JP2008195063A - Ejection control method for liquid, and liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a burden related to communication between a first control part and a second control part. <P>SOLUTION: The first control part carries out the residual quantity detection step of detecting the residual quantity of a contained liquid for each of a plurality of cartridges, and the information transmission step of transmitting information related to a cartridge with a small residual quantity for the corresponding small residual quantity cartridge when the residual quantity of the liquid is detected to be not larger than a predetermined quantity. The second control part carries out the liquid ejection data generating step of deciding a substitute cartridge on the basis of the transmitted information, generating and transmitting liquid ejection data for carrying out ejection control of the liquid contained in the substitute cartridge and the residual quantity information acquisition step of acquiring from the first control part information related to the residual quantity of the liquid of the substitute cartridge every time processing of transmitting the liquid ejection data is executed after receiving of the information related to the small residual quantity cartridge. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid ejection control method and a liquid ejection apparatus.

  An ink jet printer is known as a liquid ejecting apparatus. An ink jet printer ejects ink such as cyan (C), magenta (M), yellow (Y), and black (K) toward a medium such as paper. An image is printed on the medium by the ejected ink. Ink of each color such as cyan (C), magenta (M), yellow (Y), and black (K) is individually accommodated in a cartridge mounted on the ink jet printer. When the ink stored in the cartridge runs out, printing can be performed again by replacing the cartridge storing the ink with a new one.

By the way, as such an ink jet printer, a printer in which a plurality of cartridges containing ink of the same color is mounted has been proposed. Specifically, for example, there is an ink jet printer in which two cartridges containing black (K) ink can be mounted. In such an ink jet printer, when the remaining amount of ink stored in one of the two cartridges storing ink of the same color decreases, the other cartridge storing ink of the same color is used. Has been proposed (see Patent Document 1). In addition to this, there is also proposed a method of substituting a cartridge containing ink of another color when the remaining amount of ink in one cartridge is reduced (see Patent Document 2).
JP 2003-1842 A JP 2003-291324 A

  By the way, in such an ink jet printer, in order to check the remaining amount of the ink stored in each mounted cartridge, the ink from the computer side such as a personal computer connected to the ink jet printer to the ink jet printer. We were sequentially inquiring about the remaining amount. This is because it is necessary to create print data corresponding to the cartridge to be used on the computer side when executing the printing process with the ink jet printer. That is, when another cartridge is used instead of a cartridge with a small ink remaining amount, it is necessary to create print data corresponding to the cartridge on the computer side.

  However, each time the printing process is executed in the ink jet printer in this way, if the computer inquires about the ink remaining amount of each cartridge, the communication between the computer and the ink jet printer becomes complicated, and the computer side There is a risk that the processing of this will be delayed, which is a problem.

  The present invention has been made in view of such circumstances, and an object thereof is to reduce a burden related to communication.

The main invention for achieving the object is as follows:
(A) a remaining amount detecting step for detecting the remaining amount of the stored liquid for each of the plurality of cartridges storing the liquid ejected from the nozzle, which is performed by the first control unit;
(B) When the first control unit detects that the remaining amount of the liquid in the at least one cartridge is equal to or less than a predetermined amount, information related to the small remaining amount cartridge is transmitted for the corresponding small remaining amount cartridge. And an information transmission step;
(C) Based on the information relating to the small remaining amount cartridge transmitted and transmitted by the second control unit, at least one of the other cartridges excluding the small remaining amount cartridge is defined as an alternative cartridge, and the replacement A liquid discharge data generation step for generating and transmitting liquid discharge data for controlling the discharge of the liquid contained in the cartridge;
(D) When the process for transmitting the liquid ejection data is performed after the reception of the information on the small remaining amount cartridge performed by the second control unit, the information on the remaining amount of the liquid in the alternative cartridge is A remaining amount information acquisition step acquired from the first control unit;
(E) is a liquid ejection control method.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

That is, (A) a remaining amount detecting step for detecting the remaining amount of the liquid stored in each of the plurality of cartridges storing the liquid ejected from the nozzle, which is performed by the first control unit; and (B) Information transmitted by the first control unit and transmitting information related to the low remaining amount cartridge for the corresponding low remaining amount cartridge when it is detected that the remaining amount of the liquid in the at least one cartridge is equal to or less than a predetermined amount. And (C) at least one of the other cartridges excluding the low remaining amount cartridge as an alternative cartridge, based on the information relating to the low remaining amount cartridge transmitted and transmitted by the second control unit. And generating liquid discharge data for controlling the discharge of the liquid stored in the alternative cartridge. A liquid ejection data generation step for transmitting, and (D) the replacement cartridge each time a process for transmitting the liquid ejection data is executed after receiving the information on the small remaining amount cartridge by the second control unit It is clarified that it is possible to realize a remaining amount information acquisition step of acquiring information on the remaining amount of the liquid from the first control unit, and a liquid ejection control method having (E).
According to such a liquid ejection control method, the second control unit is configured to detect the first control unit until it is detected that the remaining amount of at least one of the plurality of cartridges is equal to or less than a predetermined amount. It is not necessary to obtain information on the remaining amount of liquid from Thereby, the burden regarding communication is reduced. Further, after the small remaining amount cartridge is detected, the liquid consumption of the low remaining amount cartridge can be suppressed by using the liquid of the alternative cartridge instead of the liquid of the small remaining amount cartridge. In addition, after the small remaining amount cartridge is detected, the second control unit can easily manage the remaining amount of the alternative cartridge by acquiring information on the remaining amount of liquid in the alternative cartridge from the first control unit. it can.

In this liquid ejection control method, it is preferable that in the remaining amount information acquiring step, the information regarding the remaining amount of liquid is not acquired from the first control unit until the information regarding the small remaining amount cartridge is received.
According to such a liquid ejection control method, it is possible to reduce a burden related to communication between the first control unit and the second control unit.

In this liquid discharge control method, it is preferable that the liquid stored in the alternative cartridge is the same type of liquid as the liquid stored in the small remaining amount cartridge.
According to such a liquid discharge control method, the liquid stored in the alternative cartridge can be easily used instead of the liquid stored in the small remaining amount cartridge.

In this liquid discharge control method, it is preferable that the liquid is ink.
According to such a liquid ejection control method, it is possible to reduce a burden related to communication between the first control unit and the second control unit when printing an image.

In this liquid ejection control method, it is preferable that the replacement cartridge contains ink of the same color as the ink contained in the small remaining amount cartridge.
According to such a liquid ejection control method, the ink stored in the alternative cartridge can be easily used instead of the ink stored in the small remaining amount cartridge.

In this liquid ejection control method, in the liquid ejection data generation step, the replacement cartridge and the low-remaining cartridge are alternately used until the information on the low-remaining cartridge is received. As described above, it is preferable to generate and transmit liquid discharge data for performing discharge control of the liquid stored in these cartridges.
According to such a liquid ejection control method, it is possible to suppress a decrease in the remaining amount of one cartridge in comparison with the remaining amount of the other cartridge.

