Liquid dispensing device, liquid dispensing head control device, and liquid dispensing head control method

Abstract

This prevents a decrease in liquid circulation when the discharge energy generation element is not driven. [Solution] The liquid discharge head comprises a plurality of discharge drive elements for driving a plurality of discharge energy generating elements based on discharge data, and a plurality of circulation drive elements for driving a plurality of circulation energy generating elements based on circulation data. The liquid discharge head control unit comprises means for generating discharge data based on image data, and means for generating circulation data based on discharge data, provided that inspection sections are shifted in the scanning direction, and that in each inspection section, if a discharge drive element does not drive a discharge energy generating element corresponding to the discharge drive element, a circulation drive element corresponding to the discharge drive element drives a circulation energy generating element corresponding to the circulation drive element in a drive section included in the inspection section.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection device that ejects a liquid onto a recording medium or the like, a liquid ejection head control device for controlling a liquid ejection head provided in the liquid ejection device, and a liquid ejection head control method for controlling a liquid ejection head provided in the liquid ejection device.

Background Art

[0002] In a liquid ejection head provided in a liquid ejection device, ink in a pressure chamber is ejected from a discharge port (also referred to as a "nozzle") using energy generated by a discharge energy generating element. Here, in the liquid ejection head, volatile components in the ink may evaporate from the discharge port where the ink is ejected, and the ink in the discharge port may thicken. Due to such thickening of the ink, the discharge speed of the ink may change, and discharge defects including a decrease in the landing accuracy of the ink may occur. In particular, when the pause time of the ink discharge operation is long, the increase in the viscosity of the ink becomes significant, solids in the ink adhere to the discharge port, the flow resistance of the ink increases, and ink discharge defects are likely to occur. As one countermeasure against such a liquid thickening phenomenon, a method of flowing fresh liquid through the discharge port in the pressure chamber is known. As one method of flowing the liquid, there is a method of circulating the liquid in the head by a pressure difference using a main body side pump provided separately from the fluid die that performs discharge. Also, as another method, a method of circulating ink by a circulation energy generating element disposed in the fluid die itself is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the on-demand circulation disclosed in Patent Document 1, a fluid circulation element, which corresponds to a circulation energy generation element, is driven when the liquid injection element, which corresponds to a discharge energy generation element, is not driven for a certain period of time. However, the fluid circulation element is driven only for a limited time, immediately before the next time the fluid injection element is driven. Therefore, there is a problem in that the circulation of the liquid cannot always be maintained.

[0005] This invention has been made in view of the above points, and aims to avoid a decrease in the circulatory performance of the liquid when the discharge energy generating element is not driven. [Means for solving the problem]

[0006] One embodiment of the present invention is a liquid dispensing device comprising a liquid dispensing head for dispensing liquid onto a recording medium along a scanning direction, and a liquid dispensing head control unit for controlling the liquid dispensing head, wherein the liquid dispensing head comprises a plurality of discharge ports for dispensing liquid, a plurality of pressure chambers communicating with the plurality of discharge ports, a plurality of discharge energy generating elements that generate energy for dispensing the liquid present in the plurality of pressure chambers from the plurality of discharge ports, a plurality of circulation energy generating elements that generate energy for circulating the liquid in the plurality of pressure chambers through a flow path inside the liquid dispensing head, and a plurality of components for driving the plurality of discharge energy generating elements based on dispensing data. A liquid dispensing device comprising: a number of dispensing drive elements and a plurality of circulating drive elements for driving the plurality of circulating energy generating elements based on circulating data, wherein the liquid dispensing head control unit comprises means for generating the dispensing data based on image data, and generation means for generating the circulating data based on the dispensing data, provided that inspection sections are shifted in the scanning direction, and in each inspection section, if the dispensing drive element does not drive the dispensing energy generating element corresponding to the dispensing drive element, the circulating drive element corresponding to the dispensing drive element drives the circulating energy generating element corresponding to the circulating drive element in the drive section included in the inspection section. [Effects of the Invention]

[0007] According to this disclosure, it is possible to avoid a decrease in liquid circulation when the discharge energy generating element is not driven. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic perspective view of a liquid dispensing device. [Figure 2] A schematic diagram illustrating the area near the discharge port of the liquid discharge head in detail. [Figure 3] Perspective view showing the liquid dispensing head, and plan view of the liquid dispensing tip. [Figure 4] Functional block diagram showing an example configuration of a liquid discharge head. [Figure 5] Functional block diagram showing the configuration of the liquid dispensing device. [Figure 6] Timing diagram to explain the operation of the timing generation unit. [Figure 7] Functional block diagram showing the configuration of the liquid discharge head control unit. [Figure 8] Timing diagram showing signals generated by the liquid discharge head control unit. [Figure 9] Functional block diagram of a part of the liquid dispensing device according to the first embodiment [Figure 10] Functional block diagram of the pump timing calculation unit according to the first embodiment. [Figure 11] Functional block diagrams of the pump flag signal generation unit according to the first and third embodiments. [Figure 12] Figure showing memory-stored data according to the first embodiment. [Figure 13] Diagram explaining the pump timing calculation method [Figure 14] Diagram illustrating the pump timing calculation method according to the first and third embodiments. [Figure 15] Diagram illustrating the grouping of nozzles [Figure 16] Flowchart showing the operation of the pump timing calculation unit [Figure 17]Pump flag timing calculation timing chart according to the first and third embodiments [Figure 18] Functional block diagram of part of a liquid ejection device according to the second embodiment [Figure 19] Functional block diagram of a pump timing calculation unit according to the second embodiment [Figure 20] Functional block diagram of a pump flag signal generation unit according to the second embodiment [Figure 21] Diagram showing data stored in a memory according to the second embodiment [Figure 22] Diagram for explaining a pump timing calculation method according to the second embodiment [Figure 23] Pump flag timing calculation timing chart according to the second embodiment [Figure 24] Functional block diagram of part of a liquid ejection device according to the third embodiment [Figure 25] Diagram showing data stored in a memory according to the third embodiment [Figure 26] Diagram for explaining an example

Modes for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the matters of the present disclosure, and not all combinations of the features described in the present embodiments are essential for the solution means of the present disclosure. The same reference numerals are assigned to the same components. In the following description, first, the basic configuration of the present disclosure will be described, and then the characteristic parts of the present disclosure will be described.

[0010] <Components of the circulation unit> <Liquid ejection device> First, the schematic configuration of the liquid ejection device 50 in the present embodiment will be described. FIGS. 1(a) and 1(b) are perspective views schematically showing two types of liquid ejection devices.

[0011] The liquid ejection device 50 shown in Figures 1(a) and 1(b) is a serial-type liquid ejection device that performs image recording by ejecting liquid onto the recording medium P using a liquid ejection head that scans in a direction intersecting the transport direction of the recording medium P. This disclosure is not limited to serial-type liquid ejection devices. This disclosure is also applicable to page-wide type liquid ejection devices that perform image recording by ejecting liquid onto a recording medium being transported in the transport direction using a line head (page-wide type head) that is long in the page width direction of the recording medium. In this embodiment, the liquid ejection head is capable of ejecting four types of ink: black (K), cyan (C), magenta (M), and yellow (Y), and it is possible to record full-color images using these inks. The inks that can be ejected from the liquid ejection head are not limited to the above four types of ink. This disclosure is also applicable to liquid ejection heads for ejecting other types of ink. That is, the type and number of inks ejected from the liquid ejection head are not limited.

[0012] In the serial type liquid dispensing device 50, the liquid dispensing head 1 is mounted on a carriage 60. The carriage 60 reciprocates along a guide axis 51 that extends in the main scanning direction (X direction). The recording medium is transported by transport rollers (transport means) 55, 56, 57, and 58 in the sub-scanning direction (Y direction) which intersects (in this example, is orthogonal) with the main scanning direction. In the figures referenced below, the Z direction represents the vertical direction and intersects (in this example, is orthogonal) with the XY plane defined by the X and Y directions.

[0013] Figure 1(a) shows a configuration in which a main ink tank 2 is provided outside the liquid ejection head as a liquid storage unit. The liquid (ink) stored in the ink tank 2 is supplied to the sub-ink tank 54 on the liquid ejection head 1 side via an ink supply tube (liquid communication passage) 59, etc., by the driving force of an external pump 21. On the other hand, Figure 1(b) shows a configuration in which there is no main ink tank 2 as a liquid storage unit outside the liquid ejection head, and an ink tank 54B is provided directly above the liquid ejection head 1. In the configuration of Figure 1(b), the liquid ejection head 1 may be provided integrally with the ink tank 54B and configured to be removable / attachable to the carriage 60. Alternatively, the liquid ejection head 1 may be provided integrally with the carriage 60, and only the ink tank 54B may be removable / attachable. The following explanation will use the configuration of Figure 1(a) as a representative example.

