This application is based on and claims priority under 35 U.S.C. §119 from Japanese Patent Application No. 2006-355490 filed on Dec. 28, 2006.
1. Technical Field
The invention relates to an ejection element driving device, an election element driving method, a computer readable medium that stores an ejection element driving program, and a liquid droplet ejecting apparatus.
2. Related Art
A piezoelectric element is used as an ejection element for ejecting ink droplets from an inkjet printer. When such an ejection element is continuously left in a non-ejecting state, an increase in the viscosity of ink would occur, which may result in an ejection failures or clogging.
According to an aspect of the invention, an ejection element driving device includes a signal selection section and a signal selection control section. The signal selection section selects a drive signal to be applied to each ejection element from among drive signals including a liquid droplet ejection signal for ejecting a liquid droplet from the ejection element and a viscosity increase suppression signal for suppressing increase in a viscosity of liquid to be ejected by each ejection element. The signal selection control section refers to a predetermined parameter for any of the ejection elements for which the liquid droplet ejection signal is not selected. The signal selection control section exercises control over whether or not the signal selection section selects the viscosity increase suppression signal for the ejection elements for which the liquid droplet ejection signal is not selected, at each ejection cycle.
Exemplary embodiments of the invention will be described in detailed below with reference to the accompanying drawings, wherein:
Exemplary embodiments of the invention will be described with reference to the accompanying drawings.
In this exemplary embodiment, an inkjet recording apparatus for recording an image on a recording medium by ejecting ink droplets will be described as an example of a droplet ejecting apparatus that ejects liquid droplets.
The term “liquid droplet ejecting apparatus” is not limited to an apparatus that ejects ink. This term covers any apparatus that ejects droplets of a liquid, e.g., an apparatus that ejects liquid for improving image quality by controlling the penetration of ink into a recording medium after the ink landing in the recording medium or liquid for absorbing infrared wavelengths but not absorbing visible light; a color filter manufacturing apparatus for manufacturing a color filter by ejecting ink on a film or glass; an apparatus for forming bumps for mounting components by ejecting molten solder onto a substrate; an apparatus for forming a wiring pattern by ejecting a liquid metal; and various film forming apparatus for forming a film by ejecting droplets of liquid.
First, the general configuration of an inkjet recording apparatus 100 of this exemplary embodiment will be described.
As shown in
The image recording section 114 includes inkjet recording heads 120Y, 120M, 120C, and 120K (the reference numerals will be hereinafter denoted as “120Y to 120K”) that record images on the recording media P by ejecting droplets of ink, which are shown as examples of liquid droplet ejecting heads for ejecting liquid droplets through nozzles.
The inkjet recording heads 120Y to 120K are disposed in an order of the ink colors, i.e., yellow (Y), magenta (M), cyan (C), and black (K), the yellow head being located at the most upstream end when viewed in the direction in which the recording media P are conveyed. Each of the inkjet recording heads 120Y to 120K is equipped with a pressure chamber filled with ink having a corresponding color, a piezoelectric element that changes the volume of the pressure chamber according to a drive signal input from outside, and plural ejection elements which are in communication with the pressure chamber and which have nozzles for ejecting droplets of the ink. The heads are configured to record an image by ejecting the ink droplets having the respective colors from nozzle surfaces 120A on which the plural nozzles are formed.
Each of the inkjet recording heads 120Y to 120K is capable of recording an image over a width that is equal to or greater than the width of an image recording region of the recording media P. The term “width” used here means a length in an intersection direction that intersects the conveying direction of the recording media P. Further, the inkjet recording heads 120Y to 120K are formed by connecting plural units having ink droplet ejecting nozzles provided thereon in the intersection direction, and the heads are therefore long in the intersection direction.
The inkjet recording apparatus 100 is provided with ink tanks 121Y, 121M, 121C, and 121K for storing the ink. The ink is supplied from the ink tanks 121Y, 121M, 121C, and 121K to the inkjet recording heads 120Y to 120K, respectively. Referring to the ink supplied to the inkjet recording heads 120Y to 120K, various types of ink may be used including water based inks, oil based inks, and solvent type inks.
