JP2006321160A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable detection of a feeding state of cooling water to a cooling means without installing an exclusive detecting means, and accordingly to prevent a recording head from excessively heating. <P>SOLUTION: The printer comprises the recording head 12 which carries out recording, a radiator 18 which cools the recording head 12 by using the cooling water 16, a temperature measuring means 13 which measures a temperature of the recording head 12, a control part 28, and a display means 33 which displays the fact that the cooling water 16 is insufficient. When the head temperature of the recording head 12 measured by the temperature measuring means 13 is compared with a first reference temperature and exceeds the first reference temperature, the control part 28 judges that the cooling water 16 is insufficient. When the head temperature is compared with a second reference temperature and exceeds the second reference temperature, the control part 28 judges that the printer is unable to continue operating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printer, and more particularly, to a printer having cooling means for cooling a recording head for recording an image using cooling water.

  Conventionally, a thermal printer that records an image of a desired character or graphic on a recording medium by selectively generating heat from the heating element of the recording head has high print quality, low noise, low cost, and easy maintenance. For reasons such as the nature, it is often used as an output device for computers and the like.

  This thermal printer uses, for example, a heat generating element that generates heat to heat a desired portion of thermal paper as a recording medium to develop color or transfer ink on an ink ribbon onto the recording medium. Thus, a desired image is recorded on the recording medium.

  In such a thermal printer, if the heating element is excessively heated, the color development area by one heating element becomes larger than the desired color development area, or the amount of ink transferred onto the recording medium is small. There is a possibility that it will increase, and there may be a case where a good image cannot be recorded.

  Therefore, in order to maintain the recording head heated by the heat generation of the heating element at an appropriate temperature, a thermal printer having a cooling unit for cooling the recording head is used (for example, Patent Document 1 and Patent Document 2). reference).

  In recent years, a water-cooled thermal printer that cools the recording head by supplying cooling water stored in a cooling water tank to the cooling means via a pipe using a circulation pump is used as the cooling means. .

  However, in such a water-cooled thermal printer, the cooling water supplied to the cooling means may be insufficient due to evaporation or the like, and the recording head may not be sufficiently cooled. If the recording head cannot be sufficiently cooled in this way, the head temperature of the recording head rises, and as a result, there is a possibility that good image recording cannot be obtained. Had a problem. Furthermore, if the recording head is excessively heated, the printer may be damaged.

  In addition, in order to detect that the cooling water for the cooling means is insufficient, it is conceivable to provide a dedicated detection means for detecting the supply state of the cooling water in the cooling means, piping, etc. If provided, the manufacturing cost of the printer will increase.

Japanese Utility Model Publication No. 4-075531 JP-A-6-031957

  The present invention has been made in view of these points, and can detect the lack of cooling water supplied to the cooling means without providing a dedicated detection means, whereby the recording head is excessively heated. It is an object of the present invention to provide a printer that can prevent the occurrence of the problem.

  In order to achieve the above object, the printer according to the present invention is characterized by a recording head for recording, a cooling means for cooling the recording head using cooling water, and a temperature measuring means for measuring the temperature of the recording head. The head temperature of the recording head measured by the temperature measuring means is compared with a set reference temperature, and when the head temperature exceeds the reference temperature, it is determined that the cooling water is insufficient. In a store with a control unit.

  Another feature of the printer according to the present invention is that the reference temperature is set so as to gradually increase in accordance with the head driving time of the recording head.

  Further, another printer according to the present invention has a plurality of the recording heads, the cooling means is provided corresponding to each recording head, and the temperature measuring means corresponds to each recording head. And the control unit compares the head temperatures measured by the temperature measuring means with the reference temperature.

  According to these other printers according to the present invention, the head temperature of the recording head measured by the temperature measuring means is compared with the reference temperature, and if the head temperature exceeds the reference temperature, the cooling water is insufficient. By determining that the recording water is being used, it is possible to easily detect the shortage of cooling water, thereby preventing the recording head from being heated excessively.

  Another feature of the printer according to the present invention is that it has display means for displaying that the cooling water is insufficient.