[0014] The liquid discharge head 1 is composed of individual discharge units, which will be described later. The specific configuration will be described later, but as shown in Figure 2, the individual discharge unit is provided with a discharge port 211 for discharging liquid and a pressure chamber 222 communicating with the discharge port 211. The individual discharge unit is also provided with a first energy generating element (discharge energy generating element) 214 located in the pressure chamber 222, which generates energy for discharging liquid from the discharge port 211. Furthermore, the individual discharge unit is provided with an individual flow path 223 communicating with the pressure chamber 222 and a second energy generating element (circulation energy generating element) 224 located in the individual flow path 223. The liquid discharge head 1 has a plurality of individual discharge units, and each individual discharge unit has a supply flow path for supplying liquid to its individual flow path.

[0015] When using a liquid ejection head, the ejection of liquid can become unstable due to evaporation of volatile components such as water from the ejection port, and the resulting concentration of solids near the ejection port. Various measures have been taken to prevent this. For example, the liquid ejection device may be equipped with a cap member (not shown) that can cover the ejection port surface of the liquid ejection head, located off-center in the X direction from the transport path of the recording medium. The cap member is used to cover the ejection port surface of the liquid ejection head when recording is not in progress, preventing drying and protecting the ejection port. Furthermore, an ink suction mechanism (not shown) may also be provided, in which case the cap member is used for ink suction from the ejection port. This ink suction refreshes the ink near the ejection port, maintaining the quality of the resulting image. In addition, a method called pre-ejection (pre-discharge) is known, in which concentrated ink is discarded by ejecting ink when recording is not in progress. Furthermore, a method is known in which a small amount of ink is pre-ejected (paper surface pre-ejection / in-page pre-ejection) in an inconspicuous location on the recording medium during recording. While these methods significantly improve image quality, they involve discarding some ink to refresh the ink ejection port. Therefore, it is necessary to minimize the amount of waste ink while refreshing the ejection port.

[0016] To address these challenges, a second energy generating element (circulating energy generating element) 224 is installed in each individual flow path to circulate the ink within the individual flow path. This suppresses the amount of waste ink while also preventing drying at the discharge port and concentration of ink near the discharge port. More specifically, the number of pre-discharge and suction recovery cycles can be minimized. Furthermore, minimizing the number of pre-discharge cycles leads to improvements in throughput and yield.

[0017] The circulating energy generating element 224 does not need to be installed in all individual discharge units of the liquid discharge head. The above-mentioned effects can be obtained by installing it in some individual discharge units compared to not installing it.

[0018] Furthermore, the liquid ejection head shown in Figure 1(a) may be configured such that all parts corresponding to the four types of ink are equipped with a circulating energy generating element 224, or it may be configured such that only the part corresponding to one type of ink is equipped with a circulating energy generating element 224. In other words, the liquid ejection head may not circulate all four types of ink, but may be configured to circulate at least one type of ink.

[0019] <Basic configuration of a liquid dispensing head> Figure 3(a) is an exploded perspective view of the liquid ejection head of this embodiment. As shown in Figure 3, the liquid ejection head 1 includes a sub-ink tank 54 for temporarily storing ink in the head and a liquid ejection tip 301 for ejecting the ink supplied from the sub-ink tank 54 onto the recording medium P. In this embodiment, the liquid ejection head 1 is fixedly supported on the carriage 60 of the liquid ejection device 50 by positioning means (not shown) and electrical contacts provided on the carriage 60. The liquid ejection head 1 ejects ink while moving together with the carriage 60 in the main scanning direction (X direction) shown in Figure 1, and records onto the recording medium P.

[0020] As shown in Figure 3(a), the liquid dispensing head 1 includes a dispensing unit 300. The dispensing unit 300 is composed of a first support member 303, a second support member 302, a liquid dispensing tip 301, and an electrical wiring member (electrical wiring tape) 304.

[0021] An external pump 21, connected to an ink tank 2 which serves as the ink supply source, is equipped with an ink supply tube 59 (see Figure 1(a)). A liquid connector (not shown) is provided at the tip of this ink supply tube 59. When the liquid ejection head 1 is mounted on the liquid ejection device 50, the liquid connector at the tip of the ink supply tube 59 is liquid-tightly connected to the liquid connector insertion port, which is the liquid inlet provided on the head housing 53 of the liquid ejection head 1. This forms an ink supply path from the ink tank 2 through the external pump 21 to the liquid ejection head 1. In this embodiment, since four types of ink are used, four sets of ink tanks 2, external pumps 21, ink supply tubes 59, and sub-ink tanks 54 are provided, corresponding to each ink, and four independent ink supply paths corresponding to each ink are formed. Thus, the liquid ejection device 50 of this embodiment is equipped with an ink supply system that supplies ink from an ink tank 2 located outside the liquid ejection head 1. Note that the liquid ejection device 50 of this embodiment is not equipped with an ink recovery system that recovers the ink in the liquid ejection head 1 into the ink tank. Therefore, the liquid ejection head 1 is provided with a liquid connector inlet for connecting the ink supply tube 59 of the ink tank 2, but it is not provided with a connector inlet for connecting a tube to collect the ink from the liquid ejection head 1 back into the ink tank 2. Note that a separate liquid connector inlet is provided for each ink cartridge.

[0022] Figures 3(b), 3(c), and 3(d) are plan views of the liquid discharge tip 301, which constitutes the liquid discharge head, as seen from the discharge surface side. Figure 3(b) shows a configuration with one tip per four colors, Figure 3(c) shows a configuration with one tip per two colors, and Figure 3(d) shows a configuration with one tip per color. Each liquid discharge tip 301 is provided with a discharge port 211 and a pad 1321 used for electrical mounting. Figure 3(a) shows the single-tip configuration of Figure 3(b).

[0023] Figure 3(b) shows a configuration with one chip per four colors. The four colors are, for example, black, cyan, magenta, and yellow, and each color is assigned to a column extending in the Y direction. In the example shown in the figure, the ejection ports for each color are arranged in a staggered pattern in two columns extending in the Y direction. The pitch of the ejection ports along the Y direction is constant. Alternatively, the ejection ports for each color may be arranged in a single column along the Y direction. Furthermore, the ejection ports for black may be arranged in two columns, while the ejection ports for the other colors are arranged in a single column. In that case, the total number of columns would be five.

[0024] Figure 3(c) shows a configuration where two colors are assigned to one chip, resulting in two chips. In this case, two chips may be mounted on one liquid dispensing head, or one chip may be mounted on one liquid dispensing head, resulting in two heads.

[0025] Figure 3(d) shows a configuration where one color is assigned to each chip, resulting in a total of four chips. In this case, four chips may be mounted on one liquid dispensing head, or one chip may be mounted on each liquid dispensing head, resulting in a total of four heads. Furthermore, two chips may be mounted on each liquid dispensing head, resulting in a total of two heads.

[0026] Furthermore, as shown in Figures 3(c) and 3(d), when a chip is divided into multiple parts, it is not necessary for all chips to have the same length. Also, there are no restrictions on the combination of assigning multiple colors to multiple chips. The same applies when the total number of colors exceeds four (simple straight type).

[0027] Figure 2 is a schematic diagram illustrating in detail the area near the nozzle of a liquid ejection head that ejects liquids such as ink. Figure 2(a) is a plan view taken from the direction in which the liquid droplets are ejected from the nozzle. Figure 2(b) is a cross-sectional view AA' in Figure 2(a) with the first configuration. Figure 2(c) is a cross-sectional view AA' in Figure 2(a) with the second configuration.

[0028] In Figures 2(a) to 2(c), between the recording element substrate 201 and the orifice plate 202, a partition wall 221 separates pressure chambers 222 corresponding to each discharge port 211, and individual flow paths 223 for flowing ink through these pressure chambers 222 are formed. An ink meniscus is present at the discharge port 211, forming a discharge port interface, which is the interface between the ink and the atmosphere.

[0029] The recording element substrate 201 is equipped with an ejection energy generating element 214 that generates energy to eject ink from the pressure chamber. In this example, an electrothermal conversion element is used as the ejection energy generating element 214. The position of the ejection energy generating element 214 is similar to the positions of the ejection port 211 and the pressure chamber 222, and is closer to the second opening (outlet opening) 232 than to the first opening (supply opening) 222. By driving the ejection energy generating element 214 to generate heat and foam the ink in the pressure chamber 222, the foaming energy can be used to eject ink from the ejection port 211. The ejection energy generating element 214 is not limited to an electrothermal conversion element as in this example, but can also be a piezoelectric element or the like. The recording element substrate 201 is also equipped with a circulation energy generating element 224 that generates energy to create a circulation flow 227 of ink in the individual flow channels, as indicated by the arrows. In this example, an electrothermal conversion element is used as the circulation energy generating element 224. The position of the circulating energy generating element 224 is closer to the first opening 212 than to the second opening 232.