This liquid ejection control method is performed by the second control unit, and based on the information on the remaining amount of liquid acquired from the first control unit, the remaining amount of liquid contained in the low remaining amount cartridge A difference calculating step for calculating a difference between the remaining amount of liquid stored in the alternative cartridge and a difference performed by the second control unit and determining whether the calculated difference is equal to or less than a predetermined value. A determination step.
According to such a liquid ejection control method, it is possible to recognize whether or not the remaining amount of the small remaining amount cartridge and the remaining amount of the alternative cartridge are becoming equal.

In this liquid discharge control method, in the remaining amount information obtaining step, when it is determined that the difference is equal to or less than the predetermined value, information on the remaining amount of liquid in the alternative cartridge, and the remaining amount information Information on the remaining amount of the liquid in the quantity cartridge is acquired from the first control unit, and in the liquid ejection data generation step, information on the remaining amount of the liquid in the alternative cartridge and the liquid in the small remaining amount cartridge are obtained. Of the replacement cartridge and the small remaining amount cartridge is determined based on the remaining amount information, and the discharge control of the liquid contained in the remaining remaining cartridge is performed. It is preferable to generate and transmit liquid ejection data for performing.
According to such a liquid discharge control method, both cartridges with a small remaining amount can be used equally.

It is also clarified that the following liquid ejection apparatus can be realized.
That is, (A) a liquid ejecting apparatus having a first control unit and a second control unit that can communicate with each other, and (B) the first control unit includes a plurality of liquids ejected from nozzles. A remaining amount detecting step for detecting the remaining amount of liquid contained for each of the cartridges;
(C) performing an information transmission step of transmitting information relating to the low remaining amount cartridge for the corresponding low remaining amount cartridge when it is detected that the remaining amount of the liquid in at least one cartridge is equal to or less than a predetermined amount; The second control unit determines at least one of the other cartridges excluding the low remaining amount cartridge as an alternative cartridge based on the transmitted information regarding the low remaining amount cartridge, and is accommodated in the alternative cartridge. Each time a liquid discharge data generation step for generating and transmitting liquid discharge data for performing liquid discharge control, and a process for transmitting the liquid discharge data after receiving information on the small remaining amount cartridge are executed , Information about the remaining amount of the liquid in the replacement cartridge is received from the first control unit. To, performing the remaining capacity information acquiring step, is also revealed can be realized (D) a liquid ejecting apparatus.

=== Overview of Liquid Discharge System ===
The liquid ejection system 100 includes an inkjet printer 1 and a computer 110 (see FIG. 1). Here, the printer 1 ejects liquid ink toward a sheet, which is a kind of medium, and thus corresponds to a liquid ejecting device in a narrow sense. The computer 110 controls the operation of the printer 1 by transmitting print data. For this reason, the liquid ejection system 100 corresponds to a liquid ejection device in a broad sense. Hereinafter, the liquid discharge system 100 will be described as an example.

<Overall configuration>
FIG. 1 is a diagram illustrating the configuration of the liquid ejection system 100. The illustrated liquid ejection system 100 includes an inkjet printer 1 which is a kind of printing apparatus, and a computer 110. A display device 120, an input device 130, and a recording / reproducing device 140 are communicably connected to the computer 110. The computer 110 is also communicably connected to the inkjet printer 1. Then, in order to cause the inkjet printer 1 to print an image, the computer 110 generates print data corresponding to the image and transmits the print data to the inkjet printer 1. The print data corresponds to “liquid ejection data”.

  Computer programs such as application programs and printer drivers are installed in the computer 110. The display device 120 is configured by a liquid crystal display, a CRT display, or the like. The display device 120 displays a user interface of a computer program such as an application program or a printer driver installed in the computer 110, for example. The input device 130 is composed of, for example, a keyboard 131 and a mouse 132. The recording / reproducing apparatus 140 includes, for example, a flexible disk drive device 141 and a CD-ROM drive device 142.

<Internal structure of inkjet printer>
FIG. 2 illustrates the internal configuration of the ink jet printer. A carriage 41 is provided inside the inkjet printer 1 as shown in FIG. The carriage 41 is provided so as to reciprocate in the left-right direction (carriage movement direction) as viewed from the front of the printer 1. Around the carriage 41, a carriage motor 42, a pulley 44, a timing belt 45, and a guide rail 46 are provided. The carriage motor 42 is constituted by a DC motor or the like, and is a drive source for moving the carriage 41 along the carriage movement direction. The timing belt 45 is connected to the carriage motor 42 via the pulley 44, and a part of the timing belt 45 is connected to the carriage 41, and the carriage 41 is moved along the carriage movement direction by the rotation of the carriage motor 42. The guide rail 46 guides the carriage 41 along the carriage movement direction.

  In addition, around the carriage 41, a linear encoder 51 for detecting the position of the carriage 41, a conveyance roller 17 for conveying the medium S along a conveyance direction intersecting the carriage movement direction, and the conveyance roller A conveyance motor 15 that rotationally drives 17 is provided.

  On the other hand, the carriage 41 is provided with ink cartridges 24 </ b> A, 24 </ b> B, 26 </ b> A, 26 </ b> B, 26 </ b> C containing various inks, and a head 21 that performs printing on the medium S. The ink cartridges 24A, 24B, 26A, 26B, and 26C contain inks of various colors such as yellow (Y), magenta (M), cyan (C), and black (K), for example. In this embodiment, two ink cartridges 24A and 24B are provided as black (K) ink cartridges. These ink cartridges 24A, 24B, 26A, 26B, and 26C are detachably mounted on the cartridge mounting portions 25A, 25B, 27A, 27B, and 27C provided on the carriage 41, respectively.

  In the present embodiment, the head 21 performs printing by ejecting ink onto the medium S. For this purpose, the head 21 is provided with a number of nozzles for ejecting ink.

  In addition to this, in the inkjet printer 1, printing is performed in order to prevent clogging of the nozzles of the head 21 and the pump device 31 that sucks out ink from the nozzles in order to eliminate clogging of the nozzles of the head 21. A capping device 35 that seals the nozzles of the head 21 when not in use (such as during standby) is provided.

<Configuration of head>
FIG. 3 shows the nozzle arrangement on the lower surface of the head 21. As shown in the drawing, a plurality of types of nozzle groups for ejecting ink of each color are provided on the lower surface of the head 21. In this embodiment, as the nozzle group, a yellow nozzle group 211Y that discharges yellow (Y) ink, a magenta nozzle group 211M that discharges magenta (M) ink, and a cyan nozzle group that discharges cyan (C) ink The head 21 is provided with 211C and two black nozzle groups (that is, the first black nozzle group 211K1 and the second black nozzle group 211K2) that eject black (K) ink. Each of these nozzle groups 211Y, 211M, 211C, 211K1, and 211K2 is provided corresponding to each color ink cartridge 24A, 24B, 26A, 26B, and 26C. These ink cartridges 24A, 24B, 26A, 26B, and 26C are mounted correspondingly to cartridge mounting portions 25A, 25B, 27A, 27B, and 27C provided on the carriage 41, respectively.

