JP2007007960A - Liquid delivering apparatus, computer program, and cleaning method for nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress wasting of ink when a nozzle where a liquid is not delivered is detected. <P>SOLUTION: When the nozzle where the liquid is not delivered is detected by a liquid delivery detecting part for detecting whether or not the liquid is delivered from nozzles, it is determined on the basis of preliminarily set information whether or not to clean the nozzle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejection apparatus having a function of detecting whether or not liquid is ejected from a nozzle, a computer program, and a nozzle cleaning method.

As a liquid ejecting apparatus having a function of detecting whether or not a liquid is ejected from a nozzle, for example, an ink jet printer (hereinafter referred to as a printer) that ejects ink as a liquid from the nozzle is known. The printer forms an image by ejecting ink toward a medium to form dots on the medium. For this reason, when ink is not ejected due to nozzle clogging or the like, white streaks appear in the image or an image having a color different from the actual color is formed. For this reason, a predetermined pattern is printed using all the nozzles, and the nozzle on which ink is not ejected is detected by reading the printed image with a sensor provided in the apparatus (see, for example, Patent Document 1). When a nozzle that does not eject ink is detected, some nozzles are cleaned by a cleaning mechanism provided in the apparatus to eliminate clogging.
JP 2003-291318 A

  However, in such a printer as described above, a nozzle cleaning operation is always executed when a nozzle that does not eject ink is detected. The nozzle cleaning includes, for example, flushing that forcibly ejects ink from the nozzle, and a method of sucking ink in the nozzle. At this time, it is structurally impossible to execute cleaning for one nozzle, and therefore a plurality of nozzles are cleaned at a time. For this reason, the nozzles ejecting ink are also cleaned, and ink is wasted. In addition, even if there is a clogged nozzle as in draft printing, there is a case where there is no support as an image, but in the printer as described above, cleaning is executed when a nozzle that does not eject ink is detected. Therefore, there is a problem that even if it is not originally necessary, cleaning is performed and ink is wasted, and the time spent for cleaning cannot be printed.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a liquid ejection apparatus and a computer program capable of suppressing waste of liquid due to cleaning when a nozzle that does not eject liquid is detected. And a nozzle cleaning method.

  The main invention is: (a) a nozzle for discharging liquid, (b) a liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle, and (c) for cleaning the nozzle. And (d) whether or not the nozzles are not cleaned by the cleaning mechanism when the nozzles that are not discharging liquid are detected by the liquid discharge detection unit based on preset information. And (e) a liquid ejection device characterized by comprising:

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

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

  (A) a nozzle for discharging liquid, (b) a liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle, and (c) a cleaning mechanism for cleaning the nozzle; (D) To determine whether or not the nozzle is to be cleaned by the cleaning mechanism based on preset information when the nozzle that is not discharging liquid is detected by the liquid discharge detection unit. And (e) a liquid ejecting apparatus.

  According to such a liquid ejecting apparatus, whether or not to clean the nozzle is determined based on preset information. Therefore, when it is set not to perform cleaning, cleaning is not executed. That is, even when a nozzle to which no liquid is ejected is detected, the nozzle may or may not be cleaned depending on the setting. For this reason, since the nozzle is not necessarily cleaned, it is possible to prevent waste of liquid due to cleaning and waste of time spent for cleaning.

In the liquid ejecting apparatus, it is preferable that the information is information indicating whether or not the nozzle is allowed to be cleaned after the nozzle that has not ejected the liquid is detected.
According to such a liquid ejecting apparatus, information indicating whether or not to allow cleaning of the nozzle after the detection of the nozzle that has not ejected the liquid is set in advance, so that no liquid is ejected. Whether or not to perform cleaning when a nozzle is detected can be set in advance as desired by the user or the like.

In such a liquid ejecting apparatus, when the information is information indicating that the cleaning is not permitted, the nozzle is not cleaned by the cleaning mechanism after the nozzle that has not ejected the liquid is detected. Is desirable.
According to such a liquid ejecting apparatus, when information indicating that cleaning is not permitted is set, the nozzle is not cleaned after the nozzle that has not ejected the liquid is detected. By setting information indicating that this is not permitted, it is possible to prevent unnecessary cleaning from being performed.

