JP2003001842A - Printing in which ink tank to be used is changed according to ink level in ink tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use ink in two ink tanks housing ink of the same color. SOLUTION: In a printer, the ink tank to be used for forming an ink dot is selected according to an ink level of each of the ink tanks housing the ink of the same color, so that the ink dot can be formed by using a nozzle array supplied with the ink from the ink tank housing the remaining ink, for example, when the ink remains in either of the ink tanks. This allows the effective use of the ink in the two ink tanks housing the ink of the same color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for printing by forming dots on a print medium using a print head.

[0002]

2. Description of the Related Art As a printing apparatus that prints using a print head while scanning in a main scanning direction and a sub scanning direction, there is an ink jet printer such as a serial scan type printer or a drum scan type printer. An inkjet printer forms characters and images on a print medium by ejecting ink from a plurality of nozzles of a print head.

[0003]

In recent years, as a method of printing with such a printer, high-speed monochrome printing using two nozzle rows arranged in a staggered manner has been proposed. However, when ink of the same color is supplied to two nozzle rows arranged in a staggered manner from different ink tanks, it is conceivable that the ink consumption is biased to one ink tank. As a result, there may be a case where the ink in one of the tanks runs out and printing cannot be continued.

The present invention has been made to solve the above-mentioned problems in the prior art, and provides a technique capable of efficiently using ink in two ink tanks containing ink of the same color. The purpose is to do.

[0005]

Means for Solving the Problems and Their Actions / Effects In order to solve at least some of the above problems, the present invention provides
A printing apparatus for printing by ejecting ink droplets from a print head to form dots, the first nozzle row for ejecting ink, and the staggered arrangement with respect to the first nozzle row. And a print head having a second nozzle row capable of being supplied with ink of the same color as that of the first nozzle row independently of the first nozzle row, and the first head. One or a plurality of ink cartridges having a first ink tank for containing ink for supplying to the nozzle row and a second ink tank for containing ink for supplying to the second nozzle row A cartridge mounting unit that can be mounted, an ink remaining amount measuring unit that measures the remaining amount of ink in each of the first ink tank and the second ink tank, and an ink remaining amount in the first ink tank. Serial in accordance with the remaining amount of ink in the second ink tank, characterized by comprising an ink tank selection section that selects an ink tank to be used for formation of an ink dot.

In the printing apparatus of the present invention, the ink tanks used for forming the ink dots are selected according to the respective ink remaining amounts of the plurality of ink tanks containing the same color ink, so that, for example, a plurality of ink tanks are used. If ink remains in any one of the ink tanks, the ink rows can be formed using the nozzle row that receives the ink supplied from the remaining ink tank. That is, the inks in the two ink tanks containing the same color ink can be used efficiently.

In the above-described printing apparatus, the ink tank selection unit is configured such that at least one of the ink remaining amount of the first ink tank and the ink remaining amount of the second ink tank is
When it is less than the predetermined threshold value, it is preferable to select the other ink tank as the ink tank used for forming ink dots.

With this configuration, it is possible to easily select an ink tank to be used for forming ink dots by determining whether or not the remaining ink amount of each of the two ink tanks is smaller than a predetermined threshold value. be able to.

In the above printing apparatus, the ink tank selection unit determines which ink tank has a larger remaining ink amount, depending on the remaining ink amount in the first ink tank and the remaining ink amount in the second ink tank. Is preferably selected for the ink tank used to form the ink dots.

In this way, since the inks in both ink tanks can be used evenly for printing, it is possible to prevent uneven consumption of one of the ink tanks.

In the above printing apparatus, the ink tank selection unit is configured to, whenever the printing apparatus receives a print start instruction,
It is preferable to select the ink tank used to form the ink dots.

With this configuration, it is possible to easily switch the nozzle row used for forming ink dots each time printing is started.

In the above printing apparatus, it is preferable that the ink tank selection section selects an ink tank to be used for forming ink dots each time printing of a new page is started.

With this arrangement, the ink tanks used for forming ink dots can be switched page by page even during printing.

In the above printing apparatus, the ink is preferably black ink.

This is because it is possible to print black-and-white text and line drawings at high speed using the two nozzle arrays.

In the above printing apparatus, when the ink tank selecting section is performing relatively high speed black and white printing using both the first ink tank and the second ink tank, the first ink tank selecting section When it is determined that at least one of the remaining amount of ink in the ink tank and the remaining amount of ink in the second ink tank is less than a predetermined threshold value, the other ink tank is used at a relatively low speed. It is preferable to switch to monochrome printing.

In this way, when high-speed black-and-white printing is performed, even when the ink remaining amount in one of the ink tanks is low, ink is supplied from the ink tank on the side where the ink remaining amount is sufficient. Printing can continue using the receiving nozzle row.

In the printing apparatus, the ink tank selection unit calculates the unused periods of the first nozzle row and the second nozzle row, respectively, and the first nozzle row and the second nozzle row are not used. When the non-use period of at least one of the second nozzle lines is longer than a predetermined period that has been set in advance, the nozzle line having the longer non-use period is included in the nozzle line used for forming the ink dots. It is preferable to make a tank selection.

When the non-use period becomes long, the viscosity inside the nozzle tends to increase and the clogging tends to occur. However, with this configuration, such clogging can be suppressed.

In the above printing apparatus, the ink tank selection unit may be configured such that when at least one of the nozzle row and the additional nozzle row is not used in the printing immediately before the selection, It is preferable to select the ink tank so that the unused nozzle row is included in the nozzle row used for forming the ink dots.

In this way, the non-use period of the nozzle row can be further shortened, so that the clogging caused by the increase of the viscosity inside the nozzle can be further suppressed.

