JP2019195911A - Liquid discharge device - Google Patents

Abstract

To solve the problem that a further device is required to efficiently perform heating of ink while cooling a print head in a conventional inkjet recording device.SOLUTION: A liquid discharge device comprises: a head drive circuit 13 driving a liquid discharge head 17; an ink flow passage 9 through which liquid supplied to the liquid discharge head 17 flows; and a flow passage heating part 41 having a circulation flow passage 45 through which circulation liquid flows and a circulation pump 47 circulating the circulation liquid in the circulation flow passage 45, cooling the head drive circuit 13 by the circulation liquid and heating the liquid flowing through the ink flow passage 9 by the circulation liquid raised in temperature by absorption of heat from the head drive circuit 13.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a liquid ejection device that ejects liquid.

  Conventionally, as disclosed in Patent Document 1, an ink jet recording apparatus having a cooling mechanism for cooling a print head that discharges ink droplets is known.

JP 2001-287349 A

  However, in the conventional ink jet recording apparatus, it is necessary to further devise for efficiently heating the ink while cooling the print head.

  A liquid ejection apparatus according to the present invention includes a head drive circuit that drives a liquid ejection head, a liquid channel through which the liquid supplied to the liquid ejection head flows, a circulation channel through which the circulating liquid flows, and circulating fluid in the circulation channel. A circulation driving unit that circulates, cools the head drive circuit with the circulating fluid, and heats the liquid flowing through the liquid channel with the circulating fluid heated by heat absorption from the head drive circuit. And.

1 is a diagram illustrating a schematic configuration of a printing apparatus according to an embodiment of the present invention. It is a figure which shows the structure of a flow path heating part. It is a figure which shows the structure around a sliding part. It is a flowchart which shows the control processing which a main control circuit performs. It is a figure which shows the modification of a flow path heating part.

  Hereinafter, a printing apparatus 1 that is an embodiment of a liquid ejection apparatus will be described with reference to the accompanying drawings. It should be noted that the numerical values indicating the number of each part are merely examples, and do not limit the present invention.

  A schematic configuration of the printing apparatus 1 will be described with reference to FIG. The printing apparatus 1 performs printing by ejecting ultraviolet curable ink (hereinafter referred to as “UV ink”) onto the printing medium S by an inkjet method. The print medium S may be a continuous medium or a single sheet medium. The material of the print medium S is not particularly limited, and may be made of paper, cloth, or resin, for example.

  The printing apparatus 1 includes a medium transport unit 3, a carriage case 5, a carriage moving unit 7, an ink flow path 9, a main control circuit 11, a head drive circuit 13, a sliding unit 15, and a liquid discharge head 17. And a UV irradiation unit 19.

  The medium transport unit 3 transports the print medium S. The medium transport unit 3 includes a transport roller pair 21 and a transport motor 23. The transport roller pair 21 sandwiches the print medium S and transports the sandwiched print medium S. The transport motor 23 is a drive source for the transport roller pair 21. The carriage case 5 accommodates a liquid discharge head 17 and a head drive circuit 13. The carriage case 5 is an example of the “circuit case” in the present invention. The carriage moving unit 7 moves the carriage case 5 in a direction that intersects the transport direction of the print medium S. The carriage moving unit 7 includes a belt mechanism (not shown), a carriage guide 25, and a carriage motor 27. The belt mechanism moves the carriage case 5 in a direction that intersects the transport direction of the print medium S. The carriage guide 25 extends in a direction intersecting the transport direction of the print medium S and guides the movement of the carriage case 5. The carriage motor 27 is a drive source for the belt mechanism.

  The ink flow path 9 has flexibility and connects the ink cartridge 29 (see FIG. 2) and the liquid ejection head 17. The UV ink stored in the ink cartridge 29 is supplied to the liquid ejection head 17 via the ink flow path 9. That is, UV ink supplied from the ink cartridge 29 to the liquid ejection head 17 flows through the ink flow path 9. The ink flow path 9 is an example of the “liquid flow path” in the present invention. UV ink is an example of the “liquid” of the present invention.

