JP2006327143A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which can supply a cooling liquid of an equal temperature to each heat sink of a plurality of recording units. <P>SOLUTION: The heat sink 20 equipped with a passage 21 of the cooling liquid C is arranged in each recording head 10 of a plurality of the recording units 9 aligned along a conveyance route of a recording medium RM. At the same time, the passages of respective heat sinks 20 are connected in parallel to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printer, and more particularly, to a printer suitable for cooling each recording head of a plurality of recording units arranged along a conveyance path of a recording medium.

  2. Description of the Related Art Conventionally, in a printer that records an image on a recording medium using a plurality of ink ribbons coated with different color inks, a thermal head as a plurality of recording heads provided corresponding to each ink ribbon. There is known a printer called a tandem system that records a desired image on a recording medium by transferring the ink of each ink ribbon to the recording medium (see, for example, Patent Document 1).

  Such a printer includes a plurality of ink ribbons each coated with a plurality of colors (for example, cyan (C), magenta (M), yellow (Y), and black (BK)), and each of the ink ribbons. And a plurality of thermal heads corresponding to the number. These thermal heads are arranged so as to be arranged in parallel at predetermined intervals along the conveyance path of the recording medium, and are arranged so as to face the recording medium via an ink ribbon.

  In such a printer, a thermal head having a plurality of heating elements is used as a recording head. Therefore, when continuous printing is performed, the thermal head accumulates heat and the temperature rises. Even the temperature of the heating element in the vicinity reaches the temperature necessary for the ink transfer of the ink ribbon, and more ink than necessary is transferred to the recording medium, and a good quality image is formed on the recording medium. There was a fear that it was not done. Further, if the temperature of the thermal head rises above the allowable temperature, the heat generating element may be destroyed.

  For this reason, the thermal head has been cooled so that the thermal head does not store heat above a predetermined temperature, and only energized heating elements reach the temperature required for ink transfer to form a good quality image. I was trying to do it.

  By the way, the cooling of the thermal head is generally an air-cooling type that is cooled by air with a simple configuration.

  However, a thermal head in which a large number of minute heating elements are arranged with minute intervals, in particular, a line thermal head having a length that can face the printing range in the vertical direction or the horizontal direction of the recording medium is used as the recording head. In recent printers that perform high-speed printing, the recording head cannot be sufficiently cooled by air. For this reason, the recording head may be cooled by a heat sink using a coolant called a water-cooled heat sink (see, for example, Patent Document 2).

  In some cases, a coolant circulation path is provided in the heat sink (see, for example, Patent Document 3).

JP 2000-263864 A JP-A-6-31957 Japanese Utility Model Publication No. 4-73551

  By the way, in the case of the printer having the plurality of recording units described above, there is a problem of how to supply the cooling liquid to the respective heat sinks of the recording heads provided in the respective recording units.

  That is, it is necessary to supply a coolant having the same temperature to each heat sink of each recording unit, and it is also necessary to reduce the size of the pump and piping in order to reduce the size of the entire printer.

  The present invention has been made in view of this point, and an object of the present invention is to provide a printer capable of supplying a cooling liquid having an equal temperature to each heat sink of a plurality of recording units.

  Another object of the present invention is to provide a printer that can reduce the size of a pump and piping.

  In order to achieve the above-described object, a printer according to the present invention is characterized in that a plurality of recording units are arranged along a conveyance path of a recording medium. Each of these recording units includes a recording head and the recording head. And a heat sink having a coolant passage for cooling the printer, wherein the passages of the heat sinks are connected in parallel to each other. By adopting such a configuration, it is possible to cool each recording head by supplying a cooling liquid having the same temperature to each of the passages of each heat sink.

  In the printer according to the present invention, the supply side of each passage is connected to one storage tank via an individual supply pipe, and the introduction pipe is provided with a pump for supplying a cooling liquid to the storage tank. Are preferably connected. By adopting such a configuration, the coolant can be branched from the storage tank and supplied to the passages of the respective heat sinks, so that the coolant having the same temperature as each of the passages of the respective heat sinks can be reliably and easily provided. Can be supplied.