In the above printing apparatus, one of the first nozzle row and the second nozzle row can receive the supply of the liquid agent from a tank containing a liquid agent other than ink, The ink tank selection unit selects a tank containing a liquid agent to be supplied to the one nozzle row as an ink tank to be used for applying the liquid agent, and also supplies an ink to be supplied to the other nozzle row. It is preferable that the ink tank to be contained is selected as the ink tank used for forming the ink dots.

Further, in the above printing apparatus, either one of the first nozzle row and the second nozzle row can receive the supply of the ink from a tank containing ink other than the ink. Yes, the ink tank selection unit selects the tank containing the ink to be supplied to the one nozzle row as the ink tank used for forming the ink dots, and supplies the ink to the other nozzle row. The ink tank containing the ink is preferably selected as the ink tank used to form the ink dots.

By doing so, it is possible to prevent deterioration of image quality due to erroneous ejection of a liquid agent other than ink as ink, and it is possible to use another liquid agent or ink.

The present invention can be implemented in various modes, for example, a printing method and a printing device,
A computer program for realizing the functions of those methods or apparatuses, a recording medium recording the computer program, a data signal embodied in a carrier wave including the computer program, and the like can be realized.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in the following order based on examples. A. Device Configuration: B. Contents of print processing: C. Ink remaining amount measurement method: D. Modification:

A. Device Configuration: FIG. 1 is a block diagram showing the configuration of a printing system as an embodiment of the present invention. This printing system includes a computer 90 as a print control device, a color printer 20 as a printing unit,
Is equipped with. The combination of the color printer 20 and the computer 90 can be called a “printing device” in a broad sense.

In the computer 90, the application program 9 is executed under a predetermined operating system.
5 is working. A video driver 91 and a printer driver 96 are incorporated in the operating system, and the application program 95 outputs print data PD to be transferred to the color printer 20 via these drivers. The application program 95 performs desired processing on the image to be processed, and also displays the image on the CRT 21 via the video driver 91.

When the application program 95 issues a print command, the printer driver 9 of the computer 90
6 receives the image data from the application program 95 and converts it into print data PD to be supplied to the color printer 20. In the example shown in FIG. 1, inside the printer driver 96, a resolution conversion module 97, a color conversion module 98, a halftone module 99, a rasterizer 100, and a color conversion table L.
A UT, a print mode selection unit 101, and an ink tank selection unit 102 are provided.

The resolution conversion module 97 plays a role of converting the resolution (that is, the number of pixels per unit length) of the color image data handled by the application program 95 into a resolution that can be handled by the printer driver 96. The image data whose resolution has been converted in this way is still image information consisting of three colors of RGB. The color conversion module 98 converts the RGB image data into multi-tone data of a plurality of ink colors usable by the color printer 20 for each pixel while referring to the color conversion table LUT.

The color-converted multi-gradation data is, for example, 25
It has 6 gradation values. The halftone module 99 disperses and forms ink dots,
The color printer 20 executes halftone processing for expressing the gradation value. The halftone-processed multi-tone data is rearranged by the rasterizer 100 in the order of data to be transferred to the color printer 20 and output as final print data PD. The print data PD
Includes raster data indicating a dot recording state during each main scan, and data indicating a sub-scan feed amount indicating a sub-scan feed amount performed between the main scans. The functions of the print mode selection unit 101 and the ink tank selection unit 102 will be described later.

The printer driver 96 corresponds to a program for realizing the function of generating the print data PD. The program for realizing the functions of the printer driver 96 is supplied in the form recorded in a computer-readable recording medium. Examples of such a recording medium include a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a ROM cartridge, a punch card, a printed matter on which codes such as a bar code are printed, and an internal storage device (RAM, ROM, etc.) of a computer. memory)
Also, various computer-readable media such as an external storage device can be used.

FIG. 2 is a schematic block diagram of the color printer 20. The color printer 20 includes a sub-scan feed mechanism that conveys the print paper P in the sub-scan direction by the paper feed motor 22, and a main scan feed that reciprocates the carriage 30 in the axial direction (main scan direction) of the platen 26 by the carriage motor 24. Mechanism, a head drive mechanism that drives a print head unit 60 (also referred to as a “print head assembly”) mounted on the carriage 30 to control ink ejection and dot formation, the paper feed motor 22, and the carriage motor. 24, print head unit 60 and operation panel 32
And a control circuit 40 that controls the exchange of signals with the. The control circuit 40 is connected to the computer 90 via the connector 56.

The sub-scan feed mechanism for conveying the printing paper P is
A gear train (not shown) that transmits the rotation of the paper feed motor 22 to a platen 26 and a paper transport roller (not shown) is provided. Further, the main scanning feed mechanism for reciprocating the carriage 30 is provided in parallel with the axis of the platen 26, and a drive shaft 36 which is endless between the slide shaft 34 which slidably holds the carriage 30 and the carriage motor 24. And a position sensor 39 for detecting the origin position of the carriage 30.

FIG. 3 is a block diagram showing the configuration of the color printer 20 centering on the control circuit 40. The control circuit 40 includes a CPU 41 and a programmable ROM (PRO
M) 43, RAM 44, character generator (CG) 45 that stores a dot matrix of characters, and MIB (Management Information Base) 46 that is a database that holds the operating environment of the color printer 20. Is configured as. The control circuit 40 further has an I / F dedicated circuit 50 dedicated to interface with an external motor and the like, and a head connected to the I / F dedicated circuit 50 for driving the print head unit 60 to eject ink. A drive circuit 52 and a motor drive circuit 54 that drives the paper feed motor 22 and the carriage motor 24 are provided. The head drive circuit 52 is
A data reading unit 53 and an ink remaining amount measuring unit 55 are provided. The function of the remaining ink amount measuring unit 55 will be described later.

The I / F dedicated circuit 50 has a built-in parallel interface circuit and can receive print data PD supplied from the computer 90 via the connector 56. The color printer 20 executes printing according to the print data PD. The RAM 44 functions as a buffer memory for temporarily storing the raster data. Also, the computer 90 uses the MIB 46
By accessing, the information regarding the operating environment of the printer 20 can be obtained. This operating environment also includes information about the installed cartridge.

