JP2003334980A - Label printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a label printer in which a fan can be driven while giving little offense to the ear. <P>SOLUTION: The label printer comprises a thermal head 15, a thermistor 21 for detecting the ambient temperature To of the thermal head in the casing of the label printer, a thermistor 22 for detecting the temperature Tt of the thermal head, a fan 16 for suppressing temperature rise in the casing of the label printer, and a means for driving the fan for a time T corresponding to the difference (To-Tt) between the ambient temperature of the thermal head detected by the thermistor 21 upon finishing print operation by means of the thermal head and the temperature of the thermal head detected by the thermistor 22. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label printer for printing characters, barcodes, etc. on labels and tags.

[0002]

Label printers equipped with thermal heads are used not only in supermarkets but also in hospitals and offices. When such a label printer is driven, the thermal head generates heat, so that the temperature inside the label printer housing rises.

Therefore, a fan is driven in order to suppress the temperature rise in the label printer housing. This fan was always running when the power was turned on.

[0004]

Depending on the environment in which the label printer is used, the printing operation is not always performed. Therefore, the temperature inside the label printer housing may not rise even if the fan is not always driven. In such a usage environment, if the fan is driven at all times when the power is turned on, there is a problem that the sound becomes harsh.

Therefore, there is a demand for operation control of the fan suitable for the operating environment.

It is an object of the present invention to provide a label printer which can drive the fan of the label printer so as not to be audible.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a fan is driven only for a time corresponding to the difference between the temperature around the thermal head and the temperature of the thermal head after printing with the thermal head is completed.

Therefore, a large difference between the temperature around the thermal head and the temperature of the thermal head indicates that the temperature inside the printer housing has risen significantly. In such a case, if the temperature difference between the ambient temperature of the thermal head and the temperature of the thermal head is large, keep the fan running for a long time after printing is complete, and if the temperature difference is small, complete printing. After that, I try to keep the fans running for a short time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the system configuration of a label printer. In FIG.
Reference numeral 11 denotes a CPU (central processing unit) that controls the entire label printer. System bus 11 from this CPU 11
In a, a RAM (random access memory) 1 that stores various work areas in addition to a PLU (price lookup) table that stores product information for each product number
2. ROM (read only memory) 13 for storing various control programs; sensor 14 such as a transmissive sensor for detecting a gap between labels or a reflective sensor for detecting a black mark; A thermal head 15 having heating elements arranged therein, a fan motor 17 for driving a fan 16, a stepping motor 18 for rotationally driving a platen roller to convey a mount, a DC motor 19 for a conveying system, a key input unit 20, a label Temperature (outside air temperature) T around the thermal head 15 in the printer housing 31
Thermistor 2 as first temperature detecting means for detecting o
1, a thermistor 22 as second temperature detecting means for detecting the temperature Tt of the thermal head 15, and a communication I / F 23 for communicating with an externally connected host computer.

The RAM 12 has a thermal head 1
The time T from the end of the printing process of 5 to the stop of the fan 16 is stored according to the value of To-Tt. For example, the time T is set so as to be proportional to To-Tt. The time T may have a width of To-Tt, and the same time T may be set within the width, and the time T may be increased stepwise.

Next, referring to FIG. 2, a cross-sectional view of the main part of the label printer will be described. In FIG. 2, reference numeral 31 is a housing of the label printer. The thermal head 15 is installed in the housing 31. This thermal head 15
Is provided with a thermistor 22 as a second temperature detecting means for detecting the temperature Tt of the thermal head 15. Further, in a part of the housing 31, the temperature (outside air temperature) To around the thermal head 15 inside the label printer housing 31 is To.
Thermistor 21 as first temperature detecting means for detecting
Is provided. Further, an exhaust slit 32 is opened in a part of the housing 31. This exhaust slit 3
A fan 16 is provided inside the unit 2. here,
Although not shown, a power switch is provided on a part of the housing 31.

Next, the operation of the embodiment of the present invention configured as described above will be described. First, fan 16
The drive mode is designated as an automatic control mode in which the drive of the fan 16 is automatically controlled, a continuous drive mode in which the fan 16 is always driven, or a constant OFF mode in which the fan 16 is always turned off. As the designation method, setting may be performed by a DIP switch of the printer, or after the printer is set to the system mode, key operation designation from the key input unit 20 or setting by a command. The drive mode of the fan 16 set in this way is RA
It is stored in the specific area of M12. The specific area of the RAM 12 in which the drive mode of the fan 16 is stored is backed up so that its contents are retained even when the power switch is turned off.