[0030] The individual channel 223 extends in a second direction that intersects (in this example, perpendicular to) the row of discharge ports arranged in a first direction. The individual channel 223 includes a pressure chamber 222, an inlet (upstream) side connecting channel 213A in Figure 2(b) that communicates with one end of the pressure chamber 222, and an outlet (downstream) side channel 213B in Figure 2(b) that communicates with the other end of the pressure chamber 222. The individual channel 223 communicates with a first opening 212 and a second opening 232 that penetrate the recording element substrate 201 on both sides. Therefore, in Figures 2(a), 2(b), and 2(c), the connecting channel 213A is located to the left of the row of discharge ports. The connecting channel 213B is located to the right of the row of discharge ports. Both ends of the individual channel 223 are located on opposite sides of the row of discharge ports.

[0031] The ink flow in the individual channel 223 can be broadly classified into the following two types.

[0032] (1) The ink flow that drives the first energy element 214 and refills after ejection. (2) Ink flow to drive the second energy element 224 and form a circulating flow When the first energy element 214 is driven and liquid is discharged from the discharge port 211, ink flows in from the first opening 212 and the second opening 232 to supply the ink associated with the discharge.

[0033] When the second energy element 224 is driven to form a circulating flow, the ink flows into the individual channel 223 via the first opening 212, which is on the connecting channel side, and flows out to the outside via the second opening 232, which is not on the connecting channel side. In this example, the ink that has flowed out from the second opening 232 is returned to the first opening 212 and circulated, thereby forming a circulating flow 227 indicated by the arrow within the individual channel 223.

[0034] Figure 2(b) shows a configuration in which the first opening 212 and the second opening 232 are connected to individual flow paths 223 and shared outside the liquid discharge head. Figure 2(c) shows a configuration in which the first opening 212 and the second opening 232 are not shared within the tip. Either configuration may be adopted.

[0035] Filters for removing foreign matter from the ink may be provided in the ink circulation channels inside and outside the liquid ejection head 1. For example, filters may be placed on the inflow side and outflow side, which are outside the individual channel 223. Alternatively, a filter may be placed between the ejection energy generating element 214 and the circulation energy generating element 224 in the individual channel 223. In this case, a filter does not need to be placed on the upstream side (circulation energy generating element 224 side), which is outside the individual channel 223.

[0036] <Drive system of this embodiment: toggle drive> In this embodiment, a selective drive circuit 403, as shown in Figure 4, is formed on the recording element substrate 201. A voltage source (+V) and an external circuit 402 located outside the recording element substrate 201 are connected to the selective drive circuit 403 on the recording element substrate 201. The selective drive circuit 403 includes an on-on drive circuit 404 that turns on and drives either the discharge energy generating element 214 or the circulating energy generating element 224 in response to control signals at each address (for example, N1 to N16) received from the controller 401. Here, the controller 401 controls the drive pulse for driving the discharge energy generating element 214 or the circulating energy generating element 224, and the time interval for applying the drive pulse to each element. Furthermore, if the circulating energy generating element 224 is selected by the on-on drive circuit 404, the on-off drive circuit 405 controls the driving of the circulating energy generating element 224 according to the drive availability signal 406. As described above, in this embodiment, the drive of the circulating energy generating element 224 is controlled by the on-on drive circuit 404 and the on-off drive circuit 405.

[0037] Therefore, if the discharge energy generating element 214 is selected by the on-on drive circuit 404, the discharge energy generating element 4 is driven, and the circulating energy generating element 224 is not driven, regardless of the drive capability signal 406.

[0038] If the second energy generating element 224 is selected by the on-on drive circuit 404, the discharge energy generating element 214 will not be driven, regardless of the drive availability signal 406.

[0039] If the on-on drive circuit 404 selects the second energy generating element 224, and the on-off drive circuit 405 is turned on by the drive feasibility signal 406, the circulating energy generating element 224 is driven.

[0040] If the second energy generating element 224 is selected by the on-on drive circuit 404 and the on-off drive circuit 405 is turned off by the drive availability signal 406, the circulating energy generating element 224 is not driven. Therefore, if the second energy generating element 224 is selected by the on-on drive circuit 404 and the on-off drive circuit 405 is turned off by the drive availability signal 406, neither the discharge energy generating element 214 nor the circulating energy generating element 224 is driven.

[0041] Therefore, the circulating energy generating element 224 is driven according to the drive data of the discharge energy generating element 214 (control signals at each address received from the controller 401) and the drive feasibility signal 406. In this way, the configuration shown in Figure 4 does not require dedicated drive data for the circulating energy generating element 224. Therefore, this configuration has the advantage of reducing the amount of drive data by about half compared to a configuration where dedicated drive data for the circulating energy generating element 224 is required.

[0042] Furthermore, it is possible to control the drive of multiple circulating energy generating elements 224 together based on a common drive / fail signal 406. For example, it is possible to control the drive of circulating energy generating elements B1 to Bn based on a common drive / fail signal 406. In the example shown in Figure 4, n is set to 16. In other words, a total of 32 elements (16 sets of elements) consisting of discharge energy generating elements A1 to A16 and circulating energy generating elements B1 to B16 constitute one group. The circulating energy generating elements B1 to B16 are then controlled on / off by a common drive / fail signal 406. However, n may be changed to other values. If n is 8, the number of elements in the group is 16, and if n is 12, the number of elements in the group is 24.

[0043] Furthermore, while an electrothermal conversion element or a piezoelectric element can be used as the circulating energy generating element 224, an electrothermal conversion element is used in this embodiment. The direction of the circulating flow is as indicated by arrow 227. When a piezoelectric element is used, the direction of the circulating flow may be opposite to the direction of arrow 227 depending on its driving method.

[0044] In this embodiment, a configuration is shown in which a drive enable / disable signal 406 is introduced to the recording element substrate 201 to control the drive of the circulating energy generating element 224. The controller 401, selective drive circuit 403, and on / off drive circuit 405 shown in Figure 4 are formed on the recording element substrate 201. However, this is not limited to this configuration, and some or all of the parts that control the drive of the circulating energy generating element 224 may be provided in the part of the liquid discharge head 1 excluding the recording element substrate 201, or in the part of the liquid discharge device 50 excluding the liquid discharge head 1. For example, at least a part of the controller 401, selective drive circuit 403, and on / off drive circuit 405 may be provided in the part of the liquid discharge head 1 excluding the recording element substrate 201, or in the part of the liquid discharge device 50 excluding the liquid discharge head 1.

[0045] Figure 5 is a block diagram showing the control configuration of the liquid ejection device 50. The host interface 502 receives image data from the host device 501. This image data is stored in the receive buffer 506A provided in the RAM 506. The image processing unit 504 converts the image data into multi-level data of CMYK color components and stores it in the multi-level data buffer 506B provided in the RAM 506. The print data processing unit 505 converts the multi-level data into dot data (binary data) and stores it in the dot data buffer 506C. The liquid ejection head control unit 510 transfers the binary data stored in the dot data buffer 506C to the liquid ejection head 1. The processing in the print data processing unit 505 is synchronized with the heat trigger signal 314 (see Figure 6) output by the timing generation unit 509. The processing in the liquid ejection head control unit 510 is synchronized with the block trigger signal 514 output by the timing generation unit 509. Here, as will be described later, both the heat trigger signal 513 and the block trigger signal 514 are synchronized with encoder signals 511 and 512, which have position information along the scanning direction (main scanning direction) of the liquid ejection head 1. Therefore, the processing in the print data processing unit 505 and the processing in the liquid ejection head control unit 510 are synchronized with the scanning timing of the liquid ejection head 1.

[0046] In Figure 5, 503 indicates an operation panel for the user to give instructions to the liquid dispensing device 50. The processor 507 performs control of the recording element's drive and relative transport control between the recording element and the recording medium (e.g., paper) according to the control program stored in the ROM 508.

[0047] The generation of data transfer timing will be explained using Figure 6. Here, we will explain a method in which the print data for one column is divided into 16 timings (time-division drive). From the encoder that generates an encoder signal having position information along the scanning direction of the liquid ejection head 1, an encoder signal (phase A) 511 and an encoder signal (phase B) which is phase-shifted by one-quarter of a period are input to the timing generation unit 509. The timing generation unit 509 generates a reference pulse 601 at the timing of the rising edge of the encoder signal 511, and generates and outputs a heat trigger signal 513 having intervals equal to the recording resolution by multiplying it. Furthermore, the timing generation unit 509 generates a block trigger signal 514 by dividing the interval of the heat trigger signal 513 into 16. Data is supplied to the liquid ejection head 1 at the timing of this block trigger signal 514. By transferring data within the period of the block trigger signal 514, which is generated based on encoder signals 511 and 512 that have position information of the liquid discharge head 1, images and the like can be recorded at a desired position along the main scanning direction.

