JP2002103577A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder arranged to enhance heat dissipation effect of a head unit furthermore. SOLUTION: The ink jet recorder comprises a head unit 100 integrating a recording head 102 having a plurality of pressure generating elements for ejecting ink drops from nozzle openings by pressuring ink in the pressure generating chambers, a carriage 101 containing an ink cartridge 150 for supplying ink into the pressure generating chambers, a board 103 mounting a circuit for driving the pressure generating chambers, and a member 104 for dissipating heat generated from the circuit utilizing an air flow being generated in the moving direction at the time of movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet recording apparatus such as an ink-jet printer or an ink-jet plotter, and more particularly, to a structure of a head unit for ejecting ink droplets while moving to perform recording.

[0002]

2. Description of the Related Art FIG. 10 is a functional block diagram of an ink jet recording apparatus such as a conventional ink jet printer or ink jet plotter. As shown in FIG. 10, the ink jet recording apparatus includes an apparatus main body 1 and a head unit 2. On the device body 1 side, a waveform generation circuit 11 for generating a signal for driving the head unit 2 and the like are provided.

On the head unit 2 side, a recording head 3 having a plurality of pressure generating elements 31 and the like for discharging ink droplets from nozzle openings by pressurizing ink in a pressure generating chamber, and a push-pull connected transistor, for example, are provided. The substrate 4 on which the current amplification circuit 41 used and the head drive circuit 42 for selecting which of the plurality of pressure generating elements 31 to drive based on the recording data and the like are provided. The apparatus main body 1 and the head unit 2 are connected via a flexible wiring board 5 having a sufficient length for the carriage to move.

In such a configuration, the waveform generation circuit 1
The drive signal COM generated in 1 is amplified by the current amplifying circuit 41 and applied to the pressure generating element 31 selected by the head drive circuit 42. As a result, the selected pressure generating element 31 pressurizes the ink in the corresponding pressure generating chamber and discharges the ink from the nozzle opening as an ink droplet. Thus, the head unit 2 includes a plurality of pressure generating elements 31.
And a current amplifying circuit 41 and a head driving circuit 42, which generate heat mainly due to the transistors of the head driving circuit 42.
To take heat dissipation measures.

FIG. 11 is a sectional view showing a cooling mechanism of the head unit 2. As shown in FIG. 11, a head unit 2 includes a recording head 3 projecting downward from a bottom surface 61 of a carriage 6 and an ink supply unit in which a manifold for supplying ink from an ink cartridge 7 to the recording head 3 is formed. 8, and a substrate 4 on which a circuit pattern rising vertically from a side surface of the ink supply unit 8 is formed, and a radiator plate 9 is attached to the substrate 4.

A vertically extending rib or boss 63 is provided on the inner surface 62 of the carriage 6 facing the heat radiating plate 9.
Are formed at predetermined intervals. A cooling air passage 64 is formed between the rib 63 and the heat radiating plate 9. An opening 65 is formed in a portion of the bottom surface 61 of the carriage 6 located at the lower end of the cooling air passage 64. When the carriage 6 moves in the direction of the arrow A shown in the figure, the arrows B and C shown in the figures move through the cooling air passage 64 and the opening 65.
Air flows in the direction. As a result, heat can be radiated from the radiator plate 9 (see Japanese Patent Application Laid-Open No. 12-141819).

[0007]

With the recent improvement in image quality of printing accuracy, the number of nozzle openings in one nozzle row has increased from, for example, 32 to 64, and further increased to 128.
It is expected that the number of transistors integrated in the head drive circuit 42 will continue to increase because the number of transistors can be increased. For this reason, further measures for heat radiation in the head unit 2 are desired.

However, in the above-described conventional example, as shown in FIG. 11, heat is radiated from the heat radiating plate 9 by the air flow in the directions indicated by arrows B and C which are substantially perpendicular to the movement of the carriage 6 in the direction indicated by arrow A. I have. For this reason, the air flow must be bent at substantially a right angle and taken in, and the loss increases and the flow rate decreases. Further, the heat radiating plate 9 needs to be disposed between the substrate 4 and the inner surface 62 of the carriage. For this reason, the shape of the heat radiating plate 9 is limited, and the heat radiating plate 9 is reduced in size and heat capacity is reduced. Therefore, the cooling effect as expected cannot be obtained, and the temperature of the ink in the ink cartridge 7 in contact with the substrate 4, which has become high in temperature, may rise and deteriorate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording apparatus having a structure capable of further improving the heat radiation effect in a head unit.

