JP4186883B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus in which an ink jet head and a drive circuit thereof are mounted, and a heat radiator that dissipates heat generated by the drive circuit is composed of two heat sinks.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus that performs printing by mounting an ink jet head on a carriage and ejecting ink from the ink jet head onto a recording medium while reciprocating the carriage in the main scanning direction is known. In the ink jet recording apparatus, a drive circuit that outputs a drive signal for driving the ink jet head is mounted on the carriage, and the ink jet head is configured to eject ink onto a recording medium by the drive signal from the drive circuit. ing.

  However, since the drive circuit outputs a drive signal to the inkjet head, a large current instantaneously flows through the drive circuit, and the temperature rises rapidly. In addition, the drive circuit requires a drive element for each nozzle, and as the number of nozzles increases, the number of drive elements increases and the density increases, so the operation of simultaneously ejecting ink from a large number of nozzles of the inkjet head continues for a long time. As a result, the temperature rises significantly. This increase in temperature has caused the drive circuit to malfunction or become unstable, thereby inhibiting stable ink ejection. Therefore, in order to cool the driving circuit that generates heat, a radiator is mounted on the carriage so as to come into contact with the driving circuit, and the heat of the driving circuit is radiated by the radiator.

In the invention disclosed in Japanese Patent No. 2927141, in order to dissipate heat of the drive circuit, a fan is provided and heat is transferred by a heat pipe.
Japanese Patent No. 2927141 (FIG. 2 etc.).

  However, there is a problem that it is expensive to equip a high-performance radiator as described above, and at the same time, since the cooling device is large, the ink jet recording apparatus becomes large and requires time and labor for assembly. There was also the problem of doing.

  The present invention has been made to solve the above-described problems, and provides an ink jet recording apparatus that is particularly easy to assemble and has good assembly properties and can efficiently dissipate heat generated by a drive circuit. It is aimed.

  In order to achieve this object, an ink jet recording apparatus according to claim 1 includes an ink jet head that ejects ink onto a recording medium, and a drive circuit that applies a voltage to the ink jet head in order to eject ink onto the ink jet head. An ink jet recording apparatus having a carriage for mounting a first heat sink and a second heat sink mounted on the carriage and disposed in a substantially square shape having a space therein. One end of the first heat sink and the second heat sink are connected to each other, and the other end is disposed so as to sandwich the heat generating part of the drive circuit.

  The ink jet recording apparatus according to claim 2, wherein the carriage includes an ink tank for supplying ink to the ink jet head, and the first heat sink and the second heat sink are The ink tank is disposed so as to surround the periphery.

According to a third aspect of the present invention, there is provided an ink jet recording apparatus that ejects ink onto a recording medium, a drive circuit that applies a voltage to the ink jet head in order to eject ink onto the ink jet head, an inkjet recording apparatus equipped with a carriage for mounting an ink tank for supplying, while being mounted on the carriage, first heat sink and second heat sink that is disposed so as to surround the periphery of the ink tank One end of the first heat sink and the second heat sink are connected to each other, and the other end is disposed so as to sandwich the heat generating portion of the drive circuit.

The ink jet recording apparatus according to claim 4, wherein the space surrounded by the first heat sink and the second heat sink is a space in which both ends are open. , and the wherein the first heat sink and the second heat sink, the direction of the open space in which the both ends are opened is disposed so as to be substantially parallel to the moving direction of the carriage.

  6. The ink jet recording apparatus according to claim 5, wherein the other end of the first heat sink and the second heat sink is an elastic member having thermal conductivity. It is arrange | positioned so that the said heat-emitting part may be pinched | interposed through.

  The ink jet recording apparatus according to claim 6 is the ink jet recording apparatus according to any one of claims 1 to 5, wherein the heat generating portion is a semiconductor integrated circuit.

  According to the ink jet recording apparatus of the first aspect, the heat generated by the heat generating part is transmitted to the first heat sink and the second heat sink, and both the heat sinks are connected to each other at one end. The heat is also transmitted to the other heat sink and has an effect that heat can be efficiently radiated because the area in contact with air is large. Further, since the heat generating part is sandwiched between the other ends of the two heat sinks and the other ends are connected to each other, there is an effect that the two heat sinks can be easily assembled.

  According to the ink jet recording apparatus of the second aspect, in addition to the effect exhibited by the ink jet recording apparatus of the first aspect, the carriage is mounted with an ink tank that supplies ink to the ink jet head, and the first heat sink and the first heat sink Since the second heat sink is disposed so as to surround the periphery of the ink tank, there is an effect that the ink tank and the heat sink can be compactly mounted on the carriage.