  In the printer according to the present invention, the discharge side of each passage is connected to one manifold via individual discharge pipes, and the manifold is connected to the pump via a recovery pipe to circulate coolant. It is preferable to form a path. And by employ | adopting such a structure, while being able to circulate and utilize a cooling fluid, a piping path | route can be shortened.

  The storage tank is preferably disposed above the heat sink in the direction of gravity. And by adopting such a configuration, it is possible to supply the coolant having the same temperature to the passages of the respective heat sinks using gravity, so that the output of the pump can be reduced and the diameter of the passages can be reduced. Can be small. As a result, it is possible to reduce the size of the pump and the respective passages, so that it is possible to reduce the size of the recording head provided with the water-cooled heat sink and hence the size of the printer.

  According to the printer of the present invention, since the paths of the heat sinks are connected in parallel to each other, it is possible to supply the cooling liquid having the same temperature to each of the paths of the heat sinks to cool the recording heads.

  In addition, the supply side of each passage is connected to one storage tank via an individual supply pipe, and the introduction pipe having a pump for supplying the coolant is connected to the storage tank. Can be branched from the storage tank and supplied to the path of each heat sink. As a result, it is possible to reliably and easily supply the coolant having the same temperature to each of the heat sink passages.

  In addition, the discharge side of each passage is connected to one manifold via an individual discharge pipe, and the manifold is connected to a pump via a recovery pipe to form a coolant circulation path. Can be circulated and the piping path can be shortened.

  Further, since the storage tank is disposed above the heat sink in the direction of gravity, the coolant flows in each passage due to gravity, and the pump and each passage can be downsized. As a result, it is possible to reduce the size of the recording head provided with the water-cooled heat sink, and hence the size of the printer.

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

  FIG. 1 to FIG. 5 show an embodiment of a printer according to the present invention. FIG. 1 is a schematic diagram showing the main part of the overall configuration in a simplified manner. FIG. 2 is an enlarged schematic diagram showing the main part of a recording unit. 3 is an enlarged schematic view showing the main part of the recording unit in the vicinity of the recording head, FIG. 4 is a schematic diagram showing the main part of the recording head, and FIG. 5 is supplied to the heat sink passage for cooling the recording head of each recording unit. It is a systematic diagram which shows the connection system of piping of a cooling fluid.

  As shown in FIG. 1, the printer 1 of the present embodiment includes a supply unit disposed substantially horizontally along the left-right direction in the lower part of FIG. 1 inside the printer main body 2 indicated by a two-dot chain line in FIG. 1. 3, a recording unit 4 disposed substantially vertically along the vertical direction on the right side of FIG. 1, and a discharge unit 5 disposed substantially horizontally along the left-right direction on the top of FIG. 1. ing. That is, the supply unit 3, the recording unit 4, and the discharge unit 5 are arranged so as to be substantially U-shaped as a whole, and are formed so that the conveyance path of the recording medium RM is substantially U-shaped as a whole. ing.

  The supply unit 3 is for holding a long recording medium RM supplied to the recording unit 4, and a supply roll 6 around which the recording medium RM is wound is detachably attached to the supply unit 3. Has been. The recording medium RM is fed out from the supply roll 6 by a driving force of a supply roller (not shown), and is guided along a predetermined transport path by a supply guide means such as a guide plate 7 and a guide roll 8. It is designed to be conveyed. The recording medium RM can be selected from various types such as plain paper and glossy paper.

  The recording unit 4 is for recording a desired image on the recording medium RM. In the recording unit 4, a plurality of recording units RM are arranged along the conveying direction of the recording medium RM from the lower side to the upper side in FIG. In the embodiment, four recording units 9 for performing full color recording are arranged. These recording units 9 are arranged in this order from the most upstream side in the conveyance direction of the recording medium RM shown in the lower part of FIG. 1 to the downstream side shown in the upper part of FIG. A third recording unit 9C and a fourth recording unit 9D are provided.