[0010]

According to the present invention, there is provided a recording head having a plurality of pressure generating elements for discharging ink droplets from nozzle openings by pressurizing ink in a pressure generating chamber. A carriage that accommodates an ink cartridge that supplies the ink into the pressure generating chamber, a substrate on which a circuit that drives the pressure generating element is mounted, and an air flow that is generated in the moving direction during movement generates the circuit. A head unit in which a heat radiating member for radiating heat is integrated is provided.

Since an air flow parallel to the movement during the printing operation is forcibly generated around the heat radiating member, the flow rate can be increased, so that the cooling effect can be enhanced and the inside of the ink cartridge can be improved. In addition, it is possible to prevent the deterioration of the ink due to the rise in the temperature of the ink and the drying of the ink inside the recording head, and to suppress the thermal runaway of the electronic components mounted on the substrate.

[0012] Further, the substrate and the heat radiating member include:
It is characterized in that the carriage is integrated with a gap. This allows the generated heat to escape to the contacting radiator plate side and not to be transmitted to the vacant carriage side or recording head side, thereby suppressing a temperature rise in the ink cartridge and the recording head. it can.

Further, the heat radiating member is provided with a fin extending in a moving direction. Alternatively, the heat dissipating member is provided with fins extending in the moving direction and both ends extending obliquely upward. And
A plurality of the fins are arranged in parallel in a direction orthogonal to a moving direction. Accordingly, an air flow parallel to the movement during the printing operation is forcibly generated around the plurality of rows of the radiating fins, so that the flow rate can be increased and the heat radiation effect can be enhanced.

According to another aspect of the present invention, there is provided a recording head having a plurality of pressure generating elements for discharging ink droplets from nozzle openings by pressurizing ink in a pressure generating chamber. A carriage accommodating an ink cartridge for supplying the ink, a substrate on which a circuit for driving the pressure generating element is mounted, and a forced airflow generated in the moving direction at the time of movement and a direction perpendicular to the moving direction at the time of stop A head unit in which a heat radiating member for radiating heat generated in the circuit by utilizing a natural air flow generated in the head unit is provided.

An air flow parallel to the movement during the printing operation is forcibly generated around the heat radiating member, and an air flow orthogonal to the movement, ie, an upflow, is generated while the printing operation is stopped. Since it is generated naturally by the chimney effect around the heat radiating member, the flow rate can be further increased. As a result, the cooling effect can be further enhanced, the deterioration of the ink in the ink cartridge due to the temperature rise and the drying of the ink inside the print head can be prevented, and the thermal runaway of the electronic components mounted on the substrate can be prevented. Can be suppressed.

Further, the substrate and the heat radiating member may include:
It is characterized in that the carriage is integrated with a gap. This allows the generated heat to escape to the contacting radiator plate side and not to be transmitted to the vacant carriage side or recording head side, thereby suppressing a temperature rise in the ink cartridge and the recording head. it can.

Further, the heat radiating member is provided with fins extending intermittently in the moving direction. Alternatively, the heat radiating member is provided with fins extending intermittently in the moving direction and having both ends extending obliquely upward. The plurality of fins are arranged in parallel in a direction orthogonal to the moving direction. Thereby, an air flow parallel to the movement during the printing operation and an air flow orthogonal to the movement during the printing operation stop are forcibly generated around the plurality of rows of the radiation fins. Can be increased, and the heat radiation effect can be dramatically increased.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording apparatus to which the present invention is applied will be described with reference to the drawings.

(Overall Configuration of Inkjet Recording Apparatus) FIG. 1 is a perspective view showing a main part of an inkjet recording apparatus according to an embodiment of the present invention. As shown in FIG. 1, the inkjet recording apparatus includes a head unit 100, a carriage mechanism 110, a paper feed mechanism 120, a capping device 130, a wiping device 140, and the like.

The head unit 100 includes a carriage 10
1 is connected to a carriage motor 112 via a timing belt 111 of a carriage mechanism 110, and is configured to reciprocate in the sheet width direction of the recording sheet P while being guided by a guide member 113. Then, the head unit 100
An ink jet recording head 102 is attached to a surface facing the recording paper P, in the example shown in FIG.