The inkjet recording apparatus 100 further includes maintenance units 122Y, 122M, 122C, and 122K (the reference numerals will be hereinafter denoted as “122Y to 122K”) provided for the maintenance operation of the inkjet recording heads 120Y to 120K. The maintenance units 122Y to 120K are configured so as to be movable between (i) opposite positions (see
Each of the maintenance units 122Y to 120K includes a capping device that covers the nozzle surface 120A of the corresponding one of the inkjet recording heads 120Y to 120K, a receiving member that receives liquid droplets ejected for an auxiliary purpose (idle ejection) and a cleaning member that cleans the nozzle surface 120A of the corresponding one of inkjet recording heads 120Y to 120K. When the maintenance operation of the inkjet recording heads 120Y to 120K is carried out, the inkjet recording heads 120Y to 120K are lifted to a predetermined height, and then the maintenance units 122Y to 120K are moved to the opposite positions to perform various maintenance operations.
The conveying device 116 includes a feed roll 124 for feeding out a recording medium P contained in the recording medium containing section 112, conveying roll pairs 125 for sandwiching and conveying the recording medium P fed out by the feed roller 124, and an endless conveyor belt 130 for causing a recording surface of the recording medium P conveyed by the conveying roll pair 125 to face the inkjet recording heads 120Y to 120K.
The conveyor belt 130 is wound around a driving roll 126 disposed on the downstream, in the conveying direction, of the recording medium P and a driven roll 128 disposed on the upstream, in the conveying direction, of the recording medium P. The belt 130 is configured to circulate in a predetermined direction (direction A in
A press roll 132 for pressing the recording medium P against the conveyor belt 130 is provided above the driven roll 128. The press roll 132 moves pursuant to the conveyor belt 130 and also serves as a charging roll. The conveyor belt 130 is charged by the press roll 132, and the recording medium P is electrostatically absorbed by the conveyor belt 130 while being conveyed by the conveyor belt 130.
Conveying of the recording medium P by the conveyor belt 130 as thus described causes a relative movement between the inkjet recording heads 120Y to 120K and the recording medium P, and droplets of ink are ejected onto the recording medium P, which is relatively moving, to form an image on the recording medium P.
Alternatively, a configuration in which the inkjet recording heads 120Y to 120K are moved with the recording medium kept stationary may be employed. Any configuration may be employed as long as there is a relative movement between the recording medium P and the inkjet recording heads 120Y to 120K.
The conveyor belt 130 is not limited to the configuration for holding the recording medium P through electrostatic absorption. Alternatively, such a configuration may be employed, that the recording medium P is held using friction between the belt and the recording medium P or using non-electrostatic means such as absorption or adhesion.
A separating nail for separating the recording medium P from the conveyor belt 130 is disposed on the downstream of the conveyor belt 130 so that the separating nail can move toward and away from the belt 130. After the image is recorded by the inkjet recording heads 120Y to 120K, the recording medium P is separated from the conveyor belt 130 due to the curvature of the conveyor belt 130 and the action of the separating nail. In
Plural conveyor roll pairs 138 are provided on the downstream of the separating nail. The rolls of the roll pairs 138 on the recording surface side of the recording medium P are star wheels. The conveyor roll pairs 138 convey the recording medium P having the image recorded by the image recording section 114 to the recording medium discharge section 118.
An inverting section 136 that inverts the recording medium P is provided below the conveyor belt 130. After the recording medium P is once conveyed downstream by the conveyor roll pairs 138, the conveyor roll pairs 138 reversely rotate to convey the recording medium P to the inverting section 136.
Plural conveyor roll pairs 139 are provided in the inverting section 136. The rolls of the roll pairs 139 on the recording surface side of the recording medium P are star wheels. The recording medium P conveyed into the inverting section 136 is conveyed to the conveyor belt 130 again.
The inkjet recording apparatus 100 includes an ejection control device 141 that controls operations of the inkjet recording heads 120Y to 120K and a system control device, which is not shown, that controls operations of the inkjet recording apparatus 100 as a whole.
The ejection control device 141 is connected to the inkjet recording heads 120Y to 120K. The ejection control device 141 determines timings when ink droplets are ejected according to image data input from outside, determines which ejection elements of the inkjet recording heads 120Y to 120K are used, and applies a drive signal to the ejection elements. The ejection control device 141 also determines ejection elements to which a viscosity increase suppression signal is to be applied as described later from among ejection elements that eject no ink droplet, and applies the viscosity increase suppression signal to such ejection elements.