  The main control circuit 11 comprehensively controls each unit of the printing apparatus 1. The main control circuit 11 generates print data based on the image data received from the external device 100 such as a personal computer, and transmits the generated print data to the head drive circuit 13. The main control circuit 11 includes a processor 31 and a memory 33. As the processor 31, for example, a CPU (Central Processing Unit) can be used. The memory 33 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The main control circuit 11 is connected to the head drive circuit 13 via a flexible inter-circuit cable 35. As the inter-circuit cable 35, for example, a flexible flat cable can be used.

  The head drive circuit 13 generates a discharge drive signal based on the print data received from the main control circuit 11, and transmits the generated discharge drive signal to the liquid discharge head 17. The head drive circuit 13 is connected to the liquid ejection head 17 via a head cable 37. As the head cable 37, for example, a flexible flat cable can be used. The head drive circuit 13 is screwed to the carriage case 5. The head drive circuit 13 is provided with a heat sink 39.

  The sliding portion 15 is formed in a substantially rectangular parallelepiped shape that is long in a direction intersecting with the conveyance direction of the print medium S and is opened upward. Inside the sliding portion 15, the ink flow path 9 and the inter-circuit cable are provided. 35 has been routed. The ink flow path 9 and the inter-circuit cable 35 are bundled by a plurality of bands (not shown). When the ink flow path 9 and the inter-circuit cable 35 move along with the movement of the carriage case 5, the band slides with respect to the bottom surface of the sliding portion 15. In addition, the sliding part 15 is comprised with material with high heat conductivity, such as steel.

  The liquid discharge head 17 moves the UV ink supplied from the ink flow path 9 in the direction intersecting the transport direction of the print medium S, and based on the discharge drive signal received from the head drive circuit 13, the print medium S. To discharge.

  The UV irradiation unit 19 is provided on the downstream side of the liquid ejection head 17 in the transport direction of the print medium S. The UV irradiation unit 19 irradiates the UV ink discharged onto the printing medium S with ultraviolet rays. As a result, the UV ink discharged onto the print medium S is cured and fixed to the print medium S.

  The flow path heating unit 41 of the printing apparatus 1 will be described with reference to FIG. The printing apparatus 1 includes a flow path heating unit 41 in addition to the above configuration. The flow path heating unit 41 cools the head drive circuit 13 and heats the UV ink flowing through the ink flow path 9.

  In the present embodiment, four ink flow paths 9 are provided corresponding to four types of ink cartridges 29 in which different colors of UV ink are stored. The ink cartridge 29 is detachably attached to the cartridge attachment portion 43. The colors of the UV ink are cyan, magenta, yellow, and black, but are not limited to this, and for example, white may be included in addition to these four colors.

  The channel heating unit 41 includes four circulation channels 45, four circulation pumps 47, a heater 49, a cooling fan 51, four ink temperature sensors 53, and a circuit temperature sensor 55. .

  Four circulation channels 45 are provided corresponding to the four ink channels 9. A circulating fluid flows through the circulation channel 45. As the circulating liquid, for example, water can be used. One circulation pump 47 is provided for one circulation channel 45, and a total of four circulation pumps 47 are provided. The circulation pump 47 circulates the circulating liquid in the circulation channel 45. The circulation pump 47 is an example of the “circulation drive unit” in the present invention.

  Each circulation channel 45 is divided into a circuit cooling unit 57, an ink heating unit 59, a first circulation unit 61, a second circulation unit 63, and a third circulation unit 65.

  The circuit cooling unit 57 is in contact with the carriage case 5. The flow path heating unit 41 cools the head drive circuit 13 via the carriage case 5 with the circulating fluid flowing through the circuit cooling unit 57. Thereby, even when the head drive circuit 13 operates and generates heat, the temperature of the head drive circuit 13 can be maintained in a circuit proper temperature range that is a temperature range in which the head drive circuit 13 operates properly. Further, by cooling the head drive circuit 13 with the circulating liquid, the UV ink mist generated by the discharge of the UV ink by the liquid discharge head 17 is less than the liquid discharge head 17 compared with the configuration in which the head drive circuit 13 is cooled by air cooling. Scattering around the head 17 is suppressed. Thereby, it is possible to suppress the occurrence of problems such as a short circuit of the head drive circuit 13. Further, as described above, since the head drive circuit 13 is provided with the heat sink 39, the heat generated by the head drive circuit 13 can be efficiently released to the carriage case 5. The material of the carriage case 5 is not particularly limited, but a material having high thermal conductivity is preferable. For example, a metal material can be used.