[0048] <Liquid Dispensing Head Control Unit> The liquid discharge head control unit 510 will be explained using Figures 7 and 8.

[0049] Figure 7 is a block diagram showing the configuration of the liquid discharge head control unit 510. The liquid discharge head control unit 510 operates based on the timing of the block trigger signal 514 generated by the timing generation unit 509.

[0050] When the clock signal generation unit 701 receives a block trigger signal 514 from the timing generation unit 509, it generates a clock signal of a predetermined number of cycles and transfers that clock signal to the liquid discharge head 1. In the example shown in Figure 8, the clock signal generation unit 701 generates a clock signal for 23 cycles for each period of the latch signal. The number of cycles of the generated clock signal is variable by setting, and the required number of cycles is determined by the number of bits of data to be transferred to the liquid discharge head 1. The clock signal is used, for example, to transmit serial data from the liquid discharge head control unit 510 to the recording element board 201 as a data signal.

[0051] When the latch signal generation unit 702 receives the block trigger signal 514, it generates a latch signal LT and transfers it to the recording element board 201 included in the liquid discharge head 1. The latch signal LT is used, for example, to parallelize and latch serial data transmitted from the liquid discharge head control unit 510 to the recording element board 201.

[0052] The enable signal generation unit 704 generates an enable signal EN based on the data read from the RAM 506 by the data signal generation unit 703 and transfers it to the liquid discharge head 1. The enable signal EN is used to specify the time length for driving the selected energy generating element in one cycle of the latch signal LT.

[0053] The pump flag signal generation unit 902 generates a pump flag signal. Details of the pump flag signal will be described later.

[0054] The data signal generation unit 703 generates a data signal that includes a group selection signal for ejection and a time-division selection signal for ejection. When a block trigger signal 514 is input, the data signal generation unit 703 reads data such as image data from the RAM 506. The data signal generation unit 703 then temporarily stores the group selection signal for ejection and the time-division selection signal for ejection, based on the read data, in an internal buffer. When the next block trigger signal 514 is input, the data signal generation unit 703 transfers the data signal to the recording element board 201 included in the liquid ejection chip 301 of the liquid ejection head 1. For each block trigger signal 514, data for one time-division drive is transmitted from the liquid ejection head control unit 510 to the recording element board 201 via the data signal.

[0055] The data signal generation unit 703 also receives the pump flag signal. The discharge group selection signal includes information for selecting which circulating heater (electric heat conversion element) RhB to drive at the timing of driving the circulating heater (electric heat conversion element) RhB.

[0056] Figure 8 shows a data signal including a 40-bit ejection group selection signal (0-39) and a 6-bit ejection time-division selection signal (G0-G5). Of the multiple ejection drive elements MD1 included in the liquid ejection head 1, the ejection drive element MD1 to be operated is determined by the ejection group selection signal and the ejection time-division selection signal transmitted from the liquid ejection head control unit 510. The ejection drive element MD1 thus determined drives the ejection energy generating element 214 corresponding to the period during which the enable signal indicates the enable level, thereby ejecting ink. The ejection group selection signal and the ejection time-division selection signal constitute the ejection data. In this embodiment, circulation data for driving the circulation drive element MD2 can be embedded in the ejection data, but a detailed explanation of this is omitted.

[0057] Here, activating a specific discharge drive element MD1 means driving the corresponding discharge energy generating element 214 with the specific discharge drive element MD1. Similarly, activating a specific circulation drive element MD2 means driving the corresponding circulation energy generating element 224 with the specific circulation drive element MD2.

[0058] Figure 8 shows an example where the time-division selection signal for ejection is composed of 6 bits (G0 to G5). This allows for a configuration in which up to 64 ejection energy generating elements 214 are included in a single block. However, in this embodiment, since only 16 ejection energy generating elements 214 are included in a single block, the time-division selection signal for ejection only needs to be composed of 4 bits (G0 to G3).

[0059] The time-division selection signal for discharge changes cyclically to select the discharge drive element MD1 and the circulating drive element MD2 to be activated within a group with each latch signal. If the number of discharge drive elements MD1 and circulating drive elements MD2 in a group is N, then the process completes every N latch signals. Here, for example, if the time-division selection signal for discharge is adjusted to alternately enable / disable every N latches for the circulating drive element MD2, the period over which the discharge time-division signal completes a cycle of N circulating drive elements MD2 can be doubled.

[0060] Figure 9 is a functional block diagram of a part of the liquid dispensing device according to the first embodiment.

[0061] In the first embodiment, as shown in Figure 9, the print data processing unit 505 has a pump timing calculation unit 901, and the liquid discharge head control unit 510 has a pump flag signal generation unit 902. In the first embodiment, the pump timing calculation unit 901 calculates the timing to drive the circulating energy generating element in the next scan period during the inter-scan period between the scan period for printing and the next scan period. The pump flag signal generation unit 902 operates in real time during the scan period.

[0062] The multi-level output data DA1 generated by the image processing unit 504 is first stored in the multi-level data buffer 506B and then supplied to the print data processing unit 505.

[0063] The print data processing unit 505 generates binary output data DA2 based on the multi-level output data DA1. The binary output data DA2 is stored in the dot data buffer 506C.

[0064] The pump timing calculation unit 901, included in the print data processing unit 505, generates pump-on time setting data TM, which contains information about the timing to change the pump flag from LOW to HIGH, based on the binary discharge data DA2. The pump-on time setting data TM is also stored in the dot data buffer 506C.

[0065] The binary discharge data DA2 and pump-on time setting data TM stored in the dot data buffer 506C during the inter-scan period are supplied to the liquid discharge head control unit 510 during the next scan period.

[0066] The pump flag signal generation unit 902 included in the liquid discharge head control unit 510 generates a pump flag signal based on the pump-on time setting data TM. The pump flag signal is supplied to the recording element substrate 201 included in the liquid discharge chip 301. The pump flag signal may be supplied directly to the recording element substrate 201, but as described above, it may also be included in the data signal DATA by the data signal generation unit 703.

[0067] The pump timing calculation unit 901 may be located within the liquid discharge head control unit 510. In that case, the pump timing calculation unit 901 generates pump-on time setting data TM based on the binary discharge data DA2.

[0068] Figure 10 is a functional block diagram of the pump timing calculation unit 901 according to the first embodiment.

[0069] Referring to Figure 10, the discharge data holding unit 1001 holds the multi-level discharge data DA1 received from the multi-level data buffer 506B.

[0070] The analysis setting retention circuit 1002 is, • Number of analysis columns used for one determination: n • Analysis grouping settings • Column number k when driving the circulating energy generation element 224 • Number of columns per scan It holds.

[0071] The pump timing determination unit 1003 calculates the timing for driving the circulating energy generating element 224 by the circulating drive element MD2 based on the binary discharge data DA2 received from the discharge data holding unit 1001 and the information held in the analysis setting holding circuit 1002. The pump timing determination unit 1003 then stores the pump-on time setting data TM containing this timing information in the pump flag timing holding unit 1004. The pump-on time setting data TM is then read from the pump flag timing holding unit 1004 and transferred to the dot data buffer 506C. These operations are performed during the inter-scan period.

[0072] The pump-on time setting data TM includes the column number that drives the circulating energy generating element 224. The pump flag signal generation circuit 902 can hold information about two column numbers. After one of these column numbers is used for signal generation processing by the pump flag signal generation unit 1802, that column number is updated to the next column number.

[0073] As an example, assume that clm1, clm2, and clm3 (clm1 < clm2 < clm3) are the column numbers that drive the circulating energy generating element 224. In this case, the dot data buffer 506C initially holds the column numbers of clm1 and clm2. Then, when the pump flag signal generation unit 902 generates a pump flag signal based on clm1, the dot data buffer 506C updates the column numbers it holds to clm2 and clm3. Note that the number of column numbers held by the pump flag signal generation unit 902 is not limited to 2 and may be other numbers.

[0074] FIG. 11 is a functional block diagram of the pump flag signal generation unit 902 according to the first embodiment.

[0075] The pump flag signal generation unit 1802 includes a pump-on time holding circuit 1101 that holds the pump-on time setting data TM received from the dot data buffer 506C, and a pump-on width time holding circuit 1102 that holds the time TN during which the pump flag remains HIGH. Here, the pump flag becomes HIGH at the time specified by the pump-on time setting data TM and then remains HIGH for the period specified by the time TN. Then, the circulating energy generating element 224 is driven by the circulating drive element MD2 during the period when the pump flag is HIGH. That is, the circulation pump is driven during the period when the pump flag is HIGH.