In such a liquid ejecting apparatus, when an event to be notified occurs, the liquid ejecting apparatus has a notifying unit for notifying the event, and when the information is information indicating that the cleaning is not permitted, It is desirable to notify the event that the liquid is not discharged from the nozzle in the notification unit after the nozzle that has not been discharged is detected.
According to such a liquid ejecting apparatus, when information indicating that cleaning is not permitted is set, the liquid is not ejected from the nozzle after the nozzle that has not ejected the liquid is detected. Since the event is notified to the notification unit, the user can recognize that there is a nozzle that does not eject liquid. For this reason, when a nozzle that does not eject liquid is detected, cleaning can be executed as necessary.

In the liquid ejecting apparatus, it is preferable that the information input unit for inputting the information is provided, and the information is set when a user inputs the information from the information input unit.
According to such a liquid ejecting apparatus, the information indicating whether or not to allow the nozzle to be cleaned after the nozzle that has not ejected the liquid is detected is input from the information input unit by the user. It is possible for the user to set and change as desired whether or not to perform nozzle cleaning after a nozzle that has not been discharged is detected. In addition, since the information is set by inputting from the information input unit, the user can easily set the information.

In such a liquid ejection device, whether or not the liquid is ejected from the nozzle is determined based on a detection result by the liquid ejection detection unit and a predetermined threshold set in advance for a predetermined condition. It is desirable.
According to such a liquid ejection device, it is determined whether or not the liquid is ejected from the nozzle based on the detection result by the liquid ejection detection unit and the threshold for a predetermined condition set in advance. It is possible to set the detected level different depending on the setting condition and threshold value. For example, even when there are nozzles that are detected not to discharge liquid to an acceptable level, there may be no nozzles that do not discharge liquid. For this reason, it is possible to set so that cleaning is not performed even when there are nozzles that are detected not to discharge liquid to an allowable level.

In the liquid ejecting apparatus, it is desirable that the threshold value can be arbitrarily set.
According to such a liquid ejecting apparatus, the threshold value to be set can be arbitrarily set, and therefore it is possible to set whether or not to permit cleaning in accordance with the user's desire. For example, when there are nozzles that are detected not to discharge liquid to an allowable level, it is possible to set so that cleaning is not performed, but the allowable level also has a degree of freedom. It is possible to make settings.

In such a liquid ejecting apparatus, immediately after cleaning the nozzle, it is detected whether or not liquid has been ejected from the nozzle, and when the nozzle that has not ejected liquid is detected, the set information is displayed. Regardless, it is desirable to clean the nozzle.
Since cleaning is performed in order to discharge liquid from nozzles that did not discharge liquid, liquid should be discharged from all nozzles after cleaning. For this reason, according to the above-described liquid ejecting apparatus, immediately after cleaning, when a nozzle that has not ejected liquid is detected, cleaning is performed again. It is possible to return so that the liquid is discharged.

In the liquid ejecting apparatus, the cleaning mechanism can clean the nozzle by a plurality of types of cleaning methods, and the cleaning performed when the nozzle that has not ejected the liquid is detected is the liquid ejecting detection. It is desirable that any cleaning method among the plurality of types of cleaning methods can be set according to the detection result of the part.
According to such a liquid ejection apparatus, any cleaning method can be set from among a plurality of types of cleaning methods according to the detection result of the liquid ejection detection unit, so that cleaning is performed according to the occurrence of nozzles that do not eject liquid. The method will be set. For this reason, it is possible to execute appropriate cleaning according to the occurrence state of nozzles that do not eject liquid.

In the liquid ejecting apparatus, the liquid is ink.
According to such a liquid ejection apparatus, it is possible to prevent waste of ink due to cleaning of liquid ejection detection.