  According to the ink jet recording apparatus of the third aspect, the heat generating portion is sandwiched between the first heat sink and the second heat sink, and one ends of the first heat sink and the second heat sink are connected to each other, and the periphery of the ink tank is formed. Since it is disposed so as to surround, the heat generated by the heat generating part is transmitted to the first and second heat sinks, and both the heat sinks are connected at one end. By transmitting to the heat sink, the area in contact with the air is large and heat can be radiated efficiently. Further, since the ink tank is disposed so as to surround the periphery of the ink tank, when the ink tank is mounted, the space on the carriage can be used effectively, and the overall size can be reduced. .

According to the ink jet recording apparatus of the fourth aspect, in addition to the effect exhibited by the ink jet recording apparatus according to any one of the first to third aspects, the space surrounded by the first heat sink and the second heat sink has both ends. Is an open space, and the first heat sink and the second heat sink are disposed so that the opening direction of the space is substantially parallel to the carriage movement direction. Air circulates in the space formed by the first heat sink and the second heat sink. Therefore, there is an effect that the heat sink can be efficiently cooled.

  According to the ink jet recording apparatus of the fifth aspect, in addition to the effect exhibited by the ink jet recording apparatus according to any one of the first to fourth aspects, the other ends of the first heat sink and the second heat sink are thermally conductive. Since the heat generating part is disposed so as to sandwich the elastic member having the property, the heat sink and the heat generating part can be more closely adhered, and the heat generated by the heat generating element can be efficiently radiated. There is.

  According to the ink jet recording apparatus of the sixth aspect, in addition to the effect exhibited by the ink jet recording apparatus according to any one of the first to fifth aspects, the semiconductor integrated circuit which is a heat generating portion by the first heat sink and the second heat sink Therefore, the heat generated by the semiconductor integrated circuit that generates the largest amount of heat can be efficiently radiated.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view showing an internal configuration of an ink jet recording apparatus 1 according to an embodiment of the present invention. The inkjet recording apparatus 1 includes a main body frame 2 made of a flame-retardant plastic, a recording head unit 3 that is included in the main body frame 2 and that ejects ink onto a recording medium, and supplies the recording head unit 3 to the recording head unit 3. An ink supply source 4 for storing ink, a tube 5 for supplying ink from the ink supply source 4 to the recording head unit 3, and a purge device 6 are provided.

  The recording head unit 3 is mounted on a carriage 13 that reciprocates (arrow A) in the longitudinal direction of the main body frame 2, and ejects ink onto a recording medium from an inkjet head 15 (see FIG. 3) disposed on the lower surface of the carriage 13. . The recording head unit 3 will be described in detail with reference to FIGS.

One end of the carriage 13 is slidably inserted into a guide rod 7 horizontally mounted in the longitudinal direction of the main body frame, and the other end of the carriage 13 is supported by a guide bar 8 horizontally mounted in the longitudinal direction of the main body frame 2. Has been. Further, a belt is attached to the carriage 13, and the belt is wound around a roller attached to a CR motor (carriage motor) 16 (see FIG. 9 ). When the CR motor 16 is driven, the belt rotates and the carriage 13 can be reciprocated in the longitudinal direction of the printer body 2.

  The ink supply source 4 includes four ink cartridges 4 a to 4 d arranged in series in the longitudinal direction of the main body frame 2, and black, yellow, cyan, and magenta inks are respectively contained in the ink cartridges 4 a to 4 d. Each is sealed. The inks of the ink cartridges 4a to 4d are supplied to the buffer tanks (ink tanks) 3c, 3d, 3e, and 3f on the carriage 13 through the tubes 5a to 5d, and the four colors of the inkjet head 15 are supplied from the buffer tanks. Supplied to the ink channel.

  At the left end portion of the main body frame 2, a purge device 6 that executes a purge process for recovering the ink ejection state from the inkjet head 15 is disposed. The arrangement position of the purge device 6 is a position outside the range of printing on the recording medium by the ink jet head 15 and is a retracted position of the carriage 13.

  The purge device 6 abuts on the ink ejection port forming surface of the inkjet head 15 to form a suction cap 6a that forms a sealed space with the ink ejection port forming surface, and makes the sealed space formed by the suction cap 6a a negative pressure. A suction pump (not shown), a discharge tube 6c that communicates the suction pump and the suction cap 6a, and a wiper 6b that wipes off ink adhering to the ink ejection port forming surface by the purge process.