  The ink heating unit 59 is in contact with the ink flow path 9. The flow path heating unit 41 heats the UV ink flowing through the ink flow path 9 with the circulating fluid flowing through the ink heating unit 59. Accordingly, the UV ink is heated to an ink proper temperature range that is an appropriate temperature range of the UV ink, for example, 35 ° C. or more and 40 ° C. or less, and has a viscosity suitable for ejection from the liquid ejection head 17. The ink heating unit 59 is an example of the “liquid heating unit” in the present invention.

  The first circulation unit 61 is a portion between the circulation pump 47 and the circuit cooling unit 57. The second circulation unit 63 is a portion between the circuit cooling unit 57 and the ink heating unit 59. The third circulation unit 65 is a portion between the ink heating unit 59 and the circulation pump 47.

  Based on FIG. 3, the structure around the sliding portion 15 will be described. Of the circulation channels 45, the sliding unit 15 is provided with the first circulation unit 61 and the ink heating unit 59 together with the ink channel 9 and the inter-circuit cable 35. More specifically, the first circulation part 61, the inter-circuit cable 35, the ink flow path 9 and the ink heating part 59 are provided on the bottom surface of the sliding part 15 in order from the bottom. As described above, the ink flow path 9 is preferably separated from the bottom surface of the sliding portion 15. As a result, the inter-circuit cable 35 made of a material having low thermal conductivity is disposed between the bottom surface of the sliding portion 15 and the ink flow path 9 to restrict the heat transfer of the UV ink. Can be prevented from being cooled. On the other hand, the first circulation portion 61 is preferably in contact with the bottom surface of the sliding portion 15. Thereby, the circulating fluid which flows through the 1st circulation part 61 can be cooled more. The inter-circuit cable 35 may be any cable as long as it has a heat insulating effect, and may be a flexible flat cable or a bundle of a plurality of cables so that a gap is generated between the cables.

  Returning to FIG. 2, the heater 49 heats the circulating fluid flowing through the third circulating unit 65. The cooling fan 51 cools the circulating fluid flowing through the third circulation unit 65. The heater 49 is provided closer to the circulation pump 47 than the cooling fan 51. On the contrary, the cooling fan 51 is provided closer to the circulation pump 47 than the heater 49. But you can. In this case, since the heater and the ink heating unit 59 are close to each other, the ink in the ink heating unit 59 can be heated quickly. The heater 49 is an example of the “circulating fluid heating unit” in the present invention. The cooling fan 51 is an example of the “circulating fluid cooling unit” in the present invention.

  Four ink temperature sensors 53 are provided corresponding to the four ink flow paths 9. The ink temperature sensor 53 is provided at the end on the downstream side of the ink flow path 9, that is, the end on the liquid ejection head 17 side. The ink temperature sensor 53 detects an ink detection temperature Ti_d that is the temperature of the UV ink flowing through the ink flow path 9. The ink temperature sensor 53 is an example of the “liquid temperature detection unit” in the present invention.

  The circuit temperature sensor 55 is provided in the carriage case 5. The circuit temperature sensor 55 detects a circuit detection temperature Tc_d that is the temperature of the head drive circuit 13. The circuit temperature sensor 55 is an example of the “circuit temperature detection unit” in the present invention.

  The main control circuit 11 controls the circulation pump 47, the heater 49, and the cooling fan 51 based on the detection results of the ink temperature sensor 53 and the circuit temperature sensor 55. The main control circuit 11 is an example of the “control unit” in the present invention.