An image recording operation of the inkjet recording apparatus 100 will now be described.
First, the recording medium P is fed from the recording medium containing section 112 by the feed roll 124 and conveyed to the conveyor belt 130 by the conveyor roll pairs 125 located on the upstream of the conveyor belt 130.
The recording medium P conveyed to the conveyor belt 130 is absorbed and held on the conveyance surface of the conveyor belt 130 and conveyed to a recording position of the inkjet recording heads 120Y to 120K, and an image is recorded on the recording surface of the recording medium P. After the image recording is completed, the recording medium P is separated from the conveyor belt 130 by the separating nail.
When an image is to be recorded only on one side of the recording medium P, the medium is discharged to the recording media discharge section 118 by the conveyor roll pairs 138 located on the downstream of the conveyor belt 130.
When an image is to be recorded on both sides of the recording medium P, after an image is recorded on one side, the recording medium P is inverted by the inverting section 136 and conveyed to the conveyor belt 130 again. An image is then similarly recorded on the other side of the recording medium P, and the recording medium P having images thus recorded on the both sides thereof is discharged to the recording media discharge section 118.
The recording control section 10 includes a central processing unit (CPU) and a program for controlling process operations of the central processing unit, and outputs a clock signal, a selection signal for selecting a signal generated by the signal generation section 12, and a latch signal for controlling the operation of a latch 18. The selection signal is generated based on image data to be recorded. The recording control section 10 also includes a signal selection control section 11 for exercising control over whether or not the signal selection section 24 constituting the drive control section 14 selects a viscosity increase suppression signal at each ejection cycle which will be described later. The viscosity increase suppression signal is selected when none of a large droplet signal, a medium droplet signal, and a small droplet signal, which will be described later, is selected. Further, the recording control section 10 outputs, to the signal generation section 12, waveform data which is digital data for generating the drive signals (the large droplet signal, medium droplet signal, small droplet signal, and viscosity increase suppression signal).
The signal generation section 12 includes digital/analog (D/A) conversion sections 12a-1 to 12a-4 and amplifiers 12b-1 to 12b-4. The D/A conversion sections 12a-1 to 12a-4 convert the waveform data received from the recording control section 10 into analog voltage signals to generate drive signals for ejection elements 30-1 to 30-n. The drive signals include the large droplet signal, medium droplet signal, and small droplet signal for determining sizes (e.g., large, medium, and small) of droplets ejected from the ejection elements 30-1 to 30-n and the viscosity increase suppression signal for suppressing increase in the viscosity of ink. Of those drive signals, the large droplet signal, medium droplet signal, and small droplet signals are liquid droplet ejection signals for ejecting liquid droplets from the ejection elements 30-1 to 30-n, and the viscosity increase suppression signal is a signal for agitating ink in the ejection elements without ejecting liquid droplets. The drive signals are amplified by the amplifiers 12b-1 to 12-4 associated with the respective D/A conversion sections 12a-1 to 12a-4 which have generated the signals, and the signals are then output to the signal selection section 24.
The drive control section 14 includes a shift register 16, the latch 18, a decoder 20, a level shifter 22, the signal selection section 24, a latch counter 26, and a head information storage section 28.
The shift register 16 accepts the selection signals as described above in synchronism with the clock signal, performs parallel conversion of the signals, and outputs the resultant signals to the latch 18. When the number of the ejection elements 30-1 to 30-n in total is 256 (n=256), the selection signals represent 512 bits, that is, 2 bits per each of the ejection elements 30-1 to 30-n. The shift register 16 accepts the selection signal when a latch signal is “H”, and the latch 18 accepts the parallel-converted selection signal from the shift register 16 when the latch signal is “L.”
The latch 18 outputs the selection signals each having 2 bits (256×2 bits) thus acquired to the decoder 20, and the decoder 20 decodes the signals to obtain selection instruction signals for selecting any of the four types of drive signals (the large droplet signal, medium droplet signal, small droplet signal, and viscosity increase suppression signal). The level shifter 22 converts the voltage of the selection instruction signals output from the decoder 20 into a voltage level at which the signal selection section 24 constituted by a switch element and the like can be driven. The decoder 20 generates, according to the 2-bit selection signal received from the latch 18, the selection instruction signal for selecting, for example, the viscosity increase suppression signal when the 2-bit selection signal represents “00;” the small droplet signal when the 2-bit selection signal represents “01;” the medium droplet signal when the 2-bit selection signal represents “10;” and the large droplet signal when the 2-bit selection signal represents “11.”