  Each of the recording units 9 arranged in the recording unit 4 (symbol 9 is a generic term for the first recording unit 9A, the second recording unit 9B, the third recording unit 9C, and the fourth recording unit 9D). It has a line thermal head 10 as a head, a platen roller 11 as a platen, a conveying means 13 having a conveying roller 12, a disturbance blocking means 15 having a friction roller 14, and a ribbon cassette 16.

  As shown in FIG. 1 and FIG. 2, each recording unit 9 has a line thermal head 10 and a conveying roller 12 in a recording state of the recording unit 9 located on the upstream side between a pair of adjacent recording units 9. The line thermal head 10 in the recording state of the recording unit 9 located on the downstream side with respect to the extending direction of the conveying path for connecting, more specifically, the conveying path connecting the opposing surfaces of the line thermal head 10 and the recording medium RM of the conveying roller 12. In this embodiment, the transport path connecting the transport roller 12 and the transport roller 12 is shifted to the left in FIGS. 1 and 2.

  That is, the conveyance path connecting the line thermal head 10 and the conveyance roller 12 in the recording state of each recording unit 9 of the present embodiment is formed in a descending step shape as a whole.

  Thereby, the recording medium RM can be loosened (curved) when the recording medium RM is supplied to supply the recording medium RM from the upstream recording unit 9 to the downstream recording unit 9.

  Further, the friction roller 14 can establish a conveyance path to the downstream recording unit 9 when the recording medium is introduced between a pair of adjacent recording units 9. Each recording unit 9 has the same configuration.

  The discharge unit 5 is for storing and holding the recording medium RM on which an image is recorded by the recording unit 4 after being cut into a predetermined length. As shown in FIG. It has a cutting means 17 having a cutting blade for cutting a long recording medium RM in a width direction perpendicular to the longitudinal direction, and a tray 18 for storing the recording medium RM after being cut. The recording medium RM discharged from the recording unit 4 is guided along a predetermined transport path by a driving force of a discharge roller (not shown), and then is cut into a predetermined length by the cutting unit 17 to the tray 18. It is designed to be stored sequentially.

  Here, the configuration of each recording unit 9 will be described with reference to FIGS.

  The recording unit 9 of this embodiment has a line thermal head 10 formed in a substantially flat plate shape. The line thermal head 10 is fixedly arranged with its longitudinal direction oriented in a direction orthogonal to the conveyance direction of the recording medium RM. As shown in FIG. 4, the recording surface 10a facing the conveyance path of the line thermal head 10 has a direction perpendicular to the conveyance direction of the recording medium RM during the recording operation, that is, the conveyance direction of the recording medium RM. A number of heating elements 10b are arranged over a length corresponding to the dimension (recording width) in the row direction of the recording range orthogonal to the recording range.

  As shown in FIGS. 3 and 4, the line thermal head 10 is attached to a head mounting base 19 made of a metal material such as an aluminum alloy that is lightweight and excellent in heat dissipation (thermal conductivity). The head mounting base 19 is provided with a substantially horizontally long heat sink 20 called a water-cooled heat sink for cooling the line thermal head 10 so that the line thermal head 10 does not store heat above a predetermined temperature. Yes. As shown in FIG. 4, the heat sink 20 is formed with a passage 21 for the coolant C (FIG. 5) having a substantially horizontal U shape, and a pipe for the coolant C is connected to the passage 21. . The connection system of the coolant C piping will be described later.

  The formation position, length, cross-sectional shape and the like of the passage 21 can be changed according to the design concept and the like.