  The main control circuit 11 can switch the operation mode of the circulation pump 47 to the first mode, the second mode, and the third mode. In the first mode, the circulating fluid flows in the first circulation direction 67 at the first flow rate. In the second mode, the circulating fluid flows in the first circulation direction 67 at a second flow rate that is faster than the first flow rate. In the third mode, the circulating fluid flows in the second circulation direction 69 opposite to the first circulation direction 67. Note that the flow rate of the circulating fluid in the third mode is not particularly limited. Here, the first circulation direction 67 means that the circulating fluid is from the circulation pump 47 in the order of the first circulation unit 61, the circuit cooling unit 57, the second circulation unit 63, the ink heating unit 59, and the third circulation unit 65. It is the direction of flow. In the second circulation direction 69, the circulating fluid flows from the circulation pump 47 in the order of the third circulation unit 65, the ink heating unit 59, the second circulation unit 63, the circuit cooling unit 57, and the first circulation unit 61. It is a direction.

  A process in which the main control circuit 11 controls the circulation pump 47, the heater 49, and the cooling fan 51 based on the detection results of the ink temperature sensor 53 and the circuit temperature sensor 55 will be described with reference to FIG. For example, the main control circuit 11 performs the following control process after the printing apparatus 1 is powered on and performs a predetermined initialization process. For example, the main control circuit 11 performs the following control process when the processor 31 executes a program stored in the memory 33.

  In step S1, the main control circuit 11 operates the circulation pump 47 in the third mode, operates the heater 49, and stops the operation of the cooling fan 51. In this way, by operating the heater 49, the temperature of the circulating fluid is increased and the UV flowing through the ink flow path 9 even when the head drive circuit 13 does not generate much heat, such as when the operation of the printing apparatus 1 is started. The ink can be heated. In this state, since the circulating fluid flows in the second circulating direction 69 when the heater 49 is operating, the circulating fluid heated by the heater 49 in the third circulating unit 65 is supplied from the circuit cooling unit 57. Also reaches the ink heating section 59 first. Thereby, the UV ink flowing through the ink flow path 9 can be efficiently heated. Further, since the heater 49 is provided on the downstream side of the circulation pump 47 and the upstream side of the ink heating unit 59 in the second circulation direction 69, the circulating fluid heated by the heater 49 is sent to the circulation pump 47. Is suppressed. As a result, it is possible to suppress the occurrence of adverse effects such as the deterioration of the circulation pump 47 due to the high-temperature circulating fluid being sent to the circulation pump 47 and the life shortening.

  In step S <b> 2, the main control circuit 11 acquires the circuit detection temperature Tc_d from the circuit temperature sensor 55.

  In step S <b> 3, the main control circuit 11 determines whether or not the circuit detection temperature Tc_d acquired in step S <b> 2 exceeds the first circuit temperature Tc_1 stored in the memory 33. Here, the first circuit temperature Tc_1 is included in the circuit proper temperature range.

  In step S3, when the main control circuit 11 determines that the circuit detection temperature Tc_d is higher than the first circuit temperature Tc_1, the process proceeds to step S4.

  In step S3, when the main control circuit 11 determines that the circuit detection temperature Tc_d does not exceed the first circuit temperature Tc_1, the process returns to step S2. That is, until the circuit detection temperature Tc_d exceeds the first circuit temperature Tc_1, the heater 49 operates and the circulation pump 47 operates in the third mode with the cooling fan 51 stopped.

  In step S4, the main control circuit 11 switches the circulation pump 47 to the first mode, stops the operation of the heater 49, and operates the cooling fan 51. That is, after the circuit detection temperature Tc_d exceeds the first circuit temperature Tc_1, the heater 49 stops operating, and the circulation pump 47 operates in the first mode with the cooling fan 51 operating. In this state, since the circulating fluid flows in the first circulation direction 67, the circulating fluid cooled by the cooling fan 51 is supplied to the circuit cooling unit 57. As a result, the head drive circuit 13 that has generated heat to the extent that it exceeds the first circuit temperature Tc_1 can be efficiently cooled. The circulating liquid is heated by the heat absorption from the head drive circuit 13 in the circuit cooling unit 57 and then sent to the ink heating unit 59. Thereby, the UV ink flowing through the ink flow path 9 can be efficiently heated. Further, since the cooling fan 51 is provided on the downstream side of the ink heating unit 59 and the upstream side of the circulation pump 47 in the first circulation direction 67, the circulating liquid cooled by the cooling fan 51 is supplied to the circulation pump 47. Sent. Thereby, it can suppress that a bad influence arises in the circulation pump 47 by a high temperature circulating fluid.

