JP3061091B2 - Serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for detecting a home position 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 using a dot matrix are widely used because of their excellent cost performance. In many of these dot matrix printers,
In general, in order to specify the printing position in the printing line direction, position detection is 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. 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 carriage 2 is provided with a shielding plate 10. In the figure, the ribbon cartridge and the printing paper are not shown.

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

Further, in the serial printer having the configuration shown in FIG. 5, when high positional accuracy is required for characters to be printed, a detector 6 mounted on a carriage and a high-resolution mounted parallel to a guide shaft supporting the carriage are required. The printing position is managed by the linear scale 7. In general, two types of detectors are used: an optical type and a magnetic type.

[0006]

However, in the conventional method of setting the origin position provided with the linear scale 7, 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 match, and the accuracy of 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 disadvantage that the cost ratio is higher than the function. Further, in the origin position setting method using only the detector 6 by the linear scale 7, the origin position is determined by stopping the movement of the carriage. When the printer stops at the origin position, it becomes impossible to distinguish between them, and there is also a problem that a mistake in setting the origin position is detected after print data is received from an external device and printing is started.

[0007]

Means for Solving the Problems] serial printer of the present invention in order to solve such a problem, tower the printhead
The linear scale located in the movement path of the mounted carriage
And mounted on the carriage, and moved by the carriage.
Linear scale reader that outputs pulses in response to movement
In the serial printer having a stage, moving the carriage in the direction of the original point position, the linear scale reading
Triggered by the leading edge of the pulse from the
A carriage stop detecting means for detecting stop of the carriage, which comprises a timer for stopping the carriage, and a stop position detected by the carriage stop detect means as a starting point, and moving the carriage in a direction opposite to the origin position. the carriage is moved, a movement termination determining means for determine a constant whether to move the moving distance that is set in advance, of the determination by the mobile end determining unit result, the transfer Do距 release said set in advance to There, characterized in that it e Bei a, and an error signal generating means for generating error signals if it can not move.

[0008]

According to the serial printer of the present invention, the detector and the linear scale mounted on the carriage allow the carriage to hit a stop part of the mechanism of the printer when the printer is initialized, such as when the power is turned on or when the printer is reset.
The time between the leading and trailing edges of the pulse on the linear scale.
Detection in a very short time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described according to one embodiment.

FIG. 1 shows the appearance of an impact type serial printer. 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. In the figure, the ribbon cartridge and the printing paper are not shown for easy understanding of the configuration. A high-resolution linear scale 7 is provided in parallel with the carriage guide shaft 3, and a position is detected by a detector 6 mounted on the carriage. 5
Is a stopper for stopping the carriage.

FIG. 2 shows the 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 detecting the carriage stop, the carriage moves by a distance corresponding to the maximum printable area of the printer from the origin position as an origin (operation (a)). Then, when the carriage is moved by the distance of the maximum printing area, the carriage moves to a preset home position and stops (operation c).

FIG. 4 is an explanatory diagram of the carriage stop determination. The carriage moving speed profile shows how the speed changes from the stop of the carriage to the set speed v1.
Encoder A generated by linear scale and detector
The signal is output in accordance with the carriage moving speed, and the cycle of the encoder A signal becomes shorter as the signal is accelerated from the stopped state. Here, the carriage stop detecting means sets a timer value Td every time the edge of the encoder A signal is inverted, and performs a timing operation. In a normal state, the timer value Td
Is set longer than the inversion cycle of the encoder A signal in the state of acceleration or deceleration of the carriage, the inversion of the encoder A signal always occurs before the timer finishes timing.

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

By an initial operation such as turning on the power of the printer,
First, the moving speed 1 for the carriage movement is set, and the movement is started in the direction of the origin (steps 1 and 2).

An encoder A signal is generated at the start of the 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 to the timer 1, and starts the timer (steps 3 and 4).

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

If the timer 1 finishes counting the timer earlier than the change in the level of the encoder A signal, it is determined that the carriage has stopped, the timer 1 stops counting, and the carriage stops moving (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 determined by the movement end determining means whether or not the movement has been completed for the movable distance set in advance by 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 moving is performed in the direction of the home position which is the starting point of the printing start, and after confirming the home position, the driving of the motor is stopped and the carriage is stopped (step 1).
3,14,15,16).

If the movement of the movable distance is not possible in step 12, the detected origin position is inaccurate, and 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 circumvented by the printer's own operation due to the error notification, the printer is restored and then the printer's initial operation is performed again.

[0024]

According to the serial printer of the present invention, the detector and a linear scale mounted on the carriage, that the carriage has stopped me per stop part of the mechanical part of the printer at the time of initialization of the printer, linear Scale
Very short time detected by the time between the leading edge and the trailing edge
Can be detected between.

[Brief description of the 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 detecting operation according to the present invention.

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

FIG. 4 is an explanatory diagram of 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 Carriage Stopper 6 Linear Detector 7 Linear Scale 8 Side Frame 9 Home Detector 10 Detection Flag

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41J 19/18 B41J 29/46

Claims (1)

(57) [Claims] 1. Movement of a carriage on which a print head is mounted
The linear scale placed on the path and the carriage
Mounted and emits pulses in response to the movement of the carriage.
In the serial printer having a linear scale reading means for force, moving the carriage in the direction of the original point position, the linear
Triggered by leading edge of pulse from ascale reading means
Said carry comprising a timer stopped by the trailing edge.
A carriage stop detecting means for detecting a stop of the carriage, a stop position detected by the carriage stop detecting means as a starting point, and a carriage opposite to the origin position.
Moved in direction, a movement termination determining means for determine a constant whether to move the transfer Do距 away that is set in advance, of the determination by the mobile end determining unit that said preset
Serial printer and a error signal generating means for generating error signals if could not move the shift Do距 away that the carriage is.