Based on the selection instruction signal, the signal selection section 24 selects one of the four types of the drive signals input from the signal generation section 12 for each of the ejection elements 30-1 to 30-n, and outputs the resultant signal to each of the ejection elements 30-1 to 30-n. Each of the ejection elements 30-1 to 30-n performs a piezoelectric operation according to the input drive signal to eject an ink droplet or suppress increase in the viscosity of ink.
The latch counter 26 counts cycles of ejection from the election elements 30-1 to 30-n from the period of the H and L levels of the latch signal. Ejection cycles will be described later.
The head information storage section 28 is a device in which information can be recorded appropriately, such as electrical or magnetic storage section. The head information storage section 28 stores information on the liquid droplet ejecting heads 120Y to 120K. In the exemplary embodiment 1, information on the type of the ink used is stored as the information on the liquid droplet ejection heads.
Referring to
In this exemplary embodiment, the signal selection control section 11 exercises control over whether or not to select the viscosity increase suppression signal, based on the count value of the ejection cycles. Specifically, the signal selection control section 11 generates or stores predetermined parameters to exercise the control over whether or not to select the viscosity increase suppression signal, and causes the signal selection section 24 to select the viscosity increase suppression signal when a predetermined condition is satisfied between the predetermined parameters and the count value.
The predetermined parameters are determined based on, for example, parameter determination information such as ink type information stored in the head information storage section 28. A description will now be made on an example in which the control over whether or not the viscosity increase suppression signal is selected is exercised based on the type of ink. The signal selection control section 11 reads in advance the information on the ink type from the head information storage section 28 to determine a count value for selecting the viscosity increase suppression signal for each ink color as a predetermined parameter. The information stored in the head information storage section 28 may be information identifies the types of the liquids (which are inks, in this example) ejected by the liquid droplet ejecting heads in which the head information storage section 28 is provided. Data format of such information is arbitrarily set. The selection signal control section 11 compares the predetermined parameter determined for each ink color with the count value of the latch counter 26. When the count value of the latch counter 26 matches the predetermined parameter for each ink, the recording control section 10 controls the signal selection section 24 so that the viscosity increase suppression signal is applied to the ejection elements which eject ink having the relevant color among the ejection elements 30-1 to 30-n. When any of the large droplet signal, medium droplet signal, and the small droplet signal, which are liquid droplet ejection signals, is applied to the ejection elements 30-1 to 30-n, the signal selection section 24 does not select the viscosity increase suppression signal. Therefore, the signal selection control section 11 does not exercise the control described above.
For example, a predetermined parameter is set for each ink color as shown in a predetermined-parameter setting example 1 in
Referring to
The predetermined parameter value for each ink color may be appropriately set within the range of the count values. For example, as shown in the predetermined-parameter setting example 2 in
It is not essential that the maximum of the count values agrees with the maximum of the predetermined parameter values set for the respective ink colors. The maximum count value may be greater than the maximum of the predetermined parameter values as long as the set maximum count value results in no ejection failure attributable to increase in ink viscosity. For example, the latch counter 26 may be configured to count ejection cycles using count values 1 to 8 so long as there is no ejection failure attributable to increase in ink viscosity. The frequency of application of the viscosity increase suppression signal is lower, the greater the maximum count value.
The function of comparing the predetermined parameters and the count value may be provided in the drive control section 14. In this case, such a configuration is employed that the drive control section 14 is provided with a storage section for storing the predetermined parameters determined by the signal selection control section 11 and a comparison section that compares the predetermined parameters with a count value. The signal selection section 24 is controlled based on the output of the comparison section.
While the exemplary embodiment shown in
The signal selection control section 11 determines as to any of the large droplet signal, the medium droplet signal, and the small droplet signal, which are liquid droplet ejection signals among the drive signals, has been selected for any of the ejection elements 30-1 to 30-n (S3). This determination may be made by the signal selection section 24. When it is determined at step S3 that a liquid droplet ejection signal has been selected for any of the ejection elements 30-1 to 30n, the signal selection section 24 applies the liquid droplet ejection signal to such ejection elements among the ejection elements 30-1 to 30-n (S4) to eject liquid droplets. Thereafter, step S2 and the subsequent steps are repeated, and the process proceeds to control over the next ejection cycle.
