JP2010184476A - Liquid ejector and liquid ejection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress poor ejection caused by insufficient refilling of liquid. <P>SOLUTION: A liquid ejector (combined machine 1) includes a liquid ejection head (head HD), a head movement section (carriage-moving mechanism), and a controller (main control part 7). The controller controls the moving-ejection movement and makes the number of times of the moving-ejection movement for a certain range more than the case of judgement conditions being unfulfilled when fulfilling the judgement conditions showing that the moving ejection rate of a liquid in time series is excessive. When the consumption of the liquid stored in a liquid storage part (ink cartridge IC) is the first consumption, the controller defines the number of times of the moving-ejection movement for a certain range according to the judgement conditions by which the ejection rate has been defined to be excessive with the ejection rate less than the second consumption different from the first consumption. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus and a liquid ejecting method.

  In a liquid ejecting apparatus such as an ink jet printer, when the amount of liquid replenished from the liquid replenishing unit is smaller than the amount of liquid ejected from the nozzle, a problem of poor liquid ejection at the nozzle occurs. was there. In order to solve such a problem, an apparatus for controlling dot formation based on the temperature of the liquid jet head has been proposed (see Patent Document 1).

JP 2004-66550 A

However, in the conventional apparatus, sufficient study has not been made on the relationship between the change in the injection amount in time series and the replenishment property when the liquid is continuously ejected from the nozzle.
The present invention has been made in view of such circumstances, and an object thereof is to effectively suppress ejection failure caused by insufficient replenishment of liquid when liquid is continuously ejected.

The main invention for achieving the object is as follows:
A liquid ejecting head that has a plurality of a series of flow paths from the liquid replenishing unit to the nozzle, replenishes the liquid from the liquid storing unit stored in the common liquid chamber through the liquid replenishing unit, and ejects the liquid from the corresponding nozzle;
A head moving unit that moves the liquid ejecting head in a moving direction;
When the liquid jet head is moved in the moving direction, the moving jet operation for jetting the liquid from the nozzle is controlled, and the determination condition indicating that the liquid jet rate in the moving jet operation is excessive is satisfied. A controller that increases the number of times of the moving injection operation with respect to a certain range as compared with a case where the determination condition is not satisfied,
When the consumption amount of the liquid stored in the liquid storage unit is a first consumption amount, the injection rate is determined to be excessive with an injection rate smaller than a second consumption amount different from the first consumption amount A controller for determining the number of times of the moving injection operation for the certain range according to a determination condition;
A liquid ejecting apparatus having
Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

FIG. 1A is a block diagram illustrating a configuration of a printing system. FIG. 1B is a diagram illustrating each unit realized by the main control unit. It is a perspective view explaining a printing mechanism. It is a figure explaining a nozzle row. FIG. 4A is a diagram illustrating an ink flow path from the ink cartridge to the head. FIG. 4B is a diagram illustrating the in-head flow path. It is a figure explaining a mode that a dot is formed with a nozzle row of a certain color. FIG. 6A is a front view illustrating the internal structure of the ink cartridge. FIG. 6B is a perspective view illustrating the internal structure of the ink cartridge. FIG. 7A is a front view illustrating the internal structure of the ink cartridge in a state where ink is sufficiently stored. FIG. 7B is a perspective view illustrating the internal structure of the ink cartridge in the same state. FIG. 8A is a front view illustrating the internal structure of the ink cartridge in a state where ink is stored in the lower storage chamber. FIG. 8B is a perspective view illustrating the internal structure of the ink cartridge in the same state. FIG. 9A is a front view illustrating the internal structure of the ink cartridge in a state where ink is stored in the buffer chamber. FIG. 9B is a perspective view illustrating the internal structure of the ink cartridge in the same state. It is a figure explaining the relationship between each state shown to FIGS. 7-9, and a hydrostatic head pressure. FIG. 11A is a diagram illustrating the relationship between the hydrostatic head pressure and the ink consumption. FIG. 11B is a diagram illustrating each threshold value used in the continuity evaluation process. FIG. 11C is a diagram illustrating each threshold value used in the replenishment evaluation process. It is a flowchart explaining printing operation. It is a flowchart explaining a continuity evaluation process. It is a flowchart explaining a replenishment evaluation process. It is a figure explaining an example of a division | segmentation scanning process. It is a figure explaining the other example of path number switching. It is a figure explaining the 1st modification of a division | segmentation scanning process. It is a figure explaining the 2nd modification of a division | segmentation scanning process. It is a figure explaining the 3rd modification of a division | segmentation scanning process.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

That is, a liquid ejecting head that has a plurality of a series of flow paths from the liquid replenishing unit to the nozzle, replenishes the liquid from the liquid storing unit stored in the common liquid chamber through the liquid replenishing unit, and ejects the liquid from the corresponding nozzle. A head moving unit that moves the liquid ejecting head in the moving direction; and a moving ejecting operation that ejects the liquid from the nozzle while moving the liquid ejecting head in the moving direction, and the liquid in the moving ejecting operation A controller that increases the number of times of the moving jetting operation for a certain range in comparison with a case where the determination condition is not satisfied when the determination condition indicating that the injection rate of the liquid is excessive is stored in the liquid storage unit. When the consumed amount of the liquid is the first consumption amount, it is determined that the injection rate is excessive with an injection rate smaller than the second consumption amount different from the first consumption amount. By the above determination condition, and the controller for determining the number of the mobile injection operation with respect to the certain range, it can be realized a liquid ejecting apparatus having the be revealed.
According to such a liquid ejecting apparatus, when the ejection rate of the liquid in the moving ejection operation is excessive, the number of times of the moving ejecting operation with respect to a certain range is increased, so the liquid resulting from the excessive ejection rate. Insufficient supply can be suppressed. Furthermore, since the liquid pressure in the common liquid chamber is taken into account in determining whether or not to increase the number of moving jetting operations, insufficient liquid replenishment can be reliably suppressed.

In such a liquid ejecting apparatus, it is preferable that the ejection rate of the liquid is a ratio between a liquid amount ejected at a certain timing and a maximum liquid amount ejectable at the certain timing.
According to such a liquid ejecting apparatus, it is possible to reliably recognize the shortage of liquid replenishment.

In such a liquid ejecting apparatus, the controller evaluates continuity when the liquid is ejected at a predetermined number of times within a certain time-series range when the liquid is ejected at an ejection rate equal to or higher than the first ejection rate. And when the continuity evaluation evaluates that there is continuity, the liquid injection at the injection rate equal to or higher than the second injection rate is a predetermined number of times within another time series range following the certain time series. It is preferable to perform a replenishment evaluation that evaluates that there is no replenishment when performed, and to determine that the determination condition is satisfied when the replenishment evaluation evaluates that there is no replenishment.
According to such a liquid ejecting apparatus, it is determined by the two types of evaluation that the determination condition is satisfied, so that the determination accuracy can be improved.

In the liquid ejecting apparatus, in the continuity evaluation, an evaluation value is added when the ejection rate at a certain timing is equal to or higher than the first ejection rate, while the ejection rate at a certain timing is Preferably, the evaluation value is subtracted when the injection rate is equal to or less than a third injection rate lower than one injection rate, and it is evaluated that there is continuity when the evaluation value exceeds a determination value corresponding to the specified number of times.
According to such a liquid ejecting apparatus, since the continuity is evaluated based on the evaluation value, the accuracy of the evaluation can be increased.