  As shown in FIG. 3, a ribbon cassette 16 is disposed on the left side of the line thermal head 10. Inside the ribbon cassette 16 is disposed an ink ribbon 23 wound between a pair of rotatable ribbon rollers 22, and the ink ribbon 23 is rotatably disposed on the ribbon cassette 16. Are guided by a plurality of ribbon guide rollers 24 and a pair of external guide rollers 25 rotatably arranged above and below (upstream and downstream) in FIG. The travel path of the ink ribbon 23 led out from the ribbon cassette 16 is disposed so as to pass between the line thermal head 10 and the platen roller 11. At this time, the ink ribbon 23 is transported so that the ink coating surface faces the recording medium RM and the back surface of the ink coating surface faces the heating element 10 b of the line thermal head 10. The ribbon cassette 16 is detachably attached to a cassette holder (not shown) disposed inside the printer main body 2. The ink ribbon 23 can be run by a conventionally known ink ribbon running mechanism (not shown) during a recording operation.

  As the ink ribbon 23 of the present embodiment, for example, in order to form a full-color image on the recording medium RM, the ink ribbon 23 coated with cyan (C) ink as the ink ribbon 23 of the first recording unit 9A. The ink ribbon 23 coated with magenta (M) ink is used as the ink ribbon 23 of the second recording unit 9B, and the yellow (Y) ink is coated as the ink ribbon 23 of the third recording unit 9C. The processed ink ribbon 23 is used, and the ink ribbon 23 coated with black (BK) ink is used as the ink ribbon 23 of the fourth recording unit 9D.

  A platen roller 11 having a length corresponding to the length of the recording medium RM and the line thermal head 10 is disposed at a position facing the line thermal head 10 via the ink ribbon 23 and the recording medium RM. . The platen roller 11 is rotatably supported by a platen support frame (not shown), and a down position where the platen roller 11 is pressed against the line thermal head 10 with a predetermined contact force by a head contact / separation mechanism (not shown), The roller 11 is formed so that it can selectively take two positions, the up position separated from the line thermal head 10.

  The pressure contact position between the line thermal head 10 and the platen roller 11 in the down state where the platen roller 11 is pressed against the line thermal head 10 via the recording medium RM transfers the ink on the ink ribbon 23 to the recording medium RM. The recording position RP for recording is set.

  Above the platen roller 11 on the downstream side, a transporting means 13 for transporting the recording position RP, that is, the recording medium RM that has passed through the line thermal head 10 to the downstream side is disposed. The conveying means 13 is a rotation provided so as to be opposed to the conveying roller 12 and to the conveying roller 12 disposed on the downstream side of the line thermal head 10. And a free conveying pressure contact roller 26. The recording roller RM is driven between the conveying roller 12 and the conveying pressure contact roller 26 by rotationally driving the conveying roller 12 with a driving force of an unillustrated conveying drive motor. It is formed so that it can be held and conveyed.

  The pressure contact of the conveying pressure roller 26 against the outer peripheral surface of the conveying roller 12 is formed prior to the pressure contact of the platen roller 11 with the line thermal head 10.

  Further, the transport unit 13 of the recording unit 9D located on the most downstream side in the present embodiment is used for sending the recording medium RM from the recording unit 4 to the discharge unit 5.

  Disturbance blocking means 15 for blocking the disturbance that adversely affects the conveyance of the recording medium RM generated on the downstream side from propagating to the upstream side through the recording medium RM is provided above the conveyance roller 12. It is arranged. The disturbance blocking means 15 is disposed on the downstream side of the conveying roller 12 in parallel with the conveying roller 12, and faces the friction roller 14 via the conveying path and is in contact with and separated from the friction roller 14. And a friction friction contact roller 27 that can be freely provided. The friction roller 14 and the friction pressure contact roller 27 are configured to press the recording medium RM so that a friction load can be applied to the recording medium RM. Has been. Further, the friction roller 14 and the friction pressure roller 27 are formed so as to be rotatable about the conveying roller 12 and are always fixed so as to restrain the friction roller 14 from rotating about the conveying roller 12. It can be held in a state. Thereby, the conveyance path of the recording medium RM to the recording unit 9 on the downstream side between the pair of adjacent recording units 9 can be established.