The print head unit 60 includes the print head 2
8 and an ink cartridge can be mounted. The print head unit 60 is attached to and detached from the color printer 20 as one component. That is, when the print head 28 is replaced, the print head unit 60 is replaced.

The print head unit 60 is equipped with two black ink cartridges 171K and one color ink cartridge 170F. The black ink cartridge 171K and the color ink cartridge 170F are provided with memories 181K and 180F, respectively. These memories 181K and 180F store information for specifying the remaining amount and expiration date of the ink contained in the ink cartridge. The ink information is read by the data reading unit 53 and sent to the computer 90 via the I / F dedicated circuit 50 and the connector 56. In addition, this memory 181
Various information such as the type of ink stored may be stored in K and 180F.

In this printing apparatus, instead of the black ink cartridge 171K, a dark yellow ink cartridge 171DY containing dark yellow ink can be mounted. Here, the dark yellow ink means an ink having a lower brightness than the yellow ink,
Also called dark yellow ink. Specifically, the dark yellow ink is an ink in which a color material for another ink (for example, dark cyan and dark magenta) is mixed with the yellow ink. When a dark yellow ink containing a dark cyan component and a dark magenta component is used, the amount of ink ejected onto the print medium (especially the amount of solvent) is greater than when ejecting yellow, dark cyan, and dark magenta ink droplets separately. ) Is less. As a result, there is an advantage that the print quality of the shadow portion can be improved. Also, instead of the black ink cartridge 171K, a liquid agent other than ink,
For example, a cartridge (not shown) containing a protective agent for protecting printed printing paper can be mounted.

FIG. 4 is an explanatory view showing the nozzle arrangement on the lower surface of the print head 28. On the lower surface of the print head 28, in order to eject color ink, a cyan ink nozzle row C for ejecting cyan ink, a light cyan ink nozzle row LC for ejecting light cyan ink, and magenta ink are ejected. A magenta ink nozzle row M for ejecting, a light magenta ink nozzle row LM for ejecting light magenta ink, and a yellow nozzle row Y for ejecting yellow ink. Further, in order to eject the black ink, a nozzle row K for ejecting the black ink and an additional nozzle row S for ejecting an additional ink selectable from either the black ink or the dark yellow ink are formed. ing. The nozzle row K is the "first nozzle row" in the claims.
The additional nozzle row S corresponds to the “second nozzle row” in the claims.

In the present specification, the four inks C, M, Y and K other than the light ink are referred to as "four basic color inks". More specifically, the “four basic color inks” are cyan ink, magenta ink, which can reproduce black by mixing almost equal amounts,
And yellow ink and non-gray black ink. In this specification, the four nozzle arrays Y, M, C, and K for ejecting these four basic color inks are called "basic color nozzle arrays".

The plurality of nozzles in each nozzle row are arranged at a constant nozzle pitch KD in the sub-scanning direction SS. Here, K is an integer, and D is a pitch (“dot pitch”) corresponding to the printing resolution in the sub-scanning direction.
Is called).

The additional nozzle rows S are staggered with the black ink nozzle rows K for ejecting black ink. Therefore, when the black ink is selected as the additional ink, as can be seen from FIG. 4, the nozzle pitch of the plurality of nozzles for ejecting the black ink becomes (k / 2) × D and the number of nozzles doubles. Become. As a result, the number of raster lines that can be formed by one main scan is twice as large as that when dark yellow ink is selected as the additional ink during monochrome printing. The additional nozzle row S is provided at an interval of δ with respect to the black ink nozzle row K in the main scanning direction.

Each nozzle is provided with a piezo element (not shown) as a driving element for driving each nozzle to eject ink droplets. When printing, print head 2
Ink droplets are ejected from each nozzle while 8 moves in the main scanning direction MS.

The plurality of nozzles in each nozzle row need not be arranged in a straight line along the sub-scanning direction.
For example, they may be arranged in a staggered pattern. Even when the nozzles are arranged in a staggered pattern, the nozzle pitches K and D measured in the sub-scanning direction can be defined as in the case of FIG.

FIG. 5 is a perspective view of the print head unit 60. The print head unit 60 includes a cartridge mounting portion including a color ink cartridge mounting portion 65 for five colors, a black ink cartridge mounting portion 66, and an additional cartridge mounting portion 67. here,
The additional cartridge refers to a cartridge having an additional ink tank that stores additional ink to be supplied to the additional nozzle row S, and the additional ink can be selected from either black ink or dark yellow ink. .

The print head 28 below the print head unit 60 is provided with a total of seven nozzle rows corresponding to the additional ink, the black ink, and the five color inks contained in the additional cartridge. At the bottom of the print head unit 60, inlet tubes 72 to 78 for guiding the ink from the cartridges to the nozzle rows are provided upright. The introduction pipe 72 is a pipe for guiding ink from the additional cartridge. The introduction tube 73 is a tube for guiding the ink from the black ink cartridge. Introductory pipe 74
Reference numerals 78 to 78 are tubes for guiding ink from the color ink cartridge. These introduction pipes are connected to each nozzle row included in the print head 28.

The black ink cartridge 171K mounted in the black ink cartridge mounting portion 66
Corresponds to a black ink tank, and the black ink cartridge 171K mounted in the additional cartridge mounting portion 67 has an ink tank
It corresponds to an additional ink tank. As described above, in this embodiment, each ink tank of the two black ink cartridges 171K corresponds to a "black ink tank" or an "additional ink tank" depending on the cartridge mounting portion to be mounted. The black ink tank corresponds to the "first ink tank" in the claims, and the additional ink tank corresponds to the "second ink tank" in the claims.