In the liquid ejecting apparatus, the first injection rate at the first consumption amount is smaller than the first injection rate at the second consumption amount, and the second injection rate at the first consumption amount. Is preferably smaller than the second injection rate at the second consumption.
According to such a liquid ejecting apparatus, it is possible to reliably make a determination according to the liquid pressure in the common liquid chamber.

In the liquid ejecting apparatus, the liquid ejecting head includes a nozzle row in which a plurality of the nozzles are arranged in an intersecting direction intersecting the moving direction, and the controller includes the nozzle row when the determination condition is satisfied. It is preferable that a part of the nozzles to which the nozzle belongs belongs to perform the first moving injection operation and the other part of the nozzles to perform the subsequent movement injection operation.
According to such a liquid ejecting apparatus, it is possible to easily limit the amount of liquid ejected.

In such a liquid ejecting apparatus, the controller causes the nozzle to perform the above-described moving ejecting operation using each of the nozzles belonging to the nozzle row and located in one half of the crossing direction, and the remaining nozzles. It is preferable to perform a later moving jetting operation using a nozzle.
According to such a liquid ejecting apparatus, since the ejected liquid and each nozzle correspond to each other, the uniformity of the ejected liquid can be improved.

It is also clarified that the following liquid ejecting method can be realized.
That is, using a liquid ejecting head having a plurality of series of flow paths from the liquid replenishing unit to the nozzle, the liquid from the liquid storing unit stored in the common liquid chamber is replenished through the liquid replenishing unit and ejected from the corresponding nozzle. A determination condition indicating that an ejection rate of the liquid is excessive in a moving ejection operation in which the liquid is ejected from the nozzle while moving the liquid ejecting head in a moving direction. When the consumption amount of the liquid stored in the liquid storage unit is the first consumption amount, a determination condition indicating that the injection rate is excessive with an injection rate smaller than the second consumption amount different from the first consumption amount If the determination condition is satisfied and the determination condition is satisfied, the number of the movement injection operations for a certain range in the moving injection operation may not satisfy the determination condition. It will become apparent that it possible to realize a liquid-jet method with the method comprising many, the.

=== First Embodiment ===
<About the printing system>
The printing system illustrated in FIG. 1A is for printing an image on paper S (see FIG. 2 and the like), and includes a computer CP and a multifunction device 1. The multifunction machine 1 operates also as an ink jet printer, and is a kind of liquid ejecting apparatus that ejects liquid ink (water-based ink, oil-based ink) to print an image on a medium such as paper S. The computer CP performs control for causing the multi-function device 1 to perform a liquid ejecting operation.

  The multifunction device 1 includes an image reading mechanism 2, a printing mechanism 3, a drive signal generation unit 4, a card slot 5, a sensor group 6, and a main control unit 7. In the multi function device 1, the control target unit, that is, the image reading mechanism 2, the printing mechanism 3, and the drive signal generation unit 4 are controlled by a main control unit 7 as a controller.

  The image reading mechanism 2 is a part that reads a document and acquires multi-gradation image data. For example, RGB image data expressed with 256 gradations for each color of RGB is acquired. The printing mechanism 3 is a portion that prints an image by ejecting ink onto a sheet S as a medium, and corresponds to a liquid ejecting mechanism. For example, as shown in FIG. 2, the printing mechanism 3 includes a paper transport mechanism 10, a carriage CR, and a carriage movement mechanism 20. The paper transport mechanism 10 is for transporting the paper S in the paper feed direction, and includes a platen 11 that supports the paper S from the back side, and a transport roller 12 that is disposed upstream of the platen 11 in the paper feed direction. , The sheet discharge roller 13 disposed downstream of the platen 11 in the paper feeding direction, and the conveyance motor 14 serving as a drive source for the conveyance roller 12 and the sheet discharge roller 13. The carriage CR is a member to which the ink cartridge IC and the head HD are attached. With the head HD attached to the carriage CR, the nozzle forming surface faces the platen 11.

  As shown in FIG. 3, the head HD is provided with a plurality of nozzles Nz. A plurality of nozzles Nz arranged in the paper feed direction (corresponding to a crossing direction intersecting the carriage movement direction) constitutes a nozzle row, and the plurality of nozzle rows are arranged in the carriage movement direction. Specifically, two nozzle rows are provided for one type of ink. These nozzle rows are shifted by 40 shots (40 dots) in the carriage movement direction and by a half nozzle pitch in the paper feed direction. That is, the nozzles Nz belonging to these nozzle rows are arranged in a staggered manner. In the present embodiment, one nozzle row is composed of 180 nozzles Nz, and adjacent nozzles Nz are provided at an interval equivalent to 180 dpi. Therefore, printing equivalent to 360 dpi can be performed by using one set of nozzle rows. In the example of FIG. 3, in order from the left end, black ink nozzle rows Nk1 and Nk2 that eject black ink, yellow ink nozzle rows Ny1 and Ny2 that eject yellow ink, cyan ink nozzle rows Nc1 and Nc2 that eject cyan ink, and The magenta ink nozzle rows Nm1 and Nm2 for ejecting magenta ink are provided. Therefore, the multifunction machine 1 performs color printing with four colors.

  As shown in FIGS. 4A and 4B, the ink in the ink cartridge IC disposed above the head HD is supplied to the head HD. That is, the ink in the ink cartridge IC passes through the ink supply needle 8 inserted in the bottom of the ink cartridge IC and the ink supply pipe 9 that communicates between the ink supply needle 8 and the head HD to the head HD. Supplied. The head HD is a type of liquid ejecting head, and the ink cartridge IC is a type of liquid storage unit that stores the liquid to be ejected. The head HD is provided with a series of in-head flow paths from the common ink chamber 31 through the ink supply path 32 and the pressure chamber 33 to the nozzle Nz. The ink from the ink supply pipe 9 is once stored in the common ink chamber 31 and then supplied from the ink supply path 32 to the pressure chamber 33. The common ink chamber 31 is a kind of common liquid chamber that temporarily stores ink (liquid) from the ink cartridge IC. The ink supply path 32 is an ink flow path for supplying ink in the common ink chamber 31 to the pressure chamber 33, and is a kind of liquid supply section. The pressure chamber 33 is provided for each nozzle Nz. Part of the pressure chamber 33 is partitioned by an elastic plate, and the pressure in the ink in the pressure chamber 33 is changed by deforming the elastic plate by a piezo element 34 (corresponding to an element that operates to eject liquid). Is given. Ink droplets can be ejected from the nozzles Nz according to the pressure change of the ink in the pressure chamber 33. Here, the degree of deformation of the piezo element 34 is determined according to the voltage of the applied drive signal. For this reason, the magnitude of the pressure change applied to the ink in the pressure chamber 33 can be determined according to the voltage waveform of the drive signal (the waveform of the ejection pulse), and thus the amount of ink droplets ejected from the corresponding nozzle Nz. Can be determined in various ways.

  The carriage movement mechanism 20 is for moving the carriage CR in the carriage movement direction. In the multi-function device 1, since the head HD is attached to the carriage CR, the carriage moving mechanism 20 is a kind of head moving unit that moves the liquid ejecting head in the moving direction. As shown in FIG. 2, the carriage moving mechanism 20 has a timing belt 21, a carriage motor 22, and a guide shaft 23. The timing belt 21 is connected to the carriage CR and is spanned between the drive pulley 24 and the idler pulley 25. The carriage motor 22 is a drive source that rotates the drive pulley 24. The guide shaft 23 is a member for guiding the carriage CR in the carriage movement direction. In the carriage moving mechanism 20, the carriage CR can be moved in the carriage movement direction by operating the carriage motor 22. Then, a dot formation operation (corresponding to a movement ejection operation) in which ink is intermittently ejected while moving the carriage CR is performed, whereby a row of dots arranged in the carriage movement direction is formed on the paper S. This row of dots is also called a raster line. By alternately repeating the dot forming operation and the paper S transporting operation, a plurality of raster lines arranged in the paper feeding direction are formed on the paper S, and an image is printed.