  Each of the nozzle groups 211Y, 211M, 211C, 211K1, and 211K2 includes a plurality of nozzles that are ejection ports for ejecting ink. In the present embodiment, 180 nozzles # 1 to # 180 are provided. The nozzles # 1 to # 180 of each of the nozzle groups 211Y, 211M, 211C, 211K1, and 211K2 are linearly arranged at a constant interval (nozzle pitch: k · D) along the transport direction. Here, D is the minimum dot pitch in the carrying direction (that is, the interval at the highest resolution of dots formed on the medium S). K is an integer of 1 or more. For example, when the nozzle pitch is 120 dpi (1/120 inch) and the dot pitch in the transport direction is 360 dpi (1/360 inch), k = 3.

  In the present embodiment, the second black nozzle group 211K2 is arranged at a position shifted in the transport direction by a half nozzle pitch, that is, “(k / 2) · D” with respect to the first black nozzle group 211K1. Has been. The first black nozzle group 211K1 is arranged side by side with other nozzle groups, that is, the yellow nozzle group 211Y, the magenta nozzle group 211M, and the cyan nozzle group 211C. Only the second black nozzle group 211K2 is arranged at a position shifted from the first black nozzle group 211K1, the yellow nozzle group 211Y, the magenta nozzle group 211M, and the cyan nozzle group 211C.

  The nozzles # 1 to # 180 of the nozzle groups 211Y, 211M, 211C, 211K1, and 211K2 are assigned a lower number with respect to the transport direction of the medium S as the nozzles on the downstream side. That is, the nozzle # 1 is located downstream of the nozzle # 180 in the transport direction. Piezo elements (not shown) are provided corresponding to the nozzles # 1 to # 180. The piezo element corresponds to a drive element for ejecting ink. This piezo element is deformed when a voltage having a predetermined time width is applied between electrodes sandwiching the piezoelectric body. Along with the deformation of the piezo element, the side wall of the ink flow path is also deformed. A part of the ink flow path contracts according to the deformation of the piezo element, and ink droplets are ejected from the corresponding nozzles # 1 to # 180.

<System configuration>
FIG. 4 is a block diagram illustrating the configuration of the computer 110 and the inkjet printer 1. The computer 110 includes an external interface unit (I / F) 112, a CPU 113, and a memory 114. An external interface unit (I / F) 112 is interposed between the inkjet printer 1 and performs data communication. The CPU 113 is an arithmetic processing unit for performing overall control of the computer 110. The memory 114 is for securing an area for storing a computer program used by the CPU 113, a work area, and the like. The memory 114 is composed of, for example, a RAM, an EEPROM, a ROM, and a magnetic disk device. The computer program stored in the memory 114 includes the application program and printer driver described above. The CPU 113 performs various controls according to the computer program stored in the memory 114.

  The print data is data in a format that can be interpreted by the inkjet printer 1. The print data includes various command data and pixel data. Here, the command data is data for instructing the inkjet printer 1 to execute a specific operation. The command data includes, for example, command data for instructing paper feed, command data for indicating the carry amount, and command data for instructing paper discharge.

  The pixel data is data related to the pixels constituting the image to be printed. Here, the pixel data is composed of data (for example, dot gradation values) relating to dots formed on the paper corresponding to each pixel constituting the printed image. In the present embodiment, the pixel data is composed of 2-bit data. Specifically, the pixel data includes data [00] corresponding to no dot (no ink ejection), data [01] corresponding to the formation of small dots, and data [10] corresponding to the formation of medium dots. And data [11] corresponding to the formation of large dots. That is, the inkjet printer 1 can print an image having four gradations per pixel.

  Then, the computer 110 generates this print data (liquid ejection data). Further, as will be described later, the computer 110 determines an alternative ink cartridge as a substitute when a small remaining ink cartridge in which the remaining amount of ink is equal to or less than a predetermined amount is detected, and print data for this ink cartridge. Is generated. In addition, the computer 110 calculates the difference between the ink remaining amount of the low remaining ink cartridge and the ink remaining amount of the alternative ink cartridge, or makes a determination based on the difference. The computer 110 that performs such an operation corresponds to a second control unit.

  On the other hand, the inkjet printer 1 includes a paper transport mechanism 20, a carriage moving mechanism 30, a head unit 40, a drive signal generation circuit 50, a detector group 60, and a controller 70. The controller 70 includes a CPU 72, an external interface unit (I / F) 71, a memory 73, and a control unit 74. The control unit 74 controls the paper transport mechanism 20 and the carriage moving mechanism 30 according to a command from the CPU 72. The external interface unit (I / F) 71 performs data communication with the external interface unit (I / F) 112 of the computer 110. The memory 73 stores programs executed by the CPU 72 and various data. The CPU 72 controls the control unit 74, the drive signal generation circuit 50, the head unit 40, and the like. As will be described later, the controller 70 in the present embodiment detects the remaining amount of ink stored in the ink cartridges 24A, 24B, 26A, 26B, and 26C. Further, when it is detected that the remaining amount of ink is equal to or less than a predetermined amount, the controller 70 generates information related to the corresponding ink cartridge and transmits it to the computer 110. The controller 70 that performs such an operation corresponds to a first control unit.

  The head unit 40 includes a head controller HC and a head 21. The head controller HC controls the head 21 according to a command from the CPU 72. The head 21 includes a plurality of nozzles, and performs printing by discharging ink from each nozzle toward the medium.

  The detector group 60 detects the state of each part in the ink jet printer 1 and transmits the detection result to the controller 70. The detector group 60 includes a linear encoder 51 and the like. Upon receiving the detection result from the detector group 60, the controller 70 controls the control target unit based on the detection result.

=== Printer driver ===
Next, the printer driver will be described. This printer driver is a program for controlling the inkjet printer 1 installed in the computer 110. FIG. 5 explains the outline of processing of this printer driver.

  In the computer 110, various computer programs such as a video driver 162, an application program 160, and a printer driver 164 are executed under an operating system installed in the computer 110. The video driver 162 has a function of causing the display device 120 to display a user interface, for example, in accordance with a display command from the application program 160 or the printer driver 164. The application program 160 has a function of performing image editing, for example, and creates data related to an image (image data). The user can give an instruction to print an image edited by the application program 160 via the user interface of the application program 160. Upon receiving a print instruction, the application program 160 outputs image data to the printer driver 164.

  The printer driver 164 receives image data from the application program 160, converts the image data into print data, and outputs the print data to the inkjet printer 1. Here, the print data is data in a format that can be interpreted by the ink jet printer 1 and is data having various command data and pixel data. The command data is data for instructing the inkjet printer 1 to execute a specific operation. The pixel data is data relating to the pixels constituting the image to be printed (print image). For example, it is data relating to dots formed at positions on the medium S corresponding to a certain pixel (data such as dot color and size). Here, the size of the dot is determined according to the amount of ink ejected from each of the nozzles # 1 to # 180. Therefore, it can be said that the pixel data indicates the amount of ink ejected from each of the nozzles # 1 to # 180 for each dot gradation value. Accordingly, the print data (pixel data) corresponds to liquid ejection data for performing liquid ejection control.