[0076] The flag data generation circuit 1104 receives the pump-on time setting data TM, the pump-on width time held in the pump-on width time holding circuit 1102, the count value input from the latch count circuit 1103, and the pump control enable as input. Based on this input data, the flag data generation circuit 1104 generates a pump flag signal PF. Specifically, if the count value matches the pump-on time setting data TM, the flag data generation circuit 1104 sets the pump flag signal to HIGH. The flag data generation circuit 1104 then maintains the pump flag signal in HIGH state for the number of times indicated by the pump-on width time. Furthermore, the flag data generation circuit 1104 performs this operation only when the pump control enable indicates enable; if the pump control enable is disabled, it always maintains the pump flag signal in LOW state.

[0077] <Method for calculating pump flag timing> Figure 12 shows the memory-stored data according to the first embodiment.

[0078] In Figure 12, rows represent nozzles and columns represent columns. Blocks with black circles indicate that discharge occurs in the corresponding column of the corresponding nozzle. Discharge occurs when the circulating energy generating element 224 is driven by the circulating drive element MD2.

[0079] For example, the black circle in the fourth block from the left and second from the top indicates that ejection will occur in the fourth column from the second nozzle from the top (i.e., there is ejection data).

[0080] The pump timing calculation unit 901 receives binary discharge data DA2. The binary discharge data DA2 is stored in the discharge data storage unit 1001. If the stored binary discharge data DA2 does not meet the data 1202 required for analysis, the missing data is supplemented. The case in which the stored binary discharge data DA2 does not meet the data 1202 required for analysis is as follows: In other words, this is the case when binary discharge data DA2 for (n+1) columns from column m, which is the start position of the inspection, to column (m+n), which is the end position of the inspection, is required, but some of it is missing. The supplementation is performed in units of macroblocks of multiple nozzles and multiple columns, as shown by the thick frame 1201.

[0081] Figures 13 and 14 illustrate the pump timing calculation method in the pump timing determination unit 1003 included in the pump timing calculation unit 901. In this calculation method, nozzles 0 to N are examined. Also, columns m to (m+n) are examined. Therefore, (N+1) × (n+1) blocks constitute the inspection range. Note that the inspection interval is from column m to column (m+n).

[0082] The method shown in Figure 13 and the method shown in Figure 14 are the same. However, the procedure after confirmation differs depending on whether or not there is output data.

[0083] Figure 13 shows the method when at least one discharge occurs from all nozzles (nozzle 0 to nozzle N). In this case, the circulation pump is not driven.

[0084] Figure 14 shows a situation where there is no discharge data for the specified number of columns from at least one nozzle. Here, the specified number of columns is (n+1). In this case, the circulation pump is activated.

[0085] Here, the driven circulation pumps are basically (N+1) circulation pumps corresponding to nozzles 0 to N. However, adjustments may be made so that the circulation pumps corresponding to the driven discharge energy generating elements 214 among the (N+1) discharge energy generating elements 214 corresponding to nozzles 0 to N are not driven.

[0086] The pump timing determination unit 1003 first determines whether or not there is discharge data in the column range (from column m to column (m+n)) for the first nozzle (nozzle 0). This is repeated from the second nozzle (nozzle 1) to the last nozzle (nozzle N).

[0087] However, as will be explained later, if it is determined that there is no discharge data for an intermediate nozzle, the determination for subsequent nozzles may be omitted.

[0088] In the example shown in Figure 13, since there is discharge data for all nozzles (from nozzle 0 to nozzle N), a determination is made as to whether or not there is discharge data for all nozzles.

[0089] In the example shown in Figure 14, since there is no discharge data for the intermediate nozzle, no determination is made as to whether or not there is discharge data for the nozzles after that intermediate nozzle.

[0090] Furthermore, in the example in Figure 14, the circulation pump is turned on at the position corresponding to the range m to (m+n). Here, the circulation pump that is turned on only needs to be the one corresponding to the nozzle for which there is no discharge data. Therefore, a procedure or circuit may be added to not turn on the circulation pump corresponding to the nozzle for which there is discharge data. This procedure or circuit performs a process that corrects the signal for operating the discharge drive element to B' = not(A)·B, where A is the signal for operating the circulation drive element and B is the signal for operating the circulation drive element.

[0091] As shown in FIG. 13, when there is ejection data in at least one column for all nozzles, the inspection range is shifted by 1 in the column direction (i.e., the scan direction). Then, the same method is implemented in the newly set column range (from column (m + 1) to column (m + n + 1)).

[0092] As shown in FIG. 14, when there is no ejection data in the range from column m to column (m + n) for a certain nozzle, the column number corresponding to the setting (for example, m + n / 2 (rounded up) in FIG. 14) is recorded. The column number is transferred to the pump flag timing holding unit 1,004. Therefore, the circulation pump is driven in one or more columns corresponding to the column number m + n / 2.

[0093] As an example, the set column number is m + n / 2. However, for example, when the set column number is m + n, if ejection data comes immediately after the timing of driving the circulation pump, the effect of the circulation pump will be weakened. However, this set value is not limited to m + n / 2. By setting the column number to m + n / 2, a non - driving section where neither the ejection energy generating element 214 nor the circulation energy generating element 224 is driven can be provided after the column where the circulation energy generating element 224 is driven. Similarly, by setting the column number to m + n / 2, a non - driving section where neither the ejection energy generating element 214 nor the circulation energy generating element 224 is driven can be provided before the column where the circulation energy generating element 224 is driven.

[0094] When driving the circulation pump, the column number is advanced by m + n / 2, and the above operation is repeated.

[0095] Note that the above m + n / 2 (rounded up) is not limited to this. For example, it may be m + n / 2 (rounded down), or m + α×n (0 < α < n) (rounded up), m + α×n (0 < α < n) (rounded down), etc.

[0096] In Figures 13 and 14, the number of nozzles is set to (N+1), but as shown in Figure 15, instead of checking all the nozzles on the head, you can limit the check to a portion of the nozzles by grouping them. For example, suppose the total number of nozzles is 160. In this case, for example, the nozzles can be evenly divided into 10 groups. In this case, each group will contain 16 nozzles. Then, the above method is performed for each group. In other words, the method for N=16 is repeated 10 times.

[0097] <Flowchart for calculating pump flag timing> Figure 16 is a flowchart showing the operation of the pump timing calculation unit 901.

[0098] First, set the necessary values.

[0099] In S1601, the pump timing calculation unit 901 sets the number of target columns n per inspection. This is stored in the analysis setting holding circuit 1002. The pump timing determination unit 1003 receives the number of target columns n and uses it for processing.

[0100] In S1602, the pump timing calculation unit 901 sets the nozzles to be divided into groups. The number of nozzles in each group (g: group number) is l_max(g).

[0101] In S1603, the pump timing calculation unit 901 checks for the presence or absence of discharge data in columns m to (m+n) for each group, and if no discharge data is found, it sets which column k will drive the circulation pump. For example, k = n / 2 (rounded up).

[0102] In S1604, the pump timing calculation unit 901 sets the number of columns s per scan.

[0103] In S1605, substitute 0 for g.

[0104] Furthermore, we define an initial flag here. The initial flag is set to 0 (active) upon reset.

[0105] In S1606, the pump timing calculation unit 901 checks this initial flag (ini_flag). If the initial flag is active (YES), in S1607, the pump timing calculation unit 901 initializes the nozzle number l and the first column number m for checking the presence or absence of discharge data to 0, and sets the initial flag to 1 (inactive).

[0106] In S1606, if the initial flag is inactive (NO), then in S1608, the pump timing calculation unit 901 checks whether the nozzle number l for checking the presence or absence of discharge data is greater than or equal to the maximum number of nozzles l_max(g).

[0107] In S1608, if nozzle number l exceeds the maximum number of nozzles l_max(g) (YES), in S1609, the pump timing calculation unit 901 initializes nozzle number l to 0 and checks the next column (let's set m=m+1). The calculation m=m+1 shifts the inspection interval by one column. As a result, the starting position of the next inspection shifts by one column relative to the starting position of the current inspection.

[0108] If, in S1608, nozzle number l does not exceed the maximum number of nozzles l_max(g) (NO), then in S1610, the pump timing calculation unit 901 increments nozzle number l by 1 (l=l+1).

[0109] In S1611, the pump timing calculation unit 901 checks whether the range m+n for checking the discharge data is less than or equal to the number of columns s per scan.

[0110] If m+n>s in S1611, then in S1617, the pump timing calculation unit 901 checks the next nozzle group (g=g+1). At that time, the initial flag is set to 0 (active).

[0111] If m+n≦s in S1611, then in S1612, the pump timing calculation unit 901 checks for the presence or absence of discharge data within the specified range (nozzle l, column m to column (m+n)).

[0112] In S1612, the pump timing calculation unit 901 repeats the operation from S1606 if there is discharge data within the range.

[0113] In S1612, if there is no discharge data within the range, in S1614, the pump timing calculation unit 901 determines whether the calculated timing is between scans. If the calculated timing is between scans (YES), the process proceeds to S1615; otherwise, the process proceeds to S1616.