  The ink ejected from each nozzle Nz is landed on the paper S and becomes dots in units of nozzle rows arranged along the nozzle rows. As described above, the head HD included in the multifunction device 1 ejects the same color (type) of ink from the two nozzle rows. In this embodiment, dots in units of nozzle rows are formed by ink ejected from 360 nozzles Nz. A raster line in which a plurality of dots are arranged in the main scanning direction is formed on the surface of the paper S by sequentially forming these dots while shifting their positions in the main scanning direction. FIG. 5 is an explanatory diagram showing a state in which dots in units of nozzle rows are formed by two nozzle rows that eject the same color ink. In this figure, a raster area where dots are formed in one pass (main scan) is schematically represented by white circles and black circles. That is, the black circles indicate the positions of dots formed at the positions of the nozzle rows shown in FIG. 5, and the white circles indicate dots formed when the nozzle rows are at different positions. For convenience of explanation, in the movement direction in which the carriage CR is moving, the preceding nozzle row is also referred to as a preceding nozzle row, and the following nozzle row is also referred to as a trailing nozzle row. The raster area is configured by arranging a plurality of raster lines in which dots are arranged in a line in the movement direction in the paper feed direction. As described above, one set of nozzle rows has 360 nozzles Nz. Therefore, in one dot forming operation, 360 raster lines corresponding to 360 nozzles Nz are formed in the raster area. In the example of FIG. 5, the raster area has N dots in the paper feed direction and L dots in the movement direction. That is, it has N × L dots in total.

  The drive signal generation unit 4 is a part that generates a drive signal used when ejecting ink from each nozzle Nz. The drive signal generator 4 generates drive signals having various waveforms based on a control signal from the print control unit 68 included in the main controller 7 (ASIC 51). The card slot 5 is a part that is electrically connected to the memory card. An image file or the like to be printed is stored in a memory card that is attached to and detached from the card slot 5. The sensor group 6 includes a plurality of sensors for detecting the state of each part in the multifunction device 1. The sensor group 6 includes, for example, a linear encoder 41 for detecting the position of the carriage CR, a rotary encoder (not shown) for detecting the transport amount of the paper S, and a temperature around the head HD ( A temperature sensor 42 for detecting a kind of environmental temperature is included. Then, detection signals from the sensors are output to the main control unit 7.

  The main control unit 7 corresponds to a controller that controls the multifunction device 1. As shown in FIG. 1A, the main control unit 7 includes an ASIC (application specific IC) 51, a ROM 52, and an SDRAM (Synchronous DRAM) 53. The ASIC 51 is an integrated circuit in which a CPU and a control circuit necessary for operating the multifunction device 1 are incorporated. The ROM 52 is a memory that stores various programs and data for controlling the multifunction machine 1. The SDRAM 53 functions as a work memory, such as storing image files. The ASIC 51 includes a CPU 61, a host I / F 62, a USB host circuit 63, a decoding circuit 64, a card I / F 65, a reading control unit 66, an image processing unit 67, a printing control unit 68, and an SDRAM_I / F 69.

  The CPU 61 operates according to a program stored in the ROM 52 and controls the operation of the multifunction device 1 in an integrated manner. For example, the CPU 61 controls the reading control unit 66 to execute reading processing of an image printed on the paper S, or controls the image processing unit 67 to execute color conversion processing. The CPU 61 controls the printing control unit 68 to cause the printing mechanism 3 to execute image printing processing. In this printing process, the CPU 61 calculates an ink ejection amount from the relationship between dot formation data (described later) and the amount of ejected ink droplets. Then, the CPU 61 acquires the ink consumption amount for the ink cartridge IC by integrating the calculated ejection amount. The ink consumption acquired by the CPU 61 is stored in the memory. For example, it is stored in a memory (not shown) or SDRAM 53 provided in the ink cartridge IC.

  The host I / F 62 controls communication with the computer CP. For example, print data transmitted from the computer CP is received, or status is transmitted to the computer CP. The USB host circuit 63 communicates with a USB connection type external device HW. The decoding circuit 64 performs a decoding process for obtaining RGB image data from a JPEG format image file. Then, the decoding circuit 64 stores the RGB image data obtained by controlling the SDRAM_I / F 69 in the SDRAM 53. The card I / F 65 communicates with the memory card installed in the card slot 5. The reading control unit 66 controls the image reading mechanism 2. Further, the reading control unit 66 controls the SDRAM_I / F 69 to store the RGB image data from the image reading mechanism 2 in the SDRAM 53.

  The image processing unit 67 converts multi-tone RGB image data into multi-tone CMYK image data. Further, the image processing unit 67 converts CMYK image data into dot formation data for the head HD. The dot formation data obtained by the conversion is stored in the SDRAM 53. The multifunction device 1 can form dots with three sizes of large dots, medium dots, and small dots. That is, dot formation is controlled with four gradations including the non-formation of dots. In order to express four gradations, the dot formation data is composed of 2-bit data for each unit area where dots can be formed. That is, data [11] indicating the formation of large dots, data [10] indicating the formation of medium dots, data [01] indicating the formation of small dots, and data [00] indicating the formation of non-formed dots. Composed.

  The print control unit 68 controls the printing mechanism 3 and the drive signal generation unit 4. The print control unit 68 outputs a motor control signal for controlling the motor, for example. This motor control signal is output to the transport motor 14 and the carriage motor 22, for example. The print control unit 68 outputs DAC data for determining the voltage of the generated drive signal. The DAC data is stored in, for example, the ROM 52, and is read out when the drive signal is generated and output to the drive signal generation unit 4. Further, the print control unit 68 controls the transfer of dot formation data to the head HD.

  As shown in FIG. 1B, the main control unit 7 configured as described above executes an image data acquisition unit 71, a print control unit 72 (an ejection control unit 73, a scan control unit) by executing a computer program stored in the ROM 52. 74), functions as an injection rate calculation unit 75, a normal scanning unit 76, a division scanning unit 77, and a consumption acquisition unit 78. The operation of the main control unit 7 will be described later.

=== Operation of MFP 1 ===
<About features of operation>
In the multi-function device 1, when the amount of ink replenished from the common ink chamber 31 into the pressure chamber 33 is smaller than the amount of ink ejected from the nozzle Nz, that is, when the ink refill speed is slow, There has been a problem that injecting failure occurs. This problem is particularly noticeable when ink is continuously ejected from the nozzle Nz.

  In view of such circumstances, in this multifunction device 1, it is likely that the change in the ejection amount in time series will be grasped from the ink ejection amount in the nozzle array for each ejection timing, and the ink supply to the pressure chamber 33 will be insufficient. Predict whether or not. When it is determined that there is a possibility that ink replenishment will be insufficient (when the determination condition indicating that the liquid ejection rate is excessive in the moving ejection operation is satisfied), a predetermined area on the sheet S (a certain range) The number of dot formation operations for () is larger than when it is determined that this is not the case (when the determination condition is not satisfied). Specifically, an image is printed by a two-pass dot forming operation on a predetermined area on the paper S on which an image can be printed by the one-pass dot forming operation. In short, printing in which the number of nozzles Nz that can eject ink is limited (printing in which the amount of ink ejected is limited) is performed.