  According to another printer according to the present invention, by detecting the lack of cooling water, it is possible to notify the user of the printer that the cooling water is insufficient, and thereby the recording head is heated excessively. Can be prevented.

  Furthermore, another feature of the printer according to the present invention is that when the control unit determines that the cooling water is insufficient, the operation of the recording head is interrupted or stopped.

  According to the other printer of the present invention, it is possible to interrupt the recording operation by detecting the lack of cooling water, thereby preventing the recording head from being heated excessively. .

  As described above, according to each printer according to the present invention, it is possible to prevent the recording head from being excessively heated by detecting the lack of cooling water, which may cause a recording failure. Furthermore, it is possible to prevent the printer from being broken. Further, since it is possible to detect the lack of cooling water supplied to the cooling means without providing a dedicated detection means for detecting the lack of cooling water, the manufacturing cost of the printer is increased. Therefore, the recording head can be prevented from being overheated excessively.

  Hereinafter, an embodiment of a printer according to the present invention will be described with reference to FIGS.

  FIG. 1 is a conceptual diagram showing a printer according to this embodiment. As shown in FIG. 1, in the printer 1, the recording medium 2 is conveyed along a predetermined conveyance path 4 while being guided by a plurality of guide rollers 3. It has come to be.

  Further, the printer 1 has a plurality of (four in the present embodiment) recording units 6 provided so as to be spaced apart from each other at a predetermined interval along the conveyance path 4. Each recording unit 6 has an ink ribbon 8 to which inks of colors Y, M, C, and BK are applied in order from the most upstream side in the conveyance direction of the recording medium 2. The ink application surface is provided so as to be opposed to the recording medium 2.

  Each recording unit 6 is provided with a recording head 12 composed of a thermal head at a position facing the recording medium 2 via the ink ribbon 8, and a plurality of recording heads 12 are positioned at positions facing the ink ribbon 8. The heating elements 9 are arranged in parallel. Each recording head 12 heats a desired heating element 9 based on the recording data input to the printer 1 to transfer the ink on the ink ribbon 8 to the recording medium 2.

  Further, each recording unit 6 is provided with a platen roller 14 at a position facing the recording head 12 via the ink ribbon 8 and the recording medium 2.

  A cooling tank that stores cooling water 16 for cooling the recording head 12 heated by the heat generated by the heating elements 9 to an appropriate temperature is provided below the recording head 12 below the recording head 12. It has been.

  Each recording head 12 is provided with a radiator 18 as a cooling means for cooling the recording head 12 heated by the heat generated by the heat generating element 9 to an appropriate temperature, using a material having good thermal conductivity such as aluminum. It is attached via a configured attachment plate (not shown).

  As shown in FIG. 2, temperature measuring means 13 for detecting the temperature of each recording head 12 is provided in the vicinity of each recording head 12.

  Above the cooling water tank 18, a circulation pump 21 that pumps the cooling water 16 from the cooling water tank 18 and supplies the cooling water 16 to the radiators 18 is provided. Specifically, in the printer 1, the cooling water 16 is pumped from the cooling water tank 18 through the pipe 20 by the circulation pump 21, and the cooling water 16 is supplied from the circulation pump 21 to each radiator 18. The cooling water 16 is refluxed to the tank 17.

  The printer 1 has a plurality of transport units 24 corresponding to the respective recording units 6, and each transport unit 24 is in the vicinity of the transport path 4, and is downstream of each recording unit 6 in the transport direction. Has been placed. Each transport unit 24 has a pair of transport rollers 25 that are opposed to each other with the recording medium 2 interposed therebetween and sandwich the recording medium 2 from both sides. The recording medium 2 is transported in a predetermined transport direction by rotating the both transport rollers 25 while sandwiching them from each other.

  A cutting blade 26 is provided in the vicinity of the conveyance path 4 of the recording medium 2 and downstream of each recording head 12 in the conveyance direction. The cutting blade 26 is a long recording that has finished recording an image. The medium 2 is cut into a predetermined length.