By the way, when the power switch (not shown) is turned on, if the automatic control mode is stored in the specific area of the RAM 12, the process shown in the flowchart of FIG. 3 is started. First, the outside air temperature To detected by the thermistor 21 and the thermal head temperature Tt detected by the thermistor 22 are read (step S1). Then, it is determined whether To-Tt is equal to or greater than the specified value α (step S2). When it is determined to be "NO" in step S2, the process of turning off the fan motor 17 is performed (step S3). On the other hand, if the result of the determination in step S2 is “YES”, the fan motor 17
Is controlled to be turned on. As a result, the fan 16
Is rotated, and hot air accumulated in the housing 31 is discharged to the outside.

In this way, when the temperature inside the casing 31 is rising, the temperature inside the casing 31 is controlled to fall.

Next, it is determined whether or not there is received data (step S5). "YES" in the determination in step S5
If it is determined that the command is the received data, the command is analyzed (step S6). As a result of this analysis, it is determined whether the command is an issue command (step S7). “YES” in the determination in step S7
If it is determined that the fan motor 17 is turned on, a process for turning on the fan motor 17 is performed (step S8). Then, the printing process is performed (step S9). In this printing process,
Since the fan 16 is driven, the heat radiated from the thermal head 15 during the printing operation can be discharged to the outside of the housing 31.

Next, it is judged whether the printing process is completed (step S10). In the determination of step S10, "N
While it is determined to be "O", the printing process of step S9 described above is continuously performed. By the way, in the case where “YES” is determined in step S10, the thermistor 21
The outside air temperature To detected in step S1 and the thermal head temperature Tt detected in the thermistor 22 are read (step S
10a). Then, To-set in the RAM 12
After a time T corresponding to Tt, control is performed to turn off the fan motor 17 (step S11).

Thus, the fan 16 is not stopped immediately after the printing process is finished, but the time until the fan 16 is stopped is determined according to To-Tt at the time when the printing process is finished. Therefore, by driving the fan 16 before the end of the time T, the heat remaining in the housing 31 after the printing is completed can be reliably discharged to the outside.

By the way, "NO" in the determination in step S7.
If it is determined that the command is not issued, command processing other than the issued command is performed (step S12).

As described above, when the automatic control mode is set as the driving method of the fan 16, the fan 16 is driven only when necessary, so the fan 16 is not driven when it is not necessary. It is possible to suppress the generation of unnecessary noise.

Furthermore, in the case where the noise of the fan 16 is annoying even though the label is being issued in a very quiet environment such as a user or a hospital which issues only a few sheets to a few dozen sheets a day, the fan 16 is a fan. Always off as 16 drive method
Set it to mode. By setting in this way, the noise of the fan 16 can be eliminated altogether.

Further, in an environment of high temperature and high humidity such as a factory or warehouse, it is only necessary to set a constant drive mode in which the fan 16 is always driven regardless of issuance. This makes it possible to meet the user's request.

[0022]

As described in detail above, according to the present invention, it is possible to provide a label printer which can drive the fan of the label printer so as not to be audible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of a label printer according to an embodiment of the invention.

FIG. 2 is a diagram showing a main configuration of the label printer.

FIG. 3 is a flowchart for explaining the operation of the same embodiment.

[Explanation of symbols]

11 ... CPU, 15 ... Thermal head, 16 ... fans, 21, 22 ... Thermistor.

Claims (2)

[Claims] 1. A thermal head, a first temperature detecting means for detecting a temperature around the thermal head in a label printer housing, a second temperature detecting means for detecting a temperature of the thermal head, and the label printer. A fan for suppressing an increase in temperature inside the housing; a temperature around the thermal head detected by the first temperature detecting means after printing by the thermal head;
And a means for driving the fan for a time corresponding to the difference from the temperature of the thermal head detected by the temperature detecting means. 2. The label printer according to claim 1, further comprising setting means for setting a constant drive mode in which the fan is always driven and an automatic mode in which the fan is automatically turned on and off.