  The printer driver 164 converts the image data output from the application program 160 into print data. Therefore, the printer driver 164 includes a resolution conversion processing unit 166, a color conversion processing unit 168, a halftone processing unit 170, and a rasterization processing unit 172. Hereinafter, various processes performed by the processing units 166, 168, 170, and 172 of the printer driver 164 will be described.

  The resolution conversion processing unit 166 performs resolution conversion processing for converting image data (text data, image data, etc.) output from the application program 160 into a resolution for printing on the medium S. In the resolution conversion process, for example, when the resolution when printing an image on paper is specified as 720 × 720 dpi, the image data received from the application program 160 is converted into image data having a resolution of 720 × 720 dpi. Note that the image data after the resolution conversion process is multi-gradation (for example, 256 gradations) RGB data represented by an RGB color space. Hereinafter, RGB data obtained by performing resolution conversion processing on image data is referred to as RGB image data.

  The color conversion processing unit 168 performs color conversion processing for converting RGB data into CMYK data represented by the CMYK color space. The CMYK data is data corresponding to the ink color of the inkjet printer 1. This color conversion processing is performed by the printer driver 164 referring to a table (color conversion lookup table LUT) in which gradation values of RGB image data and gradation values of CMYK image data are associated with each other. Through this color conversion process, RGB data for each pixel is converted into CMYK data corresponding to the ink color. The data after the color conversion processing is CMYK data with 256 gradations represented by the CMYK color space. Hereinafter, CMYK data obtained by performing color conversion processing on RGB image data is referred to as CMYK image data.

  The halftone processing unit 170 performs halftone processing for converting high gradation number data into gradation number data that can be formed by the inkjet printer 1. The halftone process is, for example, a process of converting data indicating 256 gradations into 1-bit data indicating 2 gradations or 2-bit data indicating 4 gradations. In this halftone process, pixel data is created using the dither method, γ correction, error diffusion method, and the like so that the inkjet printer 1 can form dots in a dispersed manner. When halftone processing is performed, the halftone processing unit 170 refers to a dither table when performing a dither method, refers to a gamma table when performing γ correction, and is diffused when performing an error diffusion method. Reference is made to an error memory for storing errors. The data subjected to halftone processing has a resolution (for example, 720 dpi × 720 dpi) equivalent to the above-described RGB data. The halftoned data is composed of 1-bit or 2-bit data for each pixel, for example. Hereinafter, of the halftone processed data, 1-bit data is referred to as binary data, and 2-bit data is referred to as multi-value data.

  The rasterization processing unit 172 performs rasterization processing for changing data such as binary data and multi-value data obtained by the halftone processing by the halftone processing unit 170 in the order of data to be transferred to the inkjet printer 1. As a result, the rasterized data is output to the inkjet printer 1.

<Head control unit>
FIG. 6 illustrates the head controller HC. The head control unit HC includes a plurality of mask circuits 222 as shown in FIG. The mask circuit 222 is provided corresponding to a plurality of piezo elements that individually eject ink from the nozzles # 1 to # 180 of the head 21. The drive signal ODRV generated and output by the drive signal generation circuit 50 is input to each mask circuit 222. This drive signal ODRV has two pulses of a first pulse W1 and a second pulse W2, as shown in the lower part of the figure, within a period of one pixel (within a time during which the carriage 41 crosses the interval of one pixel). Signal.

  In addition, a print signal PRT (i) is input to each mask circuit 222. The print signal PRT (i) is a signal generated based on the head control signal output from the CPU 72, and is pixel data corresponding to the pixel. This print signal PRT (i) is, for example, a binary signal having 2-bit information for one pixel. Each bit corresponds to the first pulse W1 and the second pulse W2, respectively. The mask circuit 222 is a gate for blocking or passing the original drive signal ODRV in accordance with the level of the print signal PRT (i). That is, when the print signal PRT (i) is at level “0”, the pulse of the original drive signal ODRV is cut off, while when the print signal PRT (i) is at level “1”, the corresponding pulse of the original drive signal ODRV is output. It passes as it is and is output as an actual drive signal DRV toward the piezoelectric elements of the nozzles # 1 to # 180. The piezo elements of the nozzles # 1 to # 180 are driven based on the actual drive signal DRV from the mask circuit 222 and eject ink from the corresponding nozzles.

<Each signal waveform>
FIG. 7 is a timing chart of the drive signal ODRV, the print signal PRT (i), and the actual drive signal DRV (i) for explaining the operation of the head controller HC. As shown in the figure, the drive signal ODRV sequentially generates a first pulse W1 and a second pulse W2 in each one pixel section. Here, when the print signal PRT (i) corresponds to the 2-bit pixel data “10”, only the first pulse W1 is output in the first half of one pixel section. Thereby, small ink droplets are ejected from the nozzles # 1 to # 180, and a small dot (small dot) is formed on the medium S. When the print signal PRT (i) corresponds to 2-bit pixel data “01”, only the second pulse W2 is output in the second half of one pixel interval. As a result, medium size ink droplets are ejected from the nozzles # 1 to # 180, and medium size dots (medium dots) are formed on the medium S. When the print signal PRT (i) corresponds to the 2-bit pixel data “11”, the first pulse W1 and the second pulse W2 are output in one pixel section. As a result, large-sized ink droplets are ejected from the nozzles # 1 to # 180, and a large-sized dot (large dot) is formed on the medium S.

  As described above, the actual drive signal DRV (i) in one pixel section is shaped to have three different waveforms according to three different values of the print signal PRT (i), and is based on these signals. Thus, the head 21 can form dots of three types and adjust the amount of ink ejected in the pixel section. When the print signal PRT (i) corresponds to the 2-bit pixel data “00”, no ink droplets are ejected from the nozzles # 1 to # 180, and no dots are formed on the medium S. .

  In the ink jet printer 1 according to the present embodiment, such head driving units HC of the nozzles # 1 to # 180 are individually provided for each of the nozzle rows 211C, 211M, 211Y, 211K1, and 211K2, and each nozzle row 211C is provided. , 211M, 211Y, 211K1, and 211K2, the piezo elements are individually driven for each nozzle # 1 to 180.

=== Conventional Problems and Solutions ===
<Conventional problems>
By the way, in such an ink jet printer, when the remaining amount of ink stored in one of the two ink cartridges 24A and 24B storing the same color ink decreases, the same color ink is supplied. The other cartridge accommodated is used. Therefore, in order to check the remaining amount of ink stored in each of the mounted ink cartridges 24A and 24B, the computer 110 inquires the ink jet printer 1 about the remaining amount of ink each time printing processing is executed. Was performed sequentially.
However, whenever the printing process is executed in the ink jet printer 1 in this way, the computer 110 side inquires about the ink remaining amount of each cartridge, so that the communication between the computer and the ink jet printer becomes complicated, and the computer There was a risk that processing on the side would be delayed, which was a problem.