  In step S <b> 5, the main control circuit 11 acquires the circuit detection temperature Tc_d from the circuit temperature sensor 55 and acquires the ink detection temperature Ti_d from the ink temperature sensor 53.

  In step S6, the main control circuit 11 determines whether or not the circuit detection temperature Tc_d acquired in step S5 is lower than the second circuit temperature Tc_2 stored in the memory 33, and the ink temperature acquired in step S5 is stored in the memory 33. It is determined whether or not the stored first ink temperature Ti_1 is exceeded. Here, the second circuit temperature Tc_2 is lower than the first circuit temperature Tc_1 and is included in the circuit proper temperature range. The first ink temperature Ti_1 is included in the appropriate ink temperature range. The first ink temperature Ti_1 is an example of the “first liquid temperature” in the present invention.

  If the main control circuit 11 determines in step S6 that the circuit detection temperature Tc_d is lower than the second circuit temperature Tc_2 regardless of whether or not the ink detection temperature Ti_d is higher than the first ink temperature Ti_1, step S6 is performed. Return to S1. That is, after the circuit detection temperature Tc_d falls below the second circuit temperature Tc_2, the circulation pump 47 operates in the third mode with the heater 49 operating and the cooling fan 51 stopped operating. Thereby, the UV ink flowing through the ink flow path 9 can be efficiently heated.

  In step S6, when the main control circuit 11 determines that the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2 and the ink detection temperature Ti_d is higher than the first ink temperature Ti_1, the process proceeds to step S7.

  In step S6, when the main control circuit 11 determines that the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2 and the ink detection temperature Ti_d is not higher than the first ink temperature Ti_1, the process returns to step S5. That is, until the ink detection temperature Ti_d exceeds the first ink temperature Ti_1, the heater 49 stops operating, and the circulation pump 47 operates in the first mode with the cooling fan 51 operating.

  In step S7, the main control circuit 11 switches the circulation pump 47 to the second mode. That is, in a state where the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2, after the ink detection temperature Ti_d exceeds the first ink temperature Ti_1, the heater 49 is deactivated and the cooling fan 51 is activated. The circulation pump 47 operates in the second mode. In this state, compared to when the circulation pump 47 is operating in the first mode, the circulating fluid flow rate rises from the first flow rate to the second flow rate, so the endothermic amount of the circulating fluid in the circuit cooling unit 57 decreases, An increase in the temperature of the circulating fluid flowing through the ink heating unit 59 is suppressed. Thereby, it can suppress that the UV ink which flows through the ink flow path 9 is heated too much.

  In step S <b> 8, the main control circuit 11 acquires the circuit detection temperature Tc_d from the circuit temperature sensor 55 and acquires the ink detection temperature Ti_d from the ink temperature sensor 53.

  In step S9, the main control circuit 11 determines whether or not the circuit detection temperature Tc_d acquired in step S8 is lower than the second circuit temperature Tc_2 and the ink temperature acquired in step S8 is stored in the memory 33. It is determined whether or not the temperature is lower than Ti_2. Here, the second ink temperature Ti_2 is lower than the first ink temperature Ti_1 and is included in the appropriate ink temperature range. The second ink temperature Ti_2 is an example of the “second liquid temperature” in the present invention.

  If the main control circuit 11 determines in step S9 that the circuit detection temperature Tc_d is lower than the second circuit temperature Tc_2 regardless of whether or not the ink detection temperature Ti_d is lower than the second ink temperature Ti_2, step S9 is performed. Return to S1. That is, after the circuit detection temperature Tc_d falls below the second circuit temperature Tc_2, the circulation pump 47 operates in the third mode with the heater 49 operating and the cooling fan 51 stopped operating. Thereby, the UV ink flowing through the ink flow path 9 can be efficiently heated.

