JP2023125947A - Droplet discharge device and program - Google Patents

Abstract

An object of the present invention is to prevent the amount of ejection data for instructing ejection of ink droplets from a nozzle from becoming large while making it less noticeable that missing dots are present. Five types of ejection signals are generated: a dot non-formation signal, a small dot signal, a medium dot signal, a large dot signal, and an extra large dot signal. a first table in which values of "00", "01", "10", and "11" of the 2-bit ejection data are respectively associated with a small dot signal, a medium dot signal, and a large dot signal; A second table is stored that is associated with a small dot signal, a medium dot signal, and an extra large dot signal, respectively. If there is no abnormal nozzle, the first table is referred to from the values of the ejection data, and an ejection signal for each dot is selected and generated. If there is an abnormal nozzle, the second table is referred to from the ejection data values to select and generate an ejection signal for each dot. [Selection diagram] Figure 6

Description

The present invention relates to a droplet ejection device that ejects droplets from a nozzle, and a program executed in an external device connected to the droplet ejection device.

As an example of a droplet ejection device that ejects droplets from a nozzle, Patent Document 1 describes a printing device that performs printing by ejecting ink from a nozzle. In the recording apparatus of Patent Document 1, the line head has a plurality of nozzles arranged in a direction perpendicular to the conveyance direction of the recording medium. When an ejection failure nozzle is detected among multiple nozzles of a line head, the size of the ink dot formed by the ink ejected from the nozzles other than the complementary nozzle adjacent to the ejection failure nozzle is set to be the same size as normal. , the size of the ink dot formed by the ink ejected from the complementary nozzle is made larger than usual. As a result, in Patent Document 1, missing dots are made less noticeable in areas of the recording medium where ink dots are formed by ink ejected from defective ejection nozzles.

Japanese Patent Application Publication No. 2017-193140

Here, in the recording apparatus of Patent Document 1, as described above, when a defective ejection nozzle is detected, control is performed to make the size of the ink dot formed by the ink ejected from the complementary nozzle larger than normal. In order to do this, for example, the data for instructing the line head to eject ink from the nozzles must be combined with a value corresponding to the size of the ink dot that will be ejected if no ejection failure nozzle is detected, and It is conceivable that the data can take a value corresponding to the size of a dot larger than the size of the ink dot. However, in this case, compared to the case where the above data can take only a value corresponding to the size of the ink dot that is ejected when no ejection failure nozzle is detected, the amount of data is There is a risk that it may become large.

An object of the present invention is to instruct a droplet ejection head to eject droplets from the nozzle while making the missing dots less noticeable when there is an abnormal nozzle with an abnormality in ejecting droplets. It is an object of the present invention to provide a droplet ejection device that does not increase the amount of dot data for a droplet ejection device, and a program that is executed in an external device connected to the droplet ejection device.

The droplet ejection device of the present invention ejects droplets in accordance with a plurality of types of ejection signals in which the ejection signal is a droplet amount that forms one dot on a medium to be ejected, and the droplet amounts are different. a head having a plurality of nozzles; a data receiving unit that receives ejection data having a plurality of types of values for selecting the ejection signal from an external device; a signal receiving unit that receives an abnormal nozzle signal related to an abnormal nozzle; a storage unit that stores a table in which values of the ejection data and the ejection signal are associated with each other; and a control unit; a first table in which a first value, which is one of the plurality of types of values, is associated with a first ejection signal, which is one of the plurality of types of ejection signals; is one of the plurality of types of the ejection signals and is associated with a second ejection signal having a larger amount of droplets than the first ejection signal, and the control unit: a determination process of determining whether or not there is an abnormal nozzle based on the abnormal nozzle signal; and when the data receiving unit receives the ejection data, the ejection signal is determined by referring to the table from the plurality of types of values. and ejecting the droplets by driving the head using the generated ejection signal, and when it is determined in the determination process that there is no abnormal nozzle, The ejection process is executed with reference to the first table, and when it is determined in the determination process that there is an abnormal nozzle, the ejection process is executed with reference to the second table.

Further, the droplet ejection device of the present invention is characterized in that the ejection signal is in accordance with the amount of droplet forming one dot on the medium to be ejected, and the droplet is ejected in accordance with a plurality of types of the ejection signals having different amounts of droplets. a head having a plurality of ejecting nozzles; a signal receiving section that receives an abnormal nozzle signal related to an abnormal nozzle that has an abnormality in ejecting the droplets among the plurality of nozzles; a storage unit that stores a table in which ejection data having a value and the ejection signal are associated with each other; and a control unit, the storage unit storing one of the plurality of types of values as the table. a first table associated with a first ejection signal in which the first value is one of the plurality of types of ejection signals; and a first table in which the first value is one of the plurality of types of the ejection signals. and a second table associated with a second ejection signal having a larger amount of droplets than the first ejection signal, and the control unit is capable of generating a plurality of types of the ejection signals; A data generation process for generating the ejection data, a determination process for determining whether or not there is an abnormal nozzle based on the abnormal nozzle signal, and after the data generation process, referring to the table from the plurality of types of values. select and generate the ejection signal, and use the generated ejection signal to drive the head to eject the droplet; and in the determination process, it is determined that there is no abnormal nozzle. If so, the first table is referred to and the discharge process is executed, and if the determination process determines that there is an abnormal nozzle, the second table is referred to and the discharge process is executed.

The program of the present invention is an ejection signal that corresponds to the amount of a droplet forming one dot on a medium to be ejected, and a plurality of nozzles that ejects droplets according to a plurality of types of the ejection signals having different amounts of droplets. a data receiving unit that receives ejection data having a plurality of types of values for selecting the ejection signal from an external device, and an abnormal nozzle that has an abnormality in ejecting the droplets among the plurality of nozzles. a signal transmitting unit that transmits an abnormal nozzle signal to the external device; a recording unit that stores a table in which values of the ejection data are associated with the ejection signals; and a signal generating unit that generates a plurality of types of the ejection signals. and, the storage unit, as the table, associates a first value, which is one of the plurality of types of values, with a first ejection signal, which is one of the plurality of types of the ejection signals. and a second table in which the first value is one of the plurality of types of ejection signals and is associated with a second ejection signal having a larger droplet amount than the first ejection signal. A program executed by a control unit of the external device connected to the droplet ejection device that stores the data, the program includes a data transmission process for transmitting the ejection data to the data reception unit, and a process for transmitting the signal to the computer. a determination process of determining whether or not there is an abnormal nozzle based on the abnormal nozzle signal transmitted by the transmitter; and a determination process that refers to the table from the plurality of types of values of the ejection data received by the data receiver. a command transmission process of selecting and generating the ejection signal and transmitting an ejection command to the droplet ejection device to instruct the head to eject the droplet by driving the head using the generated ejection signal; , and when it is determined in the determination process that there is no abnormal nozzle, the command transmission process is executed to transmit the ejection command instructing to refer to the first table, and in the determination process If it is determined that there is an abnormal nozzle, the ejection process is executed to transmit the ejection command instructing to refer to the second table.

In the present invention, when there is no abnormal nozzle, the ejection process is executed with reference to the first table in which the first value is associated with the first ejection signal. If there is an abnormal nozzle, the ejection process is executed with reference to a second table in which the first value is associated with a second ejection signal having a larger droplet volume than the first ejection signal. Thereby, the size of the dot corresponding to the first value can be made larger when there is an abnormal nozzle than when there is no abnormal nozzle, without changing the amount of ejection data.

FIG. 1 is a schematic configuration diagram of a printer according to a first embodiment. FIG. 3 is a diagram for explaining electrodes arranged in the cap and connection relationships between the electrodes and a high voltage power supply circuit and a signal processing circuit. (a) is a diagram showing a signal output from a signal processing circuit when ink is ejected from a nozzle during test drive, and (b) is a diagram showing a signal output when ink is not ejected from a nozzle during test drive. FIG. 3 is a diagram showing signals output from a processing circuit. FIG. 2 is a block diagram showing the electrical configuration of the printer. 7 is a flowchart showing the flow of processing during recording in the first embodiment. (a) is a diagram for explaining the ejection signal, (b) is a diagram for explaining the first table, and (c) is a diagram for explaining the second table. 7 is a flowchart showing the flow of ejection signal selection processing in FIG. 6; (a) is a diagram for explaining a filled pattern recorded when there is no abnormal nozzle, and (b) is a diagram showing a filled pattern recorded by ejecting ink droplets when there is an abnormal nozzle in the same way as when there is no abnormal nozzle. FIG. 6C is a diagram for explaining a case in which a filled pattern is recorded by making the adjacent dots larger in size when there is an abnormal nozzle than when there is no abnormal nozzle. It is a flowchart which shows the flow of ejection signal selection processing in a 2nd embodiment. It is a flow chart which shows the flow of ejection signal selection processing in a 3rd embodiment. 12 is a flowchart showing the flow of processing during recording in the fourth embodiment. 12 is a flowchart showing the flow of processing during recording in the fifth embodiment. FIG. 7 is a sequence diagram showing the flow of processing in a printer and an external device during recording in a sixth embodiment. FIG. 7 is a diagram for explaining another example of the second table. (a) is a diagram for explaining an example of generating seven types of ejection signals, (b) is a diagram for explaining a first table corresponding to the ejection signals of (a), and (b) FIG. 6 is a diagram for explaining a second table corresponding to the ejection signal in FIG. (a) is a diagram for explaining an example of generating six types of ejection signals, (b) is a diagram for explaining a first table corresponding to the ejection signals of (a), and (b) is a diagram for explaining an example of generating six types of ejection signals. FIG. 6 is a diagram for explaining a second table corresponding to the ejection signal in FIG.