<Solution>
Therefore, in the present embodiment, in order to reduce communication between the inkjet printer 1 and the computer 110, the remaining ink stored in the ink cartridges 24A, 24B, 26A, 26B, and 26C attached to the inkjet printer 1 is determined. The computer 110 does not make an inquiry about the remaining amount of ink in the ink cartridges 24A, 24B, 26A, 26B, and 26C from the computer 110 to the inkjet printer 1 until the amount becomes a predetermined amount or less. That is, the ink remaining amount in the ink cartridges 24A, 24B, 26A, 26B, and 26C of the ink jet printer 1 is not notified from the ink jet printer 1 to the computer 110 only after the ink remaining amount becomes a predetermined amount or less. To do.

  Of the ink cartridges 24A, 24B, 26A, 26B, and 26C installed in the inkjet printer 1, two black (K) ink cartridges 24A and 24B that contain the same color ink are used as one of the ink cartridges. When the remaining amount of ink becomes equal to or less than the predetermined amount, the other ink cartridge is used as an alternative cartridge.

  Then, after receiving a notification from the inkjet printer 1 that there is an ink cartridge whose ink remaining amount is equal to or less than a predetermined amount, the computer 110 generates print data and sends it to the inkjet printer 1 each time the print data is transmitted to the inkjet printer 1. On the other hand, information on the remaining ink level of the alternative cartridge is requested, and information on the remaining ink level of the alternative cartridge is acquired from the inkjet printer 1. Thereby, the computer 110 manages the remaining ink amount of the alternative cartridge.

=== Communication between computer and printer ===
FIG. 8 schematically illustrates the exchange between the inkjet printer 1 and the computer 110.

  When there is sufficient ink in the black (K) ink cartridges 24 </ b> A and 24 </ b> B attached to the inkjet printer 1, the computer 110 generates normal print data by the printer driver and transmits it to the inkjet printer 1. (S1 to S2).

  Then, the remaining amount of the black (K) ink stored in one of the two black (K) ink cartridges 24A and 24B mounted on the inkjet printer 1 is less than a predetermined amount. In some cases, the inkjet printer 1 notifies the computer 110 that there is an ink cartridge whose remaining ink amount is equal to or less than a predetermined amount (S3). At this time, the inkjet printer 1 (the controller 70 as the first control unit) transmits information related to the ink cartridge whose remaining ink amount is equal to or less than a predetermined amount to the computer 110. That is, the ink jet printer 1 notifies the computer 110 which ink cartridge of the two black (K) ink cartridges 24A and 24B has reached a predetermined amount or less.

  Here, the predetermined amount is not necessarily limited to the case where the remaining amount of ink is very small, and may be set to about half of the amount of ink that can be accommodated in the ink cartridges 24A and 24B, for example. Alternatively, it may be set to 1/3 or 1/4. A method for detecting the remaining ink levels of the two black (K) ink cartridges 24A and 24B in the inkjet printer 1 will be described later. Here, an ink cartridge whose remaining ink amount is equal to or less than a predetermined amount is also referred to as a “low remaining amount cartridge” below. The information relating to the ink cartridge that has become equal to or less than the predetermined amount corresponds to “information relating to the small remaining amount cartridge”.

  When the computer 110 receives a notification from the inkjet printer 1 that the remaining amount of ink in one of the two black (K) ink cartridges 24A and 24B has become a predetermined amount or less, the computer 110 then When the print data is transmitted to the printer to execute the printing process, instead of the low remaining amount cartridge whose remaining ink amount is equal to or less than the predetermined amount, another ink cartridge, that is, the other black (K) in this case, is used. An ink cartridge is used as an alternative cartridge. That is, the computer 110 (second control unit) generates print data for using the other ink cartridge as an alternative cartridge, instead of the print data using the small remaining amount cartridge. As a result, consumption of ink remaining in the low remaining amount cartridge whose remaining ink amount is equal to or less than the predetermined amount is suppressed. Note that a print data generation method for using the other ink cartridge executed here as an alternative cartridge will be described in detail later.

  Then, the computer 110 (second control unit) transmits print data generated to use the other ink cartridge as an alternative cartridge to the ink jet printer 1 (S4 and S6). At this time, the computer 110 requests the ink jet printer 1 for information regarding the remaining amount of ink in the ink cartridge used as a substitute cartridge (S4 and S6).

  In response to a request from the computer 110 for information regarding the remaining amount of ink in the replacement cartridge, the inkjet printer 1 (the controller 70 as the first control unit) sends information regarding the remaining amount of ink in the other ink cartridge serving as the replacement cartridge to the computer. It transmits toward 110 (S5 * S7).

  The computer 110 (second control unit) can manage the remaining ink level of the alternative cartridge based on the information regarding the remaining ink level of the alternative cartridge transmitted from the inkjet printer 1. That is, for example, the computer 110 compares the remaining amount of ink stored in the replacement cartridge with the remaining amount of ink in the low remaining amount cartridge, and compares the remaining ink amount in the alternative cartridge and the remaining ink amount in the small remaining amount cartridge. To determine how close the ink level of the alternative cartridge is to the ink level of the low level cartridge. Here, by checking whether the difference between the ink remaining amount of the alternative cartridge and the ink remaining amount of the low remaining amount cartridge is equal to or less than a predetermined value, the ink remaining amount of the alternative cartridge is less than the ink of the low remaining amount cartridge. You can easily check whether the remaining amount is approaching. In addition, since the check is performed every time information on the ink remaining amount is received, the remaining amount management can be performed with high accuracy. In this case, the computer 110 corresponds to a “remaining amount information acquisition unit”.

  Here, the predetermined value is set to a value close to zero, for example. If the predetermined value is set to a value close to zero, it is possible to detect that the ink remaining amount of the alternative cartridge has approached the ink remaining amount of the low remaining amount cartridge. Further, if a value smaller than zero is set as the predetermined value, it can be detected that the ink remaining amount of the alternative cartridge is smaller than the ink remaining amount of the low remaining amount cartridge.

  Then, when the calculated difference is equal to or smaller than the predetermined value, the computer 110 (second control unit), for example, when the ink jet printer executes printing processing, instead of the low remaining amount cartridge, The ink cartridge (here, black (K) ink cartridge) can be stopped from being used as an alternative cartridge. That is, the computer 110 can stop generating the print data for using the ink stored in the alternative cartridge, instead of the print data using the ink stored in the low remaining amount cartridge. As a result, the computer 110 subsequently generates normal print data using ink stored in the low-remaining amount cartridge when the inkjet printer 1 executes print processing, for example.

  On the other hand, when the calculated difference is not less than or equal to the predetermined value, the computer 110 may continue to generate print data for using the alternative cartridge.

=== Detection of remaining ink amount ===
Here, an example of a method for detecting the remaining amount of ink in the black (K) ink cartridges 24A and 24B in the inkjet printer 1 will be described.