The color ink cartridge 170F
(FIG. 3) is a combination of five ink tanks for five types of ink. Instead of such an ink cartridge 170F, an independent ink tank for each ink can be attached to the print head unit 60,
The print head unit 60 may be configured. In this case, a memory is provided for each ink tank. As can be understood from this description, in the present specification, the “ink tank” means a container for containing one type of ink. Further, the ink cartridge means a container which is integrally formed and has at least one ink tank.

FIG. 6 is an explanatory diagram showing the configuration and operation of the head drive circuit 52 (FIG. 3). FIG. 6A is a block diagram showing the main configuration of the head drive circuit 52 (FIG. 3). The head drive circuit 52 includes the original drive signal generator 220.
And a plurality of mask circuits 222 and a piezo element PE of each nozzle. The mask circuit 222 is provided corresponding to each nozzle # 1, # 2, ... Of the print head 28. In FIG. 6, the number in parentheses added to the end of the signal name indicates the nozzle number to which the signal is supplied.

FIG. 6B is a timing chart showing the operation of the head drive circuit 52 in the printing method in which the main scan line is recorded by one main scan. The original drive signal generator 220 uses the original drive signal CO commonly used for each nozzle.
The MDRV is generated and supplied to the plurality of mask circuits 222. The original drive signal COMDRV is a signal including one pulse within the main scanning period Td for one pixel. The i-th mask circuit 222 outputs the original drive signal COMDR according to the level of the serial print signal PRT (i) of the i-th nozzle.
Mask V.

Specifically, the mask circuit 222 outputs the original drive signal COM when the print signal PRT (i) is 1 level.
Pass DRV as it is. Then, the original drive signal is supplied to the piezo element PE as the drive signal DRV. on the other hand,
When the print signal PRT (i) is at 0 level, the original drive signal COMDRV is cut off. This serial print signal PRT
(I) is a signal indicating the printing state of each pixel printed by the i-th nozzle in one main scan, and is the print data PD (FIG. 1) given from the computer 90 decomposed for each nozzle. is there. Note that FIG. 6B is an example in which dots are recorded every other pixel, and when dots are recorded in all pixels, the original drive signal COMDRV is used as it is as the drive signal DRV in the piezo element PE. Supplied.

The color printer 20 having the above-described hardware configuration conveys the paper P by the paper feed motor 22 and reciprocates the carriage 30 by the carriage motor 24, and at the same time drives the piezo element of the print head 28. , Ink droplets of each color are ejected to form ink dots, and a multi-color multi-tone image is formed on the paper P.

B. Contents of print processing: FIG. 7 is a flowchart showing a procedure of print processing in the embodiment of the present invention. In step S101, the user uses the computer 90
Instruct to print. In step S102,
If you click the "Property button" (not shown) in the dialog box for printing displayed on the CRT 21,
The print mode selection unit 101 (FIG. 1) displays the property setting screen shown in FIG. 8 on the CRT 21.

The user can specify various parameters that define the print mode in this property setting screen. The print mode basic setting screen of FIG. 8 has a menu for designating various parameters, which includes an ink color selection button CLR. The ink color selection button CLR is a button for selecting whether to use color ink or only black ink.

It should be noted that the user can set other parameters other than these on the detailed setting screen of the print mode, but in the description of the present embodiment, the description of the other parameters will be omitted. .

When the user selects an ink color and gives an instruction to start printing in step S103 of FIG. 7, the ink tank selection unit 102 selects an ink tank to be used in printing in step S104.

FIG. 9 is a flow chart showing the flow of ink tank selection processing in the embodiment of the present invention. In step S201, the amount of ink remaining in each of the additional ink tank and the black ink tank is measured. The method of this measurement will be described later.

In step S202, the ink tank selection unit 102 determines usable ink tanks that can be used for printing. This determination is made according to the remaining ink amount in the additional ink tank and the black ink tank.
Specifically, when the remaining amount of ink in each ink tank is larger than a predetermined threshold value, it is determined as a usable ink tank. This threshold value may be set as, for example, the minimum ink remaining amount required for properly ejecting ink, but it is preferable to add a value used for several times of nozzle cleaning.

In step S203, it is determined whether or not both ink tanks are usable ink tanks.
If both ink tanks are usable ink tanks, the ink tank selection unit 102 determines the preferentially used nozzle row to be preferentially used (step S20).
4). When at least one of the black ink nozzle row and the additional nozzle row was not used in the printing immediately before this selection, the nozzle row that was not used is determined as the priority nozzle row. It is done by determining. Whether or not the ink tank has been used immediately before this selection is performed based on the information read from the MIB 46 (FIG. 3). If at least one ink tank is not a usable ink tank, the preferential use nozzle row is not determined.

In step S205, the ink tank selection unit 102 selects an ink tank used for printing. FIG. 10 is an explanatory diagram showing a method of selecting an ink tank in the printing process according to the embodiment of the present invention. The ink tank is selected according to the setting content of the print mode, the determination result of the usable ink tank, and the determination result of the preferentially used nozzle row. For example, as shown in FIG. 10, when the print mode is “black and white”, both ink tanks are selected when both ink tanks are available, and when only one ink tank is available. Only usable ink tanks are selected. On the other hand, when the print mode is “color”, when both ink tanks are available, only the ink tank that supplies ink to the priority use nozzle row is selected, and only one ink tank is the available ink tank. At this time, only usable ink tanks are selected. When the ink tank used for printing is selected, the ink tank selection process ends.

In step S105 (FIG. 7), the rasterizer 100 (FIG. 1) determines the content of the rasterizing process according to the ink tank selection result sent from the ink tank selection unit 102. For example, in the color printing mode, when the additional ink tank is selected, the additional nozzle row S and the color ink nozzle rows C and L
The contents of the rasterizing process are set so that color printing is performed using C, M, LM, and Y. In the color printing mode, when the black ink tank is selected, rasterization is performed so that color printing is performed using the black ink nozzle row K and the color ink nozzle rows C, LC, M, LM, and Y. The content of the process is set. Further, when both ink tanks are selected in the monochrome printing mode, high speed monochrome printing is set using both the additional nozzle row S and the black ink nozzle row K.