  The printer 1 includes a control unit 28 that controls the operation of each unit of the printer 1, and the control unit 28 includes a drive unit 29 that drives each recording unit 6, each transport unit 24, and the like.

  The memory 31 of the control unit 28 stores a reference temperature set for comparison with the head temperature of each recording head 12. Specifically, the memory 31 has a first reference temperature as a reference for determining that the cooling water 16 supplied to the radiator 18 is insufficient, and the cooling water 16 is insufficient so that the operation of the printer 1 is not continued. A second reference temperature, which is a reference for determining that it is possible, and a third reference temperature, which is a reference for determining the start of supply of the cooling water 16 to the radiator 18, are stored. As shown in FIGS. 3A and 3B, the first reference temperature is gradually set higher corresponding to the head driving time of the recording head, and the second reference temperature is set to a constant temperature. Has been.

  The first reference temperature is calculated by measuring the heat generation coefficient a of the recording head in advance based on the current reference temperature, as shown in the following equation (Equation 1), and driving the recording head at a reference interval time. The ratio D (ratio between the recording head drive time and stop time) and the heat dissipation coefficient β of the recording head obtained in advance by measurement may be used.

        Reference temperature = Current reference temperature + aD−β ··· Equation 1

  The control unit 28 includes a cooling water shortage determination unit 30 that compares the head temperature of each recording head 12 measured by each temperature measurement unit 13 with the first reference temperature and the second reference temperature. The cooling water shortage determining unit 30 determines that the cooling water 16 is insufficient when the head temperature exceeds the first reference temperature, and when the head temperature exceeds the second reference temperature. In this case, it is determined that the operation of the printer 1 cannot be continued because the cooling water 16 is insufficient. Furthermore, the control unit 28 includes a cooling water supply determination unit 32 that compares the head temperature with the third reference temperature, and the cooling water supply determination unit 32 determines that the head temperature exceeds the third reference temperature. Is instructed to start supplying the cooling water 16 to the radiator 18.

  When the cooling water shortage determination unit 30 determines that the cooling water 16 is insufficient, the printer 1 displays that the cooling water 16 is insufficient on the display means 33 including a liquid crystal display panel. When the cooling water shortage determining unit 30 determines that the operation of the printer 1 cannot be continued, the heat generation to each of the heating elements 9 is stopped and the image recording operation is interrupted. Further, when the cooling water supply determination unit 32 determines that the cooling water 16 starts to be supplied, the printer 1 pumps the cooling water 16 from the cooling water tank 17 by the circulation pump 21 and supplies the cooling water 16 to each radiator 18. It comes to supply.

  Next, the operation of this embodiment will be described.

  First, when image recording data is input to the printer 1, the printer 1 transports the recording medium 2 in a predetermined transport direction by the transport units 24 and sequentially contacts the recording heads 12 and the platen roller 14. Let Further, the printer 1 records a desired image on the recording medium 2 by causing each desired heating element 9 in the recording head 12 to generate heat and transferring the ink on the ink ribbon 8 onto the recording medium 2.

  At this time, the printer 1 starts detecting the head temperature of each recording head 12 heated by the heat generation of each heating element 9 by each temperature measuring means 13, and the head temperature measured by the cooling water shortage determining unit 30 and the first temperature. The head temperature measured by the cooling water supply determination unit 32 and the third reference temperature are compared with the reference temperature.

  When the cooling water supply determination unit 32 determines that the head temperature has exceeded the third reference temperature, the drive unit 29 pumps the cooling water 16 from the cooling water tank 18 through the pipe 20 by the circulation pump 21. Then, the cooling water 16 is supplied to the radiator 18, and each recording head is cooled while the cooling water 16 is returned to the cooling water tank 18 through the pipe 20, and the image recording is continued. On the other hand, if it is determined that the head temperature does not exceed the third reference temperature, the drive unit 29 causes the desired heating element 9 to generate heat without supplying the cooling water 16 and continues the image recording operation. At the same time, the cooling water supply determination unit 32 continues the comparison between the head temperature and the third reference temperature.

