means issues an error signal by sounding a buzzer, blinking a lamp, or the like ( Step 17), stop driving the motor.

When the printer user recognizes a state that cannot be avoided by the printer's self-operation due to the error notification, the printer is restored and the printer's initial operation is performed again.

[0024]

According to the serial printer of the present invention, the detector and the linear scale mounted on the carriage make it possible to specify the home position because the carriage hits the stop parts of the mechanical portion of the printer when the printer is initialized. Become. Further, by moving from the home position in the print line direction, the quality of the home position detection can be determined.

[Brief description of drawings]

FIG. 1 is an external view of a printer mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a position detection operation of the present invention.

FIG. 3 is a flowchart of the position detection method of the present invention.

FIG. 4 is an explanatory diagram of a carriage stop determination according to the present invention.

FIG. 5 is an external view of a mechanism of a conventional printer.

[Explanation of symbols]

 1 head 2 carriage 3 carriage guide shaft 4 platen 5 stopper for stopping carriage 6 linear detector 7 linear scale 8 side frame 9 home detector 10 detection flag

Claims (1)

[Claims] 1. In a serial type printer having a print head mounted on a carriage, the carriage is moved when a power source is turned on in a direction of an origin position virtually set in advance, and the carriage is stopped to detect that the carriage is stopped. With the detection means and the virtual origin position obtained by the carriage stop detection means as a starting point, the carriage is moved in a direction opposite to the carriage movement direction, and it is determined whether or not a preset movable distance is moved. And at least an error signal generating means for generating an error signal when the carriage cannot move within the movable distance as a result of the judgment by the movement end judging means. A serial printer characterized by.