[0114] In S1615, the column number k is stored in the pump flag timing holding unit 1004. Also, m is updated to k, and l_max(g) is substituted for l. By changing m to k (performing the operation m=k), the inspection interval is shifted by k columns. As a result, the starting position of the next inspection is shifted by k columns relative to the starting position of the current inspection.

[0115] In S1616, the pump flag nozzle data (described later) is turned ON. Also, m is updated to k, and l is assigned l_max(g).

[0116] In addition, if the number of columns driving the circulation pump in S1615 and S1616 is w and w is known, then instead of updating m to k, m may be updated to any value in the range from k to (k+w).

[0117] Then, repeat from S1606 again.

[0118] <Pump Flag Timing Calculation Timing Chart> Here, we will explain Figure 11.

[0119] As shown in Figure 11, the pump flag signal PF is generated by the pump flag signal generation circuit 902.

[0120] The pump flag signal PF rises when the counter in the latch count circuit 1103, which is linked to the latch signal generation trigger LG, reaches the value of the pump-on time setting data TM. Subsequently, the pump flag signal PF falls when the count advances by the value held in the pump-on width time holding circuit 1102.

[0121] The flag data generation circuit 1104 functions only when the pump control enable is active.

[0122] Figure 17 is a timing chart showing the timing for turning on the pump flag according to the first embodiment. As shown in Figure 17, for example, the pump-on time setting data_1 is m+n / 2 and the pump-on width time setting data is 2. Accordingly, the pump flag signal PF will be HIGH during the following two latch periods.

[0123] (a) Latch period during which the column count is m+n / 2 and the intra-column latch count is zero (b) Latch period in which the latch count is m+n / 2+1 and the intra-column latch count is zero In response to the pump flag signal being HIGH during the period described in (a) above, one of the 16 circulating pumps in the group is turned ON during each of the 16 latch periods in which the column latch count progresses from 0 to 15 during the column period where the column count is m+n / 2. Also, in response to the pump flag signal being HIGH during the period described in (b) above, one of the 16 circulating pumps in the group is turned ON during each of the 16 latch periods in which the column latch count progresses from 0 to 15 during the column period where the column count is m+n / 2+1. These circulating pump controls can be performed independently and simultaneously between groups.

[0124] Furthermore, by setting the pump-on width data to, for example, 2, the same circulation pump can be driven twice, which can address situations where sufficient ink circulation cannot be achieved with a single drive.

[0125] With the configuration of the first embodiment, the timing for driving the circulation pump can be freely set from the discharge data, so that the circulation pump can be driven in a way that does not reduce circulation efficiency.

[0126] Furthermore, since the pump-on interval can be set, the time the circulation pump is driven each time can be freely set, allowing the circulation pump to be driven in a way that minimizes the reduction in circulation efficiency.

[0127] <Second Embodiment> <Control Configuration> The control configuration of the second embodiment is the same as that of the first embodiment.

[0128] <Data transfer timing generation> The data transfer timing generation in the second embodiment is the same as in the first embodiment.

[0129] <Liquid Dispensing Head Control Unit> The liquid discharge head control unit of the second embodiment is the same as that of the first embodiment.

[0130] <Block structure> In the second embodiment, the configuration shown in Figure 9 according to the first embodiment is changed to the configuration shown in Figure 18.

[0131] In the first embodiment, the pump timing calculation unit 901 was included in the print data processing unit 505, whereas in the second embodiment, the pump timing calculation unit 1801 is included in the liquid discharge head control unit 110. In the first embodiment, the pump flag signal generation unit 902 operates during the scan period based on the pump-on time setting data TM generated by the pump timing calculation unit 901 during the inter-scan period. In contrast, in the second embodiment, the pump timing calculation unit 1801 also operates in real time during the scan period, similar to the pump flag signal generation unit 1802.

[0132] The multi-level output data DA1 output by the image processing unit 504 is stored in the multi-level data buffer 506B. The binary output data DA2 generated by the print data processing unit 505 based on the multi-level output data DA1 is stored in the dot data buffer 506C.

[0133] The binary discharge data DA2 is read from the dot data buffer 506C and supplied to the liquid discharge head control unit 510. In particular, in this embodiment, the binary discharge data DA2 is supplied to the pump timing calculation unit 1801.

[0134] The pump flag signal generation unit 1802 receives pump flag nozzle data PN, which contains pump flag timing information, from the pump timing calculation unit 1801, and generates a pump flag signal PF based on the pump flag nozzle data PN.

[0135] Figure 19 is a functional block diagram of the pump timing calculation unit 1801 according to the second embodiment.

[0136] The output data holding unit 1901 holds the binary output data DA2 received from the dot data buffer 506C.

[0137] The analysis setting retention circuit 1902 retains the number of analysis columns used for one determination, the analysis grouping settings, the column number setting for driving the pump through analysis, and the number of columns per scan setting.

[0138] The pump timing determination unit 1903 receives binary discharge data DA2 acquired from the discharge data holding unit 1901 and analysis setting information acquired from the analysis setting holding circuit 1902. Based on this input data and information, the pump timing determination unit 1903 calculates the timing to turn on the circulation pump and supplies pump flag nozzle data PN, which contains information related to this timing, to the pump flag signal generation unit 1802.

[0139] In the first embodiment, the data supplied from the pump timing calculation unit 901 to the pump flag signal generation unit 902 is pump-on time setting data TM. In contrast, in the second embodiment, the data supplied from the pump timing calculation unit 1801 to the pump flag signal generation unit 1802 is pump flag nozzle data PN. Therefore, according to the second embodiment, the pump timing calculation unit 1801 and the pump flag signal generation unit 1802 can operate in real time during the scan period.

[0140] Figure 20 is a functional block diagram of the pump flag signal generation unit 1802 according to the second embodiment.

[0141] The pump flag signal generation unit 1802 includes a pump-on width time holding circuit 2001 that holds a set time from when the circulation pump is turned ON until when it is turned OFF.

[0142] The pump flag signal generation circuit 1802 is linked to the latch signal generation trigger LG supplied from the timing generation unit 109.

[0143] The flag data generation circuit 2002 is supplied with a pump control enable signal, pump flag nozzle data PN, data indicating the pump on-width time, and a latch signal generation trigger LG. Based on these signals and data, the flag data generation circuit 2002 generates a pump flag signal PF.

[0144] <Method for calculating pump flag timing> The pump flag timing calculation method according to the second embodiment is as shown in Figure 16, similar to the first embodiment.

[0145] In the first embodiment, the determination in S1614 is YES, and S1615 is executed. However, in the second embodiment, the determination in S1614 is NO, and S1616 is executed.

[0146] Figure 21 shows the memory-stored data according to the second embodiment.

[0147] In Figure 21, as in Figure 12, rows represent nozzles and columns represent columns. Blocks with black circles indicate that dispensing occurs in the corresponding column of the corresponding nozzle.

[0148] The pump timing calculation unit 1801 receives binary discharge data DA2 from the dot data buffer 506C. If the data received is insufficient to analyze the data range 2102 corresponding to the number of set columns held in the analysis setting holding circuit 1902, the liquid discharge head control unit 510 receives additional binary discharge data DA2 from the dot data buffer 506C.

[0149] The case in which the data corresponding to the number of setting columns held in the analysis setting retention circuit 1902 is insufficient is as follows: For example, when analyzing data from the mth column to the (m+n)th column, the corresponding binary output data DA2 has not been received from the dot data buffer 506C.

[0150] The unit of receipt in this case is indicated by the black box 2101.

[0151] Similar to the first embodiment, the calculation method in the pump timing determination unit 1903 is shown as in Figure 13.

[0152] Figures 13 and 22 both show the procedure for checking the ejected data. The difference between the two figures is whether or not the ejected data is present.

[0153] Figure 13 is the same as in the first embodiment.

[0154] Next, we will explain using Figure 22 as a reference.

[0155] As shown in Figure 22, the presence or absence of discharge is checked for a given nozzle against the set column range 2202 held in the analysis setting holding circuit 1902. If a non-discharging nozzle is found where there is no discharge data from the mth column to the (m+n)th column, the pump flag nozzle data PN, which becomes active at timing 2203 (for example, m+n / 2 (rounded up) in Figure 22), is generated.

[0156] The pump flag nozzle data PN is transferred to the pump flag signal generation unit 1802.

[0157] Without checking the nozzles thereafter, perform the same procedure starting from the column following the column number (m+n / 2 (rounded up)) mentioned above (m+n / 2 (rounded up) + 1).

[0158] In the first embodiment, the pump flag signal generation unit 902 shown in Figure 11 sets the pump flag signal PF to HIGH in the column where the latch count becomes equal to the pump-on time setting data TM. In contrast, in the second embodiment, the pump flag noise data PN itself indicates the timing to set the pump flag signal PF to HIGH. The pump flag signal PF, once it is HIGH, remains HIGH for the number of columns set in the pump-on width time holding circuit 2001.