  Furthermore, the friction roller 14 and the friction pressure roller 27 include a fixed state in which the friction roller 14 and the friction pressure roller 27 are restrained from rotating about the conveying roller 12, and the friction roller 14 and the friction pressure roller 27. Is formed so that it can be easily switched to a free state in which it can be rotated around the transport roller 12.

  Note that the pressure contact of the friction pressure roller 27 against the outer peripheral surface of the friction roller 14 is after the pressure contact of the transport pressure roller 26 with respect to the outer peripheral surface of the transport roller 12 and prior to the pressure contact of the platen roller 11 with respect to the line thermal head 10. It is formed to be done.

  Further, the switching from the fixed state to the free state of the friction roller 14 and the friction pressure roller 27 is performed after the platen roller 11 is pressed against the line thermal head 10, and more specifically, the recording medium RM is supplied to the recording unit 9 on the downstream side. Thus, the recording medium RM is formed between the conveying roller 12 and the conveying pressure roller 26 of the recording unit 9 on the downstream side so as to be performed.

  Here, the connection system of the piping of the coolant C supplied to the heat sink 20 of each recording unit 9 will be described with reference to FIG.

  As shown in FIG. 5, supply pipes 28 a, 28 b, 28 c, and 28 d used for supplying individual cooling liquid C are provided at one end of each recording unit 9 located on the supply side of the passage 21 of each heat sink 20. One end is connected, and the other ends of these supply pipes 28a, 28b, 28c, and 28d are arranged in the upper direction of FIG. The storage tank 29 is connected. One end of the introduction pipe 30 is connected to the storage tank 29, and the other end of the introduction pipe 30 is connected to the discharge port of the pump 31.

  Therefore, the coolant C introduced into the storage tank 29 branches from the storage tank 29 into the four supply pipes 28a, 28b, 28c, and 28d due to gravity and flows down to reach the passages 21 of the respective heat sinks 20. Will do.

  One end of each of the discharge pipes 32a, 32b, 32c, and 32d used for discharging the individual coolant C is connected to the other end located on the discharge side of each passage 21, and these discharge pipes 32a, The other ends of 32 b, 32 c and 32 d are connected to the inlet of one manifold 33. One end of a recovery pipe 34 is connected to the outlet of the manifold 33, and the other end of the recovery pipe 34 is connected to the suction port of the pump 31.

  Therefore, the coolant C that has flowed through the passage 21 of each heat sink 20 is discharged by the pump 31. At this time, the coolant C discharged from the passage 21 of each heat sink 20 flows through the four systems of the discharge pipes 32a, 32b, 32c, and 32d and collects in the manifold 33. Thereafter, the recovery pipe 34 and the pump 31 and the supply pipes 28a, 28b, 28c, 28d in this order are returned to the storage tank 29.

  Therefore, the passage 21 of each heat sink 20 is connected in parallel with each other.

  Further, the passage 21 provided in each heat sink 20, four supply pipes 28 a, 28 b, 28 c, 28 d, four discharge pipes 32 a, 32 b, 32 c, 32 d, a recovery pipe 34 and a supply pipe 28 a, 28b, 28c, and 28d form a circulation path 35 for the coolant C.

  In addition, it is good to comprise so that heat may be taken from the cooling water in the collection piping 34, and a cooling water may be cooled by interposing the radiator provided with the fan in the collection piping 34. FIG.

  The circulation path 35 may be connected to a supply pipe for supplying the coolant C when the amount of cooling water decreases.

  Each unit of the printer 1 according to the present embodiment is controlled by a control unit having a CPU and a memory (not shown).

  Next, the operation of the present embodiment having the above-described configuration will be described.

  FIG. 1 shows a recording state by a printer, FIG. 2 shows a state where a recording medium is introduced into the third recording unit, and FIG. 3 shows a recording state of the recording unit.