When the purge process is performed by the purge device 6, the CR motor 16 is driven to move the carriage 13 to the purge process execution position. When the carriage 13 reaches the purge processing execution position, a driving source (not shown) is driven to bring the suction cap 6a disposed so as to face the ink ejection port formation surface of the inkjet head 15 into contact with the ink ejection port formation surface. . Thus, a sealed space is formed by the ink ejection port forming surface and the suction cap 6a, and the ink ejection ports drilled in the ink ejection port forming surface are included in the sealed space. In this state, the suction pump is operated to make the sealed space negative pressure through the discharge tube 6c. Therefore, bubbles, highly viscous ink, and the like are sucked from the ink ejection port, and the ink ejection state of the inkjet head 15 can be recovered.

  When the purge process is completed, the drive source is rotated in the reverse direction to separate the suction cap 6a from the ink ejection port forming surface. Further, a wiper 6b configured in a rubber plate shape is brought into contact with the ink ejection port forming surface by a cam mechanism (not shown). Then, the carriage 13 is slightly moved, and the ink adhering to the ink ejection port formation surface by the purge process is wiped by the wiper 6b. The purge device 6 may be configured to discharge ink from the inkjet head 15 by applying a positive pressure to the ink from the ink tank 4 side.

  Next, the recording head unit 3 according to the first embodiment will be described with reference to FIGS. 2 is a cross-sectional view showing the internal configuration of the recording head unit 3, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. As shown in FIGS. 2 and 3, the recording head unit 3 supports the inkjet head 15 with the lower surface of the box-shaped head holder 3a exposed, and supports buffer tanks 3c, 3d, 3e, and 3f therein. Two heat sinks 22 and 23 are arranged so as to surround the four buffer tanks. The heat sinks 22 and 23 are each configured by bending a plate metal having high thermal conductivity such as aluminum or copper into an L shape, and the two sides forming the L shape are opposed to the two sides of the other heat sinks in parallel. In addition, the two heat sinks are combined in a substantially square shape having a space inside with the inner angles of the heat sinks facing each other diagonally.

  The side 22a of the heat sink 22 forming the upper side of the square shape and the side 23b of the heat sink 23 forming the side are joined so that their tips are thermally conductive, and the side 23a of the heat sink 23 forming the lower side and the side The driver IC 17c is sandwiched between the tips 22b of the heat sink 22 forming the side so as to allow heat conduction. If necessary, an adhesive having good thermal conductivity can be interposed in these joints.

  The driver IC 17c is mounted on the flexible wiring board 17b, and one end of the flexible wiring board 17b is connected to the carriage board 17a and the other end is connected to the inkjet head 15. The driver IC 17c converts a print data signal serially transferred from a main body control board 30 to be described later into a parallel signal corresponding to a plurality of nozzles, and further applies the drive to a driving element provided for each ink ejection port. This is a drive circuit composed of a semiconductor integrated circuit that converts and outputs a voltage signal having a magnitude for driving the element. The carriage substrate 17a is connected to the main body control substrate 30 via a harness cable (not shown) when the recording head unit 3 is mounted on the carriage 13.

  Buffer tanks 3c, 3d, 3e, and 3f are arranged inside a square shape formed by two heat sinks, and each buffer tank passes through one side 23a of the heat sink 23 that forms the lower side of the square shape. 15 is in communication with the ink supply.

  4 and 5 show a second embodiment. In this embodiment, a recording head unit 3 is provided for each of two colors of ink, and correspondingly, on each of the head holders 3a and 3a, Heat sinks 22 and 23 are arranged so as to surround the buffer tanks 3c, 3d and 3e, 3f, respectively. As shown in FIGS. 5A and 5B, the inkjet head 15, the driver IC 17c, the flexible wiring substrate 17b, and the carriage substrate 17a are similarly provided for each recording head unit 3, and the inkjet head 15 is assembled in the head holder 3a. Then, the heat sinks 22 and 23 are assembled with the flexible wiring board 17b pulled out, and the driver IC 17c is sandwiched between the heat sinks 22 and 23 in the same manner as in the above embodiment. In this embodiment, the upper side 22 a of the heat sink 22 and the side 23 b of the heat sink 23 are joined by screws 25. 4C and 4D are a front view and a side view showing a state in which one recording head unit 3 is assembled.

  As shown in FIGS. 4A and 4B, the two recording head units 3 are arranged in parallel so as to correspond to the four colors of ink and are assembled to the carriage 13. The heat sinks of the two recording head units 3 are joined to each other so as to be able to conduct heat by a coupling member 26a having high thermal conductivity fixed by screws 26b. In this case, it is preferable that the driver ICs 17c are arranged on the side farthest from the other recording head unit 3 from the viewpoint of easily releasing heat.