[First embodiment]
A first preferred embodiment of the present invention will be described below.

<Overall configuration of printer>
As shown in FIG. 1, the printer 1 according to the first embodiment (the "droplet ejection device" of the present invention) includes a carriage 2, a sub-tank 3, an inkjet head 4 (the "head" of the present invention), a platen 5, a transport It includes rollers 6 and 7 (the "conveying section" of the present invention), a maintenance unit 8, and the like.

The carriage 2 is supported by two guide rails 11 and 12 extending in the scanning direction. Note that, in the following description, the right side and the left side in the scanning direction are defined as shown in FIG. 1. The carriage 2 is connected to a carriage motor 86 (see FIG. 4) via a belt (not shown) or the like. When the carriage motor 86 is driven, the carriage 2 moves along the guide rails 11 and 12 in the scanning direction.

The sub tank 3 is mounted on the carriage 2. Here, the printer 1 includes a cartridge holder 13. Four ink cartridges 14 are removably attached to the cartridge holder 13. The four ink cartridges 14 attached to the cartridge holder 13 are lined up in the scanning direction, and store black, yellow, cyan, and magenta inks in order from the one located on the right side in the scanning direction. The four ink cartridges 14 mounted on the cartridge holder 13 are connected to the sub-tank 3 via four tubes 15. As a result, the above four color inks are supplied from the four ink cartridges 14 to the sub tank 3.

The inkjet head 4 is mounted on the carriage 2 and connected to the lower end of the sub-tank 3. The inkjet head 4 is supplied with the four colors of ink from the sub-tank 3. Further, the inkjet head 4 discharges ink droplets ("droplets" in the present invention) from a plurality of nozzles 10 formed on a nozzle surface 4a, which is the lower surface thereof. More specifically, the plurality of nozzles 10 are arranged in the transport direction to form a nozzle row 9, and four nozzle rows 9 are arranged in the scanning direction on the nozzle surface 4a. Ink droplets of black, yellow, cyan, and magenta are ejected from the plurality of nozzles 10 in order from those forming the nozzle row 9 on the right side in the scanning direction.

The platen 5 is arranged below the inkjet head 4 and faces the plurality of nozzles 10. The platen 5 extends over the entire length of the recording paper P in the scanning direction and supports the recording paper P from below. The conveyance roller 6 is arranged upstream of the inkjet head 4 and the platen 5 in the conveyance direction. The conveyance roller 7 is arranged downstream of the inkjet head 4 and the platen 5 in the conveyance direction. The conveyance rollers 6 and 7 are connected to a conveyance motor 87 (see FIG. 4) via a gear (not shown) or the like. When the transport motor 87 is driven, the transport rollers 6 and 7 rotate, and the recording paper P is transported in the transport direction.

The maintenance unit 8 includes a cap 71, a suction pump 72, and a waste liquid tank 73. The cap 71 is placed on the right side of the platen 5 in the scanning direction. When the carriage 2 is positioned at the maintenance position on the right side of the platen 5 in the scanning direction, the plurality of nozzles 10 face the cap 71.

Further, the cap 71 is connected to a cap lifting mechanism 88 (see FIG. 4). When the cap raising/lowering mechanism 88 is driven, the cap 71 is raised and lowered. When the cap 71 is raised by the cap elevating mechanism 88 with the plurality of nozzles 10 and the cap 71 facing each other by positioning the carriage 2 at the maintenance position, the upper end of the cap 71 comes into close contact with the nozzle surface 4a. , the plurality of nozzles 10 are in a cap state where they are covered by the cap 71. When the cap 71 is lowered, the plurality of nozzles 10 are not covered by the cap 71. Note that the cap 71 is not limited to covering the plurality of nozzles 10 by coming into close contact with the nozzle surface 4a. The cap 71 may cover the plurality of nozzles 10 by, for example, coming into close contact with a frame (not shown) arranged around the nozzle surface 4a of the inkjet head 4.

The suction pump 72 is a tube pump or the like, and is connected to the cap 71 and the waste liquid tank 73. In the maintenance unit 8, when the suction pump 72 is driven in the cap 71 state, the ink in the inkjet head 4 can be discharged from the plurality of nozzles 10, so-called suction purge. The ink discharged by the suction purge is stored in the waste liquid tank 73.

Note that, for convenience, the explanation has been given here assuming that the cap 71 covers all the nozzles 10 at once and discharges the ink in the inkjet head 4 from all the nozzles 10 in the suction purge, but this is not limited to this. do not have. For example, the cap 71 covers a plurality of nozzles 10 that make up the rightmost nozzle row 9 that ejects black ink, and a portion that covers a plurality of nozzles 10 that make up the three left nozzle rows 9 that eject color ink. In the suction purge, either the black ink or the color ink in the inkjet head 4 may be selectively discharged. Alternatively, for example, the cap 71 may be provided individually for each nozzle row 9, so that ink can be discharged from the nozzles 10 individually for each nozzle row 9 during suction purge.

Further, as shown in FIG. 2, an electrode 76 having a rectangular planar shape is arranged inside the cap 71. Electrode 76 is connected to high voltage power supply circuit 77 via resistor 79. Then, the high voltage power supply circuit 77 applies a predetermined voltage (for example, about 600 V) to the electrode 76 when performing test driving to be described later. On the other hand, the inkjet head 4 is held at ground potential. This creates a predetermined potential difference between the inkjet head 4 and the electrode 76. A signal processing circuit 78 is connected to the electrode 76 . The signal processing circuit 78 includes a differential circuit and the like, and outputs a signal (an "abnormal nozzle signal" of the present invention) according to the voltage of the electrode 76. However, the signal output from the signal processing circuit 78 may be a current signal.

In the above-mentioned cap state, when a voltage is applied to the electrode 76 by the high-voltage power supply circuit 77 and the test drive described later is not performed, the voltage of the signal output from the signal processing circuit 78 is as follows. The voltage becomes V0 shown in FIGS. 3(a) and 3(b).

Further, in the first embodiment, ink droplets are ejected from the nozzle 10 toward the electrode 76 in the inkjet head 4 in the capped state and with voltage applied to the electrode 76 by the high voltage power supply circuit 77. Inspection driving can be performed to perform the test.

When an ink droplet is ejected from the nozzle 10 by the test drive, the ink droplet ejected from the nozzle 10 is electrically charged due to the potential difference between the electrode 76 and the inkjet head 4. As a result, the charged ink droplet approaches the electrode 76, and the potential of the electrode 76 changes until the ink droplet lands on the electrode 76. After the charged ink droplet lands on the electrode 76, the potential of the electrode 76 attenuates and returns to the potential V0 before the ink droplet was ejected.

At this time, the signal output from the signal processing circuit 78 increases from voltage V0 to voltage V1, which is higher than voltage V0, and then decreases to voltage V2, which is lower than voltage V0, as shown in FIG. 3(a). After that, the voltage repeatedly increases and decreases while attenuating and returns to the voltage V0.

On the other hand, when no ink droplets are ejected from the nozzle 10 due to the test drive, the signal output from the signal processing circuit 78 hardly changes from the voltage V0, as shown in FIG. 3(b).

In this manner, in the first embodiment, the signal output from the signal processing circuit 78 differs depending on whether ink droplets are ejected from the nozzle 10 by the test drive. In the first embodiment, this fact can be utilized to determine whether or not the nozzle 10 is an abnormal nozzle that has an abnormality in ejecting ink droplets.

Here, in the first embodiment, a predetermined voltage is applied to the electrode 76, the inkjet head 4 is held at ground potential, and the signal processing circuit 78 is configured to output a signal according to the voltage of the electrode 76. It is not limited to this. By holding the electrode 76 at ground potential and applying a predetermined voltage to the inkjet head 4, a potential difference is generated between the electrode 76 and the inkjet head 4, and the signal processing circuit 78 is connected to the inkjet head 4, and the inkjet head 4 is connected to the signal processing circuit 78. It may be configured to output a signal according to the voltage of the head 4.