  When recording data of an image such as a desired character or figure is input to the printer 1 of the present embodiment, first, the printer 1 is positioned on the most upstream side of each recording unit 9 from the supply roll 6 of the supply unit 3. The recording medium RM is conveyed to the first recording unit 9A.

  At this time, each recording unit 9 holds a standby state. In the standby state of the recording unit 9, the platen roller 11 is separated from the recording surface 10 a of the thermal head 10, the conveying pressure roller 26 is separated from the outer peripheral surface of the conveying roller 12, and the friction pressure roller 27 is the friction roller 14. It is spaced apart from the outer peripheral surface. Further, the disturbance blocking means 15 holds a fixed state.

  Next, when the recording medium RM is supplied from the supply unit 3 to the first recording unit 9A, the leading end of the recording medium RM is between the recording surface 10a of the line thermal head 10 of the first recording unit 9A and the platen roller 11. Passed and conveyed between the conveying roller 12 and the conveying pressure roller 26. When the leading edge of the recording medium RM passes between the conveying roller 12 and the conveying pressure contact roller 26, the conveying pressure roller 26 comes into a conveying roller pressure state in which the conveying pressure roller 26 is in pressure contact with the conveying roller 12 via the recording medium RM. At the same time, the recording medium RM is sandwiched between the conveying roller 12 and the conveying pressure roller 26 and the recording medium RM is conveyed toward the second recording unit 9B on the downstream side. The transport roller 12 continues to be rotationally driven so as to continue transporting the recording medium RM downstream at a predetermined speed without being intermittently driven after the transport roller is brought into a pressure contact state.

  Next, when the leading edge of the recording medium RM passes between the friction roller 14 and the friction pressing roller 27, the friction pressing roller 27 is moved to the friction roller 14 via the recording medium RM while maintaining the conveying roller pressing state. The recording medium RM is pressed against the recording medium RM by the friction roller 14 and the friction pressing roller 27, and a friction roller pressing state is applied in which a friction load is applied to the recording medium RM.

  Next, after the friction pressure roller 27 is pressed against the friction roller 14 via the recording medium RM, the platen roller 11 holds the recording medium RM and the ink ribbon 23 in this order while maintaining the conveying roller pressure state and the friction roller pressure state. Thus, the head is in pressure contact with the recording surface 10 a of the line thermal head 10. Note that the platen roller 11 has moved toward the line thermal head 10 and is close to the line thermal head 10 before the pressure contact of the friction pressure roller 27 against the friction roller 14 is completed. During this time, the transport roller 12 transports the recording medium RM downstream, and the head pressure contact is performed in a state where the transport roller 12 transports the recording medium RM downstream.

  When the head pressure contact state is reached, heat is generated by selectively energizing the heating elements of the line thermal head 10 based on the recording information, and the ink ribbon 23 is conveyed, so that the first recording unit 9A A recording operation for transferring a predetermined color, for example, C ink from the ink ribbon 28 to the image forming area of the recording medium RM is started.

  Subsequently, when the leading edge of the recording medium RM passes between the recording surface 10a of the line thermal head 10 of the second recording unit 9B and the platen roller 11 by the conveying roller 12 of the first recording unit 9A, the first recording described above. Similarly to the unit 9A, the head cam drive motor 29 of the second recording unit 9B is driven, and each part of the second recording unit 9B changes from the standby state described above to the conveying roller pressure contact state, the friction roller pressure contact state, and the head pressure contact state. Then, the recording operation by the second recording unit 9B is started, and recording is performed by transferring different colors, for example, M ink, from the ink ribbon 28 onto the image formed by the first recording unit 9A.

  At this time, the disturbance blocking means 15 of the first recording unit 9A establishes a transport path to the second recording unit 9B.

  Further, when the platen roller 11 of the second recording unit 9B is down, an image is recorded by the first recording unit 9A. The disturbance blocking means 15 of the first recording unit 9A, specifically, the friction roller 14 and the friction roller 14 are used. Since the recording medium RM is pressed against the recording medium RM by the pressing roller 27, an impact on the recording medium RM is transmitted to the recording medium RM when the platen roller 11 of the second recording unit 9B is down. Thus, transmission to the portion where the first recording unit 9A is transported and recorded can be reliably blocked.