Also, (a) a nozzle for discharging liquid, (b) a liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle, and (c) a cleaning mechanism for cleaning the nozzle. And (d) whether or not the nozzle is to be cleaned by the cleaning mechanism when the nozzle that has not discharged liquid is detected by the liquid discharge detection unit, based on preset information. (E) the information is information indicating whether or not to allow the nozzle to be cleaned after the nozzle that has not been ejected with liquid is detected, ) When the information is information indicating that the cleaning is not permitted, the cleaning machine is detected after the nozzle that has not ejected the liquid is detected. (G) Information indicating that the information does not allow the cleaning to be performed when an event to be notified occurs, and a notification unit for notifying the event is generated. In this case, after the nozzle that is not ejecting the liquid is detected, an event that the liquid is not ejected from the nozzle is notified by the notification unit, and (h) information input for inputting the information The information is set by the user inputting the information from the information input unit, and (i) whether or not the liquid is discharged from the nozzle is determined by the detection result by the liquid discharge detection unit. And (j) the threshold value can be arbitrarily set, and (k) immediately after cleaning the nozzle. Detecting whether or not the liquid is discharged from the nozzle, and cleaning the nozzle regardless of the set information when the nozzle that is not discharging the liquid is detected; and (l) the cleaning The mechanism can clean the nozzles by a plurality of types of cleaning methods, and the cleaning performed when the nozzles that are not ejecting liquid is detected depends on the detection result of the liquid ejection detection unit. The liquid ejecting apparatus can be set to any cleaning method among the plurality of types of cleaning methods, and (m) the liquid is ink.
According to such a liquid ejecting apparatus, almost all the effects described above can be achieved, and thus the object of the present invention can be achieved more effectively.

  In addition, a liquid ejection apparatus having a nozzle for ejecting liquid, a liquid ejection detection unit for detecting whether or not liquid is ejected from the nozzle, and a cleaning mechanism for cleaning the nozzle, Implementing a function of determining whether or not to clean the nozzle by the cleaning mechanism based on preset information when the nozzle from which no liquid is discharged is detected by the liquid discharge detection unit. A computer program for this can also be realized.

  Further, the step of detecting whether or not the liquid is discharged from the nozzle for discharging the liquid, and whether or not to clean the nozzle when the nozzle that is not discharging the liquid is detected are set in advance. It is also possible to realize a nozzle cleaning method characterized by including a step of determining based on the obtained information.

=== Overview of Liquid Discharge Device ===
As an example of the liquid ejection apparatus according to the present invention, an outline of a printing system having an inkjet printer (hereinafter referred to as a printer) 1 and a computer 110 connected to the printer 1 will be described as an example. Here, the liquid ejecting apparatus is a printing system, but the liquid ejecting apparatus may be configured by a single inkjet printer.

<Printing system>
FIG. 1 is a diagram illustrating the configuration of the printing system 100. The printing system is a system including at least a printer and a print control device that controls the operation of the printer. A printing system 100 according to the present embodiment includes an inkjet printer (hereinafter referred to as a printer) 1 that prints by ejecting ink as a liquid to form an image on a medium, a computer 110, and a display device 120 as a notification unit. , An input device 130 and a recording / reproducing device 140. The printer 1 prints an image on a medium such as paper, cloth, film, or OHP paper. The computer 110 is communicably connected to the printer 1. In order to cause the printer 1 to print an image, the computer 110 outputs print data corresponding to the image to the printer 1. Computer programs such as application programs and printer drivers are installed in the computer 110.

<Printer driver>
FIG. 2 is a schematic explanatory diagram of basic processing performed by the printer driver.
In the computer 110, computer programs such as the video driver 102, the application program 104, and the printer driver 111 are operating under an operating system installed in the computer 110. The video driver 102 has a function of displaying, for example, a user interface on the display device 120 in accordance with a display command from the application program 104 or the printer driver 111. The application program 104 has a function of performing image editing, for example, and creates data related to an image (image data). The user can give an instruction to print an image edited by the application program 104 via the user interface of the application program 104. When the application program 104 receives a print instruction, the application program 104 outputs image data to the printer driver 111.

  The printer driver 111 receives image data from the application program 104, converts the image data into print data, and outputs the print data to the inkjet printer 1. Here, the print data is data in a format that can be interpreted by the ink jet printer 1 and is data having various command data and pixel data. The command data is data for instructing the inkjet printer 1 to execute a specific operation. The pixel data is data relating to pixels constituting an image to be printed (printed image). For example, data relating to dots (color and size of dots) formed at positions on the medium S corresponding to a certain pixel. Etc.).

  The printer driver 111 includes a resolution conversion processing unit 112, a color conversion processing unit 114, a halftone processing unit 116, and a rasterization processing unit 118 in order to convert the image data output from the application program 104 into print data. I have.