The recording head 102 is supplied with ink from an ink cartridge 150 housed inside the carriage 101, and is adapted to the movement of the head unit 100 and the movement of the recording paper P by the paper feed roller 121 of the paper feed mechanism 120. In this way, ink droplets are ejected onto the recording paper P to form dots and print images and characters.

The capping device 130 is disposed in a non-printing area (non-printing area), seals a nozzle opening of the recording head 102 during printing pause, and performs flushing performed during printing operation. Recording head 10 by operation
2 is configured to receive the ink droplets. Therefore, it is possible to suppress the ink from thickening or forming an ink film due to the solvent being scattered from the ink during the printing pause, and to prevent clogging of the nozzles during the printing pause. . The wiping device 140 is
By wiping the surface of the recording head 102 with a blade or the like, the ink droplets and paper powder attached thereto are wiped off.

(Structure of Head Unit) FIG.
(B) is a front view and a sectional view showing an example of the head unit 100 of FIG. 1. As shown in FIGS. 2A and 2B, the head unit 100 includes a carriage 101, a recording head 102, a substrate 103, and a heat radiating plate 104. The carriage 101 has a rectangular parallelepiped plastic case shape with an open upper surface, and an ink cartridge 150 is housed inside. Recording head 102
Is attached to the bottom of the carriage 101,
Details will be described later.

The substrate 103 has mounted thereon a semiconductor IC 103a including a current amplifier circuit and a head drive circuit and other electronic components 103b, and is fixed at a predetermined distance from the bottom surface of the carriage 101. The end of the flexible wiring board is connected to the semiconductor IC 103a. The heat radiating plate 104 has a plurality of heat radiating fins 104a extending in the horizontal direction, that is, the moving direction of the head unit 100 (the direction of arrow A in the drawing) on the outer surface, and is formed in parallel with the semiconductor IC 103.
a and is fixed by screws at a predetermined interval from the side surface of the carriage 101.

The head unit 100 thus configured
In this case, the heat generated in the semiconductor IC 103a escapes to the contacting heat radiation plate 104 side, there is a gap, and it is difficult to transfer to the plastic carriage 101 side and the recording head 102 side. The temperature rise at 102 can be suppressed.
Further, the airflow in the direction indicated by arrow B parallel to the movement in the direction indicated by arrow A during the printing operation causes a plurality of rows of radiation fins 1.
Forcibly generated around the area 04a, the flow rate can be increased.

Further, since the heat radiating plate 104 can be arranged on the outermost shell, the shape of the heat radiating plate 104 can be increased in size and the heat capacity can be increased. Therefore, the cooling effect can be enhanced, and the deterioration of the ink inside the ink cartridge 150 due to a rise in the temperature and the drying of the ink inside the recording head 102 can be prevented. Further, the substrate 1
03 mounted on the electronic component, especially the semiconductor IC 103
The thermal runaway of a can be suppressed. In addition, since a conventional cooling fan is not required, the cost can be reduced and the size can be reduced.

FIG. 3 is a front view showing another example of the head unit 100 of FIG. As shown in FIG. 3, the heat radiating plate 1041 of the head unit 100 has a plurality of rows of heat radiating fins 10 extending horizontally on the outer surface, that is, intermittently in the moving direction of the head unit 100 (the direction of arrow A in the drawing).
41a are formed in parallel, are in close contact with the semiconductor IC 103a as described with reference to FIG.
1 and is fixed with screws at a predetermined interval from the side surface.

The head unit 100 thus configured
In the same manner as described with reference to FIG. 2, the heat generated in the semiconductor IC 103a escapes to the heat dissipating plate 1041 which is in contact therewith, has a gap, and is made of a plastic carriage 1.
Since it is difficult to transmit to the 01 side and the recording head 102 side, the temperature rise in the ink cartridge 150 and the recording head 102 can be suppressed.

Furthermore, since a plurality of radiating fins 1041a in the shape of a rectangular parallelepiped are arranged in a lattice on the radiating plate 1041, air in the direction of the arrow B shown in FIG. The flow is a plurality of rows of radiation fins 1
04a, the air flow in the direction indicated by arrow C perpendicular to the movement in the direction indicated by arrow A, ie, the rising flow, is generated around the plurality of rows of the radiation fins 104a while the printing operation is stopped. 2, the flow rate can be further increased as compared with the case of FIG.