  In the present embodiment, the ink remaining amounts of the black (K) ink cartridges 24A and 24B are detected by the ink ejected from the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2, respectively. Run by counting the number of drops each. That is, the controller 70 (first control unit) counts the number of ink droplets ejected from each of the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2, thereby providing two The ink consumption amounts of the black (K) ink cartridges 24A and 24B are respectively calculated. Then, the controller 70 subtracts these ink consumption amounts from the initial ink capacities of the ink cartridges 24A and 24B, thereby obtaining the remaining ink amounts of the two black (K) ink cartridges 24A and 24B, respectively. Note that the number of ink droplets ejected from the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2 is counted by the head unit 40 in addition to the controller 70, for example. Can do. In this case, the controller 70 and the head unit 40 correspond to a “remaining amount detection unit”.

  FIG. 9 illustrates a method for calculating the ink consumption amount of each ink cartridge 24A, 24B in the present embodiment. In the present embodiment, as described with reference to FIG. 7, ink droplets having different amounts are ejected from the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2, respectively. That is, ink droplets for forming “small dots”, “medium dots”, and “large dots” are ejected. Here, the “large dot” is one in which “small dot” and “medium dot” are ejected continuously.

  Therefore, the amount of ink consumed varies depending on the size of the ink droplets ejected from the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2. That is, for example, as shown in FIG. 9, the ink discharge amount in the case of “large dots” is “α” (pl: picoliter), and the ink discharge amount in the case of “medium dots” is “β” (pl ), And the ink discharge amount in the case of “small dots” is “γ” (pl).

Assuming that 1000 “large dots”, 1500 “medium dots”, and 2000 “small dots” are ejected from one nozzle, the ink consumption Qi at that nozzle can be obtained by the following equation (1). it can.
Qi = α × 1000 + β × 1500 + γ × 2000 (1)

  In this way, each time the printing process is performed on the nozzles # 1 to # 180 of the first black nozzle group 211K1 and the second black nozzle group 211K2, the ink droplets ejected from the nozzles # 1 to # 180, respectively. By counting the number, the ink consumption amount Qi for each nozzle # 1 to # 180 is obtained, and the ink consumption amount Qi obtained for each nozzle # 1 to # 180 is added to each nozzle group 211K1, 211K2. Separately, the ink consumption can be calculated easily.

  Then, by subtracting the ink consumption obtained for each of the nozzle groups 211K1, 211K2 from the known ink capacity respectively stored in the black (K) ink cartridges 24A, 24B, each ink cartridge The remaining amount of ink stored in 24A and 24B can be acquired.

  Inkjet printer 1 performs an ink discharge process called so-called flushing, in which ink is forcibly ejected from nozzles # 1 to # 180 in order to eliminate problems such as clogging of nozzles of head 21. The controller 70 (first control unit) also counts ink droplets ejected from the nozzles # 1 to # 180 in this ink discharge process. For this reason, the ink consumption can be accurately detected on the ink jet printer 1 side.

=== Computer processing ===
<Generation of print data for using alternative cartridge>
When the computer 110 (second control unit) receives a notification from the inkjet printer 1 that there is a low remaining amount cartridge whose remaining ink amount is equal to or less than the predetermined amount, the computer 110 (second control unit) causes the inkjet printer 1 to execute print processing. In addition, print data for using another ink cartridge, that is, another black (K) ink cartridge here as an alternative cartridge, is generated instead of the low remaining amount cartridge whose remaining ink amount is equal to or less than a predetermined amount. .

  A method of generating print data for using such an alternative cartridge will be described. In the present embodiment, when the remaining ink level of one of the two black (K) ink cartridges 24A and 24B falls below a predetermined amount, printing for using the other ink cartridge as an alternative cartridge is performed. Generate data. Since the two ink cartridges 24A and 24B are ink cartridges containing the same color ink, that is, black (K) ink, they are dealt with by changing the rasterization processing in the rasterization processing unit 172 described with reference to FIG. It is possible.

  That is, the rasterization processing unit 172 changes the data such as binary data and multi-value data obtained by the halftone processing by the halftone processing unit 170 in the order of rasterization processing, that is, the data to be transferred to the inkjet printer 1. When executing the process, the rasterizing process is executed so that the black nozzle group corresponding to the alternative cartridge is exclusively used without using the black nozzle group corresponding to the low remaining amount cartridge. At this time, in this embodiment, as described in FIG. 3, the second black nozzle group 211K2 is half the nozzle pitch with respect to the first black nozzle group 211K1, that is, “(k / 2) · D”. Since it is arranged at a position shifted in the transport direction, the rasterization processing unit 172 executes rasterization processing according to this arrangement.

  The computer 110 generates print data for using such an alternative cartridge every time the inkjet printer 1 executes print processing.

<Overall processing flow>
FIG. 10 is a flowchart schematically illustrating the overall processing flow of the computer 110 as the second control unit. Here, a process after receiving a notification from the inkjet printer 1 (the controller 70 as the first control unit) that an ink cartridge having a remaining ink amount equal to or less than a predetermined amount has occurred will be described.

  When the computer 110 receives a notification from the inkjet printer 1 that a small remaining amount cartridge having a remaining ink amount equal to or less than a predetermined amount has been detected, the remaining amount of ink is reduced to a predetermined amount or less instead of the small remaining amount cartridge. In order to use the other ink cartridge that has not been reached as a substitute cartridge, print data for using the substitute cartridge is generated (S102). Here, print data for using the alternative cartridge is generated by the method described above.

  Then, the computer 110 transmits the print data generated in this way to the inkjet printer 1 (S104). At this time, the computer 110 requests the ink jet printer 1 for information regarding the remaining ink amount of the alternative cartridge (S106). In response to such a request, the inkjet printer 1 transmits information regarding the remaining ink amount of the alternative cartridge to the computer 110. The computer 110 receives the information regarding the remaining amount of ink sent from the inkjet printer 1 (S108).

  Thereafter, the computer 110 calculates the difference between the ink remaining amount of the alternative cartridge and the ink remaining amount of the low remaining amount cartridge based on the information related to the ink remaining amount of the alternative cartridge acquired from the inkjet printer 1 (S110). Then, the computer 110 checks whether or not the calculated difference is equal to or less than a predetermined value (S112). If the calculated difference is equal to or smaller than the predetermined value, the computer 110 switches the print data to be generated from one that uses an alternative cartridge to one that uses a small remaining amount cartridge (S114). Thereafter, the computer 110 ends the process.

  On the other hand, if the calculated difference is not less than the predetermined value, the process returns to step S102, and print data using the alternative cartridge is generated again at the next print command (S102). The generation of print data using the alternative cartridge by the computer 110 is performed until the difference between the remaining ink amount of the alternative cartridge and the remaining ink amount of the low remaining amount cartridge becomes equal to or less than a predetermined value.

=== Other Embodiments ===
In the above-described embodiment, the relationship between the two black (K) ink cartridges 24 </ b> A and 24 </ b> B is described as an example of the case of the ink jet printer in which the two black (K) ink cartridges 24 </ b> A and 24 </ b> B are mounted. When either one of the remaining amount of ink became a predetermined amount or less, the other ink cartridge could be used as an alternative cartridge and the same color ink could be used. As a result, the replacement time of the cartridge could be delayed. However, the present invention is not necessarily limited to the case where the same color ink is used. That is, even if the ink cartridge whose remaining ink amount is equal to or less than the predetermined amount is an ink cartridge containing black (K) ink, an ink cartridge containing other color ink, for example, cyan (K An ink cartridge containing ink such as C), magenta (M), and yellow (Y) can be used as an alternative cartridge.