  The resolution conversion processing unit 112 performs resolution conversion processing for converting image data (text data, image data, etc.) output from the application program 104 into a resolution for printing on the paper S as a medium. With the resolution conversion process, for example, when the resolution when printing an image on paper is specified as 720 × 720 dpi, the image data received from the application program 104 is converted into image data with a resolution of 720 × 720 dpi. Note that the image data after the resolution conversion process is multi-gradation (for example, 256 gradations) RGB data represented by an RGB color space. Hereinafter, RGB data obtained by performing resolution conversion processing on image data is referred to as RGB image data.

  The color conversion processing unit 114 performs color conversion processing for converting RGB data into CMYK data represented by a CMYK color space. The color conversion process is performed by the printer driver referring to a table (color conversion lookup table LUT) in which the gradation values of RGB data and the gradation values of CMYK data are associated with each other. The CMYK data is data corresponding to the ink color of the inkjet printer 1. By this color conversion process, RGB data for each pixel is converted into CMYK data corresponding to the ink color. Hereinafter, CMYK data obtained by performing color conversion processing on RGB image data is referred to as CMYK image data.

  The halftone processing unit 116 performs a halftone process for converting high gradation number data into gradation number data that can be formed by the inkjet printer 1. The halftone processing is, for example, processing for converting data indicating 256 gradations into 1-bit data indicating 2 gradations or 2-bit data indicating 4 gradations.

  The rasterization processing unit 118 performs rasterization processing that changes the matrix-like image data in the order of data to be transferred to the inkjet printer 1. Thereby, the rasterized data is output to the ink jet printer 1.

<Setting by printer driver>
FIG. 3 is an explanatory diagram of the user interface of the printer driver 111. The user interface of the printer driver 111 is displayed on the display device via the video driver 102. The user can make various settings of the printer driver 111 using the input device 130.

  From this screen, the user can select various printing conditions such as the printing resolution (dot interval when printing), the type and size of the medium to be printed, and the printing mode. The printer driver 111 performs the data conversion process described above according to the selected printing condition, and converts the image data into print data.

  In addition, it is possible to make settings related to the ink ejection detection process executed to detect whether or not ink is ejected from each nozzle from the utility screen set in this screen. The ink discharge detection process will be described later.

<Printer>
FIG. 4 is a block diagram of the overall configuration of the printer 1. FIG. 5A is a schematic diagram of the overall configuration of the printer 1. FIG. 5B is a longitudinal sectional view of the overall configuration of the printer 1. Hereinafter, the basic configuration of the printer of this embodiment will be described.

  The printer 1 includes a transport unit 20, a carriage unit 30, a head unit 40, a detector group 50, and a controller 60. The printer 1 that has received print data from the computer 110, which is an external device, controls each unit (the conveyance unit 20, the carriage unit 30, and the head unit 40) by the controller 60. The controller 60 controls each unit based on the print data received from the computer 110 and prints an image on a sheet. The situation in the printer 1 is monitored by a detector group 50, and the detector group 50 outputs a detection result to the controller 60. The controller 60 controls each unit based on the detection result output from the detector group 50.

  The transport unit 20 transports a medium such as paper in a predetermined direction (hereinafter referred to as a transport direction). The transport unit 20 includes a paper feed roller 21, a transport motor 22 (also referred to as a PF motor), a transport roller 23, a platen 24, and a paper discharge roller 25. The paper feed roller 21 is a roller for feeding the paper inserted into the paper insertion slot into the printer. The transport roller 23 is a roller that transports the paper S fed by the paper feed roller 21 to a printable area. The platen 24 supports the paper S being printed. The paper discharge roller 25 is a roller for discharging the paper S to the outside of the printer 1 and is provided on the downstream side in the transport direction with respect to the printable area. The paper discharge roller 25 rotates in synchronization with the transport roller 23.

  The carriage unit 30 is for moving the head 41 in a predetermined movement direction. The carriage unit 30 includes a carriage 31 and a carriage motor 32 (also referred to as a CR motor). The carriage 31 can reciprocate along a guide portion 46 provided in the movement direction. Further, the carriage 31 detachably holds an ink cartridge that stores ink. The carriage motor 32 is a motor for moving the carriage 31 in the movement direction.