Also, as described with reference to FIG.
041 can be arranged in the outermost shell,
The heat capacity can be increased by enlarging the shape of 041. Therefore, it is possible to further enhance the cooling effect as compared with the case of FIG. 2, and it is possible to more completely prevent the deterioration of the ink inside the ink cartridge 150 due to the temperature rise and the drying of the ink inside the recording head 102. Further, thermal runaway of electronic components mounted on the substrate 103, particularly the semiconductor IC 103a, can be suppressed. Also,
Since the conventional cooling fan is not required, the cost can be reduced and the size can be reduced.

FIG. 4 is a front view showing still another example of the head unit 100 of FIG. As shown in FIG. 4, the heat radiating plate 1042 of the head unit 100 includes two rectifying plates 1 made of plastic on both sides of the heat radiating plate 104 of FIG.
042A are respectively mounted. This current plate 104
2A is formed with a rectifying fin 1042a having a shape in which both ends of the radiating fin 104a of the radiating plate 104 of FIG. 2 extend obliquely upward toward the outside.

The head unit 100 thus configured
In the same manner as described with reference to FIG. 2, the heat generated in the semiconductor IC 103a escapes to the heat dissipating plate 1042 in contact therewith, has a gap, and is made of a plastic carriage 1.
Since it is difficult to transmit to the 01 side and the recording head 102 side, the temperature rise in the ink cartridge 150 and the recording head 102 can be suppressed.

Further, since the heat radiating plate 1042 is formed with a rectifying fin 1042a having a shape in which both ends of the heat radiating fin 104a extend obliquely upward toward the outside, the heat radiating fin 104a can be moved in the direction of the arrow A during the printing operation. A plurality of rows of radiation fins 104
a, and the airflow in the direction of the arrow D shown in the figure having an elevation angle with respect to the movement in the direction of the arrow A during the printing operation is forcibly generated around the rectification fins 1042a in a plurality of rows. Since the air is generated, the air from which the heat has been taken can be discharged upward, and the influence of the heat can be further reduced.

Further, since the current plate 1042A is formed of plastic and is mounted so as to cover both sides of the heat radiating plate 104, it is possible to prevent an accident such as accidentally touching the heated heat radiating plate 104 and causing a burn. can do.

Also, as described with reference to FIG.
042 can be arranged in the outermost shell,
The heat capacity can be increased by enlarging the shape of 042. Therefore, the cooling effect can be enhanced, and the deterioration of the ink inside the ink cartridge 150 due to the temperature rise and the drying of the ink inside the recording head 102 can be more completely prevented. Further, thermal runaway of electronic components mounted on the substrate 103, particularly the semiconductor IC 103a, can be suppressed. In addition, since a conventional cooling fan is not required, the cost can be reduced and the size can be reduced.

The above-described heat radiating plate 1042 in FIG.
Although the case where the rectifying plate 1042A is attached to the radiating plate 104 of FIG. 2 has been described, the rectifying plate 1042 is attached to the radiating plate 1041 of FIG.
A similar effect can be obtained even if A is attached. Also,
The shape and arrangement of the radiating fins and the rectifying fins are not limited to those in the above embodiments. If the radiating fins are used, an air flow is formed in the moving direction (horizontal direction) of the head unit or in a direction perpendicular to the moving direction (ascending direction). Any rectifying fins may be used as long as airflow can be formed obliquely upward from both sides of the heat radiation fins.

FIGS. 5A and 5B are cross-sectional views showing the recording head 102 shown in FIGS. FIG. 5 (A),
As shown in (B), the recording head 102 has a channel unit 230 and a piezoelectric vibration unit 238. In the flow path unit 230, the nozzle opening 231 is
A plurality of nozzle plates 233, a pressure generating chamber 234 communicating with the nozzle opening 231, and a flow path forming substrate 237 having a reservoir 236 for supplying ink to the pressure generating chamber 234 via an ink supply port 235, and a piezoelectric vibration unit An elastic plate 240 that abuts on the tip of each piezoelectric vibrator 239 in the longitudinal vibration mode 238 to expand and reduce the volume of the pressure generating chamber 234 is integrally laminated.