<Electrical configuration of printer>
Next, the electrical configuration of the printer 1 will be explained. As shown in FIG. 4, the printer 1 includes a control section 80. The control unit 80 includes a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a flash memory 84 (the “storage unit” of the present invention), and an ASIC (Application Specific Integrated Circuit) 85. Consists of etc. The control unit 80 controls the operations of the carriage motor 86, the inkjet head 4, the transport motor 87, the cap lifting mechanism 88, the suction pump 72, the high voltage power supply circuit 77, and the like. The control unit 80 also receives signals from the signal processing circuit 78 and the like. In the first embodiment, the portion of the control section 80 that receives the signal from the signal processing circuit 78 corresponds to the "signal receiving section" of the present invention.

In addition to the configuration described above, the printer 1 includes a communication section 89 (the "data receiving section" of the present invention). The control unit 80 is connected to an external device 99 via a communication unit 89. The external device 99 is, for example, a PC, a smartphone, etc., and includes a control unit 98. The control unit 98 includes a CPU, ROM, RAM, flash memory, and the like. Further, the communication unit 89 may be connected to the external device 99 by wire, or may be connected to the external device 99 wirelessly. Further, the communication unit 89 may be directly connected to the external device 99, or may be connected to the external device 99 via a network such as a LAN (Local Area Network).

Note that in the control unit 80, only the CPU 81 may perform various processes, only the ASIC 85 may perform various processes, or the CPU 81 and ASIC 85 may cooperate to perform various processes. It may be something. Moreover, the control unit 80 may be one in which one CPU 81 performs the processing alone, or may be one in which a plurality of CPUs 81 share the processing. Further, in the control unit 80, one ASIC 85 may perform the processing alone, or a plurality of ASICs 85 may share the processing. The same applies to the control section 98.

<Processing during recording>
Next, the processing of the control unit 80 when recording on the recording paper P in the printer 1 will be explained. In the first embodiment, for example, when the user performs an operation on the external device 99 to instruct recording on the recording paper P, the external device 99 instructs the control unit 80 to perform recording. A recording command is transmitted, and the control unit 80 receives this recording command. Then, when the control unit 80 receives the recording command, it performs processing according to the flow shown in FIG. 5 .

To explain the flow in FIG. 5 in more detail, the control unit 80 first starts receiving ejection data from the external device 99 (S101). Here, the control unit 98 of the external device 99 performs appropriate processing on the image data of the image to be recorded, such as color conversion processing for converting RGB values into CMYK values, and generates ejection data. The ejection data is transmitted to the control unit 80 of the printer 1 following the recording command. For each of the plurality of dots forming the image, the ejection data takes one of four values: "00", "01", "10", and "11", depending on the presence or absence of the dot and the size of the dot. It is data. That is, the ejection data is 2-bit data for each of the plurality of dots. Then, in S101, reception of the ejection data transmitted from the control unit 98 of the external device 99 is started.

Subsequently, the control unit 80 executes a nozzle inspection process (S102). In the nozzle inspection process, the control unit 80 puts the inkjet head 4 in a capping state, applies voltage to the electrode 76 by the high voltage power supply circuit 77, and then drives the inkjet head 4 for inspection for each of the plurality of nozzles 10. let Then, the control unit 80 determines whether or not the nozzle 10 is an abnormal nozzle based on the signal from the signal processing circuit 78 when the test drive is performed, and determines whether or not each nozzle 10 is an abnormal nozzle. The result of the determination is stored in the flash memory 84.

Subsequently, the control unit 80 executes paper feeding processing (S103). In the paper feeding process, the control unit 80 controls a paper feeding mechanism and a transport motor 87 (not shown) to feed the recording paper P.

Next, the control unit 80 waits until reception of ejection data corresponding to the print pass to be performed in S106, which will be described later, is completed (S104: NO). Then, when the reception of the ejection data corresponding to the printing pass is completed (S104: YES), the ejection signal selection process is executed (S105).

Here, in the first embodiment, the control unit 80 generates dots as an ejection signal for driving the inkjet head 4, as shown in FIG. Five types of ejection signals can be generated: a non-formation signal, a signal for small dots, a signal for medium dots, a signal for large dots, and a signal for extra large dots. Note that the waveforms of the five types of ejection signals shown in FIG. 6(a) are merely examples, and the present invention is not limited thereto.

The dot non-formation signal is a signal that prevents ink droplets from being ejected from the nozzle 10. The small dot signal is a signal for ejecting ink droplets from the nozzles 10 to form small dots on the recording paper P. The medium dot signal causes the ink droplet to be ejected from the nozzle 10 in a larger amount than when driving the inkjet head 4 with the small dot signal, and the medium dot is larger than the small dot on the recording paper P. This is a signal to form a . The large dot signal causes the ink droplet to be ejected from the nozzle 10 so that the amount of droplet is larger than when driving the inkjet head 4 with the medium dot signal, and the large dot is larger than the medium dot on the recording paper P. This is a signal to form a . The extra-large dot signal causes the nozzle 10 to eject ink droplets in a larger amount than when driving the inkjet head 4 with the large-dot signal, thereby producing an extra-large dot on the recording paper P that is larger than the large dot. This is a signal to form a .

Further, in the first embodiment, the flash memory 84 (the "storage unit" of the present invention) includes a first table as shown in FIG. 6(b) and a second table as shown in FIG. 6(c). remembered. The first and second tables are tables in which values of ejection data are associated with ejection signals.

In the first table, four types of ejection data values "00", "01", "10", and "11" are the dot non-formation signal, small dot signal, medium dot signal, and large dot signal, respectively. is associated with. In the second table, four types of ejection data values "00", "01", "10", and "11" are the dot non-formation signal, small dot signal, medium dot signal, and extra large dot signal, respectively. is associated with. In the first embodiment, the value "11" of the ejection data corresponds to the "first value" of the present invention.

In the ejection signal selection process of S105, the control unit 80 determines how to select an ejection signal by performing processing in accordance with the flow shown in FIG. Note that the process shown in the flowchart of FIG. 7 is performed individually for each nozzle row 9.

To explain the flow in FIG. 7, first, during the nozzle inspection process in S101, the control unit 80 first checks each of the plurality of nozzles 10 of the inkjet head 4 received from the signal processing circuit 78 and stored in the flash memory 84. Based on the information as to whether or not the nozzle is abnormal, it is determined whether or not there is an abnormal nozzle (S201, "determination processing" of the present invention).

If there is no abnormal nozzle (S201: NO), the control unit 80 determines to select ejection signals for all dots from the values of the ejection data by referring to the first table (S204).

If there is an abnormal nozzle (S201: YES), the control unit 80 determines whether the ejection data indicates that an abnormal nozzle dot, which is a dot corresponding to the abnormal nozzle, is to be formed (S202). ).

If the ejection data indicates that no abnormal nozzle dots are formed (S202: NO), the control unit 80 determines to select ejection signals for all dots from the values of the ejection data by referring to the first table. (S204).

When the ejection data indicates that an abnormal nozzle dot is formed (S202: YES), the control unit 80 determines whether the ejection data indicates that an adjacent dot, which is a dot adjacent to the abnormal nozzle dot in the transport direction, is formed. (S203). Here, the adjacent dots refer to dots adjacent to the abnormal nozzle dot on the upstream side in the transport direction and dots adjacent to the abnormal nozzle dot on the downstream side in the transport direction. Then, in S203, the control unit 80 determines that the ejection data corresponds to at least one of the dots adjacent to the abnormal nozzle dot on the upstream side in the transport direction and the dots adjacent to the abnormal nozzle dot on the downstream side in the transport direction. If the ejection data indicates that adjacent dots will be formed, it is determined that the ejection data indicates that adjacent dots will be formed.

However, the adjacent dot may be a dot adjacent to the abnormal nozzle dot on the upstream side in the conveyance direction. In this case, in S203, the control unit 80 determines that the ejection data indicates that an adjacent dot will be formed on the upstream side of the abnormal nozzle dot in the conveying direction. do. On the other hand, in S203, even if the ejection data indicates that a dot adjacent to the abnormal nozzle dot is formed on the downstream side in the transport direction, the control unit 80 controls the If the ejection data indicates that adjacent dots will not be formed, it is determined that the ejection data indicates that adjacent dots will not be formed.

Alternatively, the adjacent dot may be a dot adjacent to the abnormal nozzle dot on the downstream side in the conveyance direction. In this case, in S203, the control unit 80 determines that the ejection data indicates that an adjacent dot is formed on the downstream side of the abnormal nozzle dot in the conveying direction, when the ejection data indicates that an adjacent dot is formed on the downstream side of the abnormal nozzle dot. do. On the other hand, in S203, even if the ejection data indicates that a dot adjacent to the abnormal nozzle dot is formed on the upstream side in the transport direction, the control unit 80 controls the If the ejection data indicates that adjacent dots will not be formed, it is determined that the ejection data indicates that adjacent dots will not be formed.

When the ejection data indicates that adjacent dots are not formed (S203: NO), the control unit 80 determines to select ejection signals for all dots from the values of the ejection data with reference to the first table. (S204).