  In addition, even when the ink cartridge whose remaining ink amount is equal to or less than the predetermined amount is not an ink cartridge containing black (K) ink, ink of other colors is accommodated in consideration of hue and the like. An ink cartridge can be applied as an alternative cartridge.

  Specifically, for example, as an alternative to an ink cartridge containing yellow (Y) ink, an ink cartridge containing red (R) ink or an ink cartridge containing green (G) ink is used. be able to. As an alternative to an ink cartridge containing magenta (M) ink, an ink cartridge containing red (R) ink, an ink cartridge containing blue (B) ink, or a violet (Vi) ink is contained. Ink cartridges can be used. As an alternative to an ink cartridge containing cyan (C) ink, for example, an ink cartridge containing green (G) ink, an ink cartridge containing blue (B) ink, or a violet (Vi) ink cartridge An ink cartridge containing ink can be used.

=== Summary ===
As described above, in the present embodiment, until the remaining amount of ink stored in the ink cartridges 24A, 24B, 26A, 26B, and 26C attached to the ink jet printer 1 is equal to or less than the predetermined amount (that is, the low remaining amount cartridge is related). Until the information is received), the remaining amount of ink in the ink cartridges 24A, 24B, 26A, 26B, and 26C from the computer 110 as the second control unit to the inkjet printer 1 (the controller 70 as the first control unit) Therefore, the burden on communication between the inkjet printer 1 and the computer 110 can be reduced.

  Further, when the remaining amount of one of the two black (K) ink cartridges 24A and 24B attached to the ink jet printer 1 is less than a predetermined amount, the other ink containing the same color ink is stored. Since the ink cartridge is used as an alternative cartridge, the printing process can be continued as it is.

  In addition, after the small remaining amount cartridge is detected, the computer 110 sequentially acquires information regarding the remaining amount of ink in the alternative cartridge from the inkjet printer 1, and therefore the computer 110 can easily manage the remaining amount of ink in the alternative cartridge. Can do.

=== Other Embodiments ===
As described above, the embodiment has been described. However, the above-described embodiment is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<Before the remaining amount of ink falls below a predetermined amount>
In the above-described embodiment, before one ink remaining amount of the two ink cartridges 24A and 24B falls below a predetermined amount (before receiving information on the low remaining amount cartridge), the one ink cartridge is used continuously. Alternatively, two ink cartridges may be used alternately. When two ink cartridges are used alternately, for example, the ink cartridge to be used is changed for each job or page (in other words, the print data is changed so that the ink cartridge to be used is changed for each job or page). Is generated). As a result, it is possible to suppress the remaining amount of one cartridge from being biased and less than the remaining amount of the other cartridge.

  In this way, even when two ink cartridges are used alternately, the amount of ink consumed varies from job to job or from page to page, so the remaining amount of ink in one of the ink cartridges is compared to the remaining amount of ink in the other. Can be drastically reduced. For this reason, even when two ink cartridges are used alternately, the above-described embodiment can be employed.

<After the difference is below the specified value>
In the above-described embodiment, when the difference between the ink remaining amount of the alternative cartridge and the ink remaining amount of the low remaining amount cartridge becomes equal to or smaller than the predetermined value, the normal printing process is executed. It is not limited.

  For example, when the difference between the ink remaining amount of the alternative cartridge and the ink remaining amount of the low remaining amount cartridge becomes equal to or less than a predetermined value, both the ink cartridges are in a low state, so In addition, information regarding the remaining amount of ink in both ink cartridges may be requested. In this case, the computer 110 generates print data so as to use only the ink cartridge with the larger remaining amount based on the information regarding the remaining amount of ink of both ink cartridges transmitted (obtained) from the ink jet printer 1. Is good. Thereby, both cartridges with a small remaining amount can be used equally.

  Or, if the difference between the remaining ink level of the alternative cartridge and the remaining ink level of the low-remaining cartridge falls below a predetermined value, request information on the remaining ink level of only the ink cartridge used in the previous job. May be. In other words, the present invention is not limited to a mode in which information regarding the remaining amount of ink in both ink cartridges is requested. It should be noted that the reason for requesting information on the remaining ink amount of only the ink cartridge used in the previous job is that the ink cartridge not used in the previous job has not been reduced in ink. This is because the information can be used as it is. However, even if the ink cartridge is not used for printing, if ink is ejected to prevent thickening of the nozzle (operation called flushing), the ink in the ink cartridge that was not used in the previous job Information about the remaining amount may be requested.

<About liquid>
In the above-described embodiment, the case of ink has been described as an example of “liquid”, but any type of liquid may be used as the “liquid” here.

<About liquid ejection device>
In the above-described embodiment, the “liquid ejecting apparatus” has been described by taking an example of an apparatus that ejects ink as a liquid toward a medium. However, in the “liquid ejecting apparatus” described here, liquid is ejected. Any type of device may be used as long as it is a device. Specifically, a textile printing apparatus (method) for patterning a fabric, a circuit board manufacturing apparatus (method) for forming a circuit pattern on a circuit board, and a DNA chip by applying a solution of DNA to a chip. It may be a DNA chip manufacturing apparatus (method) for manufacturing the display device, a display manufacturing apparatus (method) such as an organic EL (Organic Light Emitting Diode) display, or the like.

  The technique described above can also be applied to a liquid ejection apparatus that generates bubbles in a nozzle using a heating element and discharges liquid by the bubbles. Further, it can be applied to various printing apparatuses such as a line head printer.

<About computers>
In the above-described embodiment, various computers such as a personal computer have been described as examples of the “computer”. However, in the “computer” here, a computer that is communicably connected to the liquid ejection device, that is, Any type of computer may be used as long as the computer can be connected to the liquid ejection device so that data communication is possible.

<About each control unit>
In the above-described embodiment, the controller 70 is illustrated as the first control unit, and the computer 110 is illustrated as the second control unit. However, the configuration is not limited thereto. For example, a printer that can print an image without being connected to a computer (a liquid ejecting device in a narrow sense) includes a first control circuit corresponding to the controller 70 and a second control circuit having a printer driver function. . In this printer, the first control circuit can function as the first control unit, and the second control circuit can function as the second control unit. Even if comprised in this way, there exists the same effect.

<About liquid ejection data>
In the above-described embodiment, “print data” is transmitted as “liquid ejection data” from the computer to the liquid ejection apparatus (inkjet printer). It is not limited to such “print data”.

<About cartridge>
In the above-described embodiment, the “cartridge” has been described by way of an example of a cartridge that contains ink as a liquid. However, the “cartridge” here is not limited to a cartridge that contains such ink. That is, any cartridge may be used as long as it is a cartridge that contains liquid and is mounted on the liquid ejection device.