FIG. 11 is an explanatory diagram showing the method of rasterizing processing in the printing processing according to the embodiment of the present invention. Figure 1
1A shows a relationship between a raster formed by each nozzle row in a certain main scan and a plane for each ink color included in the halftone data. Here, the halftone data is data generated by the halftone module 99 by halftone processing the multi-tone data, and is data representing the formation state of ink dots of each color. Note that the number of nozzles used in each nozzle row is 4 for the sake of clarity.

The halftone data includes a black plane KP indicating the formation state of black ink dots, and also cyan ink dots, light cyan ink dots, magenta ink dots, light magenta ink dots, and yellow ink dots. A cyan plane CP, a light cyan plane LCP, a magenta plane MP, a light magenta plane LMP, and a yellow plane YP, which indicate the respective formation states of the above.

FIGS. 11B and 11C show the contents of the rasterizing process performed by the rasterizer 100 for a certain main scan in color printing. FIG. 11 (b)
Shows the content of the rasterizing process when the black ink tank is selected. FIG. 11C shows the content of the rasterizing process when the additional ink tank is selected.

When the black ink tank is selected, the black ink nozzle row K and the cyan ink nozzle row C, the light cyan ink nozzle row LC, the magenta ink nozzle row M, the light magenta ink nozzle row LM, and the yellow ink nozzle. Row Y is used and no additional nozzle row S is used. The dot recording state in each main scan is the black plane KP for the black ink nozzle row K.
The cyan ink nozzle row C is a cyan plane CP, the light cyan ink nozzle row LC is a light cyan plane LCP, and the magenta ink nozzle row M is a magenta plane MP.
The light magenta ink nozzle row LM is determined based on the light magenta plane LMP, and the yellow ink nozzle row Y is determined based on the yellow plane YP.

For example, in the example shown in FIG. 11B, the recording state of the black ink nozzle row K in a certain main scan is determined based on the data of the first row of the black plane KP for the # 1 nozzle, and , # 2 nozzle, the data of the 5th line of the black plane KP
For the nozzles, refer to the data on the 9th line of the black plane KP, and for the # 4 nozzle, the 1 of the black plane KP.
It is determined based on the data in the third row. The color ink nozzle rows C, LC, M, LM, and Y are similarly determined based on the planes of the respective colors.

On the other hand, when the additional ink tank is selected, the additional nozzle row S is used instead of the black ink nozzle row K. That is, the additional nozzle row S and the color ink nozzle rows C, LC, M, LM, and Y are used, and the black ink nozzle row K is not used. The recording state of dots in each main scan is determined based on the black plane KP for the additional nozzle row S, and similarly for the color ink nozzle rows C, LC, M, LM, and Y based on the planes of the respective colors. Determined.

For example, in the example shown in FIG. 11C, the recording state of the additional nozzle row S in a certain main scan is determined based on the data of the third line of the black plane K for the # 1 nozzle, and The # 2 nozzle is based on the data on the 7th line of the black plane K, the # 3 nozzle is based on the data on the 11th line of the black plane K, and the # 4 nozzle is based on the data on the 15th line of the black plane K. Determined. On the other hand, the recording states of the color ink nozzle rows C, LC, M, LM, and Y are determined based on the data of the first row of the plane of each color for the # 1 nozzle, and the planes of each color for the # 2 nozzle. Of the fifth row, the data of the # 3 nozzle on the ninth row of the plane of each color, and the # 4 nozzle of the third row of the plane of each color.

As described above, when the additional ink tank is selected, the additional nozzle row S and the color ink nozzle rows C, LC, M, LM, and Y form different raster lines in the same main scan. Will be done. This is because the additional nozzle row S is displaced from the other nozzle rows by 2 dots in the sub-scanning direction. However, in the additional nozzle row S, the same number of nozzles as other nozzle rows are used, and since the nozzle pitch k is also the same, it is possible to form a print image without gaps or duplication in other nozzle rows. If the main scanning and the sub scanning are performed, the print image can be formed even in the additional nozzle row S without any gap or overlap.

In the monochrome printing mode, if both the additional ink tank and the black ink tank are determined to be usable ink tanks, both the additional nozzle row S and the black ink nozzle row K are used. Rasterization processing is performed so that printing is performed at high speed.

Further, as shown in FIG. 4, the additional nozzle row S
Are provided at intervals of δ in the main scanning direction with respect to the black ink nozzle row K, the dot formation position will be displaced in the main scanning direction by δ unless raster data is compensated. Therefore, if 10 pixels are included in the interval of δ, the raster is generated such that the drive signal DRV shown in FIG. 6B is generated with a timing shift by the main scanning period (10 × Td) for 10 pixels. The data will also be compensated.

In step S106 of FIG. 7, the rasterizer 100 performs the rasterizing process based on the contents of the process determined in this way to print data P.
Generate D. The print data PD is stored in the computer 90.
(FIG. 1) is sent to the I / F dedicated circuit 50 of the control circuit 40 (FIG. 3) via the connector 56. Printer 20
Can perform color printing or high-speed monochrome printing according to the print data PD (S107).

As described above, in this embodiment, when at least one of the ink remaining amount of the black ink tank and the ink remaining amount of the additional ink tank is smaller than the predetermined threshold value, the other ink tank is Since it is selected for the ink tank used to form black ink dots,
If the black ink remains in either the black ink tank or the additional ink tank, it is possible to form the black ink dot by using the nozzle row that is supplied with ink from the remaining ink tank.