  The head unit 40 is for ejecting ink onto paper. The head unit 40 has a head 41. The head 41 has a plurality of nozzles, and ejects ink intermittently from each nozzle. The head 41 is provided on the carriage 31. Therefore, when the carriage 31 moves in the movement direction, the head 41 also moves in the movement direction. Then, when the head 41 is moved in the moving direction, droplets of ink (hereinafter referred to as ink droplets) are intermittently ejected, whereby dot rows (raster lines) along the moving direction are formed on a sheet as an example of the medium. It is formed.

  FIG. 6 is an explanatory diagram showing the arrangement of nozzles on the lower surface of the head 41. On the lower surface of the head 41, a black ink nozzle row 411 (K), a cyan ink nozzle row 411 (C), a magenta ink nozzle row 411 (M), and a yellow ink nozzle row 411 (Y) are formed. . Each nozzle row includes a plurality of nozzles that are ejection ports for ejecting ink of each color. The plurality of nozzles in each nozzle row are aligned at a constant interval (nozzle pitch: k · D) along the transport direction. Here, D is a minimum dot pitch in the transport direction (that is, an interval at the highest resolution of dots formed on the paper S). K is an integer of 1 or more. For example, when the nozzle pitch is 180 dpi (1/180 inch) and the dot pitch in the transport direction is 720 dpi (1/720 inch), k = 4. The nozzles in each nozzle row are assigned a smaller number as the nozzles on the downstream side (# 1 to # 180). Each nozzle is provided with an ink chamber (not shown) and a piezo element (not shown). The ink chamber is expanded and contracted by driving the piezo element, and ink droplets are ejected from the nozzle.

  The detector group 50 includes a linear encoder 51, a rotary encoder 52, a paper detection sensor 53, an optical sensor 54, and a liquid discharge for detecting whether ink is discharged from each nozzle provided in the head 41. An ink discharge detection unit 70 as a detection unit is included. The linear encoder 51 is for detecting the position of the carriage 31 in the moving direction. The rotary encoder 52 is for detecting the rotation amount of the transport roller 23. The paper detection sensor 53 is for detecting the position of the leading edge of the paper to be printed. The optical sensor 54 is attached to the carriage 31. The optical sensor 54 detects the presence or absence of a sheet by the light receiving unit detecting reflected light of the light emitted from the light emitting unit to the sheet. The ink discharge detection unit 70 will be described later.

  The controller 60 is a control unit for controlling the printer. The controller 60 includes an interface unit 61, a CPU 62, a memory 63, and a unit control circuit 64. The interface unit 61 is for transmitting and receiving data between the computer 110 which is an external device and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer. The memory 63 is for securing an area for storing a program of the CPU 62, a work area, and the like, and includes storage elements such as a RAM and an EEPROM. The CPU 62 controls each unit via the unit control circuit 64 in accordance with a program stored in the memory 63.

=== Printing method ===
<About printing operation>
FIG. 7 is a flowchart of processing during printing. Each process described below is executed by the controller 60 controlling each unit in accordance with a program stored in the memory 63. This program has a code for executing each process.

  Print command reception (S001): First, the controller 60 receives a print command from the computer 110 via the interface unit 61. This print command is included in the header of print data transmitted from the computer 110 together with information such as print conditions. Then, the controller 60 analyzes the contents of various commands included in the received print data, and performs the following paper feed processing / conveyance processing / dot formation processing using each unit.

  Paper Feed Process (S002): The paper feed process is a process for supplying paper to be printed into the printer and positioning the paper at a print start position (also referred to as a cue position). The controller 60 rotates the paper feed roller 21 and the transport roller 23 to position the paper at the print start position.

  Dot Formation Process (S003): The dot formation process is a process for forming dots on the paper by intermittently ejecting ink from the head 41 that moves along the movement direction. The controller 60 drives the carriage motor 32 to move the carriage 31 in the movement direction. During the movement of the carriage 31, the head 41 is based on data for each unit area (hereinafter referred to as unit area data) included in the print data. Ink is discharged from the nozzle. When ink droplets ejected from the head 41 land on the paper, dots are formed on the paper. Since ink is intermittently ejected from the moving head 41, a dot row (raster line) composed of a plurality of dots along the moving direction is formed on the paper. Here, the “unit area” refers to a rectangular area virtually defined on a medium such as paper, and the size and shape are determined according to the print resolution. For example, when the printing resolution is 720 dpi (moving direction) × 720 dpi (conveying direction), the unit area is a square shape having a size of about 35.28 μm × 35.28 μm (≈ 1/720 inch × 1/720 inch). Become an area. When an ink droplet is ideally ejected, the ink droplet lands on the center position of the unit area, and then spreads to form dots in the unit area.