  That is, the disturbance blocking means 15 can reliably and easily block the disturbance generated on the downstream side between the pair of adjacent recording units 9 from propagating to the upstream side via the recording medium RM. As a result, it is possible to easily improve the recording quality.

  Further, the line thermal head 10 and the transport in the recording state of the second recording unit 9B located on the downstream side with respect to the extending direction of the transport path connecting the line thermal head 10 and the transport roller 12 in the recording state of the first recording unit 9A. Since the transport path connecting the rollers 12 is arranged at a position shifted, the recording medium RM can be loosened (curved) when the recording medium for supplying the recording medium RM is introduced.

  That is, between a pair of adjacent recording units 9, with respect to a conveyance path connecting the contact positions of the line thermal head 10 of the recording unit 9 and the conveyance roller 12 with the recording medium RM located upstream in the recording state. The conveyance path connecting the line thermal head 10 and the conveyance roller 12 of the recording unit 9 located on the downstream side is arranged in a substantially stepped manner, and recording is performed from the upstream recording unit 9 to the downstream recording unit 9. The conveyance path of the recording medium RM can be formed so that the recording medium RM is slackened when the medium for supplying the medium RM is introduced. Further, the friction roller 14 can establish a conveyance path to the downstream recording unit 9 between a pair of adjacent recording units 9.

  When the recording medium RM is supplied to the second recording unit 9B, for example, at the timing when the second recording unit 9B is at least in the conveying roller pressure contact state, the disturbance blocking means 15 and the conveying pressure roller 26 are A free state in which the conveyor roller 12 can be rotated is maintained. In this way, by switching the friction roller 14 of the disturbance blocking means 15 from the fixed state to the free state, an error (speed difference) in the conveyance speed of the recording medium RM between the recording units 9 can be absorbed.

  Similarly, in the third recording unit 9C, recording is performed by transferring different colors, for example, Y ink, from the ink ribbon 28 onto the image formed by the second recording unit 9B, and then in the fourth recording unit, A recording of transferring a different color, for example, BK ink, from the ink ribbon 28 is performed on the image formed by the third recording unit 9C to form a full-color image.

  In the printer 1 of the present embodiment, when recording is performed by each recording unit 9, the line thermal head 10 is cooled by the heat sink 20 so as not to store heat above a predetermined temperature.

  That is, when the pump 31 is driven by a control signal from the control unit, the coolant C in the circulation path 35 flows counterclockwise in FIG. 5, and the coolant C discharged from the pump 31 to the introduction pipe 30 is It reaches the storage tank 29 from the introduction pipe 30 and branches from there into four separate supply pipes 28a, 28b, 28c, 28d by gravity, and the passage 21 of each heat sink 20 of each recording unit 9 is routed. The heat is taken from each heat sink 20 around.

  As a result, the heat of each line thermal head 10 that is indirectly connected to each heat sink 20 that has been deprived of heat by the coolant C is transferred to each heat sink 20, and each line thermal head 10 is cooled. Will be.

  On the other hand, the coolant C heated around the passages 21 of the respective heat sinks 20 flows through the four individual discharge pipes 32a, 32b, 32c, and 32d to reach the manifold 33. 33, gathered in the recovery pipe 34, cooled and then pumped up to the pump 31 to be recirculated. When the pump 31 is driven, it is discharged again into the introduction pipe 30 and reaches the storage tank 29. To do.

  As described above, according to the printer 1 of the present embodiment, the coolant C can be supplied to the passage 21 of the heat sink 20 of each recording unit 9 connected in parallel, and thus is equal to the passage 21 of each heat sink 20. The coolant C having the temperature can be reliably supplied.