The piezoelectric vibration unit 238 is connected to a flexible cable 242 for transmitting a driving signal from the outside, and is then housed in a housing chamber 243 of a holder 241 formed by injection molding of a polymer material and bonded. And the holder 241 and the flow path unit 2
30 are fixed by an adhesive. Holder 241
Is formed with an ink guide path 245 communicating with an external ink tank (not shown). The tip of the ink guide path 245 is connected to the ink introduction port 246 of the flow path unit 230, and the ink from the ink tank is supplied to the flow path unit 230. Is done. Then, the integrated holder 241 and the flow path unit 23
On the side of the nozzle plate 233 of No. 0, a frame (frame) 244 also serving as a shield material is inserted.
Is configured as

Each of the piezoelectric vibrators 239 in the longitudinal vibration mode constituting the piezoelectric vibration unit 238 is, for example, not shown, but is formed by sandwiching an electrode serving as one pole and an electrode serving as the other pole via a piezoelectric material. A pressure generating chamber 234 is formed by exposing one electrode to the front end side and exposing the other electrode to the rear end side, and having a piezoelectric constant d31 connected to the segment electrode and the common electrode at each end surface. Are fixed to the fixed substrate 247 in accordance with the arrangement pitch of the piezoelectric vibrating unit 238. The unillustrated segment electrodes and common electrodes of each piezoelectric vibrator 239 of the piezoelectric vibration unit 238 are connected to a conductive pattern for transmitting a drive signal of the flexible cable 242 via a solder layer.

FIG. 6 is a functional block diagram of the ink jet recording apparatus of FIG. As shown in FIG. 6, the inkjet recording apparatus includes a carriage mechanism 110, a paper feed mechanism 1
20, the apparatus main body 200, and the head unit 100. The apparatus main body 200 includes an interface 203 for receiving print data including multi-level hierarchical information from a host computer (not shown) and a RAM 2 for storing various data such as print data including multi-level hierarchical information.
04, a ROM 205 storing routines for performing various data processing, and a control unit 20 including a CPU and the like.
6, an oscillation circuit 207, and an interface 2 having a function of transmitting print data SI (recording data) developed into dot pattern data to the head unit 100.
09.

In such a configuration, print data including multilevel hierarchical information sent from a host computer or the like is held in a reception buffer 204A inside the printing apparatus via the interface 203. Receive buffer 204
The print data held in A is sent to the intermediate buffer 204B after command analysis. Intermediate buffer 2
In 04B, the recording data in the intermediate format converted into the intermediate code by the control unit 206 is held, and the process of adding the print position, the type of modification, the size, the font address, etc. of each character is performed by the control unit 206. Performed by

Next, the control unit 206
The print data in 4B is analyzed, and the binarized dot pattern data obtained by decoding the hierarchical data as described later is developed and stored in the output buffer 204C. When dot pattern data corresponding to one scan of the head unit 100 is obtained, the dot pattern data is transferred to the head unit 1 via the interface 209.
00 is serially transferred.

When dot pattern data corresponding to one scan is output from the output buffer 204C, the contents of the intermediate buffer 204B are erased and the next intermediate code conversion is performed. Here, the print data developed into the dot pattern data is composed of, for example, 2 bits as gradation data for each nozzle as described later.

The head unit 100 includes a head drive circuit 215 including a shift register 211, a latch circuit 212, a level shifter 213, and a switch circuit 214. The print data developed into the dot pattern data on the device main body 200 side is serially transferred from the interface 209 to the shift register 211 in synchronization with the clock signal (CLK) from the oscillation circuit 207.

The print data (SI
/ Recorded data) is temporarily latched by the latch circuit 212. The latched print data SI is transmitted to the switch circuit 2 by the level shifter 213 which is a voltage amplifier.
The voltage is boosted to a voltage that can drive the, for example, a predetermined voltage of about several tens of volts. The print data SI boosted to a predetermined voltage is provided to the switch circuit 214.

A drive signal (COM) from a drive signal generation circuit 210 composed of a waveform shaping circuit 208 and a current amplification circuit 216 is applied to the input side of the switch circuit 214. Piezoelectric vibrator 23
9 is connected.

The print data SI controls the operation of the switch circuit 214. For example, while the print data applied to the switch circuit 214 is “1”, the drive signal COM is applied to the piezoelectric vibrator 239, and the piezoelectric vibrator 239 expands and contracts in accordance with this signal. As a result, the ink in the pressure generating chamber is pressurized and discharged from the nozzle opening. On the other hand, during a period in which the print data applied to the switch circuit 214 is “0”, the supply of the drive signal COM to the piezoelectric vibrator 239 is interrupted, so that no ink droplet is ejected.