  Transport Process (S004): The transport process is a process of moving the paper relative to the head 41 along the transport direction. The controller 60 rotates the transport roller 23 to transport the paper in the transport direction. By this carrying process, the head 41 can form dots in the next dot forming process at a position different from the position of the dots formed by the previous dot forming process.

  Paper discharge determination (S005): The controller 60 determines whether to discharge (discharge) the paper being printed. If data to be printed remains on the paper being printed, no paper is discharged. Then, the controller 60 alternately repeats the dot formation process and the conveyance process until there is no more data to be printed, and gradually prints an image composed of dots on the paper.

  Paper Discharge Process (S006): When there is no more data to be printed on the paper being printed, the controller 60 discharges the paper by rotating the paper discharge roller. The determination of whether or not to discharge paper may be based on a paper discharge command included in the print data.

  Print end determination (S007): Next, the controller 60 determines whether or not to continue printing. If printing is to be performed on the next sheet, the printing is continued and the sheet feeding process for the next sheet is started. If printing is not performed on the next sheet, the printing operation is terminated.

=== Liquid discharge detection unit ===
<Overview of liquid discharge detection unit>
FIG. 8 is a diagram for explaining the configuration of the liquid ejection detection unit, and FIG. 9 is an explanatory diagram for explaining the detection principle of the liquid ejection detection unit.

  As shown in FIG. 8, the ink discharge detection unit 70 as a liquid discharge detection unit is connected to a sensing unit 71 that can be opposed to the moving head 41 at a predetermined position, and is connected to the detection unit 71. And a detection circuit 80. The sensing unit 71 includes a foamed member 71a that is conductive and rich in water absorption and has a mat shape, and a wire 71b that is provided in a tensioned state in the foamed member 71a and has conductivity such as metal. In addition, the sensing unit 71 is disposed such that the foam member 71 a faces a portion where the nozzles of the head 41 are provided, and the wire 71 b is parallel to the nozzle row of the head 41. When the carriage 31 moves, the sensing unit 71 is disposed so as to face the head 41 in a non-contact state with a gap D between the head 41 and the sensing unit 71. The distance D between the head 41 and the sensing unit 71 is set to about 1 mm, for example.

  A power source (not shown) is connected to the wire 71b of the sensing unit 71 via a protective resistor R1, and a high voltage such as 100 V (volt) is applied from the power source.

  On the other hand, the detection circuit 80 is configured to detect a current generated in the sensing unit 71. In the present embodiment, the detection circuit 80 includes a detection circuit including a capacitor C, an input resistor R2, a feedback resistor R3, and an operational amplifier Amp. The capacitor C serves to input the current fluctuation as an electric signal to the operational amplifier Amp via the input resistor R2 when the current fluctuation occurs in the sensing unit 71. The operational amplifier Amp serves as an amplifier circuit that amplifies and outputs a signal input through the capacitor C. An output signal from the operational amplifier Amp is A / D converted from an analog signal to a digital signal by an A / D converter, for example, and output to the controller 60 in an appropriate form such as digital data.

  When detecting the ink ejection status, that is, whether or not ink is ejected, a very high voltage such as 100 V (volts) is applied to the sensing unit 71 by the supply voltage from the power source. As a result, a very strong electric field is formed between the head 41 and the sensing unit 71.

  The controller 60 performs an operation of ejecting ink from the nozzles # 1 to # 180 of the head 41 individually toward the sensing unit 71. FIG. 9 illustrates how ink is ejected from a certain nozzle of the head 41 toward the sensing unit 71. Here, one ink droplet Ip is ejected from each nozzle # 1 to # 180 of the head 41. At this time, in the strong electric field between the head 41 and the sensing unit 71, the ink droplets Ip ejected from the nozzles # 1 to # 180 are charged.