If the ejection data indicates that adjacent dots are formed (S203: YES), the control unit 80 determines to select an ejection signal for the adjacent dots from the values of the ejection data by referring to the second table ( S205), it is determined to select ejection signals for non-adjacent dots, which are dots other than adjacent dots, with reference to the first table (S206).

Returning to the flow of FIG. 5, after the ejection signal selection process in S105, the control unit 80 executes a recording pass process (S106). In the recording pass process, the control unit 80 controls the carriage motor 86 to move the carriage 2 in the scanning direction, and drives the inkjet head 4 to perform a recording pass in which ink droplets are ejected from the plurality of nozzles 10. . At this time, the control unit 80 refers to the table selected in S105, selects and generates an ejection signal according to the ejection data, and drives the inkjet head 4 using the generated ejection signal, thereby controlling the plurality of nozzles. Ink droplets are ejected from 10.

Subsequently, the control unit 80 determines whether recording on the recording paper P is completed (S107). If recording on the recording paper P has not been completed (S107: NO), the control unit 80 executes a conveyance process (S108), and then returns to S104. In the conveyance process of S108, the control unit 80 controls the conveyance motor 87 to cause the conveyance rollers 6 and 7 to perform a conveyance operation to convey the recording paper P a predetermined distance. Here, the predetermined distance is, for example, a distance that is equal to or less than the length of the nozzle row 9 in the transport direction.

As a result, recording on the recording paper P is performed by alternately performing the recording pass and the conveyance operation. Further, when the distance of conveyance of the recording paper P in the conveyance operation is the same as the length of the nozzle row 9 in the conveyance direction, recording is performed on each area of the recording paper P by one recording pass. On the other hand, if the conveyance distance of the recording paper P in the conveyance operation is shorter than the length of the nozzle row 9 in the conveyance direction, recording is performed on each area of the recording paper P by two or more recording passes.

Furthermore, in the first embodiment, since the ejection data is data for each print pass, the ejection signal selection process in S105 is executed every time a print pass and a conveyance operation are performed.

In the first embodiment, the ejection signal selection process in S105 and the recording pass process and conveyance process that are alternately repeated in order to perform recording on the recording paper P by alternately performing the recording pass and conveyance operation. The combination of these corresponds to the "discharge process" of the present invention.

When recording on the recording paper P is completed (S107: YES), the control unit 80 executes paper ejection processing (S109). In the paper ejection process, the control unit 80 controls the transport motor 87 to cause the transport rollers 6 and 7 to transport the recording paper P in the transport direction, thereby ejecting the recording paper P.

Subsequently, the control unit 80 determines whether or not to perform recording on the next recording paper P (S110). Specifically, it is determined whether or not ejection data for recording on the next recording paper P has been received. If recording is to be performed on the next recording paper P (S110: YES), the process returns to S103. If the next recording paper P is not to be recorded (S110: NO), the process ends.

<Effect>
In the first embodiment, when there is an abnormal nozzle, print pass processing is executed with reference to a first table in which a first value of ejection data (for example, "11") is associated with a signal for large dots. On the other hand, if there is an abnormal nozzle, the ejection process is executed with reference to the second table in which the first value is associated with the extra-large dot signal whose droplet volume is larger than that of the large-dot signal. Thereby, the size of the dot corresponding to the first value can be made larger when there is an abnormal nozzle than when there is no abnormal nozzle, without changing the amount of ejection data.

Further, in the first embodiment, the control unit 80 generates five types of ejection signals. In this case, unlike the first embodiment, if the ejection data can take on five types of values corresponding to the five types of ejection signals, the ejection data will be 3-bit data.

In contrast, in the first embodiment, the ejection signal associated with the value "11" of the ejection data is changed depending on whether there is an abnormal nozzle. Therefore, regardless of whether there is an abnormal nozzle, the ejection data may take four types of values. That is, regardless of whether there is an abnormal nozzle, it is possible to generate an ejection signal using 2-bit ejection data and perform printing.

Furthermore, in the first embodiment, the value of "11" in the ejection data is associated with the large dot signal in the first table, and the value of "11" in the ejection data is associated with the extra large dot in the second table. There is. Therefore, when there is an abnormal nozzle, it is possible to form extra-large dots without increasing the amount of ejection data than when there is no abnormal nozzle, thereby making it less noticeable that no abnormal nozzle dots have been formed.

Further, in the first embodiment, when the ejection data indicates that both abnormal nozzle dots and adjacent dots are formed, ejection of non-adjacent dots is performed by referring to the first table from a plurality of types of values of the ejection data. In addition to selecting the signal, the second table is referred to from among the plurality of types of values of the ejection data to select the ejection signal for the adjacent dot. This makes it possible to increase the size of the adjacent dots set to the first value, thereby making it less noticeable that no abnormal nozzle dots are formed.

On the other hand, if there is no abnormal nozzle, the first table is referred to and the ejection signals for all dots are selected from the plurality of types of ejection data values. Further, when the ejection data indicates that either an abnormal nozzle dot or an adjacent dot is not formed, ejection signals for all dots are selected from among the plurality of values of the ejection data by referring to the first table. Thereby, it is possible to prevent the dot size set to the first value from becoming unnecessarily large.

Here, an example will be given to explain how the above-mentioned fact that the abnormal nozzle dots are not formed can be made less noticeable. For example, as shown in FIG. 8(a), consider a case where a fill pattern A formed by a plurality of large dots lined up in the scanning direction and the conveyance direction is printed when there are no abnormal nozzles. In this case, unlike the first embodiment, if each dot D is made a large dot when one nozzle 10 is an abnormal nozzle as in the case where there is no abnormal nozzle, as shown in FIG. 8(b), Because the abnormal nozzle dots D1, which would normally be formed as shown by the broken lines, are not formed, white stripes (areas with no dots) that extend in the scanning direction occur in the fill pattern A. On the other hand, in the first embodiment, as shown in FIG. 8(c), the dot D1 is formed by making the adjacent dot D2 an extra-large dot that is larger in size than the large dot when there is no abnormal nozzle. It is possible to make it less noticeable that something is not being done.

Here, a case will be described in which ejection signals for adjacent dots are selected with reference to the first table even though there is an abnormal nozzle. For example, depending on the ejection data, ink droplets may not be ejected to the entire range of the recording paper P, and ink may not be ejected from the abnormal nozzle in some cases. In this case, even if there is an abnormal nozzle, the ejection signal for the adjacent dot is selected by referring to the first table instead of the second table.

[Second embodiment]
Next, a second preferred embodiment of the present invention will be described. The second embodiment also relates to the same printer 1 as the first embodiment. Also, in the second embodiment, similarly to the first embodiment, when recording on the recording paper P, the control unit 80 performs processing in accordance with the flow shown in FIG. However, in the second embodiment, the control unit 80 performs a transport operation in which the recording paper P is transported by the same distance as the length of the nozzle array 9 in the transport direction in the transport process of S106. Furthermore, in the second embodiment, the control unit 80 performs the ejection signal selection process according to the flow shown in FIG. 9 .

To explain the flow in FIG. 9 in detail, the control unit 80 executes the same processes in S301 and S302 as in S201 and S202, as in the first embodiment. Then, if there is no abnormal nozzle (S301: NO), and if there is an abnormal nozzle and the ejection data indicates that the abnormal nozzle dot is not formed (S301: YES, S302: NO), the control unit 80 As in the first embodiment, it is determined to select ejection signals for all dots from the values of ejection data by referring to the first table (S304).

If there is an abnormal nozzle and the ejection data indicates that an abnormal nozzle dot is formed (S301: YES, S302: YES), the control unit 80 controls whether the ejection data indicates that the abnormal nozzle and the nozzle 10 adjacent to the abnormal nozzle in the conveyance direction are formed. It is determined whether or not it is indicated that an adjacent nozzle dot, which is a corresponding dot, is to be formed (S303).

Here, the adjacent nozzle dots are dots corresponding to nozzles 10 adjacent to the upstream side of the abnormal nozzle in the transport direction, and dots corresponding to nozzles 10 adjacent to the abnormal nozzle downstream in the transport direction. Therefore, in S303, the control unit 80 determines whether the ejection data corresponds to a dot corresponding to a nozzle 10 adjacent to the abnormal nozzle on the upstream side in the transport direction, and a dot corresponding to a nozzle 10 adjacent to the abnormal nozzle on the downstream side in the transport direction. If the ejection data indicates that at least one of the dots will be formed, it is determined that the ejection data indicates that the adjacent nozzle dots will be formed.

