JPH054354A - Wire dot printer - Google Patents

Abstract

PURPOSE:To always carry out stable communication with a host computer without increasing the cost by providing a control circuit to output a requirement to the effect that information of specified amount is transmitted at predetermined intervals of time to a host computer during a cooling process. CONSTITUTION:A control circuit 13 is provided to stop the operation of a wire dot head 3 when the detected temperature of a temperature sensor 10 for detecting the temperature of the wire dot head 3 has exceeded a reference value. And the circuit 13, even when the wire is not operating, outputs a requirement that information of specified amount be transmitted to a host computer 15 at predetermined intervals of time in order to enable receiving the information from the computer 15. In this manner, stable communication with the host computer can always be carried out without increasing the cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot printer having a wire dot head, and more particularly to a wire dot printer capable of continuing communication with a host computer even when the wire dot head temperature exceeds a reference value. ..

[0002]

2. Description of the Related Art Conventionally, a carriage is provided movably along a platen, a wire dot head is mounted on the carriage, and a ribbon cassette containing an ink ribbon is mounted on the carriage. Part is installed so as to be interposed between the wire dot head and the paper wound around the platen, and by driving the wire of the wire dot head, the ink of the ink ribbon is transferred to the paper and printed on the paper. There is known a wire dot printer which is designed to perform printing. In such a wire dot printer, there is a usage mode in which information is received from a host computer and printing is performed.

By the way, in such a wire dot printer, when the wire dot printer is used for a long time, the coil of the solenoid generates heat due to its electric resistance, and the wire dot head becomes abnormally high in temperature. There is a risk of breakage or melting of the solder holding the coil.

As a countermeasure against such a high temperature, conventionally, the temperature of the wire dot head is detected by a sensor provided in the wire dot head, and the wire driving of the wire dot head is stopped to wait for the print head to cool, or A control circuit is provided to stop the wire drive and continue the carriage movement. During the movement, the communication with the host computer, that is, the reception of print data is continued at the normal timing. Was there.

[0005]

However, in the conventional device as described above, even when the wire driving is stopped, printing is performed at the same intervals as in normal printing (for example, 1 byte every 500 μsec). Since data is received, the printer's buffer may become full before the wire dot head cooling is completed, that is, the buffer may become full. In such a case, the printer side prints the print data from the host computer. Since it becomes impossible to receive any more, communication error with the host computer occurs, the connection with the host computer is disconnected, the communication error is detected on the host computer side, and the process being executed is interrupted. I had.

It is an object of the present invention to provide a wire dot printer which overcomes the above-mentioned problems in the prior art and enables stable and constant communication with the host computer without increasing the cost.

[0007]

A wire dot printer according to the present invention for solving the above-mentioned problems is provided with a carriage movably along a platen, and a wire dot head is mounted on the carriage. In a wire dot printer that drives a wire of a wire dot head to record an image and character information on a recording paper on the platen, a temperature sensor that detects the temperature of the wire dot head, and a temperature detected by the temperature sensor is a reference value. Means to stop the wire drive of the wire dot head when the wire drive is exceeded, and to enable the host computer to receive information from the host computer even while the wire drive is stopped A control circuit that outputs a request to transmit a predetermined amount of information for each That.

[0008]

According to the present invention having the above-described structure, the control circuit informs the host computer of a predetermined amount of information every predetermined time even during the time when the wire driving is stopped to cool the wire dot head. Since a request to send is sent, the printer buffer does not become full memory due to a large amount of information sent from the host computer while the wire drive is stopped. There is no risk of communication errors. There is no possibility that the connection with the host computer is cut off, a communication error is detected on the host computer side, and the process being executed is interrupted.

[0009]

The present invention will be described below with reference to the embodiments shown in the drawings.

1 to 3 show an embodiment of a wire dot printer according to the present invention.

In FIGS. 2 and 3, a platen 1 which defines a printing position is arranged along the longitudinal direction. A paper guide (not shown) is provided for guiding the paper 2 wound around the platen 1 along the platen 1, and a paper feed mechanism (not shown) is provided above the paper guide. Is provided.