  Here, the replenishment property of the ink to the pressure chamber 33 changes according to the ink pressure in the common ink chamber 31. This is because the ink flow in the ink supply path 32 is determined by the pressure loss (pressure loss) generated by the ink flowing between the ink cartridge IC and the pressure chamber 33. For example, consider a case where the ink pressure is a second pressure lower than the first pressure. In this case, it can be said that the replenishment property of the ink into the pressure chamber 33 is worse than that in the case of the first pressure. For this reason, it can be said that it is preferable to consider the ink pressure in the common ink chamber 31 when determining whether or not to increase the number of dot forming operations for a certain range. In the apparatus that supplies ink from the ink cartridge IC (liquid storage unit) disposed above to the common ink chamber 31 as in the multi-function device 1, the water head of the ink stored in the ink cartridge IC is used as the common ink chamber. Affects the ink pressure at 31.

Here, the above water head can be expressed by the following equation (1).
Water head P = flow rate Q × channel resistance R + density ρ × constant g × height h (1)
The flow rate Q is a flow rate of ink in a section from the ink cartridge IC to the boundary position with the ink supply path 32 indicated by reference numeral 31a in FIG. 4B. The flow path resistance R is a degree indicating the ease of ink flow, and can be said to be an internal loss of ink. Regarding this flow path resistance R, the flow path resistance R _straight in a substantially rectangular flow paths, the following equation (2), the channel resistance R _circular of the circular cross-section respectively represented by the following formula (3).
Channel resistance R _straight = (12 × viscosity μ × length L) / (width W × height H ³ ) (2)
Channel resistance R _circle = (8 × viscosity μ × length L) / (π × radius r ⁴ ) (3)
The density ρ indicates the density of the ink, and the constant g indicates the gravitational acceleration. The height h is a difference in the height direction between the ink level in the ink cartridge IC and the boundary position 31a.

  In this multifunction device 1, focusing on the fact that the ink head affects the ink pressure in the common ink chamber 31, the amount of ink consumed in the ink cartridge IC (corresponding to the amount of liquid consumed) is taken into consideration in the above determination. It has a feature in that. Specifically, based on the ink consumption amount, the main control unit 7 ejects less than the second consumption amount different from the first consumption amount when the ink consumption amount in the ink cartridge IC is the first consumption amount. It is also characterized in that the determination condition determined that the injection rate is excessive at the rate is used. Details will be described below.

<About ink cartridge IC>
The internal structure of the ink cartridge IC will be described. As shown in FIGS. 6A and 6B, a partition plate is provided inside the ink cartridge IC, and an upper storage chamber 81, a lower storage chamber 82, and a buffer chamber 83 are partitioned. The upper storage chamber 81 is provided in the upper half portion of the ink cartridge IC, and the lower storage chamber 82 is provided in the lower half portion of the ink cartridge IC. The buffer chamber 83 is provided at an intermediate position in the height direction so as to be sandwiched between the upper storage chamber 81 and the lower storage chamber 82. In the ink cartridge IC, the upper storage chamber 81, the lower storage chamber 82, and the buffer chamber 83 are communicated with each other through a thin channel. Specifically, the upper storage chamber 81 is in communication with the lower storage chamber 82, and the lower storage chamber 82 is in communication with the buffer chamber 83. Then, the ink in the buffer chamber 83 is supplied to the ink supply needle 8 (see FIG. 4A). Accordingly, it can be said that an ink flow path meandering up and down is provided inside the ink cartridge IC.

  As shown in FIGS. 7A and 7B, the chambers 81, 82, 83 are filled with ink in the initial state. As the ink is consumed, the amount of ink stored in the upper storage chamber 81 decreases. As shown in FIGS. 8A and 8B, when more ink is consumed than the storage amount in the upper storage chamber 81, the upper storage chamber 81 becomes empty and the ink storage amount in the lower storage chamber 82 decreases. . As shown in FIGS. 9A and 9B, when more ink is consumed than the amount stored in the upper storage chamber 81 and the lower storage chamber 82, the upper storage chamber 81 and the lower storage chamber 82 are emptied and buffered. The amount of ink stored in the chamber 83 is reduced. Further, when the ink is consumed, the buffer chamber 83 is also emptied (FIGS. 6A and 6B).

  Here, the ink pressure in the common ink chamber 31 will be examined. Since the ink cartridge IC is disposed above the head HD, the ink pressure in the common ink chamber 31 is determined by the amount of ink stored in the ink cartridge IC and the height of the liquid surface in contact with the atmosphere. Here, in the case of the ink flow path meandering up and down like the above-described ink cartridge IC, the ink consumption and the ink pressure have a non-linear relationship. This is because the liquid level in contact with the atmosphere moves in the vertical direction as the ink is consumed, and the area of the liquid level changes depending on the part. The relationship between the ink consumption and the hydrostatic head pressure in the ink cartridge IC is as shown in FIG. Here, the hydrostatic head pressure indicates the pressure of ink in the common ink chamber 31. Specifically, the ink pressure at the boundary position 31a with the ink supply path 32 is shown. This hydrostatic head pressure means the head in the case where the flow rate is the value [0] in the above-described equation (1). In a state where the ink shown in FIGS. 7A and 7B is sufficiently stored, the hydrostatic head pressure has the highest value as indicated by reference numeral X1. Thereafter, in a state where ink is consumed and less than 40% of the total amount is consumed, that is, in a state where the liquid level shown in FIGS. 8A and 8B is located in the lower storage chamber 82, the hydrostatic head pressure is indicated by reference numeral X2. It decreases with ink consumption. When ink is further consumed, the hydrostatic head pressure shows the lowest value as indicated by reference numeral X3. This is presumably because the liquid level in contact with the atmosphere is located in a narrow flow path that connects the lower storage chamber 82 and the buffer chamber 83. This liquid level rises in the flow path as the ink is consumed. For this reason, the hydrostatic head pressure after code | symbol X3 is rising with the consumption of ink. In the state where the liquid level shown in FIGS. 9A and 9B exists in the buffer chamber 83, the hydrostatic head pressure rises again as indicated by reference numeral X4. Thereafter, the hydrostatic head pressure further increases as the ink is consumed, and decreases after 95%.

<About threshold>
Next, a threshold for determining whether or not to increase the number of dot forming operations for a certain range will be described. This threshold value is used as a judgment criterion in the continuity evaluation process (S13, FIG. 12) and the replenishment evaluation process (S15, FIG. 12) in the printing operation, and is acquired for each specific environmental temperature in the manufacturing process of the multifunction device 1. Is done. The acquired threshold value is stored in advance in the SDRAM 53 or the ROM 52 of the main control unit 7 at the shipping stage of the multifunction device 1.

  As will be described in detail later, the continuity evaluation process is a process for evaluating whether or not there is continuity in the time-series change of the ink ejection rate. That is, in the dot forming operation of the pass to be evaluated (corresponding to a certain time-series range), there are other ink ejecting operations that are equal to or greater than the ejection amount defined by the threshold value (Th1, corresponding to the first ejection rate). This is a process of determining whether or not it has been performed continuously over the number of times specified by the threshold value (Pc, corresponding to the determination value corresponding to the specified number of times).