  In each of the embodiments, since the heat sinks 22 and 23 enclose a space and both ends thereof are open, the heat generated by the driver IC 17c is transmitted to the heat sinks 22 and 23 and is efficiently released to the air inside and outside the heat sinks 22 and 23. .

  FIG. 6 shows a third embodiment. The same parts as those in the above-described embodiments are denoted by the same reference numerals, and the description thereof is omitted. 3A is a perspective view of the recording head unit 3, and FIG. 2B is a cross-sectional view of the recording head unit 3 cut along a plane perpendicular to the moving direction of the carriage 13. FIG. As in the previous embodiment, a L-shaped space is formed by the L-shaped heat sinks 22, 23, and buffer tanks 3c, 3d, 3e, 3f (other than 3c are not shown) are arranged in the space. However, the difference from the previous embodiment is that the heat sinks 22 and 23 are arranged so that the opening direction of both ends of the space formed by the heat sinks 22 and 23 is substantially parallel to the moving direction of the carriage 13. Is a point. That is, the planes of the sides constituting the L-shaped heat sinks 22 and 23 are arranged in parallel with the longitudinal direction of the guide rod 7 or the guide bar 8 that is the moving direction of the carriage 13. Thus, when printing is performed, the carriage 13 is moved, and air flows into the space inside the square shape from the square shape opening formed by the heat sinks 22 and 23, and the inflow of the air The air in the space flows out. Therefore, the heat sinks 22 and 23 can be cooled more efficiently.

  Further, as shown in FIG. 5B, the driver IC 17c is mounted on the flexible wiring board 17b, and one end of the flexible wiring board 17b is connected to the inkjet head 15, and the driver IC 17c and the driver IC 17c are mounted. The flexible substrate 17b is sandwiched between one end of the heat sink 23 and one end of the heat sink 22 via a rubber 27 which is an elastic member having thermal conductivity. As a result, the heat-conductive rubber 27 brings the heat sink 23 and the driver IC 17c into close contact with each other due to its elasticity, so that the heat generated by the driver IC 17c is efficiently conducted to the heat sink 23. In FIG. 4B, the rubber 27 having thermal conductivity is disposed between the flexible substrate 17b and the heat sink 22. However, the rubber 27 may be disposed between the driver IC 17c and the heat sink 23.

  FIG. 7 shows various joining methods of the heat sinks 22 and 23. FIG. 7A shows that the end face of the other heat sink 22 is joined to the side surface of one heat sink 23 (butting assembly). In FIG. 7B, conversely, the end surface of the other heat sink 23 is joined to the side surface of one heat sink 22. In FIG. 7C, the end surfaces of the heat sink 22 and the heat sink 23 are joined with a 45-degree slope (fastening assembly). In FIG. 7D, the tip of the heat sink 22 is bent 90 degrees and joined to the side surface of the heat sink 23. As a result, the bonding area can be increased as compared with the cases of FIGS. In FIG. 7 (e), the tip of the heat sink 23 is bent 90 degrees and joined to the side surface of the heat sink 22.

  FIG. 8 shows various methods of sandwiching the driver IC 17c (heat generating portion). FIG. 8A shows the side of the heat sink 22 brought into contact with the flexible wiring board 17b on which the driver IC is mounted. The end surface of the heat sink 23 is brought into contact with the upper surface. In FIG. 8B, the heat sink 22 and the flexible substrate 17b are similarly brought into contact with each other, and the heat sink 23 is bent and brought into contact with the upper surface of the driver IC 17c. Thereby, compared with the case of FIG. 8A, the contact area can be increased and the thermal conductivity is improved. FIG. 8C shows a case where the bending direction of FIG. 8B is different.

  Next, the electrical circuit configuration of the inkjet recording apparatus 1 configured as described above will be described with reference to FIG. FIG. 9 is a block diagram illustrating an outline of an electric circuit configuration of the inkjet recording apparatus 1. A control device for controlling the inkjet recording apparatus 1 includes a main body control board 30 and a carriage board 17a. The main body control board 30 includes a microcomputer (CPU) 32 having a one-chip configuration and a CPU 32 thereof. A ROM 33 that stores various control programs to be executed and fixed value data, a RAM 34 that is a memory for temporarily storing various data and the like, an image memory 37, a gate array 36, and the like are mounted.

  The CPU 32 which is an arithmetic unit executes control of each process such as the purge process described above in accordance with a control program 33a stored in advance in the ROM 33. Further, a print timing signal and a reset signal are generated, and each signal is transferred to a gate array 36 described later. The CPU 32 includes an operation panel 38 for a user to give a printing instruction, a motor drive circuit 39 for driving a carriage motor (CR motor) 16 for operating the carriage 13, and a conveyance motor (LF motor) for conveying a recording medium. ) A motor drive circuit 41 for operating 40, a paper sensor 42 for detecting the leading edge of the paper, an origin sensor 43 for detecting the origin position of the carriage 13, and the like are connected. The operation of each connected device is controlled by the CPU 32.