With regard to ejection elements among the ejection elements 30-1 to 30n for which it is determined that no liquid droplet ejection signal has been selected, the signal selection control section 11 determines as to whether a predetermined condition is satisfied between the count value and the predetermined parameters of those ejection elements (S5). In this exemplary embodiment, the predetermined condition is that the count value and the predetermined parameter agree with each other.
When it is determined at step S5 that the predetermined condition is satisfied, the signal selection section 24 applies the viscosity increase suppression signal to the ejection elements satisfying the condition among the ejection elements 30-1 to 30-n (S6). Thereafter, the step S2 and the subsequent steps are repeated, and the process proceeds to control over the next ejection cycle.
When it is determined at step S5 that the predetermined condition is not satisfied, none of the drive signals is selected. Then, the step S2 and the subsequent steps are repeated, and the process proceeds to control over the next ejection cycle.
It has been described above that the signal selection section 24 is configured to select the viscosity increase suppression signal when the predetermined relationship holds true between the count value and the predetermined parameter, e.g., when the count value and the predetermined parameter the agree with each other. However, the invention is not limited thereto. For example, such a configuration may be employed that the viscosity increase suppression signal is selected once when a predetermined count value is reached, e.g., once per two ejection cycles or that the signal is selected periodically. For example, this configuration is implemented by providing the signal selection control section 11 with a select switch which is switched between plural states in a certain sequence. The select switch is switched at each ejection cycle, and the signal selection section 24 selects the viscosity increase suppression signal for ejection elements for which the selection signal “00” is generated when the select switch is in a predetermined state.
Such an alternative configuration may be employed that the signal selection control section 11 generates a random number at each ejection cycle in addition to the counting of ejection cycles by the latch counter 26. The signal selection section 24 selects the viscosity increase suppression signal when a predetermined condition holds true between the random number and a predetermined parameter. For example, the configuration involving such a random number is implemented by generating a pseudo random number 0 or 1 at each ejection cycle and setting 0 or 1 as a predetermined parameter in advance. Then, the signal selection section 24 selects the viscosity increase suppression signal for ejection elements for which the selection signal “00” has been generated when the pseudo random number thus generated agrees with the predetermined parameter.
Such a further alternative configuration may be employed that the number of recorded pixels is stored in the head information storage section 28, and that the signal selection control section 11 determines a parameter according to the number of recorded pixels, in order to control the frequency of selection of the viscosity increase suppression signal according to deterioration of the ejection elements 30-1 to 30-n with time. For example, the number of pixels recorded as a result of ejection from a liquid droplet ejection head is stored in the head information storage section 28 in the exemplary embodiment 1. The signal selection control section 11 selects a predetermined parameter corresponding to the number of recorded pixels read from the head information storage section 28, based on the relations between the number of recorded pixels and the predetermined parameter which is shown in
The relation shown in
Control may be exercised so that the viscosity increase suppression signal is not selected for an ejection element which ejects ink in a different color at each ejection cycle (the application of the viscosity increase suppression signal is omitted at an ejection element ejecting ink having a different color at each ejection cycle). The above description has addressed an example in which the viscosity increase suppression signal is applied to an ejection element when the count value agrees with the predetermined parameter. Alternatively, control may be exercised so that the viscosity increase suppression signal is not applied to an ejection element for which the selection signal “00” is generated when the count value agrees with the predetermined value and that the viscosity increase suppression signal is applied to an ejection element for which the selection signal “00” is generated when the count value does not agree with the predetermined parameter value.
In the exemplary embodiment 1 and its modifications, information on the liquid droplet ejection heads is stored in the head information storage section 28 provided in the liquid droplet ejection heads. The signal selection control section 11 acquires this information on the liquid droplet ejection heads from the head information storage section 28. Instead of such a configuration, the information on the heads may be stored in an information storage section (not shown) provided on the main body side of the liquid droplet ejecting apparatus. Such an alternative configuration may be used that the information on the heads is transmitted to the signal selection control section 11 from a computer which transmits image data to the liquid droplet ejecting apparatus.