In the present embodiment, when at least one of the black ink nozzle row and the additional nozzle row is not used in the printing immediately before the ink tank selection, the nozzle row which is not used is selected. Since ink tanks are selected to be included in the nozzle row used to form black ink dots, the nozzle row is not used for a short period of time to prevent clogging caused by an increase in viscosity inside the nozzle. There is also an advantage that you can.

Further, the unused periods of the black ink nozzle row and the additional nozzle row are respectively calculated, and the unused period of at least one of the black ink nozzle row and the additional nozzle row is a predetermined period. When it is longer than that, it is possible to select the ink tank such that the nozzle row having the longer non-use period is included in the nozzle row used for forming the black ink dots. Even in this case, it is possible to suppress the clogging caused by the increase in the viscosity inside the nozzle.

Further, it is preferable to select the ink tank having the larger remaining ink amount as the ink tank used for forming the black ink dots. This is because printing can be performed using ink in both ink tanks evenly, and it is possible to suppress uneven consumption of one of the ink tanks. The ink tank whose expiration date is approaching may be preferentially used.

C. Ink Remaining Measurement Process: FIG. 12 is a flowchart showing a flow of a process of measuring the remaining ink amount. The remaining ink amount is measured by the remaining ink amount measuring unit 55 (FIG. 1) in the head drive circuit 52 of the printer 20 as described below.

(A) Reading of accumulated ink ejection amount (step S300) When the power of the printer 20 is turned on, the ink remaining amount measuring routine is started immediately and the data reading unit 53 (FIG. 3) stores it in the memories 181K and 180F. The accumulated value of the discharged ink weight is read (step S300). When the ink remaining amount measurement routine finishes processing, the accumulated value of the ink ejection amount is written in the non-volatile memory for the purpose of starting the routine next time. Is read. The color printer 20 of this embodiment uses six color inks of C (cyan), LC (light cyan), M (magenta), LM (light magenta), Y (yellow), and K (black). Corresponding to, the cumulative value of the ink discharge weight is also stored for each color ink.

The ink remaining amount in the cartridge is measured by reading the accumulated ink discharge amount value and then comparing the read value with the ink storage amount of the ink cartridge.

(B) Ink supply condition detection (step S3)
02) After reading the ink discharge amount cumulative value, the remaining ink amount measuring unit 55 detects the ink supply condition (step S30).
2). As conditions relating to the supply of ink to the ink chamber of the nozzle, for example, the ink temperature, the ink type, and the remaining ink amount in the ink cartridge are detected.

(C) Counting the number of ink drops within a predetermined period (step S304) After the detection of the ink supply condition is completed, the ink remaining amount measuring section 55 determines the number of ink drops ejected within a predetermined period for each color ink. The number is counted (step S304). Color printer 2
When 0 forms, for example, three types of large, medium, and small ink dots, the remaining ink amount measuring unit 55 distinguishes and counts the sizes of the ink dots.

(D) Calculation of ink discharge amount (step S30
6) When the number of ink drops within a predetermined period is counted, the remaining ink amount measuring unit 55 multiplies the count value by the ink drop weight (ink weight per ink drop) to calculate the ink ejection weight (step S306). ). When the ink supply conditions relating to the ink supply are different, the weight of the ejected ink droplets is also different. Therefore, in the process of step S306, the ink supply condition previously detected in step S302 is reflected to determine the ink ejection weight. The calculation accuracy of is improved. It is also possible to store the volume, not the weight per ink droplet, and calculate the ink ejection volume by multiplying the number of ink ejections by the ink volume.

(E) Ink discharge amount accumulation / ink remaining amount display, etc. (steps S308 to S311) When the ink discharge weight within a predetermined period is calculated, the ink remaining amount measuring unit 55 uses the obtained value as the previously calculated ink. Add to the discharge weight.

When the above process is completed, it is judged whether or not the printing is completed (step S310). If the printing is not completed, the process returns to step S304 again to repeat the subsequent series of processes. If the printing is completed, the ink ejection amount cumulative value is stored in the memories 181K and 180F so that it can be read at the next ink tank selection (step S31).
1). In this way, even if the power of the printing apparatus is turned off, the ink discharge amount can be accumulated and the ink remaining amount in the ink cartridge can be measured.

D. Modifications: The present invention is not limited to the above-described embodiments and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are also possible. is there.

D-1. In the above embodiment, the print head includes two staggered black ink nozzle rows that can be independently supplied with ink, but the nozzle rows that eject ink of other colors are not included. May be. Generally, a print head used in the present invention is arranged in a staggered manner with respect to a first nozzle row for ejecting ink, and independently of the first nozzle row. It suffices to have a second nozzle row capable of receiving the ink of the same color as the first nozzle row of the lever.

D-2. In the above embodiment, the ink remaining amount measuring unit measures the ink remaining amount by subtracting the ink consumption amount from the ink amount initially contained in the ink tank. You may measure according to the change of a value. Generally, the remaining ink amount measuring unit used in the present invention may be any unit that can measure the remaining amount of ink in each of the black ink tank and the additional ink tank.

D-3. In the above-described embodiment, the ink tank used for forming the black ink dots is selected every time the start of printing is instructed, but for example, the ink tank is selected each time printing of a new page is started. It may be done. However, the latter configuration has an advantage that the ink tanks can be switched for each page even during printing.

When high-speed black-and-white printing is performed using both the black ink tank and the additional ink tank, at least one of the ink remaining amount in the black ink tank and the ink remaining amount in the additional ink tank is predetermined. It is preferable to select only the other ink tank when it is determined that it has become less than the predetermined threshold value. By doing this, even when high-speed black-and-white printing is performed and the ink level in one ink tank becomes low,
This is because it is possible to continue printing by using the nozzle row that receives the ink supply from the ink tank on the side where the remaining ink amount is sufficient.