(Configuration of Drive Signal Generation Circuit) FIG.
3 is a block diagram illustrating a configuration of a drive signal generation circuit 210 of FIG. FIG. 8 is an explanatory diagram showing a process in which the drive signal generation circuit 210 generates each pulse included in the drive signal. FIG. 9 is a timing chart showing the timing of each signal when the drive signal generation circuit 210 sets the amount of voltage change in the memory using the data signal.

Referring to FIG. 7, drive signal generation circuit 210
Is a waveform generation circuit 20 for generating a waveform of the drive signal COM.
8 and a current amplifying circuit 216 that amplifies the current of the signal output from the waveform generating circuit 208 and outputs the amplified signal as a drive signal COM.

The waveform generating circuit 208 includes a memory 81 for receiving and recording a signal from the control unit 206, a first latch 82 for reading and temporarily storing the contents of the memory 81, and a first latch 82 An adder 83 that adds the output of the second latch 84 and an output of another second latch 84 described later.
A D converter 86, a voltage amplifying circuit 88 for amplifying the converted analog signal up to the voltage of the drive signal, and a current amplifying circuit for performing current amplification on the drive signal output from the voltage amplify circuit 88 and outputting it as a drive signal COM 89.

Here, the memory 81 stores predetermined parameters for determining the waveform of the drive signal. As described later, the waveform of the drive signal COM is controlled in advance by the control unit 2.
It is determined by the predetermined parameters received from 06. That is, the waveform generation circuit 208 outputs the clock signal 8
01, 802, 803, the data signal 830, the address signals 810, 811, 812, 813, and the reset signal 820.

The drive signal generation circuit 21 thus configured
At 0, as shown in FIG. 8, prior to generation of the drive signal COM, some data signals indicating the amount of voltage change of the control unit 206 and the addresses of the data signals are synchronized with the clock signal 801. Are output to the memory 81 of the drive signal generation circuit 8. As shown in FIG. 9, the data signal 830 exchanges data by serial transfer using the clock signal 801 as a synchronization signal.

That is, when transferring a predetermined amount of voltage change from the control unit 206, first, a data signal of a plurality of bits is output in synchronization with the clock signal 801, and then an address for storing this data is set to an enable signal. Output as address signals 810 to 813 in synchronization with 840.

The memory 81 stores the enable signal 840
The address signal is read at the timing when is output, and the received data is written to the address. Since the address signals 810 to 813 are 4-bit signals, up to 16 types of voltage change amounts can be stored in the memory 81.
Note that the most significant bit of the data is used as a code.

After the setting of the amount of voltage change for each address A, B,... Is completed, the address B becomes the address signal 810.
813, the voltage change amount corresponding to the address B is held by the first latch 82 by the first clock signal 802. In this state, when the clock signal 803 is output next, the value obtained by adding the output of the first latch 82 to the output of the second latch 84 is held in the second latch 84.

That is, as shown in FIG. 8, once the voltage change amount corresponding to the address signal is selected, every time the clock signal 803 is received thereafter, the output of the second latch 84 changes the voltage change amount. Increase or decrease according to quantity. The voltage change amount of the drive waveform is determined by the voltage change amount ΔV1 stored in the address B of the memory 81 and the unit time ΔT of the clock signal 803. The increase or decrease is determined by the sign of the data stored at each address.

In the example shown in FIG. 8, the address A stores a value 0 as a voltage change amount, that is, a value for maintaining a voltage. Therefore, when the address A becomes valid by the clock signal 802, the waveform of the drive signal is maintained in a flat state with no increase or decrease. Further, the address C stores a voltage change amount ΔV2 per unit time ΔT in order to determine a voltage change amount of the drive waveform. Therefore, after the address C becomes valid by the clock signal 802, the voltage decreases by this voltage ΔV2. Thus, the waveform of the drive signal COM can be freely controlled only by outputting the address signal and the clock signal from the control unit 206.

As described above, the present invention has been described with respect to the specific embodiments. However, the present invention is not limited to these embodiments, and may be applied to other embodiments within the scope of the claims. For example, in the above embodiment, the piezoelectric vibrator 239 is used as the pressure generating element. However, the pressure generating element may be applied to an ink jet recording apparatus using a magnetostrictive element or the like, or a so-called bubble jet (registered trademark) type ink jet recording apparatus using a heating element. Can also be applied.