  The replenishment evaluation process is a process for determining whether or not replenishment is present (whether or not sufficient ink can be replenished to the pressure chamber 33). That is, when it is determined that there is continuity in the continuity evaluation process described above, the threshold value (Th3, corresponding to the second injection rate) in the subsequent predetermined movement range (corresponding to R1, other time series). This is a process for determining whether or not an ink ejection operation exceeding a prescribed ejection amount is performed. When this ink ejection operation is performed within a predetermined movement range (when the determination condition is satisfied), it is evaluated that there is no replenishment, and the number of dot formation operations for a certain range is increased (nozzles capable of ejecting ink). Nz number is limited).

  FIG. 11A is a diagram illustrating the relationship between the threshold application range, the ink consumption, and the hydrostatic head pressure. In the continuity evaluation process, an evaluation value C (see FIG. 7 and the like) is used as an evaluation index. This evaluation value C is incremented (+1) when the ejection duty D1 in one dot forming operation is equal to or larger than the upper threshold Th1 (first ejection rate), and is smaller than the lower threshold Th2 (third ejection rate). Decrement (-1). Then, when the evaluation value C exceeds another threshold (Pc), it is determined that there is continuity.

  Here, the ejection duty is a ratio between the amount of ink ejected at a certain timing and the maximum amount of ink that can be ejected, and is also referred to as an ejection rate. For example, consider a nozzle array that ejects ink of a certain color. In this case, the maximum amount of ink that can be ejected is a case where ink droplets necessary for forming a large dot are ejected from all nozzles Nz that can eject ink of that color. The ejection duty of 100% means a case where ink droplets for forming large dots are ejected from all nozzles Nz. Further, the ejection duty of 0% means a case where ink droplets are not ejected from all the nozzles Nz.

  In this embodiment, in order to obtain the ejection duty by calculation, the amount of ink droplets is numerical data. Specifically, the data value for large dots is [4], the data value for medium dots is [2], the data value for small dots is [1], and the data value for non-ejection is [0]. In other words, the ratio of the amount of ink droplets in large dots, medium dots, small dots and non-ejection is set to 4: 2: 1: 0. Therefore, when the medium dot forming ink is ejected from all the nozzles Nz, the ejection duty is 50%, and when the small dot forming ink is ejected from all the nozzles Nz, the ejection duty is 25%. Become.

  In this embodiment, as shown in FIG. 11B, the upper threshold Th1 used in the continuity evaluation process is changed according to the ink consumption. Specifically, the upper threshold Th1 is set to 58% when the ink consumption is 30% or less, and the upper threshold Th1 is set to 54% when the ink consumption is more than 30% and 70% or less. Further, the upper threshold Th1 is set to 50% when the ink consumption is greater than 70% and 85% or less, and the upper threshold Th1 is set to 58% when the ink consumption is greater than 85%. Similarly, the lower threshold Th2 is also changed according to the ink consumption. Specifically, the lower threshold Th2 is set to 29% when the ink consumption is 30% or less, and the upper threshold Th2 is set to 27% when the ink consumption is more than 30% and 70% or less. Further, when the ink consumption is greater than 70% and 85% or less, the lower threshold Th2 is set to 25%, and when the ink consumption is greater than 85%, the lower threshold Th2 is set to 29%. The threshold value Pc for the evaluation value C is a constant value [8] regardless of the ink consumption.

  As described above, the threshold values Th1 and Th2 are determined according to the hydrostatic head pressure (ink pressure in the common ink chamber 31). Therefore, in the continuity evaluation process, with respect to the ink pressure in the common ink chamber 31, the first pressure (for example, the hydrostatic head pressure indicated by the symbol X1 in FIG. 10) corresponding to a certain consumption (corresponding to the second consumption). When compared with other consumption (corresponding to the first consumption) and a second pressure lower than the first pressure (for example, the hydrostatic head pressure indicated by X3 in FIG. 10), the second pressure is more However, it can be said that the evaluation value C tends to be high. That is, it is easy to be evaluated as having continuity.

  In the replenishment evaluation process, for each ink ejection operation in the predetermined movement range R1, the ejection duty D2 and the threshold Th3 (second ejection rate) are compared, and an operation in which the ejection duty D2 is greater than the threshold Th3 is performed once (specified number of times). However, if it is performed, it is determined that there is no replenishment, and it is determined that there is replenishment if the injection duty D2 is equal to or less than the threshold Th3 at all times. In this embodiment, as shown in FIG. 11C, the threshold Th3 used in the replenishment evaluation process is changed according to the ink consumption. Specifically, the threshold Th3 is set to 29% when the ink consumption is 30% or less, and the threshold Th3 is set to 27% when the ink consumption is more than 30% and 70% or less. Further, when the ink consumption is greater than 70% and 85% or less, the threshold Th3 is set to 25%, and when the ink consumption is greater than 85%, the upper threshold Th1 is set to 29%. The predetermined movement range R1 is a constant value [40] regardless of the temperature. That is, the evaluation is performed within the range of 40 dots.

  Therefore, in the replenishment evaluation process, when comparing the first pressure at a certain consumption amount with the second pressure at another consumption amount, the second pressure is more easily evaluated as having no replenishment property.

<About printing operation>
Hereinafter, a printing operation by the multifunction machine 1 will be described. Here, FIG. 12 is a flowchart for explaining the printing operation. In this embodiment, when a print request from the computer CP is accepted, a print request from an external device is accepted, or a print request for image data stored in a memory card connected to the card slot 5 is combined. When made by the user of the machine 1, the main control unit 7 of the multifunction machine 1 controls the printing operation. This printing operation is performed by the CPU 61 of the main control unit 7 performing an operation according to the computer program, but a part or all of the operation may be performed by hardware (electronic circuit).

  First, the main control unit 7 of the multifunction machine 1 operates as the image data acquisition unit 71 and performs an image data acquisition process (S10). In this image data acquisition process, the main control unit 7 acquires JPEG format image data. For example, image data is acquired from a computer CP, a memory card, and an external device HW. Thereafter, the main control unit 7 prepares dot formation data for one pass (for one main scan in the normal scan process) based on the image data acquired in the image data acquisition process (S11). That is, the main control unit 7 acquires the dot formation data by converting the acquired image data by the image processing unit 67.

  If the dot formation data for one pass is acquired, the main control unit 7 sets the column number i to the value [1] and sets the evaluation value C to the value [0] (S12). Here, the column number i indicates the position of the dot in the moving direction as shown in FIG. For example, the column number i at the scanning start point is the value [1], and the column number i becomes the value [2] when moving from this starting point by one dot. As described above, the head HD of this embodiment has two nozzle rows that eject the same color ink. For this reason, the row number i is determined based on the nozzle row that precedes the moving direction. The evaluation value C is an index for evaluating continuity as described above.

  Thereafter, the main control unit 7 performs continuity evaluation processing for evaluating whether or not there is continuity in the time-series change of the ink ejection rate for the dot formation data for one pass (S13). The specific contents of the continuity evaluation process will be described later.

  When it is determined in the continuity evaluation process that the change in the ink ejection rate in time series is continuous (Y in S14), the main control unit 7 performs the replenishment evaluation process (S15). In this replenishment evaluation process, the main control unit 7 determines the presence or absence of replenishment for the dot formation data for one pass. That is, when it is determined that the ink has continuity, the main controller 7 determines whether or not sufficient ink can be supplied to the pressure chamber 33 thereafter. The specific contents of this replenishment evaluation process will also be described later.