[0159] In the second embodiment, as in the first embodiment, the nozzles may be grouped together.

[0160] <Pump Flag Timing Calculation Timing Chart> Figures 23(a) and 23(b) show the pump flag timing calculation timing chart according to the second embodiment.

[0161] As shown in Figures 23(a) and 23(b), the pump flag data generation circuit 2002 included in the pump flag signal generation unit 1802 generates the pump flag signal PF.

[0162] As shown in Figures 23(a) and 23(b), the pump flag signal PF becomes HIGH in the column where the pump flag nozzle data PN is 1. The pump flag signal PF then remains HIGH for the pump-on width time (2 in the example in Figure 23) held by the pump-on width time holding circuit 2001.

[0163] Note that the flag data generation circuit 2002 only functions when pump control enable is active.

[0164] According to the second embodiment, similar to the first embodiment, the timing for driving the circulation pump can be freely set based on the discharge data. Also, according to the second embodiment, similar to the first embodiment, the period for driving the circulation pump can be freely set. Therefore, according to the second embodiment, similar to the first embodiment, the circulation pump can be driven in a way that minimizes the reduction in liquid circulation.

[0165] Furthermore, according to the second embodiment, the pump timing calculation unit 1801 is located inside the liquid discharge head control unit 110. Therefore, it becomes possible to calculate the timing for controlling the circulation pump based on the image-processed data present in the liquid discharge head control unit 110. Consequently, the discharge data used to determine the timing for controlling the circulation pump approaches the discharge data for driving the discharge energy generating element 214 present on the recording element substrate 201. Therefore, the accuracy of the timing for driving the circulation pump can be improved.

[0166] <Third Embodiment> <Control Configuration> The control configuration of the third embodiment is the same as that of the first embodiment.

[0167] <Data transfer timing generation> The data transfer timing generation in the third embodiment is the same as in the first embodiment.

[0168] <Liquid Dispensing Head Control Unit> The liquid discharge head control unit of the third embodiment is the same as that of the first embodiment.

[0169] <Block structure> In the third embodiment, the configuration shown in Figure 9 according to the first embodiment is changed to the configuration shown in Figure 24. In the third embodiment, the print data processing unit 505 and the pump timing calculation unit 901 included therein in the first embodiment are replaced by a processor 2401 that executes a program stored in ROM 1103. In the third embodiment, similar to the first embodiment, the pump flag signal generation unit 902 operates during the scan period based on the pump-on time setting data TM generated during the inter-scan period by the processor 2401, which functions as the pump timing calculation unit 901. The pump timing calculation unit 901, which is realized by the program-operated processor 2401, is the same as that in the first embodiment, so a redundant explanation is omitted.

[0170] The pump flag signal generation unit 2402 according to the third embodiment is the same as the pump flag signal generation unit 902 according to the first embodiment, so redundant explanations will be omitted.

[0171] <Method for calculating pump flag timing> In the first embodiment, the ejection data was acquired by the ejection data holding unit 1001 in units shown in the thick frame in Figure 12. In contrast, in the third embodiment, the processor 2401 acquires the ejection data in units shown in the thick frame in Figure 25. The rest is the same as in the first embodiment, so redundant explanations will be omitted.

[0172] <Flowchart for calculating pump flag timing> This is the same as the first embodiment.

[0173] <Pump Flag Timing Calculation Timing Chart> This is the same as the first embodiment.

[0174] According to the third embodiment, the same effects as the first embodiment can be achieved. Furthermore, according to the third embodiment, since the processor 2401 performs the processing, the pump timing calculation unit 901, which is configured by hardware, becomes unnecessary.

[0175] <Examples> Figure 26 is a diagram illustrating an embodiment. In this embodiment, one group includes two discharge ports (discharge port A and discharge port B).

[0176] Ink is ejected from outlet A through columns 1, 2, 4, 7, 11, 16, 22, and 29. Ink is ejected from outlet B through columns 2, 11, 18, and 22. In this embodiment, n is 4 and k is 2, as described in the embodiment.

[0177] In this case, as shown in the diagram, the circulation pumps are turned ON in columns 4, 6, 8, 13, 15, 18, 24, and 26. This will be explained.

[0178] The regions where outlet A is continuously turned OFF for 4 columns are the five regions shown from A1 to A5. The regions where outlet B is continuously turned OFF for 4 columns are the 11 regions shown from B1 to B11.

[0179] First, region C1, which is the same as region B1, is detected as a region where either outlet A or outlet B is turned OFF for four consecutive columns. In response to this, the circulation pump in column 4 is turned ON.

[0180] As the inspection progresses through k=2 columns, region B3 is detected as region C2 because either outlet A or outlet B is OFF for 4 consecutive columns. Correspondingly, the circulation pump is turned ON in column 6.

[0181] As the inspection progresses through k=2 columns, region C3 is detected, which is the same region as region B5, as either outlet A or outlet B is OFF for 4 consecutive columns. Correspondingly, the circulation pump is turned ON in column 8.

[0182] The inspection proceeds by advancing k=2 columns at a time after advancing k=2 columns, so region C4, which is the same as region A1, is detected as a region where either outlet A or outlet B is OFF for 4 consecutive columns. In response to this, the circulation pump is turned ON in column 13.

[0183] As the inspection progresses through k=2 columns, region C5 is detected as the same region as region B8, where either outlet A or outlet B is OFF for 4 consecutive columns. Correspondingly, the circulation pump in column 15 is turned ON.

[0184] The inspection proceeds by advancing k=2 columns at a time after advancing k=2 columns, so region C6, which is the same as region A2, is detected as a region where either outlet A or outlet B is OFF for 4 consecutive columns. In response to this, the circulation pump is turned ON in column 18.

[0185] The inspection proceeds by advancing k=2 columns at a time after advancing k=2 columns, so region C7, which is the same as region A3, is detected as a region where either outlet A or outlet B is OFF for 4 consecutive columns. Correspondingly, the circulation pump is turned ON at column 24.

[0186] As the inspection progresses through k=2 columns, region C8, which is the same as region A5, is detected as a region where either outlet A or outlet B is OFF for 4 consecutive columns. Correspondingly, the circulation pump is turned ON in column 26.

[0187] As mentioned above, the circulation pump is turned ON in columns 4, 6, 8, 13, 15, 18, 24, and 26. However, in column 4, the discharge from outlet A and the ON state of the circulation pump corresponding to outlet A occur simultaneously, resulting in an overlap. Therefore, in column 4, the discharge from outlet A is prioritized, and the circulation pump corresponding to outlet A is not turned ON. For example, the recording element board 201 is equipped with a circuit for making this adjustment.

[0188] In column 18, the discharge from outlet B and the ON state of the circulation pump corresponding to outlet B overlap. Therefore, in column 18, the discharge from outlet B is prioritized, and the circulation pump corresponding to outlet B is not turned ON. For example, the recording element board 201 is equipped with a circuit for making this adjustment.

[0189] <Other Embodiments> In the above embodiment, if discharge occurs from at least one nozzle belonging to a group in any column within the inspection range, all circulation pumps belonging to the group are, in principle, turned on. However, this is not limited to cases where there are N or more such discharge ports, all circulation pumps belonging to the group may, in principle, be turned on. Here, N is between 2 and the total number.

[0190] <Technical Features of This Disclosure> This disclosure includes the following configuration and method:

[0191] [Configuration 1] A liquid dispensing head for dispensing liquid onto a recording medium along the scanning direction, A liquid discharge head control unit for controlling the liquid discharge head, A liquid dispensing device comprising, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control unit is A means for generating the output data based on image data, The inspection section is provided while shifting in the scanning direction, and if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the generation means generates the circulation data based on the discharge data so that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section. Equipped with, Liquid discharge device.

[0192] [Configuration 2] The generation means generates the circulation data such that, when the discharge drive element drives the discharge energy generating element corresponding to the discharge drive element in each inspection section, the circulation drive element corresponding to the discharge drive element does not drive the circulation energy generating element corresponding to the circulation drive element in the inspection section. A liquid dispensing device as described in Configuration 1.

[0193] [Configuration 3] The aforementioned multiple discharge drive elements are divided into multiple groups, The aforementioned multiple circulating drive elements are divided into the aforementioned multiple groups. A liquid dispensing device as described in Configuration 1.

[0194] [Structure 4] The generating means generates the circulation data such that, in each inspection section, if at least one of the plurality of discharge drive elements belonging to each group does not drive the at least one discharge energy generating element corresponding to the at least one discharge drive element, the plurality of circulation drive elements corresponding to each of the plurality of discharge drive elements belonging to each group in the drive section drives the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements. The liquid dispensing device described in configuration 3.

[0195] [Composition 5] The generation means generates the circulation data such that, in each inspection section, when all of the multiple discharge drive elements belonging to each group drive the multiple discharge energy generating elements corresponding to all of the multiple discharge drive elements, the multiple circulation drive elements corresponding to each group do not drive the multiple circulation energy generating elements corresponding to the multiple circulation drive elements in the drive section. The liquid dispensing device described in configuration 4.