[0059]

As described above, in the ink jet recording apparatus according to the present invention, the generated heat escapes to the contacting radiator plate side, has a gap, and has a plastic side of the carriage or the recording head. It is hard to reach,
The temperature rise in the ink cartridge and the recording head can be suppressed. Further, an air flow parallel to the movement during the printing operation is forcibly generated around the plurality of rows of the radiation fins, so that the flow rate can be increased. Further, since the heat radiating plate can be arranged on the outermost shell, the shape of the heat radiating plate can be increased in size and the heat capacity can be increased. Therefore, it is possible to enhance the cooling effect, and it is possible to prevent the deterioration of the ink in the ink cartridge due to the temperature rise and the drying of the ink inside the recording head.
Further, thermal runaway of the electronic component mounted on the substrate can be suppressed. In addition, since a conventional cooling fan is not required, the cost can be reduced and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a front view and a cross-sectional view illustrating an example of the head unit shown in FIG.

FIG. 3 is a front view showing another example of the head unit shown in FIG. 1;

FIG. 4 is a front view showing still another example of the head unit shown in FIG. 1;

FIG. 5 is a sectional view showing the recording head of FIGS. 1 and 2;

FIG. 6 is a functional block diagram of the ink jet recording apparatus of FIG.

FIG. 7 is a block diagram illustrating a configuration of a drive signal generation circuit of FIG. 6;

FIG. 8 is an explanatory diagram showing a process of generating each pulse included in a drive signal in the drive signal generation circuit of FIG. 6;

9 is a timing chart showing the timing of each signal when a voltage change amount is set in a memory using a data signal in the drive signal generation circuit of FIG. 6;

FIG. 10 is a functional block diagram of an ink jet recording apparatus such as a conventional ink jet printer or ink jet plotter.

11 is a cross-sectional view illustrating a cooling mechanism of a head unit of the ink jet recording apparatus of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Head unit 101 Carriage 102 Recording head 103 Substrate 103a Semiconductor ICs 104, 1041, 1042 Heat sink 104a, 1041a Heat sink fin 1042A Rectifier 1042a Rectifier fin 110 Carriage mechanism 111 Timing belt 112 Carriage motor 113 Guide member 120 Paper feed mechanism 121 Paper feed Roller 130 Capping device 140 Wiping device 150 Ink cartridge

Claims (10)

[Claims] A recording head having a plurality of pressure generating elements for discharging ink droplets from nozzle openings by pressurizing ink in the pressure generating chamber; and a carriage accommodating an ink cartridge for supplying the ink to the pressure generating chamber. A head unit in which a substrate on which a circuit for driving the pressure generating element is mounted, and a heat radiating member that dissipates heat generated in the circuit by using an air flow generated in a moving direction during movement are integrated. An ink jet recording apparatus comprising: 2. The ink jet recording apparatus according to claim 1, wherein the substrate and the heat radiating member are integrated with the carriage with a gap therebetween. 3. The ink jet recording apparatus according to claim 1, wherein the heat radiating member includes a fin extending in a moving direction. 4. The ink jet recording apparatus according to claim 1, wherein the heat radiating member includes fins extending in a moving direction and both ends extending obliquely upward. 5. The ink jet recording apparatus according to claim 3, wherein the plurality of fins are arranged in parallel in a direction orthogonal to a moving direction. 6. A recording head having a plurality of pressure generating elements for discharging ink droplets from nozzle openings by pressurizing ink in a pressure generating chamber, and a carriage containing an ink cartridge for supplying the ink to the pressure generating chamber. And a substrate on which a circuit for driving the pressure generating element is mounted, and using a forced airflow generated in a moving direction when moving and a natural airflow generated in a direction orthogonal to the moving direction when stopped. An ink jet recording apparatus comprising a head unit integrated with a heat radiating member for radiating heat generated in the circuit. 7. The ink jet recording apparatus according to claim 6, wherein the substrate and the heat radiating member are integrated with the carriage with a gap. 8. The ink jet recording apparatus according to claim 6, wherein the heat radiating member includes fins extending intermittently in a moving direction. 9. The ink jet recording apparatus according to claim 6, wherein the heat radiating member includes fins extending intermittently in a movement direction and both ends extending obliquely upward. . 10. The ink jet recording apparatus according to claim 8, wherein the plurality of fins are arranged in parallel in a direction orthogonal to a moving direction.