  In step S9, when the main control circuit 11 determines that the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2 and the ink detection temperature Ti_d is lower than the second ink temperature Ti_2, the process returns to step S4. That is, in a state where the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2, after the ink detection temperature Ti_d is lower than the second ink temperature Ti_2, the heater 49 is stopped and the cooling fan 51 is operated. The circulation pump 47 operates in the first mode. In this state, compared to when the circulation pump 47 is operating in the second mode, the circulating fluid flow rate is decreased from the second flow rate to the first flow rate, so that the endothermic amount of the circulating fluid in the circuit cooling unit 57 increases. The temperature of the circulating fluid flowing through the ink heating unit 59 rises. Thereby, it can suppress that the temperature of UV ink which flows through the ink flow path 9 falls.

  In step S9, when the main control circuit 11 determines that the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2 and the ink detection temperature Ti_d is not lower than the second ink temperature Ti_2, the process returns to step S8. That is, in a state where the circuit detection temperature Tc_d is not lower than the second circuit temperature Tc_2, the heater 49 stops operating and the cooling fan 51 is operated until the ink detection temperature Ti_d falls below the second ink temperature Ti_2. Circulation pump 47 operates in the second mode.

  As described above, after the circuit detection temperature Tc_d exceeds the first circuit temperature Tc_1, the heater 49 stops operating and the cooling fan 51 operates, and the circulation pump 47 operates in the first mode or the second mode. After the circuit detection temperature Tc_d falls below the second circuit temperature Tc_2, the circulation pump 47 operates in the third mode, so that the temperature of the head drive circuit 13 can be maintained in the circuit proper temperature range. In addition, after the ink detection temperature Ti_d exceeds the first ink temperature Ti_1, the circulation pump 47 operates in the second mode, and after the ink detection temperature Ti_d falls below the second ink temperature Ti_2, the circulation pump 47 By operating in the 1 mode, the temperature of the UV ink flowing through the ink flow path 9 can be maintained in the appropriate ink temperature range.

  As described above, the ink temperature sensor 53 is provided for each ink flow path 9. Therefore, the control for the circulation pump 47 based on the ink detection temperature Ti_d acquired from the ink temperature sensor 53 is performed for each circulation pump 47. For example, in step S6, the ink detection temperature Ti_d acquired from the ink temperature sensor 53 provided in the ink flow path 9 corresponding to one circulation pump 47 exceeds the first ink temperature Ti_1, and the other circulation pumps If the ink detection temperature Ti_d acquired from the ink temperature sensor 53 provided in the ink flow path 9 corresponding to 47 does not exceed the first ink temperature Ti_1, the one circulation pump 47 switches to the second mode. The other circulation pump 47 operates in the first mode.

  As described above, the printing apparatus 1 according to the present embodiment includes the head drive circuit 13, the ink flow path 9, and the flow path heating unit 41. The head drive circuit 13 drives the liquid discharge head 17. UV ink supplied to the liquid discharge head 17 flows through the ink flow path 9. The channel heating unit 41 includes a circulation channel 45 through which the circulating fluid flows and a circulation pump 47 that circulates the circulating fluid in the circulation channel 45. The flow path heating unit 41 cools the head drive circuit 13 with the circulating liquid, and warms the UV ink flowing through the ink flow path 9 with the circulating liquid heated by the heat absorption from the head drive circuit 13. According to this configuration, it is possible to efficiently heat the UV ink while cooling the liquid discharge head 17.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the spirit of the present invention. For example, the above-described embodiment can be changed to the following form in addition to the above.

  As shown in FIG. 5, in addition to the circulation flow path 45 used for cooling the head drive circuit 13 and heating the UV ink, the flow path heating unit 41 drives the head without being used for heating the UV ink. A cooling circulation channel 71 used for cooling the circuit 13 may be provided. A part of the cooling circulation channel 71 is in contact with the carriage case 5. According to this configuration, the heat generated in the head drive circuit 13 is absorbed not only by the circulating fluid circulating through the circulation channel 45 but also by the circulating fluid circulating through the cooling circulation channel 71. An excessive increase in the temperature of the circulating fluid circulating in 45 is suppressed. Therefore, it is possible to prevent the UV ink flowing through the ink flow path 9 from being excessively heated. In this case, it is not necessary to provide the heater 49 in the cooling circulation channel 71, but it is preferable to provide the cooling fan 51.