However, the adjacent nozzle dot may be a dot corresponding to a nozzle 10 adjacent to the abnormal nozzle on the upstream side in the transport direction. In this case, in S303, when the ejection data indicates that a dot corresponding to the nozzle 10 adjacent to the upstream side of the abnormal nozzle in the conveyance direction is to be formed, the ejection data determines that the adjacent nozzle dot is to be formed. It is determined that the On the other hand, in S303, even if the ejection data indicates that a dot corresponding to the nozzle 10 adjacent to the downstream side of the abnormal nozzle in the transport direction is formed, the control unit 80 controls the If it is determined that the dot corresponding to the adjacent nozzle 10 is not formed, it is determined that the ejection data indicates that the adjacent nozzle dot is not formed.

Alternatively, the adjacent nozzle dot may be a dot corresponding to a nozzle 10 adjacent to the abnormal nozzle on the downstream side in the transport direction. In this case, in S303, when the ejection data indicates that a dot corresponding to the nozzle 10 adjacent to the downstream side of the abnormal nozzle in the transport direction is formed, the control unit 80 determines that the ejection data forms an adjacent dot. It is judged that it shows. On the other hand, in S203, even if the ejection data indicates that a dot corresponding to the nozzle 10 adjacent to the upstream side of the abnormal nozzle in the transport direction is formed, the control unit 80 If it is determined that the dot corresponding to the adjacent nozzle 10 is not formed, it is determined that the ejection data indicates that the adjacent nozzle dot is not formed.

When the ejection data indicates that adjacent nozzle dots are not formed (S303: NO), the control unit 80 selects ejection signals for all nozzles 10 from the values of the ejection data by referring to the first table. Determine (S304).

If the ejection data indicates that adjacent nozzle dots are formed (S303: YES), the control unit 80 determines to select an ejection signal for the adjacent nozzle from the values of the ejection data with reference to the second table. (S305), it is determined to select ejection signals for nozzles 10 other than the adjacent nozzles with reference to the first table (S306).

<Effect>
In the second embodiment, when the ejection data indicates that both abnormal nozzle dots and adjacent nozzle dots are formed, the first table is referred to from a plurality of types of values of the ejection data for nozzles other than the adjacent nozzles. In addition to selecting an ejection signal, for the adjacent nozzles, an ejection signal is selected from a plurality of values of ejection data by referring to the second table. At this time, compared to the case where a table is selected for each adjacent dot as described in the first embodiment, there is no need to select a table to be referred to for each dot, and a table to be referred to is selected for each nozzle 10. Therefore, the complexity of control in the ejection process is reduced, and the process can be performed more quickly. Furthermore, by increasing the size of the adjacent nozzle dots set to the first value, it is possible to make it less noticeable that no abnormal nozzle dots are formed.

For example, in the second embodiment, when there is an abnormal nozzle and one nozzle 10 forms one raster line, the adjacent nozzle always forms a dot adjacent to the dot that should be formed by the abnormal nozzle. Therefore, as shown in FIG. 8C, the fact that the dot D1 is not formed can be made less noticeable.

On the other hand, when there is no abnormal nozzle, the first table is referred to and the ejection signals for all dots are selected from the plurality of types of ejection data values. Further, when the ejection data indicates that either an abnormal nozzle dot or an adjacent nozzle dot is not formed, ejection signals for all dots are selected from among multiple types of ejection data values by referring to the first table. . Thereby, it is possible to prevent the dot size set to the first value from becoming unnecessarily large.

[Third embodiment]
Next, a third preferred embodiment of the present invention will be described. The third embodiment also relates to the same printer 1 as the first embodiment. Also, in the third embodiment, similarly to the first embodiment, when recording on the recording paper P, the control unit 80 performs processing in accordance with the flow shown in FIG. However, in the third embodiment, the control unit 80 performs the ejection signal selection process in accordance with the flow shown in FIG. 10 .

To explain the flow in FIG. 10 in detail, the control unit 80 executes the processes of S401 and S402, which are similar to S201 and S202, as in the first embodiment. Then, if there is no abnormal nozzle (S401: NO), and if there is an abnormal nozzle and the ejection data indicates that the abnormal nozzle dot is not formed (S401: YES, S402: NO), the control unit 80 As in the first embodiment, it is determined to select ejection signals for all dots from the values of ejection data by referring to the first table (S403).

If there is an abnormal nozzle and the ejection data indicates that an abnormal nozzle dot is formed (S401: YES, S402: YES), the control unit 80 calculates the ejection signals for all dots from the value of the ejection data. 2 table and decides to select it (S404).

Accordingly, in the third embodiment, when receiving the ejection data for each printing pass, the control unit 80 sends ejection signals for all dots in the printing pass corresponding to the ejection data indicating that no abnormal nozzle dots are to be formed. is selected based on the value of the ejection data by referring to the first table. On the other hand, ejection signals for all dots in the print pass corresponding to ejection data indicating formation of abnormal nozzle dots are selected from the values of the ejection data with reference to the second table.

<Effect>
In the third embodiment, as described in the first embodiment, the ejection data is data for each printing pass, and the ejection signal selection process is executed every time a printing pass is performed. Then, when the ejection data indicates that an abnormal nozzle dot is formed, a second table is referred to from the ejection data to select an ejection signal for each dot to be formed in the printing pass corresponding to the ejection data. . This makes it possible to increase the size of the dot set to the first value, thereby making it less noticeable that no abnormal nozzle dots are formed.

On the other hand, if the ejection data indicates that no abnormal nozzle dots will be formed, refer to the first table from the ejection data and select an ejection signal for each dot to be formed in the printing pass corresponding to the ejection data. do. Thereby, it is possible to prevent the dot size set to the first value from becoming unnecessarily large.

[Fourth embodiment]
Next, a fourth preferred embodiment of the present invention will be described. The fourth embodiment also relates to the same printer 1 as the first embodiment. However, in the fourth embodiment, when the control unit 80 performs recording on the recording paper P, the control unit 80 performs processing according to the flow shown in FIG.

To explain the flow in FIG. 11 in detail, the control unit 80 starts receiving ejection data (S501) similarly to S101 of the first embodiment, and then performs a nozzle inspection process similar to S101 of the first embodiment. is executed (S502), and then paper feeding processing (S503) similar to S103 of the first embodiment is executed.

Subsequently, the control unit 80 waits until reception of ejection data corresponding to one sheet of recording paper P is completed (S504: NO). Then, when the reception of ejection data corresponding to one sheet of recording paper P is completed (S504: YES), the control unit 80 executes ejection signal selection processing (S505). In the ejection signal selection process of S505, the control unit 80 executes the process according to the flow of FIG. 10, as in the third embodiment. However, in the fourth embodiment, the ejection data is data for each recording paper P, unlike the third embodiment. In the fourth embodiment, in S403, it is determined to select an ejection signal with reference to the first table for all dots from the ejection data for the recording paper P to be printed this time. Further, in S404, it is determined to select an ejection signal by referring to the second table for all dots from the ejection data for the recording paper P to be recorded this time.

After the ejection signal selection process in S505, the control unit 80 executes the processes in S506 to S510, which are similar to S106 to S110 in the first embodiment. However, in the fourth embodiment, unlike the first embodiment, the process returns to S506 after the transport process in S508. That is, in the fourth embodiment, since the ejection data is data for each recording paper P, when recording is performed continuously on a plurality of recording papers P, the recording on one recording paper P is Every time the process is completed, the ejection signal selection process in S505 is executed.

<Effect>
In the fourth embodiment, when ejection data regarding a plurality of recording sheets P is continuously received, if the ejection data indicates that an abnormal nozzle dot is formed, the ejection data is selected from a plurality of types of values of the ejection data. With reference to the second table, an ejection signal for each dot to be formed for recording on the recording paper P corresponding to the ejection data is selected. This makes it possible to increase the size of the dot set to the first value, thereby making it less noticeable that no abnormal nozzle dots are formed.

On the other hand, if the ejection data indicates that no abnormal nozzle dots will be formed, the first table is referred to from the plurality of values of the ejection data, and the information on the recording paper P corresponding to the ejection data is determined. Select an ejection signal for each dot to be formed for printing. Thereby, it is possible to prevent the dot size set to the first value from becoming unnecessarily large.

Further, in the fourth embodiment, in the ejection signal selection process of S505, the control unit 80 executes the process according to the flow of FIG. 10, but in the ejection signal selection process of S505, the control unit 80 The process may be executed according to the flow shown in FIG.

In addition, when the ejection signal selection process in S505 is executed according to the flow shown in FIG. When performing the operation, if the most upstream nozzle 10 in the transport direction among the plurality of nozzles 10 constituting the nozzle row 9 is the abnormal nozzle, the most upstream nozzle 10 in the transport direction among the plurality of nozzles 10 constituting the nozzle row 9 The processes of S303 to S306 may be performed with the downstream nozzle 10 as an adjacent nozzle and the dot corresponding to this nozzle 10 as an adjacent nozzle dot. Furthermore, if the most downstream nozzle 10 in the transport direction among the plurality of nozzles 10 constituting the nozzle row 9 is an abnormal nozzle, the most upstream nozzle in the transport direction among the plurality of nozzles 10 constituting the nozzle row 9 10 as an adjacent nozzle, and the dot corresponding to this nozzle 10 as an adjacent nozzle dot, the processes of S303 to S306 may be performed.