  When it is determined in the replenishment property evaluation process that there is no replenishment property (N in S16), the main control unit 7 operates as the divided scanning unit 77 and performs a divided scanning process (S17). In this divided scanning process, the main control unit 7 performs the dot formation operation by dividing the dot formation data for one pass, which is the evaluation target, into a plurality of passes. Specifically, the number of nozzles Nz to be used is limited, and the dot formation operation is performed in two passes. Thereby, the raster area corresponding to the dot formation data to be evaluated is printed in two passes. Specific contents of this divided scanning process (S17) will also be described later.

  Further, when it is determined that there is no continuity in the above-described continuity evaluation process (N in S14), or when it is determined in the replenishment evaluation process that there is replenishment (Y in S16), the main control unit 7 Adds “1” to the column number i (S18). Thereafter, on condition that the column number i does not exceed the last column L of the raster area (N in S19), the main control unit 7 repeatedly performs the processing from the continuity evaluation processing (S13). On the other hand, when the column number i exceeds the last column L of the raster area (Y in S19), the main control unit 7 operates as the normal scanning unit 76 and performs normal scanning processing (S20). In this normal scanning process, the main control unit 7 performs a dot formation operation using the dot formation data for one pass as an evaluation target as it is (S20). In this case, the raster area corresponding to the dot formation data to be evaluated is printed in one pass.

  When the divided scanning process (S17) or the normal scanning process (S20) is completed, the main control unit 7 performs subsequent dot formation data that has not been evaluated in the continuity evaluation process (S13) or the replenishment evaluation process (S15). It is determined whether or not there is (S21). When there is subsequent dot formation data (Y in S21), the main control unit 7 performs the same determination for the subsequent dot formation data. That is, the main control unit 7 prepares subsequent dot formation data (S22), and repeats the processing from S12 on for this dot formation data. On the other hand, when there is no subsequent dot formation data (N in S21), the main control unit 7 ends the series of printing operations.

<About continuity evaluation processing>
Next, the continuity evaluation process will be described. FIG. 13 is a flowchart illustrating specific contents of the continuity evaluation process (S13).

  In this continuity evaluation process, the main control unit 7 first operates as the injection rate calculation unit 75 and performs the injection rate calculation process (S31). As described above, the ejection rate is the ejection duty (ratio between the maximum amount of ink that can be ejected and the amount of ink that is ejected). For this reason, the main control unit 7 calculates a combined data value when the preceding nozzle row is at the position of row number i (S31a). Here, the summed data value is a sum of values ejected at the same timing with respect to numerical data indicating the amount of ejected ink droplets for each nozzle Nz. As described above, the large dot data value in this embodiment is [4], the medium dot data value is [2], the small dot data value is [1], and the non-ejection data value is [0]. . Therefore, when ink droplets for forming large dots are ejected from 360 nozzles Nz at the same timing, the total data value is [1440 (= 4 × 360)]. When ink droplets for forming medium dots are ejected from 180 nozzles Nz, the total data value is [360 (= 2 × 180)].

  If the total data value is calculated, the main control unit 7 calculates the injection duty D1 (S31b). Here, the maximum amount of ink that can be ejected at a certain timing for a certain color of ink is expressed as a data value [1440]. Therefore, the ratio with respect to [1440] is the injection duty D1. As described above, when the total data value is [1440], the injection duty D1 is 100%. When the total data value is [360], the injection duty D1 is 25%.

  If the injection duty D1 is calculated, the main control unit 7 determines whether or not the calculated injection duty D1 is equal to or greater than the upper threshold Th1 (S32). As described with reference to FIG. 11B and the like, the upper threshold value Th1 is determined based on the relationship between the ink pressure in the common ink chamber 31 and the ejection duty D1, so that the ejection amount is excessive and the supply to the pressure chamber 33 is insufficient. It is a reference value for Since the ink pressure in the common ink chamber 31 is determined according to the ink consumption amount in the ink cartridge IC, the main control unit 7 functions as the consumption amount acquisition unit 78, and from the memory or SDRAM 53 provided in the ink cartridge IC. Get ink consumption. The consumption amount is updated when, for example, one-pass dot formation operation is completed. For example, the data value obtained by adding the data values used in the one-pass dot formation operation is updated by adding to the already stored consumption.

  If the ink consumption is acquired, the main control unit 7 acquires the upper threshold value Th1 corresponding to the acquired ink consumption from the SDRAM 53. For example, when the ink consumption is 15%, 58% is acquired as the upper threshold Th1, and when the ink consumption is 80%, 50% is acquired as the upper threshold Th1. By doing so, it is possible to perform control corresponding to the degree of ink replenishment to the pressure chamber 33 that changes according to the ink pressure in the common ink chamber 31. That is, under the second pressure lower than the first pressure, the ink supply to the pressure chamber 33 tends to be insufficient compared to the case of the first pressure. However, in the multi-function device 1, it is possible to proceed to the divided scanning process (S 17) so that the ink supply to the pressure chamber 33 is not insufficient even at the second pressure. When the injection duty D1 is equal to or greater than the upper threshold Th1 (Y in S32), the main control unit 7 increments the evaluation value C by 1.

  On the other hand, when the injection duty D1 is smaller than the upper threshold Th1 (N in S32), the main control unit 7 determines whether or not the injection duty D1 is equal to or lower than the lower threshold Th2 (S34). The lower threshold Th2 is determined from the relationship between the ink pressure in the common ink chamber 31 and the ejection duty D1 that the replenishment property of the ink into the pressure chamber 33 is sufficiently high and the ink exceeding the ejection amount can be replenished to the pressure chamber 33. It is a reference value for. Again, the main control unit 7 functions as the consumption amount acquisition unit 78 and acquires the ink consumption amount. Then, the lower threshold Th2 corresponding to the acquired environmental temperature is acquired from the SDRAM 53. For example, when the ink consumption is 15%, 29% is acquired as the upper threshold Th1, and when the ink consumption is 80%, 25% is acquired as the upper threshold Th1. By doing in this way, similarly to the upper threshold Th1, control corresponding to the degree of ink replenishment to the pressure chamber 33 that changes according to the ink pressure in the common ink chamber 31 can be performed. When the injection duty D1 is equal to or lower than the lower threshold Th2 (Y in S34), the main control unit 7 decrements the evaluation value C by 1 (S35). When the evaluation value C is smaller than [1], the evaluation value C is set to [0]. As a result, the shift to the division scanning process is delayed. On the other hand, when the injection duty D1 is larger than the threshold value Th2 (N in S34), that is, when the injection duty D1 is smaller than the upper threshold value Th1 and larger than the lower threshold value Th2, the main control unit 7 keeps the evaluation value C as it is. Maintain (S36).

  If the evaluation value C is determined according to the injection duty D1, the main control unit 7 determines whether or not the evaluation value C is larger than the continuity determination value Pc (S37). As described with reference to FIG. 11B, the determination value Pc in the multi function device 1 is set to [8]. However, the determination value Pc is appropriately set according to the specifications of the multi-function device 1, for example, the structure of the ink storage portion in the ink cartridge IC, the structure of the common ink chamber 31 and the pressure chamber 33, and the ink characteristics. The

  When the evaluation value C exceeds the continuity determination value Pc (Y in S37), the main control unit 7 determines that the change in the ink ejection rate in time series is continuous (S38). On the other hand, when the evaluation value C is equal to or less than the determination value Pc (N in S37), the main control unit 7 determines that there is no continuity in the time series change of the ink ejection rate (S39).