  The main control circuit 11 is not limited to the configuration that controls the heater 49 based on the detection result of the circuit temperature sensor 55, and may control the heater 49 based on the detection result of the ink temperature sensor 53. The heater 49 may be controlled based on both the detection result of the sensor 55 and the detection result of the ink temperature sensor 53. For example, in step S3, the main control circuit 11 has two conditions: the circuit detection temperature Tc_d exceeds the first circuit temperature Tc_1, and the ink detection temperature Ti_d exceeds the first ink temperature Ti_1. If it is determined that at least one of them is satisfied, the process of step S4 may be executed.

  The ink temperature sensor 53 is not limited to the configuration provided for each ink flow path 9, and is common to the plurality of ink flow paths 9 when the temperature of the UV ink does not change much between the plurality of ink flow paths 9. The temperature of the UV ink may be detected by an ink temperature sensor 53 provided.

  The main control circuit 11 may control the circulation pump 47 during the movement of the carriage case 5 so that the flow rate of the circulating fluid in the circulation flow path 45 becomes faster than when the carriage case 5 is stopped. According to this configuration, even if the circulating fluid flowing through the circulation channel 45 is affected by inertia due to movement of the circulation channel 45 as the carriage case 5 moves, the influence of inertia is canceled and The liquid can be circulated appropriately.

  The heater 49 is not limited to the configuration provided in the third circulation unit 65, and may be a configuration provided in the first circulation unit 61, for example. That is, the heater 49 may be provided on the downstream side of the circuit cooling unit 57 and on the upstream side of the circulation pump 47 in the second circulation direction 69. Similarly, the cooling fan 51 is not limited to the configuration provided in the third circulation unit 65, and may be a configuration provided in the first circulation unit 61, for example. That is, the cooling fan 51 may be provided on the downstream side of the circulation pump 47 and the upstream side of the circuit cooling unit 57 in the first circulation direction 67.

  The heater 49 is not limited to the configuration provided in common for the four circulation channels 45, and may be configured for each circulation channel 45, for example. In this case, the plurality of heaters 49 may be individually controlled based on the detection result of the corresponding ink temperature sensor 53. Similarly, the cooling fan 51 is not limited to the configuration provided in common for the four circulation channels 45, and may be configured for each circulation channel 45, for example. In this case, the plurality of cooling fans 51 may be individually controlled based on the detection result of the corresponding ink temperature sensor 53.

  The configuration is not limited to a configuration in which the ink flow path 9 and the circulation flow path 45 are provided on a one-to-one basis, and one circulation flow path 45 may be provided for a plurality of ink flow paths 9. Conversely, a plurality of circulation channels 45 may be provided for one ink channel 9. In particular, when the amount of UV ink used is large, the UV ink can be appropriately heated by providing a plurality of circulation channels 45 for one ink channel 9. Further, the heater 49 may be provided for each circulation channel 45, and the cooling fan 51 may be provided for each circulation channel 45.

  The liquid ejection head 17 is not limited to the configuration provided in common for the four types of UV ink, and may be configured for each type of UV ink, for example, and may be provided for each of the two types of UV ink. It may be configured.

  The “liquid” of the present invention is not limited to UV ink, and may be other ink such as water-based ink and oil-based ink. The “liquid” is not limited to ink, and may be, for example, a processing liquid for improving the image quality of an image printed on the print medium S.

  DESCRIPTION OF SYMBOLS 1 ... Printing apparatus, 5 ... Carriage case, 9 ... Ink flow path, 11 ... Main control circuit, 13 ... Head drive circuit, 17 ... Liquid discharge head, 29 ... Ink cartridge, 31 ... Processor, 33 ... Memory, 39 ... Heat sink , 41 ... Channel heating unit, 43 ... Cartridge mounting unit, 45 ... Circulation channel, 47 ... Circulation pump, 49 ... Heater, 51 ... Cooling fan, 53 ... Ink temperature sensor, 55 ... Circuit temperature sensor, 57 ... Circuit Cooling unit, 59 ... ink heating unit, 61 ... first circulation unit, 63 ... second circulation unit, 65 ... third circulation unit, 67 ... first circulation direction, 69 ... second circulation direction

Claims (12)