[Fifth embodiment]
Next, a fifth preferred embodiment of the present invention will be described. The fifth embodiment also relates to the same printer 1 as the first to fourth embodiments. However, in the first to fourth embodiments, the control unit 80 receives the ejection data following the recording command, whereas in the fifth embodiment, the control unit 80 records the ejection data on the recording paper P following the recording command. Receive the image data of the image to be displayed. At this time, the control unit 80 may receive a recording command and image data from the external device 99. Alternatively, in the case where the printer 1 is configured to allow a memory card to be installed, the control unit 80 may be configured to allow the user to install a Based on the operation of the operating unit or the external device 99, the recording command may be received, and image data may also be received from the memory card. Further, image data may be received from an image reading device such as a scanner. In the fifth embodiment, when recording on the recording paper P, processing is performed according to the flow shown in FIG.

To explain the flow in FIG. 12 in detail, the control unit 80 executes ejection data generation processing (S601, "data generation processing" of the present invention). In the ejection data generation process, the control unit 80 generates ejection data by performing appropriate processing on the received image data, such as color conversion processing for converting RGB values into CMYK values.

Next, the control unit 80 executes a nozzle inspection process similar to S102 of the first embodiment (S602), and then executes a paper feeding process similar to S103 (S603). Subsequently, the control unit 80 waits until the generation of ejection data corresponding to the printing pass is completed (S604: NO). Then, when the generation of ejection data corresponding to the print pass is completed (S604: YES), the control unit 80 executes the processes of S605 to S610, which are similar to S105 to S110 of the first embodiment. Further, at this time, in the ejection signal selection process of S605, the process is performed according to the flow of any one of FIGS. 7, 9, and 10, similarly to any of the first to third embodiments.

<Effect>
In the fifth embodiment as well, when there is no abnormal nozzle, an ejection signal is selected with reference to the first table in which the first value of ejection data is associated with a signal for large dots. On the other hand, if there is an abnormal nozzle, the ejection signal is selected by referring to the second table in which the first value is associated with the extra-large dot signal having a larger droplet volume than the large-dot signal. Thereby, the size of the dot corresponding to the first value can be made larger when there is an abnormal nozzle than when there is no abnormal nozzle, without changing the amount of ejection data.

[Sixth embodiment]
Next, a sixth preferred embodiment of the present invention will be described. In the sixth embodiment, when recording is performed in the printer 1, the control unit 80 of the printer 1 and the control unit 98 of the external device 99 perform processing as shown in the sequence diagram of FIG. In the sixth embodiment, when the user operates an operation unit (not shown) of the external device 99 to instruct recording on the recording paper P, the process shown in FIG. 13 is started. In the sixth embodiment, the program of the present invention is installed in the external device 99 and causes the control unit 98 of the external device 99 to perform the processing shown in FIG. 13. Furthermore, in the sixth embodiment, the communication section 89 of the printer 1 serves as both the "data receiving section" and the "signal transmitting section" of the present invention. Also, in the sixth embodiment, the control unit 80 of the printer 1 generates the ejection signal as in the first to fifth embodiments, and the control unit 80 of the printer 1 that generates the ejection signal is the “signal generation unit” of the present invention. ”.

To explain the process shown in FIG. 13 in detail, in the sixth embodiment, first, the control unit 98 of the external device 99 informs the control unit 80 of the printer 1 that each of the plurality of nozzles 10 of the inkjet head 4 is abnormal. An abnormal nozzle information request command requesting information as to whether the abnormal nozzle exists or not is transmitted (S701). When the controller 80 of the printer 1 receives the abnormal nozzle information request command, it executes the nozzle inspection process similar to S101 of the first embodiment (S702), and based on the result, the An abnormal nozzle signal indicating whether each nozzle 10 is an abnormal nozzle is transmitted to the control unit 98 of the external device 99 (S703).

When the control unit 98 of the external device 99 receives the abnormal nozzle signal, it executes the ejection data generation process similar to S601 of the fifth embodiment (S704). Subsequently, the control unit 80 executes selection information generation processing (S705). In the selection information generation process, the process is executed according to the same flow as any of FIGS. 7 to 9 based on the abnormal nozzle signal received from the control unit 80 of the printer 1.

However, in the case of the sixth embodiment, in S204 to S206 in FIG. 7, S304 to S305 in FIG. 8, and S403 and S404 in FIG. Instead of selecting a signal, selection information indicating that an ejection signal is to be selected is generated by referring to a first table or a second table based on the value of ejection data. Specifically, in S204 and S206 of FIG. 7, S304 and S306 of FIG. 8, and S403 of FIG. 9, selection information indicating that the ejection signal is selected is generated by referring to the first table from the value of the ejection data. , S205 in FIG. 7, S305 in FIG. 8, and S404 in FIG. 9, the second table is referred to from the value of the ejection data to generate selection information indicating that the ejection signal is to be selected.

Next, the control unit 80 of the external device 99 issues the ejection data generated in S704, the selection information generated in S705, and a recording command ("ejection command" of the present invention) instructing to perform recording based on these. is transmitted to the control unit 80 of the printer 1 (S706, "command transmission processing" of the present invention).

When the control unit 80 of the printer 1 receives the ejection data, selection information, and recording command, it executes ejection signal selection processing (S707). In the ejection signal selection process, the control unit 80 of the printer 1 selects an ejection signal for each dot based on the selection information by referring to at least one of the first table and the second table from the ejection data value. .

Subsequently, the control unit 80 of the printer 1 executes recording processing (S708). In the recording process, the control unit 80 of the printer 1 performs recording on the recording paper P by repeatedly performing the same recording pass process and transport process as described in the first embodiment. Further, in the printing pass process, the inkjet head 4 is driven using the ejection signal selected in S707 for each dot, and ink droplets are ejected from the nozzle 10.

<Effect>
In the sixth embodiment as well, when there is no abnormal nozzle, an ejection signal is selected with reference to the first table in which the first value of ejection data is associated with a signal for large dots. On the other hand, if there is an abnormal nozzle, the ejection signal is selected by referring to the second table in which the first value is associated with the extra-large dot signal having a larger droplet volume than the large-dot signal. Thereby, the size of the dot corresponding to the first value can be made larger when there is an abnormal nozzle than when there is no abnormal nozzle, without changing the amount of ejection data.

[Modified example]
Although the preferred first to sixth embodiments of the present invention have been described above, the present invention is not limited to the first to sixth embodiments, and various modifications can be made within the scope of the claims. .

In the first embodiment, ejection signals for all non-adjacent dots are selected with reference to the first table, but the present invention is not limited to this. For example, ejection signals for some non-adjacent dots may be selected with reference to the first table, and ejection signals for the remaining non-adjacent dots may be selected with reference to the second table.

In the second embodiment, ejection signals for all non-adjacent nozzle dots are selected with reference to the first table, but the present invention is not limited to this. For example, ejection signals for some non-adjacent nozzle dots may be selected with reference to the first table, and ejection signals for the remaining non-adjacent nozzle dots may be selected with reference to the second table.

In the sixth embodiment, when the control unit 80 of the printer 1 receives an abnormal nozzle information request command from the control unit 98 of the external device 99, it executes a nozzle inspection process, and controls the external device 99 based on the result. Although the abnormal nozzle signal is transmitted to the section 98, the present invention is not limited thereto. For example, when the control unit 80 of the printer 1 receives the abnormal nozzle information request command, the abnormal nozzle is stored in the flash memory 84 when the control unit 80 of the printer 1 executed the nozzle inspection process in the past. An abnormal nozzle signal may be transmitted to the control unit 98 of the external device 99 based on the information as to whether or not the abnormal nozzle signal is present.

In the first to sixth embodiments, the control unit 80 can generate five types of ejection signals: a dot non-formation signal, a small dot signal, a medium dot signal, a large dot signal, and an extra large dot signal. In the first table, the four types of ejection data values "00", "01", "10", and "11" are respectively the dot non-formation signal, the small dot signal, the medium dot signal, and the large dot signal. It is associated with the dot signal. In addition, in the second table, the four types of ejection data values "00", "01", "10", and "11" are respectively the dot non-formation signal, the small dot signal, the medium dot signal, and the extra large dot signal. It is associated with the dot signal. However, it is not limited to this.

In modification 1, as in the first to sixth embodiments, the values of "00", "01", "10", and "11" of the ejection data are are associated with a dot non-formation signal, a small dot signal, a medium dot signal, and a large dot signal, respectively. On the other hand, as shown in FIG. 14, in the second table, the values of "00", "01", "10", and "11" of the ejection data are the dot non-formation signal, the medium dot signal, and the large dot signal, respectively. and extra large dot signals. That is, in Modification 1, in addition to the value of "11" in the ejection data, the values of "01" and "10" are also associated in the second table with ejection signals having a larger droplet volume than in the first table. It is being

In modification 2, as shown in FIG. 15(a), the control unit 80 outputs, as ejection signals, a dot non-formation signal, a first small dot signal, a second small dot signal, a first medium dot signal, Seven types of ejection signals are generated: a second medium dot signal, a large dot signal, and an extra large dot signal. The dot non-formation signal, the large dot signal, and the extra large dot signal are the same signals as described in the first embodiment. The first small dot signal is the same signal as the small dot signal of the first embodiment. The first medium dot signal is the same signal as the medium dot signal of the first embodiment.