  When the cooling water shortage determining unit 30 determines that the head temperature has exceeded the first reference temperature, the driving unit 29 displays on the display means 33 that the cooling water 16 is insufficient, and the printer 1 The user is notified that the cooling water 16 is insufficient, and the image recording operation is continued. On the other hand, when the cooling water shortage determination unit 30 determines that the head temperature does not exceed the first reference temperature, the drive unit 29 generates the desired heat generating element 9 to continue the image recording operation and the cooling. The water shortage determination unit 30 continues the comparison between the head temperature and the first reference temperature.

  Further, after the cooling water shortage determination unit 30 determines that the head temperature has exceeded the first reference temperature, the printer 1 compares the head temperature with the second reference temperature by the cooling water shortage determination unit 30, and the head temperature is the second temperature. If it is determined that the reference temperature has been exceeded, the drive unit 29 stops heat generation for each of the heating elements 9 and interrupts the image recording operation. On the other hand, when the cooling supply determination unit 32 determines that the head temperature does not exceed the second reference temperature, the drive unit 29 causes the desired heat generating element 9 to generate heat and continues image recording, and the cooling water is insufficient. The determination unit 30 continues the comparison between the head temperature and the second reference temperature.

  According to the present embodiment, the head temperature of the recording head 12 measured by the temperature measuring unit is compared with the first reference temperature and the second reference temperature, and the head temperature exceeds the first reference temperature and the second reference temperature. If it is, the lack of cooling water 16 can be detected by determining that the cooling water is insufficient.

  Therefore, by detecting the shortage of the cooling water 16 in this way, it is possible to notify the user of the printer 1 of the shortage of the cooling water 16 or to interrupt the recording operation. As a result, it is possible to prevent a recording failure from being caused by excessive heating of the recording head 12 and further failure of the printer 1. Further, since it is possible to detect the lack of the cooling water 16 supplied to the radiator 18 without providing a dedicated detection means for detecting the lack of the cooling water 16, the manufacturing cost of the printer 1 can be reduced. Without raising, it is possible to prevent the recording head 12 from being overheated excessively.

  In addition, this invention is not limited to the said embodiment, A various change is possible as needed.

  For example, in the present embodiment, the printer 1 that performs recording using a plurality of recording units 6 has been described. However, the present invention is not limited to this, and the printer 1 includes a cooling unit that uses cooling water. If it is.

  In addition, the printer 1 according to the present embodiment has the first reference temperature and the second reference temperature as reference temperatures to be compared with the head temperature in order to determine whether the cooling water 16 is insufficient. However, the present invention is not limited to this. What is necessary is just to have one reference temperature for judging the shortage of the cooling water 16 not.

1 is a conceptual diagram showing an embodiment of a printer according to the present invention. Block diagram showing the printer shown in FIG. (A) and (b) are diagrams showing the head temperature, the first reference temperature, and the second reference temperature in relation to the recording head drive time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 2 Recording medium 6 Recording unit 9 Heating element 12 Recording head 16 Cooling water 18 Radiator 21 Circulation pump 24 Conveyance unit 25 Conveyance roller 28 Control part 29 Drive part 30 Cooling water shortage determination part 31 Memory 32 Cooling water supply judgment part 33 Display means

Claims (5)

A recording head for recording;
Cooling means for cooling the recording head using cooling water;
Temperature measuring means for measuring the temperature of the recording head;
The head temperature of the recording head measured by the temperature measuring means is compared with a set reference temperature, and when the head temperature exceeds the reference temperature, it is determined that the cooling water is insufficient. And a control unit.   The printer according to claim 1, wherein the reference temperature is set to gradually increase in accordance with a head driving time of the recording head.   A plurality of the recording heads, wherein the cooling means is provided corresponding to each recording head, the temperature measuring means is provided corresponding to each recording head, and the control unit includes each temperature. 3. The printer according to claim 1, wherein the head temperature measured by the measuring unit is compared with the reference temperature.   The printer according to any one of claims 1 to 3, further comprising display means for displaying that the cooling water is insufficient. 5. The printer according to claim 1, wherein when the control unit determines that the cooling water is insufficient, the control unit interrupts or stops the operation of the recording head. 6.

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