In front of the platen 1, the platen 1
A wire dot head 3 having a plurality of wires 3a and a coil 3b for forming a solenoid for attracting the wires 3a is disposed at a portion facing to the platen. The carriage 5 is mounted on a carriage shaft 4a, 4b arranged along the carriage 1 so as to be movable in the left-right direction in FIG. Further, a ribbon cassette (not shown) having a winding mechanism provided therein is attached to the printer body, and an ink ribbon 6 is housed in the ribbon cassette. The middle portion is interposed between the paper 2 and the wire dot head 3.

A drive pump to which the rotational drive force of a pulse motor 7 as a drive source is transmitted to both ends of the platen 1.
A pulley 8a and a driven pulley 8b are provided, and further,
A belt 9 having both ends fixed to the carriage 5 is stretched between the driving pulley 8a and the driven pulley 8b to convert the rotational driving force of the driving source into the moving force of the carriage 5.

Further, in the present embodiment, a wire dot head temperature detecting sensor 10 is provided in the vicinity of the wire dot head 3, and as shown in FIG. The wire drive circuit 11 of No. 3 and the drive circuit 12 of the carriage 5 are connected to each other. Further, a control circuit 13 for controlling the pulse motor 7 based on the temperature detected by the temperature sensor 10 is provided via the wire drive circuit 11 and the carriage drive circuit 12.

A host computer 15 is connected to the control circuit 13 via a receiving circuit 14, and information from the host computer 15 is input to the control circuit 13 via the receiving circuit 14. There is.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIG.

For normal printing, the pulse motor 7 is driven to drive the wire 3a of the wire dot head 3 while moving the carriage 5 to transfer the ink of the ink ribbon 6 to print characters on the paper 2. The symbols and the like are recorded (step ST1). Then, during printing, step ST
The temperature of No. 2 is detected, and it is determined whether the temperature detected by the temperature sensor 10 of the wire dot head 3 exceeds or exceeds the reference value due to the heat generation of the coil 3b (step ST
3) When the detected temperature of the wire dot head 3 exceeds the reference value, the control circuit 13 controls the wire drive circuit 11 of the wire dot head 3 to stop the wire drive (step ST4), and at the same time drive the carriage 5. The circuit 5 is controlled to move the carriage 5 back and forth once (idling). As a result, the wire dot head 3 is exposed to wind, heat is dissipated, and the wire dot head 3 is cooled.

When one reciprocating movement of the carriage 5 for cooling is completed, the control means 13 controls the host computer 1.
It is judged whether or not there is data from step 5 (step ST6), and if there is data, it is stored in a buffer (not shown) in the control means 13 (step ST7) and the next data is requested to the host computer 15. Yes (step ST
8). Then, the wire dot head 3 in step ST9
It is judged whether or not the temperature has dropped, and if the temperature has dropped below the reference value, the process returns to printing in step ST1.
If the temperature is not lower than the reference value, the carriage 5 is reciprocated once again.

On the other hand, if there is no data in the judgment of the data from the host computer 15 in the step ST6, the process directly goes to the judgment of the temperature of the wire dot head 3 in the step ST9. ..

As described above, according to the present embodiment, 1 byte of data is received at every interval of one reciprocating movement of the carriage 5, which is much longer than the reception interval during normal printing (for example, 1 byte every 500 μsec). In this way, the control means 13 and the host computer 1
Maintains communication with 5. That is,
The time for one reciprocating movement of the carriage 5 is used as the data reception interval.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, a special receiving circuit 14A different from the receiving circuit 14 in the first embodiment described above is provided with a control means 13 and a host computer. It is interposed between the same and the other parts, and the other structure is the same as that of FIG. 1 described above. Since the receiving circuit 14A is actually built in the control circuit 13, in the description of the claims,
It is described that the control circuit has a function of a receiving circuit.