  Further, the supply side of each passage 21 is connected to one storage tank 29 via individual supply pipes 28a, 28b, 28c, 28d, and a pump 31 for supplying the coolant C to the storage tank 29 is provided. Since the provided introduction pipe 30 is connected, the coolant C can be branched from the storage tank 29 and supplied to the passage 21 of each heat sink 20. As a result, it is possible to reliably and easily supply the coolant C having the same temperature to each of the passages 21 of the respective heat sinks 20.

  Further, the discharge side of each passage 21 is connected to one manifold 33 via individual discharge pipes 32 a, 32 b, 32 c, 32 d, and this manifold 33 is connected to the pump 31 via a recovery pipe 34. Since the circulation path 35 for the coolant C is formed, the coolant C can be circulated and used, and the piping path can be shortened.

  Furthermore, since the coolant C is supplied from the storage tank 29 to the passage 21 of the heat sink 20 of each recording unit 9 using gravity, the pump 31 stores the coolant C via the introduction pipe 30. Since it is sufficient to pump up to the tank 29, the output of the pump 31 can be reduced, and the diameter of the passage 21, that is, the cross-sectional area can be reduced.

  As a result, it is possible to reduce the size of the line thermal head 10 provided with the water-cooled heat sink 20, and hence the size of the printer 1.

  Note that the flow path configuration of the coolant supplied to each heat sink in the printer of the present invention requires cooling in various printers called a tandem system in which a plurality of recording units are arranged along the recording medium conveyance path. It can be used for cooling each recording head. In this case, the configuration of the printer itself may be different from the configuration of the printer of this embodiment.

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

  For example, in the above-described embodiment, each recording unit is arranged at an interval in the substantially vertical direction. However, each recording unit in the present invention is such that the cooling liquid can flow to each recording unit by gravity. Of course, the recording units may be arranged on the horizontal plane at intervals, or on the inclined surface.

  Further, the coolant discharged from each discharge pipe may be recovered outside the pipe connection system so that the circulation path is not formed.

FIG. 1 is a schematic diagram showing a simplified main part of an embodiment of a printer according to the present invention. FIG. 1 is an enlarged schematic view showing a main part in a state where a recording medium is introduced into a third recording unit of the recording unit in the printer of FIG. The enlarged schematic diagram which shows the principal part in the recording state of the recording unit in the printer of FIG. FIG. 2 is a schematic diagram showing a main part of a recording head in the printer of FIG. 1 is a system diagram showing a connection system of piping for coolant supplied to a heat sink passage for cooling the recording head of each recording unit in the printer of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 3 Supply part 4 Recording part 5 Ejection part 9 Recording unit 9A 1st recording unit 9B 2nd recording unit 9C 3rd recording unit 9D 4th recording unit 10 Line thermal head 10a Recording surface 10b Heating element 11 Platen roller 12 Conveyance roller 13 Conveying means 14 Friction roller 15 Disturbance blocking means 16 Ribbon cassette 19 Head mount 20 Heat sink 21 Passage 23 Ink ribbon 26 Conveying pressure roller 27 Friction pressure rollers 28a, 28b, 28c, 28d Supply piping 29 Storage tank 30 For introduction Piping 31 Pump 32a, 32b, 32c, 32d Discharge piping 33 Manifold 34 Recovery piping 35 Circulation path RM Recording medium RP Recording position C Coolant

Claims (4)

A plurality of recording units are arranged along the conveyance path of the recording medium, and each of these recording units is provided with a recording head and a heat sink having a coolant passage for cooling the recording head. Printer,
A printer characterized in that the paths of the heat sinks are connected in parallel to each other.   The supply side of each passage is connected to one storage tank via an individual supply pipe, and an introduction pipe having a pump for supplying a cooling liquid is connected to the storage tank. The printer according to claim 1.   The discharge side of each passage is connected to a single manifold via individual discharge pipes, and the manifold is connected to the pump via a recovery pipe to form a coolant circulation path. The printer according to claim 2.   The printer according to claim 2 or 3, wherein the storage tank is disposed above the heat sink in the direction of gravity.

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