  Based on the print timing signal transferred from the CPU 32 and the image data stored in the image memory 37, the gate array 36 prints the image data on a recording medium and synchronizes with the print data. A transfer clock, a latch signal, a parameter signal for generating a basic print waveform signal, and an ejection timing signal output at a constant period are output, and these signals are transferred to the carriage substrate 17a. The carriage substrate 17a transmits each signal to the driver IC 17c through the flexible wiring substrate 17b, and the driver IC 17c drives the inkjet head 15 that ejects ink.

  The gate array 36 stores image data transferred from an external device such as a computer through the Centro interface 44 in the image memory 37 and receives Centro data based on the transferred Centro data. An interrupt signal is generated and the signal is transferred to the CPU 32.

  Each signal communicated between the gate array 36 and the carriage substrate 17a is transferred via a harness cable that connects the two. Further, the CPU 32, the ROM 33, the RAM 34, and the gate array 36 are connected through a bus line 45.

  Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications and changes can be easily made without departing from the gist of the present invention. Can be inferred.

  For example, in the above embodiment, the heat sink 22 and the heat sink 23 are configured to be screwed at one end, but may be joined by a method such as a heat conductive adhesive, soldering, or welding.

  Also, in the above embodiment, a square shape is formed by two substantially L-shaped heat sinks and heat is dissipated from the driver IC. However, one heat sink has a substantially I-shape and the other is a rectangular shape. The same effect can be obtained by using a letter shape.

  In the above embodiment, the two heat sinks are disposed so as to surround the ink tank, but it is not always necessary to surround the ink tank.

  Further, instead of the buffer tank of the embodiment, an ordinary replaceable ink tank (ink cartridge) may be detachably disposed.

1 is a plan view showing an internal configuration of an ink jet recording apparatus according to an embodiment of the present invention. 2 is a plan view showing an internal configuration of a recording head unit. FIG. It is sectional drawing in the III-III line of FIG. It is a figure which shows 2nd Example. It is a figure explaining the assembly process of two heads in 2nd Example. FIG. 10 is a perspective view and a cross-sectional view of a recording head unit according to a third embodiment. It is a figure which shows the modification of a junction part. It is a figure which shows the modification of the part which pinches | interposes driver IC. 1 is a block diagram illustrating an outline of an electrical configuration of an ink jet recording apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3a Carriage holder 3c-3f Ink tank (buffer tank)
13 Carriage 15 Inkjet head 17a Carriage substrate 17b Flexible wiring substrate 17c Driver IC (semiconductor integrated circuit)
22
First heat sink 23 Second heat sink 27 Thermally conductive rubber (elastic member)

Claims (6)

In an inkjet recording apparatus provided with a carriage equipped with an inkjet head that ejects ink onto a recording medium, and a drive circuit that applies a voltage to the inkjet head in order to cause the inkjet head to eject ink,
A first heat sink and a second heat sink that are mounted on the carriage and arranged in a substantially square shape having a space therein, and one end of the first heat sink and the second heat sink Are connected to each other, and the other ends sandwich the heat generating portion of the drive circuit. Wherein the carriage, the ink mounted Inkutan click supplying to said ink jet head, and said first heat sink and the second heat sink, characterized in that it is disposed so as to surround the periphery of the ink tank Item 2. An ink jet recording apparatus according to Item 1. An inkjet head for ejecting ink onto a recording medium, in order to eject ink to the ink jet head, a carriage for mounting a drive circuit for applying a voltage to the ink jet head and an ink tank for supplying ink to the ink jet head In an inkjet recording apparatus comprising:
The first heat sink and the second heat sink are mounted on the carriage and arranged to surround the ink tank, and one ends of the first heat sink and the second heat sink are connected to each other. The other end sandwiches the heat generating part of the drive circuit with each other. The space surrounded by the first heat sink and the second heat sink is a space where both ends are open, and the first heat sink and the second heat sink are open spaces where the both ends are open. 4. The ink jet recording apparatus according to claim 1, wherein the direction is substantially parallel to a moving direction of the carriage. 5.   5. The inkjet recording according to claim 1, wherein the other end of the first heat sink and the second heat sink sandwiches the heat generating portion via an elastic member having thermal conductivity. apparatus. 6. The ink jet recording apparatus according to claim 1, wherein the heat generating part is a semiconductor integrated circuit.

Images