<About replenishment evaluation processing>
Next, the replenishment evaluation process will be described. FIG. 14 is a flowchart for explaining the specific contents of the replenishment evaluation process (S15).

  In this replenishment evaluation process, the main control unit 7 first sets the column number j used in the replenishment evaluation process. This column number j is set to a value obtained by adding 1 to the previously used column number i (S41). That is, the column region located adjacent to the column number determined to have continuity in the moving direction of the head HD is the target of evaluation. If the column number j is set, the main control unit 7 operates as the injection rate calculation unit 75 and performs an injection rate calculation process (S42). In the injection rate calculation process, the main control unit 7 calculates the combined data value when the preceding nozzle row is at the position of the column number j (S42a), and calculates the injection duty D2 (S42b). Note that the calculation of the combined data value and the calculation of the injection duty D2 are the same as the injection rate calculation process (S31) in the continuity evaluation process, and thus description thereof is omitted.

  If the injection duty D2 is calculated, the main controller 7 determines whether or not the injection duty D2 is larger than the threshold value Th3 (S43). Again, since the ink viscosity has a characteristic that changes depending on the environmental temperature, the main control unit 7 acquires the threshold value Th3 corresponding to the acquired environmental temperature from the SDRAM 53. By doing so, similarly to the upper threshold Th1 and the lower threshold Th2, it is possible to perform control corresponding to the degree of ink replenishment to the pressure chamber 33 that changes according to the environmental temperature. If the injection duty D2 is greater than the threshold Th3 (Y in S43), the main control unit 7 determines that there is no replenishment (S44). That is, it is determined that there is a high possibility that the amount of ink supplied to the pressure chamber 33 is insufficient in the dot forming operation performed after the row region determined to have continuity.

  When the injection duty D2 is equal to or less than the threshold Th3 (N in S43), the main control unit 7 increments the column number j by 1 (S45). That is, the adjacent column number j is set as an evaluation target. If the column number j is incremented by 1, the main control unit 7 determines whether or not the updated column number j exceeds the predetermined movement range R1 (S46). That is, the main control unit 7 compares the value obtained by adding the predetermined movement range R1 to the above-described column number i with the column number j. If the column number j is smaller than the added value, the main control unit 7 repeats the processing subsequent to the injection rate calculation processing (S42), assuming that the evaluation for the predetermined movement range R1 has not yet been completed. As described above, in the multi function device 1, the predetermined movement range R1 is set to [40]. For this reason, evaluation is performed for a range of 40 dots in the moving direction.

  On the other hand, if the updated column number j is greater than or equal to the value obtained by adding the predetermined movement range R1 to the column number i, or if it is greater than the final column number L (Y in S46), the main control unit 7 A value obtained by decrementing j by -1 is determined as a new column number i. Also, the evaluation value C is set to [0] (S47). Then, it is determined that there is replenishment (S48). That is, it is determined that the ink is sufficiently supplied to the pressure chamber 33 by the dot forming operation performed after the row region determined to have continuity.

<About division scan processing>
Next, the division scanning process will be described. FIG. 15 is a diagram for explaining an example of the division scanning process (S17). In this figure, a raster area when dot formation data for one pass is printed in two passes is schematically represented by hatched circles and white circles. Here, hatched circles indicate dots formed in the previous pass, and white circles indicate dots formed in the subsequent pass. In this example, a range defined by dots of N rows × L columns corresponds to a certain range that can be printed in one pass. Then, each nozzle Nz belonging to one half of the nozzle row is used in the previous pass, and a raster line is formed by dots from the first row to the N / 2nd row. In the subsequent pass, the remaining nozzles Nz are used to form a raster line of dots from the (N / 2 + 1) th row to the Nth row. In this multi-function machine 1, one color ink is printed by 360 nozzles Nz, so the raster lines from the first line to the 180th line are formed in the previous pass, and the remaining passes in the subsequent pass. Raster lines from the 181st row to the 360th row, which are raster lines, are formed. Therefore, in this example, if it is determined that there is a risk of insufficient ink supply to the pressure chamber 33, it can be said that printing is performed with the number of nozzles Nz that can eject ink limited to half.

<Summary>
As described above, in the multi-function device 1, the main control unit 7 determines whether or not there is a risk of insufficient ink replenishment to the pressure chamber 33 according to the time-series change in the ejection rate at the nozzle Nz. To do. If it is determined that there is a risk of shortage, the main control unit 7 prints the dot formation data for one pass by dividing it into a plurality of passes (performs divided main scanning). For this reason, it is possible to avoid an ejection failure of ink droplets due to ink shortage in the pressure chamber 33. Further, the main control unit 7 pays attention to the fact that the ink pressure in the common ink chamber 31 changes according to the ink consumption amount of the ink cartridge IC, and the degree of ink replenishment to the pressure chamber 33 changes. , Th3 is changed according to the ink consumption. As a result, the conditions for changing the number of passes change according to the ink consumption, and the number of passes can be changed under appropriate conditions. In addition, since the raster area is printed separately for the upstream half nozzle group and the downstream half nozzle group in the paper feed direction, it is formed by a single head scan by the normal scanning process (S20). The difference from the raster area can be reduced, and the image quality as a whole can be improved.

=== About Other Embodiments ===
The above-described embodiment is mainly described with respect to the multifunction machine 1 as a liquid ejecting apparatus, and includes a liquid ejecting method, a liquid ejecting system, a head driving device, a head driving method, a computer program, and a computer. Disclosure of storage media and the like readable by. Further, this embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About switching the number of passes>
In the above-described embodiment, the continuity evaluation process (S13) and the replenishment evaluation process (S15) are performed to determine whether a certain area is printed in one pass or two passes. That is, it is determined whether or not to perform printing with a limited number of usable nozzles Nz. Here, the determination of whether or not the number of paths needs to be switched is not limited to this method.

For example, the determination may be made according to the ink consumption. FIG. 16 is a diagram illustrating the relationship between the hydrostatic head pressure and the ink consumption, and is a diagram illustrating the relationship between the switching control of the number of passes and the range of the ink consumption rate. In this example, in the range indicated by the symbol Y1, that is, in the range where the ink consumption rate is less than 27.5%, the ink pressure in the common ink chamber 31 is sufficiently high, so the ejection duty is 50% or more in that path. Even if dot formation data is included, the dot formation operation is performed in one pass (the normal scanning process of S20 is performed). Even in the range indicated by the symbol Y3, that is, in the range where the ink consumption rate is 85% to less than 95%, the same determination as the range indicated by the symbol Y1 is made.
On the other hand, since the ink pressure in the common ink chamber 31 is not sufficiently high in the range indicated by the symbol Y2, that is, in the range where the ink consumption rate is 27.5% or more and less than 85%, the ejection duty is in that path. When dot formation data that is 50% or more is included, the dot formation operation is performed by dividing into two passes (the division scanning process of S17 is performed). Even in the range indicated by the symbol Y4 (the range where the ink consumption rate is 95% or more), the same determination as the range indicated by the symbol Y1 is made.
Even if such control is performed, insufficiency of ink replenishment can be suppressed as in the above-described embodiment.
Further, the ink pressure at a certain consumption amount in the ink cartridge IC (for example, the pressure in the common ink chamber 31) may be measured by a pressure sensor or the like, and the determination condition may be changed according to the measured pressure.