A head drive circuit for driving the liquid ejection head;
A liquid flow path through which the liquid supplied to the liquid discharge head flows;
A circulating flow path through which the circulating fluid flows, and a circulation driving unit that circulates the circulating fluid in the circulating flow path; the head driving circuit is cooled by the circulating fluid, and is increased by heat absorption from the head driving circuit. A flow path heating unit for heating the liquid flowing through the liquid flow path with the heated circulating liquid;
A liquid ejection apparatus comprising: The flow path heating unit is
A liquid temperature detector for detecting the temperature of the liquid;
Based on the detection result of the liquid temperature detection unit, a control unit for controlling the circulation drive unit,
The liquid ejecting apparatus according to claim 1, further comprising: The controller is
When the circulating drive unit is controlled so that the circulating fluid flows at the first flow rate, and the detected temperature of the liquid exceeds the first liquid temperature, the circulating fluid is more than the first flow rate. Controlling the circulating drive unit to flow at a fast second flow rate;
When the circulating drive unit is controlled so that the circulating fluid flows at the second flow rate, if the detected temperature of the liquid falls below a second liquid temperature lower than the first liquid temperature, the circulation The liquid ejecting apparatus according to claim 2, wherein the circulation driving unit is controlled so that the liquid flows at the first flow rate.   The liquid discharge apparatus according to claim 2, wherein the flow path heating unit further includes a circulating fluid heating unit that heats the circulating fluid. The flow path heating unit further includes a circuit temperature detection unit that detects the temperature of the head drive circuit,
5. The liquid according to claim 4, wherein the control unit controls the circulating fluid heating unit based on at least one of a detection result of the circuit temperature detection unit and a detection result of the liquid temperature detection unit. Discharge device. The controller is
If the detected temperature of the head drive circuit exceeds the first circuit temperature when the circulating fluid warming unit is operating, the circulating fluid warming unit is deactivated,
If the detected temperature of the head drive circuit falls below a second circuit temperature lower than the first circuit temperature when the circulating fluid warming unit is stopped, the circulating fluid warming unit is activated. The liquid discharge apparatus according to claim 5, wherein The circulation channel has a circuit cooling part and a liquid heating part,
The flow path heating unit cools the head drive circuit with the circulating liquid flowing through the circuit cooling unit, warms the liquid flowing through the liquid flow path with the circulating liquid flowing through the liquid heating unit,
The controller is
When the circulating fluid warming unit is deactivated, the circulating fluid heated by the heat absorption from the head drive circuit in the circuit cooling unit is preceded by the liquid warming unit before the circulating drive unit. Controlling the circulation drive unit to circulate in the first circulation direction to reach,
When the circulating fluid warming unit is operating, the circulating fluid heated by the circulating fluid warming unit is in a direction opposite to the first circulating direction and is more than the circuit cooling unit. The liquid ejecting apparatus according to claim 4, wherein the circulation driving unit is controlled to circulate in a second circulation direction that reaches the liquid heating unit first.   The liquid discharge apparatus according to claim 7, wherein the circulating liquid heating unit is provided on the downstream side of the circulation driving unit and the upstream side of the liquid heating unit in the second circulation direction. . The flow path heating unit further includes a circulating fluid cooling unit that cools the circulating fluid,
The controller is
When the circulating fluid warming unit is deactivated, the circulating fluid cooling unit is activated,
9. The liquid ejection device according to claim 7, wherein when the circulating fluid heating unit is operating, the circulating fluid cooling unit is deactivated.   The liquid ejection device according to claim 9, wherein the circulating liquid cooling unit is provided on the downstream side of the liquid heating unit and on the upstream side of the circulation driving unit in the second circulation direction. A circuit case for accommodating the head drive circuit,
The liquid ejection device according to claim 1, wherein at least a part of the circulation flow path is in contact with the circuit case. A sliding portion that allows movement of the liquid flow path when the liquid discharge head moves;
The circulation channel has a circuit cooling part and a liquid heating part,
The flow path heating unit cools the head drive circuit with the circulating liquid flowing through the circuit cooling unit, warms the liquid flowing through the liquid flow path with the circulating liquid flowing through the liquid heating unit,
The liquid discharging apparatus according to claim 1, wherein the liquid heating unit is provided in the sliding unit.

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