D-4. In the above-described embodiment, the print head including the nozzle row that ejects seven inks including the light ink is used, but the print head used in the present invention has four basic colors of cyan, magenta, yellow, and black. It may have five nozzle rows, a nozzle row and an additional nozzle row, or may not have a color ink nozzle row. Generally, a print head used in the present invention includes a black ink nozzle array for ejecting black ink,
It suffices as long as it has a staggered arrangement with respect to this black ink nozzle row, and has another black ink nozzle row that can independently receive the supply of black ink from this black ink nozzle row. .

D-5. In the above-described embodiment, the cartridge mounting portion can mount the color ink cartridge in which the five ink tanks respectively containing the five types of color ink are combined, the black ink cartridge, and the additional cartridge having the additional ink tank. However, for example, an independent cartridge may be attached to each ink. Generally, the cartridge mounting portion used in the present invention includes a black ink tank that stores ink for supplying one black ink nozzle row and a black ink that stores ink for supplying the other black ink nozzle row. It suffices that one or more ink cartridges having a tank can be mounted.

The present invention can also be applied to a drum printer. In the drum printer, the drum rotation direction is the main scanning direction and the carriage traveling direction is the sub scanning direction. Also,
The present invention can be applied not only to an inkjet printer, but also to a dot recording apparatus that generally records on the surface of a print medium using a recording head having a plurality of nozzle rows.

In the above embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware. Good. For example, a part or all of the functions of the printer driver 96 shown in FIG. 1 can be executed by the control circuit 40 in the printer 20. In this case, some or all of the functions of the computer 90 serving as a print control device that creates print data are performed by the printer 20.
The control circuit 40 of FIG.

When some or all of the functions of the present invention are implemented by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. In the present invention, "computer-readable recording medium"
The term is not limited to a portable recording medium such as a flexible disk or a CD-ROM, but includes an internal storage device in a computer such as various RAMs and ROMs, and an external storage device fixed to the computer such as a hard disk. I'm out.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a printing system as an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a printer.

FIG. 3 is a block diagram showing a configuration of a control circuit 40 in the color printer 20.

FIG. 4 is an explanatory diagram showing a nozzle array on the lower surface of the print head.

FIG. 5 is a perspective view of the print head unit 60.

FIG. 6 is an explanatory diagram showing the configuration and operation of a head drive circuit 52.

FIG. 7 is a flowchart showing a procedure of printing processing according to the embodiment of the present invention.

FIG. 8 is a diagram showing a basic setting screen of a print mode in the embodiment of the invention.

FIG. 9 is a flowchart showing a flow of ink tank selection processing in the embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a method of selecting an ink tank in a printing process according to an embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating a method of rasterizing processing in the printing processing according to the embodiment of this invention.

FIG. 12 is a flowchart showing the flow of processing for measuring the remaining ink amount.

[Explanation of symbols]

20 ... Color printer 21 ... CRT 22 ... Paper feed motor 24 ... Carriage motor 26 ... Platen 28 ... Print head 30 ... Carriage 32 ... Operation panel 34 ... Sliding shaft 36 ... Drive belt 38 ... pulley 39 ... Position sensor 40 ... Control circuit 41 ... CPU 44 ... RAM 46 ... MIB 50 ... I / F dedicated circuit 52 ... Head drive circuit 53 ... Data reading section 54 ... Motor drive circuit 55 ... Ink remaining amount measuring unit 56 ... Connector 60 ... Print head unit 65 ... Color ink cartridge mounting part 66 ... Black ink cartridge mounting part 67 ... Additional cartridge mounting section 72-78 ... Introduction tube 90 ... Computer 91 ... Video driver 95 ... Application program 96 ... Printer driver 97 ... Resolution conversion module 98 ... Color conversion module 99 ... Halftone module 100 ... rasterizer 101 ... Print mode selection unit 102 ... Ink tank selection section 170F ... Color ink cartridge 171DY ... Dark yellow ink cartridge 171K ... Black ink cartridge 181K ... memory 220 ... Original drive signal generator 222 ... Mask circuit

Claims (16)