The second small dot signal has a larger droplet volume than when driving the inkjet head 4 with the first small dot signal, and has a larger droplet volume than when driving the inkjet head 4 with the first medium dot signal. This is a signal for ejecting ink droplets from the nozzle 10 so as to reduce the amount of ink droplets to form dots on the recording paper P that are larger than the small dots and smaller than the medium dots.

The second medium dot signal has a larger droplet volume than when driving the inkjet head 4 with the first medium dot signal, and has a larger droplet volume than when driving the inkjet head 4 with the large dot signal. This is a signal for ejecting ink droplets from the nozzle 10 to form dots on the recording paper P that are larger than the medium dots and the large dots are also smaller.

Further, as shown in FIG. 15(b), in the first table, the values of "00", "01", "10", and "11" of the ejection data are the dot non-formation signal and the first small dot. signal, the first medium dot signal, and the large dot signal. As shown in FIG. 15(c), in the second table, the values of "00", "01", "10", and "11" of the ejection data are the dot non-formation signal and the second small dot signal, respectively. , are associated with the second medium dot signal and extra large dot signal. In other words, in Modification 2, in addition to the value of "11" in the ejection data, the values of "01" and "10" are also associated in the second table with ejection waveforms with a larger droplet volume than in the first table. It is being

In modification example 3, as shown in FIG. 16(a), the control unit 80 outputs a dot non-formation signal, a small dot signal, a first medium dot signal, a second medium dot signal, and a large dot signal as ejection signals. Five types of ejection signals are generated. The dot non-formation signal, the small dot signal, and the large dot signal are the same signals as described in the first embodiment. The first medium dot signal is the same signal as the medium dot signal of the first embodiment.

The second medium dot signal has a larger droplet volume than when driving the inkjet head 4 with the first medium dot signal, and has a larger droplet volume than when driving the inkjet head 4 with the large dot signal. This is a signal for ejecting ink droplets from the nozzle 10 to form dots on the recording paper P that are larger than the medium dots and the large dots are also smaller.

In addition, as shown in FIG. 16(b), in the first table, the values of "00", "01", "10", and "11" of the ejection data are the dot non-formation signal and the small dot signal, respectively. , are associated with the first medium dot signal and the large dot signal. As shown in FIG. 16(c), in the second table, the values of "00", "01", "10", and "11" of the ejection data are respectively the dot non-formation signal, the small dot signal, and the 2 Corresponds to the medium dot signal and the large dot signal. That is, in modification example 3, only the value "10" is associated with an ejection waveform having a larger droplet amount in the second table than in the first table. In modification 3, in the second table, the ejection signal that is associated with the value that maximizes the droplet amount among the multiple types of values of ejection data is not necessarily associated with the ejection signal that is associated with the value in the first table. This shows that the ejection signal is not limited to a large amount of ejection signal.

Further, the number of types of ejection data values and the number of types of ejection signals generated by the control unit 80 are not limited to those described above. For example, where K is an integer greater than or equal to 1, the value of the ejection data may be 2 ^K or less, and the control unit 80 may be able to generate (2 ^K +1) or more types of ejection signals.

When the control unit 80 generates ( ^2K +1) or more types of ejection signals, assuming that the ejection data can take the same number of values as the number of types of ejection signals, the ejection data becomes (K+1). The data is more than a bit. On the other hand, if the value of the discharge data is ^2K or less and the discharge signal associated with the first value of the discharge data is changed depending on whether or not there is an abnormal nozzle, it is possible to determine whether or not there is an abnormal nozzle. However, it is possible to perform recording by selecting an ejection signal from among (2 ^K +1) or more types of ejection signals using ejection data of K bits or less.

Further, the number of types of values of the ejection data and the number of types of ejection signals generated by the control unit 80 are as follows: whereas the value of the ejection data is ^2K or less, the number of types of ejection signals generated by the control unit 80 is ( ^2K) . +1) It is not necessary to satisfy the relationship that more than one type of ejection signal is generated.

Further, in the first to sixth embodiments, when the inkjet head 4 is driven for inspection, the signal processing circuit 78 outputs an output in response to a change in voltage from the nozzle 10 to the electrode 76 disposed in the cap 71. Although it has been determined whether or not ink has been normally ejected from the nozzle 10 based on the ejection determination signal, the present invention is not limited to this.

For example, instead of the electrode 76, an electrode may be provided that extends in the vertical direction and faces the space below the nozzle 10 when the carriage 2 is in the maintenance position. Then, the signal processing circuit 78 may output a signal corresponding to a change in the voltage of the electrode when the carriage 2 is driven for inspection with the carriage 2 positioned at the maintenance position.

Alternatively, for example, an optical sensor may be provided that directly detects ink ejected from the nozzles 10 while the carriage 2 is located at a predetermined position such as a maintenance position, and outputs a signal according to the detection result. Then, it may be determined whether or not the nozzle 10 is an abnormal nozzle based on the signal output from this optical sensor.

Alternatively, for example, as described in Japanese Patent No. 4929699, a voltage detection circuit that detects changes in voltage when ink is ejected from the nozzles is connected to the plate on which the nozzles of the inkjet head are formed. Then, it is determined whether or not the nozzle is an abnormal nozzle based on the signal output from the voltage detection circuit when the carriage is moved to the inspection position and the nozzle is operated to eject ink. You may.

Alternatively, the substrate of the inkjet head may be provided with a temperature sensing element, as described in Japanese Patent No. 6231759, for example. Then, after applying a first applied voltage to drive the heater to eject ink, a second applied voltage is applied to drive the heater so as not to eject ink, and after applying the second applied voltage, the heater is driven. After that, it may be determined whether or not the nozzle 10 is an abnormal nozzle based on the change in temperature detected by the temperature detection element until a predetermined period of time has elapsed.

Alternatively, a test pattern for checking whether each nozzle 10 is an abnormal nozzle may be recorded in the printer 1, and it may be determined whether or not each nozzle is an abnormal nozzle based on the recorded result of this test pattern. In this case, for example, a signal representing the test pattern recording result may be input to the control unit 80 by having the user operate an operation unit (not shown) of the printer 1 or the external device 99 based on the test pattern recording result. In this case, the operation section or the communication section 89 (not shown) of the printer 1 corresponds to the "signal receiving section" of the present invention.

Alternatively, when the printer 1 is equipped with a scanner that reads the image recorded on the recording paper P, the signal of the recording result of the test pattern may be inputted by having the scanner read the recorded test pattern. In this case, the portion of the control unit 80 that receives the signal from the scanner corresponds to the “signal receiving unit” of the present invention.

Further, in the first to sixth embodiments, all the nozzles 10 of the inkjet head 4 are driven for inspection to determine whether or not they are abnormal nozzles, but the present invention is not limited to this. For example, only some nozzles 10 of the inkjet head 4, such as every other nozzle 10 in each nozzle row 9, may be driven for inspection to determine whether or not they are abnormal nozzles. For other nozzles 10, it may be estimated whether or not they are abnormal nozzles based on the determination results for some of the nozzles 10.

Further, in the above example, it was determined whether or not the nozzle 10 is an abnormal nozzle based on whether or not ink droplets were ejected from the nozzle 10, but the present invention is not limited to this. For example, it may be determined whether the nozzle 10 is an abnormal nozzle based on the ejection direction, ejection speed, etc. of ink droplets.

In addition, although an example has been described above in which the present invention is applied to a printer equipped with a so-called serial head that ejects ink from a plurality of nozzles while moving in the scanning direction together with a carriage, the present invention is not limited to this. For example, the present invention can be applied to a printer equipped with a so-called line head that extends over the entire length of recording paper in the scanning direction.

Moreover, although an example in which the present invention is applied to a printer that records on recording paper P by ejecting ink from nozzles has been described above, the present invention is not limited to this. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, sheets for outdoor advertising, cases for mobile terminals such as smartphones, cardboard, and resin members. Further, the present invention can also be applied to a liquid ejecting device that ejects a liquid other than ink, such as a liquid resin or metal.