<About the remaining amount detection unit>
In the above-described embodiment, the “remaining amount detection unit” calculates the consumption amount by counting the number of ink droplets ejected from each of the nozzles # 1 to # 180, and each ink is calculated based on the consumption amount. The remaining amount of ink in the cartridge is detected. However, in the “remaining amount detection unit” here, it is not always necessary to detect the remaining amount of each cartridge by such a method. That is, in the “remaining amount detection unit” here, the remaining amount may be detected by any method as long as the remaining amount of the liquid such as ink stored in the cartridge is detected. . Specifically, for example, various sensors such as an optical sensor may be installed and the remaining amount of each cartridge may be detected by such a sensor.

<About alternative cartridges>
In the above-described embodiment, an ink cartridge containing the same color ink (here, a cartridge containing black (K) ink) is used as the “alternative cartridge”. The “cartridge” is not necessarily limited to only a cartridge containing the same color ink. In other words, the “alternative cartridge” here may be any cartridge as long as it can be used in place of the “low remaining amount cartridge”. That is, instead of a cartridge containing a certain color ink, if a cartridge containing two or more different color inks can be substituted, the two or more different color inks are contained. The cartridge is also included in the “alternative cartridge”.

The perspective view explaining the structural example of the liquid discharge system. FIG. 3 is a perspective view illustrating an internal configuration of the printer. Explanatory drawing of a structure of the nozzle row of a head. 2 is a block diagram illustrating configurations of a computer and a printer. FIG. Explanatory drawing of a process of a printer driver. Explanatory drawing of a head control part. 4 is a timing chart of each signal of the head control unit. Explanatory drawing of the exchange between an inkjet printer and a computer. Explanatory drawing of the calculation method of ink consumption. The flowchart explaining the process of the computer.

Explanation of symbols

1 Inkjet printer, 15 transport motor, 17A transport roller,
21 head, 20 paper transport mechanism,
24A ink cartridge, 24B ink cartridge,
25A cartridge mounting part, 25B cartridge mounting part,
26A ink cartridge, 26B ink cartridge,
26C ink cartridge, 27A cartridge mounting part,
27B cartridge mounting part, 27C cartridge mounting part,
30 Carriage moving mechanism, 40 head unit, 40 head unit,
41 Carriage, 42 Carriage motor, 44 Pulley,
45 timing belt, 46 guide rail, 49 cartridge mounting part,
50 drive signal generation circuit, 51 linear encoder, 60 detector group,
70 Controller, 71 External interface (I / F),
74 control unit, 100 liquid ejection system, 110 computer,
112 External interface unit (I / F), 113 CPU, 114 memory,
120 display device, 130 input device, 131 keyboard, 132 mouse,
140 recording / reproducing apparatus, 141 flexible disk drive apparatus,
142 CD-ROM drive device, 160 application program,
162 video drivers, 164 printer drivers,
166 resolution conversion processing unit, 168 color conversion processing unit,
170 halftone processing unit, 172 rasterization processing unit,
211Y yellow nozzle group, 211M magenta nozzle group,
211C cyan nozzle group, 211K1 first black nozzle group,
211K2 second black nozzle group, 222 mask circuit

Claims (9)

(A) a remaining amount detecting step for detecting the remaining amount of the stored liquid for each of the plurality of cartridges storing the liquid ejected from the nozzle, which is performed by the first control unit;
(B) When the first control unit detects that the remaining amount of the liquid in the at least one cartridge is equal to or less than a predetermined amount, information related to the small remaining amount cartridge is transmitted for the corresponding small remaining amount cartridge. And an information transmission step;
(C) Based on the information relating to the small remaining amount cartridge transmitted and transmitted by the second control unit, at least one of the other cartridges excluding the small remaining amount cartridge is defined as an alternative cartridge, and the replacement A liquid discharge data generation step for generating and transmitting liquid discharge data for controlling the discharge of the liquid contained in the cartridge;
(D) When the process for transmitting the liquid ejection data is performed after the reception of the information on the small remaining amount cartridge performed by the second control unit, the information on the remaining amount of the liquid in the alternative cartridge is A remaining amount information acquisition step acquired from the first control unit;
(E) The discharge control method of the liquid which has. In the remaining amount information acquisition step,
Do not obtain information about the remaining amount of liquid from the first control unit until receiving information about the low remaining amount cartridge;
The liquid discharge control method according to claim 1. The liquid contained in the replacement cartridge is
The same type of liquid as the liquid contained in the small remaining amount cartridge,
The liquid discharge control method according to claim 1. The liquid is
Is ink,
The liquid discharge control method according to claim 1. The replacement cartridge is
Contains ink of the same color as the ink contained in the low remaining amount cartridge;
The liquid discharge control method according to claim 4. In the liquid ejection data generation step,
In order to control the discharge of the liquid stored in these cartridges so that the cartridges serving as the alternative cartridges and the cartridges serving as the small remaining amount cartridges are alternately used until the information on the small remaining amount cartridges is received. Generate and send liquid ejection data for
The liquid discharge control method according to claim 1. Based on the information about the remaining amount of liquid obtained from the first control unit, which is performed by the second control unit, the remaining amount of liquid stored in the small remaining amount cartridge and the amount of liquid stored in the alternative cartridge A difference calculating step for calculating a difference with the remaining amount;
A difference determination step performed by the second control unit to determine whether the calculated difference is equal to or less than a predetermined value;
The liquid discharge control method according to claim 1, comprising: In the remaining amount information acquisition step,
When it is determined that the difference is equal to or less than the predetermined value, information on the remaining amount of liquid in the alternative cartridge and information on the remaining amount of liquid in the small remaining amount cartridge are sent from the first control unit. Acquired,
In the liquid ejection data generation step,
Based on the information on the remaining amount of the liquid in the replacement cartridge and the information on the remaining amount of the liquid in the small remaining amount cartridge, of the alternative cartridge and the small remaining amount cartridge, the one with the larger remaining amount Determine the cartridge, and generate and transmit liquid ejection data for controlling the ejection of the liquid contained in the cartridge with the larger remaining amount.
The liquid discharge control method according to claim 7. (A) A liquid ejection apparatus having a first control unit and a second control unit capable of communicating with each other,
(B) The first control unit
A remaining amount detecting step for detecting the remaining amount of the stored liquid for each of the plurality of cartridges storing the liquid discharged from the nozzle; and
An information transmission step of transmitting information relating to the low remaining amount cartridge for the corresponding low remaining amount cartridge when it is detected that the remaining amount of the liquid in at least one cartridge is equal to or less than a predetermined amount;
(C) The second control unit
Based on the transmitted information regarding the small remaining amount cartridge, at least one of the other cartridges excluding the small remaining amount cartridge is determined as an alternative cartridge, and discharge control of the liquid contained in the alternative cartridge is performed. Generating and transmitting liquid discharge data for liquid discharge data generation step;
After receiving the information on the low remaining amount cartridge, whenever the process of transmitting the liquid ejection data is executed, the information on the remaining amount of the liquid of the alternative cartridge is acquired from the first control unit. Step and do,
(D) Liquid ejection device.

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