<About division scan processing>
In the above-described embodiment, in the division scanning process (S17), each raster line belonging to the raster area is divided into two in the paper feed direction. However, the present invention is not limited to this process. For example, as shown in FIG. 17, raster lines formed by the previous dot formation operation and raster lines formed by the subsequent dot formation operation may be alternately formed, or every third. Alternatively, every four or more may be formed alternately.
Also, as shown in FIG. 18, the raster lines formed by the previous dot formation operation and the raster lines formed by the subsequent dot formation operation may be formed alternately (every other). Then, as shown in FIG. 19, a hatched circle raster line may be formed during the forward movement, and a white circle raster line may be formed during the backward movement. In this case, the column number formed during the forward movement is changed from “1” to “L”, the column number formed during the subsequent backward movement is changed from “L + 1” to “2L”, and the maximum column number is handled as “2L”. .
When one raster line is formed by a plurality of dot forming operations, the control of the above-described embodiment is applied to one dot forming operation.

<Ink viscosity>
In the above-described embodiment, the ink viscosity is not particularly considered. Here, the pressure loss in the ink supply path 32 is affected by the viscosity of the ink. That is, the higher the ink viscosity is, the higher the flow path resistance becomes, and the replenishment property becomes worse. This can also be understood from the above-described equations (2) and (3).
Accordingly, when determining whether or not to increase the number of dot forming operations for a certain range, it can be said that it is preferable to consider the viscosity of the ink. The ink viscosity is also affected by the environmental temperature and the type of ink. Therefore, it can be said that it is preferable to adjust the above-described threshold values Th1, Th2, and Th3 according to the environmental temperature detected by the temperature sensor. Similarly, it can be said that the thresholds Th1, Th2, Th3 are preferably adjusted according to the type of ink stored in the ink cartridge IC. In this way, insufficient ink supply can be more reliably suppressed.

<About liquid ejecting device>
The liquid targeted by the liquid ejecting apparatus of the present invention is not limited to the ink described above, but is intended to target various fluids such as metal paste, powder, and liquid crystal. As a typical example of the liquid ejecting apparatus, there is an ink jet recording apparatus provided with the ink jet recording head HD for image recording as described above. However, the present invention is not limited to the ink jet recording apparatus and uses other methods. Electrode used to form electrodes for conventional image recording devices, color material injection devices used in the manufacture of color filters such as liquid crystal displays, organic EL (Electro Luminescence) displays, and surface emission displays (Field Emission Displays, FEDs) The present invention can also be applied to a material ejecting apparatus, a liquid ejecting apparatus that ejects a liquid containing a bioorganic material used for biochip manufacturing, a sample ejecting apparatus as a precision pipette, and the like.

1 MFP, 2 image reading mechanism, 3 printing mechanism,
4 drive signal generators, 5 card slots, 6 sensor groups,
7 main control unit, 8 ink supply needle, 9 ink supply pipe,
10 paper transport mechanism, 11 platen, 12 transport roller,
13 paper discharge roller, 14 transport motor,
20 Carriage moving mechanism, 21 Timing belt,
22 Carriage motor, 23 guide shaft,
24 drive pulleys, 25 idler pulleys,
31 common ink chamber, 32 ink supply path, 33 pressure chamber,
34 piezo elements, 41 linear encoders,
42 Temperature sensor, 51 ASIC, 52 ROM,
53 SDRAM, 61 CPU, 62 Host I / F,
63 USB host circuit, 64 decode circuit,
65 card I / F, 66 reading control unit,
67 Image processing unit, 68 Print control unit,
69 SDRAM_I / F, 71 Image data acquisition unit,
72 printing control unit, 73 jetting control unit, 74 scanning control unit,
75 injection rate calculation unit, 76 normal operation unit, 77 division scanning unit,
78 consumption acquisition unit, 81 upper storage chamber, 82 lower storage chamber,
83 Buffer room, CP computer, S paper,
CR carriage, IC ink cartridge, HD head

Claims (8)

A liquid ejecting head that has a plurality of a series of flow paths from the liquid replenishing unit to the nozzle, replenishes the liquid from the liquid storing unit stored in the common liquid chamber through the liquid replenishing unit, and ejects the liquid from the corresponding nozzle;
A head moving unit that moves the liquid ejecting head in a moving direction;
When the liquid jet head is moved in the moving direction, the moving jet operation for jetting the liquid from the nozzle is controlled, and the determination condition indicating that the liquid jet rate in the moving jet operation is excessive is satisfied. A controller that increases the number of times of the moving injection operation with respect to a certain range as compared with a case where the determination condition is not satisfied,
When the consumption amount of the liquid stored in the liquid storage unit is a first consumption amount, the injection rate is determined to be excessive with an injection rate smaller than a second consumption amount different from the first consumption amount A controller for determining the number of times of the moving injection operation for the certain range according to a determination condition;
A liquid ejecting apparatus. The injection rate of the liquid is
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a ratio between a liquid amount ejected at a certain timing and a maximum liquid amount ejectable at the certain timing. The controller is
A continuity evaluation that evaluates continuity when the liquid is ejected at a prescribed number of times within a certain time-series range;
When it is evaluated that there is continuity in the continuity evaluation, the liquid is ejected at an injection rate that is equal to or higher than the second injection rate within a range of another time series following the certain time series. If there is no replenishment in case
The liquid ejecting apparatus according to claim 1, wherein when the replenishment evaluation evaluates that there is no replenishment, the liquid ejecting apparatus determines that the determination condition is satisfied. In the continuity assessment,
When the injection rate at a certain timing is equal to or higher than the first injection rate, the evaluation value is added, while when the injection rate at a certain timing is equal to or lower than a third injection rate lower than the first injection rate. The liquid ejecting apparatus according to claim 3, wherein the evaluation value is subtracted, and the evaluation is made as having continuity when the evaluation value exceeds a determination value corresponding to the specified number of times. The first injection rate at the first consumption amount is
Smaller than the first injection rate at the second consumption,
The second injection rate at the first consumption amount is
The liquid ejecting apparatus according to claim 3, wherein the liquid ejecting apparatus is smaller than the second ejection rate at the second consumption amount. The liquid jet head includes:
Having a nozzle row in which a plurality of the nozzles are arranged in an intersecting direction intersecting the moving direction;
The controller is
When the determination condition is satisfied, the first moving injection operation is performed using a part of the nozzles belonging to the nozzle row, and the subsequent moving injection operation is performed using another part of the nozzles. The liquid ejecting apparatus according to any one of 5. The controller is
The first moving injection operation is performed using each of the nozzles belonging to the nozzle row and located in one half of the intersecting direction, and the subsequent moving injection operation is performed using the remaining nozzles. The liquid ejecting apparatus according to claim 6. Liquid using a liquid ejecting head having a plurality of series of flow paths from the liquid replenishing unit to the nozzle, replenishing the liquid from the liquid storing unit stored in the common liquid chamber through the liquid replenishing unit, and ejecting the liquid from the corresponding nozzle An injection method,
This is a determination condition indicating that the ejection rate of the liquid is excessive in the moving ejection operation in which the liquid is ejected from the nozzle while moving the liquid ejection head in the moving direction, and is stored in the liquid storage unit. When the consumption amount of the liquid is the first consumption amount, it is determined whether or not a determination condition indicating that the injection rate is excessive with an injection rate smaller than the second consumption amount different from the first consumption amount is satisfied. And
When the determination condition is satisfied, in the moving injection operation, the number of times of the moving injection operation for a certain range is increased as compared with the case where the determination condition is not satisfied.
A liquid jetting method.

Images