1: Printer 2: Carriage 4: Inkjet head 6, 7 Conveyance roller 10 Nozzle 80: Control section 89: Communication section 99: External device

Claims (10)

a head having a plurality of nozzles that eject droplets corresponding to a plurality of types of ejection signals having different amounts of droplets, the ejection signals being ejection signals corresponding to the amount of droplets forming one dot on a medium to be ejected;
a data receiving unit that receives ejection data having a plurality of types of values for selecting the ejection signal from an external device;
a signal receiving unit that receives an abnormal nozzle signal related to an abnormal nozzle that has an abnormality in ejecting the droplets among the plurality of nozzles;
a storage unit that stores a table in which values of the ejection data and the ejection signal are associated;
comprising a control unit;
The storage unit includes, as the table, a first table in which a first value, which is one of the plurality of types of values, is associated with a first ejection signal, which is one of the plurality of types of the ejection signals. and a second table in which the first value is associated with a second ejection signal that is one of a plurality of types of ejection signals and has a larger droplet amount than the first ejection signal. ,
The control unit includes:
a determination process for determining whether or not the abnormal nozzle is present based on the abnormal nozzle signal;
When the data receiving unit receives the ejection data, the ejection signal is selected and generated by referring to the table from the plurality of types of values, and the generated ejection signal is used to drive the head. performing a discharge process of discharging the droplet;
If it is determined in the determination process that there is no abnormal nozzle, the discharge process is executed with reference to the first table, and if it is determined that there is an abnormal nozzle in the determination process, the second table is executed. A droplet ejection apparatus, characterized in that the ejection process is executed by referring to the ejection process. Let K be an integer greater than or equal to 1,
The value of the discharge data is ^2K types or less,
The droplet ejection device according to claim 1, wherein the control unit is capable of generating (2 ^K +1) or more types of the ejection signals. The control unit includes:
the ejection signal that does not eject droplets;
the ejection signal for forming small dots on the ejection target medium;
the ejection signal for forming medium dots larger than the small dots on the ejection target medium;
the ejection signal for forming large dots larger than the medium dots on the ejection target medium;
3. The droplet ejection apparatus according to claim 2, wherein the ejection signal is capable of generating five types of ejection signals, including the ejection signal for forming extra-large dots larger than the large dots on a medium to be ejected. The plurality of types of values of the dot data are four types of values including the first value,
In the first table, among the four types of values, the first value is associated with the ejection signal for forming the large dot, and the remaining three values are respectively associated with the ejection signal for forming the large dot. a table associated with an ejection signal, the ejection signal for forming the small dot, and the ejection signal for forming the medium dot;
4. The droplet ejection apparatus according to claim 3, wherein the second table is a table in which the first value is associated with the ejection signal for forming the extra large dot. the head has a plurality of nozzles arranged in a first direction,
The ejection data is data for selecting the ejection signal for each of the plurality of dots lined up in the first direction,
The control unit includes:
The determination process determines that the abnormal nozzle exists, and the ejection data forms both the dot corresponding to the abnormal nozzle and an adjacent dot adjacent to the dot in the first direction. When indicated,
In the ejection process, the ejection signal for at least one dot other than the adjacent dots is selected and generated by referring to the first table from the plurality of types of values of the ejection data, and the ejection signal is generated based on the ejection data. The droplet ejection apparatus according to any one of claims 1 to 4, wherein the ejection signal for at least the adjacent dots is selected and generated by referring to the second table from the plurality of types of values. . the head has a plurality of nozzles arranged in a first direction,
The ejection data is data for selecting the ejection signal for each of the plurality of dots lined up in the first direction,
The control unit includes:
The determination process determines that the abnormal nozzle exists, and the ejection data corresponds to the dot corresponding to the abnormal nozzle and an adjacent nozzle that is the nozzle adjacent to the abnormal nozzle in the first direction. When indicating that both adjacent nozzle dots are formed in the above dot,
In the ejection process, the ejection signal for at least one nozzle other than the adjacent nozzle is selected and generated by referring to the first table from the plurality of types of values of the dot data; The droplet ejection apparatus according to claim 1, wherein the ejection signal for at least the adjacent nozzle is selected and generated by referring to the second table from the plurality of types of values. the head has a plurality of nozzles arranged in a first direction,
a carriage carrying the droplet ejection head and moving in a second direction intersecting the first direction;
a transport unit that transports the medium to be ejected in the first direction,
The control unit includes:
Switching back and forth between a discharge path in which the droplet discharge head discharges droplets from the plurality of nozzles onto the discharge target medium while moving the carriage in the second direction, and a transport operation in which the transport unit transports the discharge target medium. forming the dots on the ejected medium by causing
The ejection data is data for selecting the ejection signal for each of the plurality of dots arranged in the first direction and the second direction formed in the ejection pass,
The control unit includes:
If it is determined in the determination process that the abnormal nozzle exists,
In the discharge process,
When the data receiving unit receives a plurality of the ejection data regarding the plurality of ejection paths,
When the ejection data indicates that the dot corresponding to the abnormal nozzle is not formed, the first table is referred to from the plurality of types of values of the ejection data, and the ejection data corresponding to the ejection data is determined. selecting and generating the ejection signal for each dot formed in the pass;
When the ejection data indicates that the dot corresponding to the abnormal nozzle is formed, the second table is referred to from the plurality of types of values of the ejection data, and the ejection data corresponding to the ejection data is determined. The droplet ejection apparatus according to claim 1, wherein the ejection signal for each dot formed in a pass is selectively generated. The control unit includes:
If it is determined in the determination process that the abnormal nozzle exists,
In the discharge process,
When the data receiving unit receives a plurality of pieces of ejection data regarding a plurality of media to be ejected,
When the ejection data indicates that the dot corresponding to the abnormal nozzle is not formed, the first table is referred to from the plurality of types of values of the ejection data, and the ejection target corresponding to the ejection data is determined. selecting and generating the ejection signal for each dot to be formed on the medium;
When the ejection data indicates that the dot corresponding to the abnormal nozzle is formed, the second table is referred to from the plurality of types of values of the ejection data, and the ejection target corresponding to the ejection data is determined. 5. The droplet ejection apparatus according to claim 1, wherein the ejection signal for each dot formed on a medium is selectively generated. a head having a plurality of nozzles that eject droplets corresponding to a plurality of types of ejection signals having different amounts of droplets, the ejection signals being ejection signals corresponding to the amount of droplets forming one dot on a medium to be ejected;
a signal receiving unit that receives an abnormal nozzle signal related to an abnormal nozzle that has an abnormality in ejecting the droplets among the plurality of nozzles;
a storage unit that stores a table in which values of ejection data having a plurality of types of values for selecting the ejection signal are associated with the ejection signal;
comprising a control unit;
The storage unit includes, as the table, a first table in which a first value, which is one of the plurality of types of values, is associated with a first ejection signal, which is one of the plurality of types of the ejection signals. and a second table in which the first value is associated with a second ejection signal that is one of a plurality of types of ejection signals and has a larger droplet amount than the first ejection signal. ,
The control unit includes:
It is possible to generate a plurality of types of the ejection signals,
a data generation process for generating the ejection data;
a determination process for determining whether or not the abnormal nozzle is present based on the abnormal nozzle signal;
After the data generation process, the ejection signal is selected and generated by referring to the table from the plurality of types of values, and the generated ejection signal is used to drive the head to eject the droplet. process and execute
If it is determined in the determination process that there is no abnormal nozzle, the discharge process is executed with reference to the first table, and if it is determined that there is an abnormal nozzle in the determination process, the second table is executed. A droplet ejection apparatus, characterized in that the ejection process is executed by referring to the ejection process. a head having a plurality of nozzles for ejecting droplets corresponding to a plurality of types of ejection signals having different amounts of droplets, the ejection signals being ejection signals corresponding to the amount of droplets forming one dot on a medium to be ejected; a data receiving unit that receives ejection data having a plurality of types of values for selecting an ejection signal from an external device; A signal transmitting section for transmitting signals to the apparatus, a recording section for storing a table in which the values of the ejection data and the ejection signals are associated with each other, and a signal generating section for generating a plurality of types of the ejection signals, The storage unit includes, as the table, a first table in which a first value, which is one of the plurality of types of values, is associated with a first ejection signal, which is one of the plurality of types of ejection signals; , a second table in which the first value is one of a plurality of types of the ejection signals and is associated with a second ejection signal having a larger droplet amount than the first ejection signal; A program executed by a control unit of the external device connected to the droplet ejection device,
to the computer,
a data transmission process of transmitting the ejection data to the data receiving section;
a determination process for determining whether or not there is an abnormal nozzle based on the abnormal nozzle signal transmitted by the signal transmitter;
The ejection signal is selected and generated by referring to the table from the plurality of values of the ejection data received by the data receiving section, and the head is driven using the generated ejection signal to generate the droplet. executing a command transmission process of transmitting an ejection command to the droplet ejection device to instruct the droplet ejection device to eject the liquid;
If it is determined in the determination process that there is no abnormal nozzle, executing the command transmission process of transmitting the ejection command instructing to refer to the first table;
A program characterized in that, when it is determined in the determination process that the abnormal nozzle exists, the program causes the ejection process to be executed to transmit the ejection command instructing to refer to the second table.

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