In the embodiment of FIG. 5, the receiving circuit 14A has a built-in timer, and the timer sets a data receiving interval (for example, 1 second).
Data is received from the host computer 15 at each interval.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIGS. 6 and 7.

FIG. 6 shows the main routine of this embodiment, and step ST1 from the start of printing to the stop of printing.
The operation from 1 to step ST14 is the same as the operation from step ST1 to step ST4 of FIG. 4 described above for the first embodiment. When the printing is stopped in step ST14, the carriage 5 may be reciprocated to cool the wire dot head 3, or the carriage 5 may be kept stationary.

Then, in this embodiment, step S
After the printing is stopped in T14, as shown in step ST15, the overheat flag is set to judge whether the temperature of the wire dot head 3 has dropped (step ST16). If the temperature has dropped, step S16
As shown in T17, the overheat flag is cleared and printing in step ST11 is restarted.

On the other hand, when data is received from the host computer 15 while the temperature is being lowered in step ST16, the receiving circuit 14 shown in FIG.
The procedure moves to the subroutine A, and this subroutine of the receiving circuit 14A is executed.

When this subroutine is started, first,
As shown in step ST21, the receiving circuit 14A receives the data from the host computer 15, and then, as shown in step ST22, stores the received data in a buffer (Buffer: not shown).

After that, as shown in step ST23,
It is determined whether the buffer is full. Note that "buffer full" here means that the remaining capacity of the buffer is 2
It means a state of about 55 bytes.

If it is determined in step ST23 that the buffer is full, the process ends as it is, and step ST23
If it is determined in step 23 that the buffer is full, step S
As shown at T24, the presence / absence of the overheat flag is determined, and if the overheat flag is not set, the process ends. Further, if the overheat flag is set in the judgment of step ST24, it waits for one second (step ST25), and then, as shown in step ST26, requests the next data from the host computer 15, and the receiving circuit 14A 6 is terminated and the process returns to the main routine of FIG.

The above-mentioned routines of FIGS. 6 and 7 are repeated to cool the wire dot head 3.

Also in this embodiment as described above, the same effect as that of the first embodiment can be obtained.

The present invention is not limited to the above-described embodiments, but various modifications can be made if necessary.

[0033]

As described above, according to the wire dot printer of the present invention, the time required for cooling the wire dot head can be communicated with the host computer without increasing the cost.
Stable communication with the host computer is possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a wire dot printer of the present invention.

FIG. 2 is a side view in vertical section of the wire dot printer of FIG.

FIG. 3 is a control circuit diagram of the wire dot printer of FIGS. 1 and 2.

FIG. 4 is a flow chart of the first embodiment.

FIG. 5 is a view similar to FIG. 3 showing a second embodiment of the wire dot printer of the present invention.

FIG. 6 is a flowchart of a main routine of the second embodiment.

FIG. 7 is a flowchart of a subroutine of the second embodiment.

[Explanation of symbols]

 1 Platen 3 Wire Dot Head 5 Carriage 6 Ink Ribbon 7 Pulse Motor 10 Temperature Sensor 11 Wire Drive Circuit 12 Drive Circuit 13 Control Circuit 14, 14A Reception Circuit 15 Host Computer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideo Kawase 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Go Miyano 1-7 Yukiya-Otsuka-cho, Ota-ku, Tokyo Alp Su Electric Co., Ltd. (72) Inventor Eisuke Takebe 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. A carriage is provided so as to be movable along a platen, a wire dot head is mounted on the carriage, and a wire of the wire dot head is driven so that a recording paper is placed on the platen. In a wire dot printer for recording images and character information, a temperature sensor for detecting the temperature of the wire dot head, and means for stopping the driving of the wire dot head when the temperature detected by the temperature sensor exceeds a reference value. A control circuit that outputs a request to transmit a predetermined amount of information to the host computer at a predetermined time during the wire drive stop so that information can be received from the host computer even during the wire drive stop A wire dot printer characterized by being provided with.