A description will be made on an example in which a temperature sensor is used as the sensor 32. In general, the lower the temperature of the ink is, the viscosity of ink becomes higher to increase the possibility of ejection failures such as clogging. Therefore, the lower the ink temperature is, the predetermined parameters are set so that a viscosity increase suppression signal is more frequently selected. It is determined based on temperatures detected by the temperature sensor, as to whether or not the viscosity increase suppression signal is selected.
Although a temperature sensor serving as the sensor 32 in this example shown in
Also, a temperature sensor may be provided at both of the main body of the liquid droplet ejecting apparatus and the liquid droplet ejection heads to control the frequency of selection of the viscosity increase suppression signal using a difference between values detected by the both sensors. The ejection elements 30-1 to 30-n eject ink a greater number of times to increase the temperature of the liquid droplet ejection heads, as the print ration getting higher. Therefore, when such a mode of control is exercised, the frequency of application of the viscosity increase suppression signal can be made lower as the above-described temperature difference getting larger. Information on the print ratio of image data may be acquired from a computer which transmits the image data to a liquid droplet ejecting apparatus employing an ejection element driving device according to this exemplary embodiment of the invention, and the signal selection control section 11 may determine parameters according to the print ratio.
Since the degree of an increase in the viscosity of ink depends also on humidity, a humidity sensor may be used as the sensor 32 in the exemplary embodiment 2. In general, the viscosity of ink increases at a higher rate at lower humidity, which increases the possibility of ejection failures such as clogging. Therefore, the predetermined parameters are set so that the viscosity increase suppression signal is more frequently selected at low humidity, and it is determined as to whether or not a viscosity-increase suppressing waveform is selected, based on the humidity detected by the humidity sensor. For example, the relation between the humidity detected by the humidity sensor and the predetermined parameters is set as shown in the table of
Recording modes set in some liquid droplet ejecting apparatus include a fine mode which is required to perform recording with high image quality and a draft mode which is required to perform recording at a high recording speed but which has not so high requirements in terms of image quality. The viscosity increase suppression signal cannot be selected at a low frequency in the fine mode because the low selection frequency of the viscosity increase suppression signal may result in reduction in image quality, whereas the frequency can be set low in the draft mode. Under the circumstance, in a liquid droplet ejecting apparatus utilizing an ejection element driving device according to the exemplary embodiment 1 or 2, information on the recording mode may be acquired from, for example, a computer which transmits image data. Then, the signal selection control section 11 may determine as to whether the viscosity increase suppression signal is selected by selecting a predetermined parameter set in association with the recording mode. Control for varying the selection frequency of the viscosity increase suppression signal according to the recording modes will be described using an example where such control is applied to the exemplary embodiment 1. The description will omit contents common to the exemplary embodiment 1.
In the above-described embodiments, driving waveforms to be applied to ejection elements are selected from among a plurality of liquid droplet ejection waveforms for ejecting ink and a coagulation preventing waveform for preventing coagulation of ink, and control is exercised at each ejection cycle with reference to predetermined parameters to determine whether the waveform selection means is to select the coagulation preventing waveform for ejection elements for which the liquid droplet ejecting wave forms are not selected. Such processes may be implemented on a hardware basis by providing a circuit to perform signal selection control, and the processes may alternatively be implemented on a software basis by causing a central processing unit (CPU) to execute a program for performing the processes. When the processes are implemented on a software basis, the program for performing the processes may be provided by storing it in a recording medium such as a CD-ROM, and the program may alternatively be provided using communication means.
The invention is not limited to the above-described embodiments, and various modifications, alterations, and improvements may be made to the same. For example, although the above embodiments have been described on an assumption that liquid droplets are ejected in three sizes, i.e., large, medium, and small sizes, the size of liquid droplets maybe appropriately selected. There may be only one droplet size or four or more droplet sizes. The above embodiments have been described as instances in which liquid droplet ejection heads are capable of recording an image over a width that is equal to or greater than the width of an image recording region of a recording medium P and in which the liquid droplet ejection heads are fixed in the width direction. The invention can be applied to liquid droplet ejecting apparatus in which liquid droplet ejection heads are capable of recording an image over a width that is smaller than the width of an image recording region of a recording medium P and in which the liquid droplets ejection heads record an image by reciprocating in the width direction.
Number | Date | Country | Kind |
---|---|---|---|
P2006-355490 | Dec 2006 | JP | national |