[0196] [Composition 6] If the generating means generates the circulation data such that the plurality of circulation drive elements corresponding to the plurality of discharge drive elements belonging to each group in the drive section do not drive the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements, it shifts the inspection section so that the next inspection section is shifted by one column from the current inspection section. The liquid dispensing device described in configuration 5.

[0197] [Composition 7] The at least one discharge drive element is any one of the plurality of discharge drive elements. A liquid dispensing device according to any one of configurations 4 to 6.

[0198] [Structure 8] The at least one discharge drive element is all of the discharge drive elements among the plurality of discharge drive elements. A liquid dispensing device according to any one of configurations 4 to 6.

[0199] [Composition 9] The at least one discharge drive element is two or more of the plurality of discharge drive elements. A liquid dispensing device according to any one of configurations 4 to 6.

[0200] [Configuration 10] When the generating means generates the circulation data such that the plurality of circulation drive elements corresponding to the plurality of discharge drive elements belonging to each group in the drive section drive the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements, it shifts the inspection section so that the start position of the next inspection section corresponds to any position between the start position and the end position of the current drive section. A liquid dispensing device according to any one of configurations 4 to 9.

[0201] [Composition 11] When the generation means generates the circulation data such that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, it shifts the inspection section so that the start position of the next inspection section corresponds to the end position of the current drive section. A liquid dispensing device as described in Configuration 1.

[0202] [Composition 12] If the generating means generates the circulation data such that the circulation drive element corresponding to the discharge drive element does not drive the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, it shifts the inspection section so that the next inspection section is shifted by one column from the current inspection section. A liquid dispensing device according to configuration 1 or 11.

[0203] [Composition 13] A first non-driving section is provided between the starting position of the inspection section and the starting position of the driving section. A liquid dispensing device according to any one of configurations 1 to 12.

[0204] [Composition 14] A second non-driving section is provided between the end position of the inspection section and the end position of the driving section. A liquid dispensing device according to any one of configurations 1 to 13.

[0205] [Composition 15] If the discharge data and the circulation data indicate that both the discharge energy generating element and the circulation drive element corresponding to the discharge energy generating element should be driven simultaneously, the generating means modifies the circulation data so that the discharge energy generating element is driven but the circulation drive element corresponding to the discharge energy generating element is not driven. A liquid dispensing device according to any one of configurations 1 to 14.

[0206] [Composition 16] Each of the pressure chambers is provided with its own circulating drive element and its corresponding circulating drive element. A liquid dispensing device according to any one of configurations 1 to 15.

[0207] [Composition 17] A liquid discharge head control device for controlling a liquid discharge head for dispensing liquid onto a recording medium, A liquid dispensing head for dispensing liquid onto a recording medium along the scanning direction, A liquid discharge head control unit for controlling the liquid discharge head, A liquid dispensing device comprising, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control unit is A means for generating the output data based on image data, The inspection section is provided while shifting in the scanning direction, and if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the generation means generates the circulation data based on the discharge data so that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section. Equipped with, Liquid dispensing head control device.

[0208] [method] A liquid dispensing head control method for controlling a liquid dispensing head for dispensing liquid onto a recording medium, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control method is as follows: A step of generating the output data based on image data, A generation step of generating circulation data based on the discharge data, such that if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, the inspection section is provided with inspection sections shifted in the scanning direction, Having, Liquid dispensing head control method.

Claims

1. A liquid dispensing head for dispensing liquid onto a recording medium along the scanning direction, A liquid discharge head control unit for controlling the liquid discharge head, A liquid dispensing device comprising, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control unit is A means for generating the output data based on image data, The inspection section is provided while shifting in the scanning direction, and if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the generation means generates the circulation data based on the discharge data so that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section. Equipped with, Liquid discharge device.

2. The generation means generates the circulation data such that, when the discharge drive element drives the discharge energy generating element corresponding to the discharge drive element in each inspection section, the circulation drive element corresponding to the discharge drive element does not drive the circulation energy generating element corresponding to the circulation drive element in the inspection section. The liquid dispensing device according to claim 1.

3. The aforementioned multiple discharge drive elements are divided into multiple groups, The aforementioned multiple circulating drive elements are divided into the aforementioned multiple groups. The liquid dispensing device according to claim 1.

4. The generating means generates the circulation data such that, in each inspection section, if at least one of the plurality of discharge drive elements belonging to each group does not drive the at least one discharge energy generating element corresponding to the at least one discharge drive element, the plurality of circulation drive elements corresponding to each of the plurality of discharge drive elements belonging to each group in the drive section drives the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements. The liquid dispensing device according to claim 3.

5. The generation means generates the circulation data such that, in each inspection section, when all of the multiple discharge drive elements belonging to each group drive the multiple discharge energy generating elements corresponding to all of the multiple discharge drive elements, the multiple circulation drive elements corresponding to each group do not drive the multiple circulation energy generating elements corresponding to the multiple circulation drive elements in the drive section. The liquid dispensing device according to claim 4.

6. If the generating means generates the circulation data such that the plurality of circulation drive elements corresponding to the plurality of discharge drive elements belonging to each group in the drive section do not drive the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements, it shifts the inspection section so that the next inspection section is shifted by one column from the current inspection section. The liquid dispensing device according to claim 5.

7. The at least one discharge drive element is any one of the plurality of discharge drive elements. The liquid dispensing device according to claim 4.

8. The at least one discharge drive element is all of the discharge drive elements among the plurality of discharge drive elements. The liquid dispensing device according to claim 4.

9. The at least one discharge drive element is two or more of the plurality of discharge drive elements. The liquid dispensing device according to claim 4.

10. When the generating means generates the circulation data such that the plurality of circulation drive elements corresponding to the plurality of discharge drive elements belonging to each group in the drive section drive the plurality of circulation energy generating elements corresponding to the plurality of circulation drive elements, it shifts the inspection section so that the start position of the next inspection section corresponds to any position between the start position and the end position of the current drive section. The liquid dispensing device according to claim 4.

11. When the generation means generates the circulation data such that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, it shifts the inspection section so that the start position of the next inspection section corresponds to the end position of the current drive section. The liquid dispensing device according to claim 1.

12. If the generating means generates the circulation data such that the circulation drive element corresponding to the discharge drive element does not drive the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, it shifts the inspection section so that the next inspection section is shifted by one column from the current inspection section. The liquid dispensing device according to claim 1.

13. A first non-driving section is provided between the starting position of the inspection section and the starting position of the driving section. The liquid dispensing device according to claim 1.

14. A second non-driving section is provided between the end position of the inspection section and the end position of the driving section. The liquid dispensing device according to claim 1.

15. If the discharge data and the circulation data indicate that both the discharge energy generating element and the circulation drive element corresponding to the discharge energy generating element should be driven simultaneously, the system further includes means for driving the discharge energy generating element and not driving the circulation drive element corresponding to the discharge energy generating element. The liquid dispensing device according to claim 1.

16. Each of the pressure chambers is provided with its own circulating drive element and its corresponding circulating drive element. The liquid dispensing device according to claim 1.

17. A liquid discharge head control device for controlling a liquid discharge head for dispensing liquid onto a recording medium, A liquid dispensing head for dispensing liquid onto a recording medium along the scanning direction, A liquid discharge head control unit for controlling the liquid discharge head, A liquid dispensing device comprising, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control unit is A means for generating the output data based on image data, The inspection section is provided while shifting in the scanning direction, and if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the generation means generates the circulation data based on the discharge data so that the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section. Equipped with, Liquid dispensing head control device.

18. A liquid dispensing head control method for controlling a liquid dispensing head for dispensing liquid onto a recording medium, The aforementioned liquid dispensing head is Multiple outlets for dispensing liquid, Multiple pressure chambers communicating with the aforementioned multiple discharge ports, Multiple discharge energy generating elements that generate energy to discharge the liquid present in the multiple pressure chambers from the multiple discharge ports, Multiple circulation energy generating elements that generate energy to circulate the liquid in the multiple pressure chambers through a flow path inside the liquid discharge head, Based on discharge data, a plurality of discharge drive elements for driving the plurality of discharge energy generating elements, Based on circulation data, a plurality of circulation drive elements for driving the plurality of circulation energy generating elements, Equipped with, The liquid discharge head control method is as follows: A step of generating the output data based on image data, A generation step of generating circulation data based on the discharge data, such that if the discharge drive element does not drive the discharge energy generating element corresponding to the discharge drive element in each inspection section, the circulation drive element corresponding to the discharge drive element drives the circulation energy generating element corresponding to the circulation drive element in the drive section included in the inspection section, the inspection section is provided with inspection sections shifted in the scanning direction, Having, Liquid dispensing head control method.

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