[Claims] 1. A printing apparatus for printing by ejecting ink droplets from a print head to form dots, the first nozzle row for ejecting ink, and the first nozzle row It is arranged in a staggered manner and the first
For supplying to the first nozzle row, a print head having a second nozzle row capable of receiving the ink of the same color as that of the first nozzle row independently of the first nozzle row. Cartridge mounting portion to which one or a plurality of ink cartridges having a first ink tank for storing the above ink and a second ink tank for storing the ink for supplying to the second nozzle row can be mounted An ink remaining amount measuring unit that measures the remaining amount of ink in each of the first ink tank and the second ink tank; and an ink remaining amount of the first ink tank and a second ink tank of the second ink tank. An ink tank selection unit that selects an ink tank to be used for forming ink dots according to the remaining amount of ink, and a printing apparatus. 2. The printing apparatus according to claim 1, wherein at least one of the ink remaining amount of the first ink tank and the ink remaining amount of the second ink tank is preset in the ink tank selection unit. A printing device that selects the other ink tank as an ink tank to be used for forming ink dots when it is less than a predetermined threshold value. 3. The printing apparatus according to claim 1, wherein the ink tank selection unit is responsive to an ink remaining amount of the first ink tank and an ink remaining amount of the second ink tank. Printer that selects the ink tank with the largest amount of ink remaining as the ink tank used to form ink dots. 4. The printing apparatus according to claim 1, wherein the ink tank selection unit is an ink tank used for forming ink dots each time the printing apparatus receives a print start instruction. Select the printing device. 5. The printing device according to claim 1, wherein the ink tank selection unit selects an ink tank to be used for forming ink dots each time printing of a new page is started. The printing device of your choice. 6. The printing device according to claim 1, wherein the ink is black ink. 7. The printing apparatus according to claim 6, wherein the ink tank selection unit performs relatively high speed monochrome printing using both the first ink tank and the second ink tank. When it is determined that at least one of the remaining ink amount in the first ink tank and the remaining ink amount in the second ink tank is less than a predetermined threshold value, the other ink tank A printing device that switches to a relatively slow black and white print that uses only. 8. The printing apparatus according to claim 4, wherein the ink tank selection unit is a non-used period in which the first nozzle row and the second nozzle row are not used. And when the non-use period of at least one of the first nozzle line and the second nozzle line is longer than a predetermined period, the nozzle line having the longer non-use period is calculated. A printing device that selects ink tanks to be included in the nozzle row used to form ink dots. 9. The printing apparatus according to claim 4, wherein the ink tank selection unit selects one of the first nozzle row and the second nozzle row in printing immediately before the selection. A printing apparatus that selects an ink tank so that when at least one of them is not used, the nozzle row that is not used is included in a nozzle row that is used for forming ink dots. 10. The printing apparatus according to claim 1, wherein one of the first nozzle row and the second nozzle row contains a liquid agent other than ink. It is possible to receive the supply of the liquid agent from a tank, and the ink tank selection unit selects a tank containing a liquid agent to be supplied to the one nozzle row as an ink tank used for applying the liquid agent. In addition, the printing apparatus selects the ink tank that contains the ink to be supplied to the other nozzle row as the ink tank used to form the ink dots. 11. The printing apparatus according to claim 1, wherein one of the first nozzle row and the second nozzle row contains ink other than ink. It is possible to receive the supply of the ink from a tank, and the ink tank selection unit selects a tank containing the ink to be supplied to the one nozzle row as an ink tank used for forming the dots of the ink. Along with
A printing apparatus in which an ink tank containing ink to be supplied to the other nozzle row is selected as an ink tank used for forming ink dots. 12. An ink cartridge attachable to a printing device for performing printing by ejecting ink droplets from a print head to form dots, wherein the printing device is a first nozzle for ejecting ink. Rows and staggered with respect to the first nozzle row, and
For supplying to the first nozzle row, a print head having a second nozzle row capable of receiving the ink of the same color as that of the first nozzle row independently of the first nozzle row. Cartridge mounting portion to which one or a plurality of ink cartridges having a first ink tank for storing the above ink and a second ink tank for storing the ink for supplying to the second nozzle row can be mounted An ink remaining amount measuring unit that measures the remaining amount of ink in each of the first ink tank and the second ink tank; and an ink remaining amount of the first ink tank and a second ink tank of the second ink tank. An ink tank selection unit that selects an ink tank to be used for forming ink dots according to the remaining amount of ink; and the cartridge, the first ink tank, and the second ink tank. An ink tank, and a memory storing first ink remaining amount information indicating the ink remaining amount of the first ink tank and second ink remaining amount information indicating the ink remaining amount of the second ink tank. The first ink remaining amount information is used for measuring the ink remaining amount of the first ink tank, and the second ink remaining amount information is used for measuring the ink remaining amount of the second ink tank. Used in the cartridge. 13. An ink cartridge attachable to a printing device for performing printing by ejecting ink droplets from a print head to form dots, wherein the printing device is a first nozzle for ejecting ink. Rows and staggered with respect to the first nozzle row, and
For supplying to the first nozzle row, a print head having a second nozzle row capable of receiving the ink of the same color as that of the first nozzle row independently of the first nozzle row. Cartridge mounting portion to which one or a plurality of ink cartridges having a first ink tank for storing the above ink and a second ink tank for storing the ink for supplying to the second nozzle row can be mounted An ink remaining amount measuring unit that measures the remaining amount of ink in each of the first ink tank and the second ink tank; and an ink remaining amount of the first ink tank and a second ink tank of the second ink tank. An ink tank selection unit that selects an ink tank used for forming ink dots according to the remaining amount of ink, and the cartridge is a cartridge to which the cartridge is attached. An ink tank corresponding to either the first ink tank or the second ink tank, and a memory storing ink remaining amount information indicating the ink remaining amount of the ink tank, depending on the mounting portion. The cartridge, wherein the remaining ink amount information is used to measure the remaining amount of ink in either the first ink tank or the second ink tank according to the cartridge mounting portion in which the cartridge is mounted. 14. A printing method for printing by ejecting ink droplets from a print head to form dots, comprising: a first nozzle row for ejecting ink; and a first nozzle row for the first nozzle row. It is arranged in a staggered manner and the first
A second nozzle row that can be supplied with ink of the same color as that of the first nozzle row independently of the first nozzle row, and the first nozzle row One or a plurality of ink cartridges having a first ink tank for storing ink for supplying to the second nozzle row and a second ink tank for storing ink for supplying to the second nozzle row are prepared. A step of measuring the amount of ink remaining in each of the first ink tank and the second ink tank, an amount of ink remaining in the first ink tank, and an amount of ink remaining in the second ink tank And a step of selecting an ink tank to be used for forming ink dots according to the above. 15. A computer program for controlling a printing apparatus that performs printing by ejecting ink droplets from a print head to form dots, wherein the printing apparatus is a first computer for ejecting ink. Nozzle rows and staggered arrangement with respect to the first nozzle row, and
For supplying to the first nozzle row, a print head having a second nozzle row capable of receiving the ink of the same color as that of the first nozzle row independently of the first nozzle row. Cartridge mounting portion to which one or a plurality of ink cartridges having a first ink tank for storing the above ink and a second ink tank for storing the ink for supplying to the second nozzle row can be mounted The computer program has a function of measuring the remaining amount of ink in each of the first ink tank and the second ink tank, the remaining amount of ink in the first ink tank, and the second ink tank. And a function of selecting an ink tank used for forming ink dots according to the remaining amount of ink in the ink tank, and a computer program that causes the printing apparatus to realize the function. 16. A computer-readable recording medium on which the computer program according to claim 15 is recorded.