  When the charged ink droplet Ip discharged from the nozzles # 1 to # 180 contacts the sensing unit 71, the potential of the sensing unit 71 varies. When the potential of the sensing unit 71 varies, the current input to the detection circuit 80 varies, and this current variation is input as an electric signal to the operational amplifier Amp via the input resistor R2. The signal input to the operational amplifier Amp is amplified and output toward the controller 60 and the like.

  On the other hand, when the ink droplet Ip is not normally ejected from the nozzles # 1 to # 180, the charged ink droplet Ip does not contact the sensing unit 71 at a predetermined timing. Variations in are not detected. For this reason, since no signal is output to the controller 60 or the like, it is detected that the ink has not been normally ejected from the nozzle where the operation for ejecting ink has been executed.

  That is, the controller 60 determines whether ink has been ejected based on the output timing of the signal from the detection circuit 80 and the presence or absence of a signal output from the detection circuit 80.

<Sensor location>
FIG. 10 is a diagram for explaining the installation position of the sensing unit 71 of the present embodiment. As shown in the figure, the sensing unit 71 of this embodiment is installed in an area An (hereinafter referred to as a non-printing area) that is out of a printing area Ap where printing is performed by ejecting ink from nozzles # 1 to # 180. Is done. In this non-printing area An, in addition to the sensing unit 71, the ink adhered to the nozzles # 1 to # 180 is used as a cleaning mechanism for the nozzles # 1 to # 180 to eliminate nozzle clogging and the like. A wiping device 36 for wiping off and a pump device 35 for sucking ink from the nozzles # 1 to # 180 are provided. The pump device 35 has a cap portion that covers the lower surface 41a of the head 41 provided with the nozzles when the ink is sucked by the pump mechanism, and the cap portion of the head 41 is not printed. It also has a function of covering the lower surface 41a and suppressing drying of ink in the nozzle.

  In the present embodiment, the sensing unit 71 is provided at a position close to the printing area Ap in the non-printing area An, that is, between the printing area Ap and the wiping device 36 and the pump device 35 as shown in FIG. . Thus, when the carriage 31 moves from the printing area Ap to the non-printing area An, it always passes above the sensing unit 71. That is, the ink ejection state can be detected at any time during non-printing when the carriage 31 moves to the non-printing area An.

<Sensing part>
FIG. 11 is a plan view of the sensing unit 71 of this embodiment, and FIG. 12 is a diagram for explaining the ink recovery unit.

  As shown in FIG. 11, the sensing unit 71 of the present embodiment is provided on a substrate 72 formed in a rectangular shape. The substrate 72 is a printed wiring board. The wire 71b of the sensing unit 71 is stretched over the opening 74 formed on the upstream side in the transport direction of the substrate 72 in a tension state along the length direction of the substrate 72, that is, here the transport direction, and the foam member 71a. Is provided so as to include the wire 71 b and cover the entire area of the opening 74. Both ends of the wire 71b are fixed to the edge of the opening 74 by fixing members 76, respectively.

  The ink droplets Ip ejected from the nozzles # 1 to # 180 of the head 41 come into contact with the foaming member 71a of the sensing unit 71 and then penetrate downward into the foaming member 71a. As shown in FIG. After passing through 71, the ink is recovered by the absorber 92 in the ink recovery unit 90 provided below. For example, the ink collection unit 90 may be provided as a groove formed in the platen 24 or the like so as to have a concave cross section.

  In this embodiment, circuit elements 82, 83, and 84 that constitute a protective resistor R 1, a capacitor C, an input resistor R 2, a feedback resistor R 3, an operational amplifier Amp, and the like that constitute the detection circuit 80 are integrally mounted on the substrate 72. ing.

<Ink ejection detection processing timing>
Timing for executing the ink discharge detection process as the liquid discharge detection process includes the following timing. Here, the ink discharge detection process refers to a series of processes for detecting the ink discharge state at each nozzle and notifying the cleaning or the detection result according to the set condition.

(1) During the printing process The ink ejection detection process is executed at an appropriate timing during the printing process. For example, in the case of “bidirectional printing”, when the movement direction is changed, the carriage 31 moves onto the sensing unit 71 and executes the ink ejection detection process of the nozzles # 1 to # 180. As a result, it is possible to avoid the occurrence of a problem in the printed image due to a situation in which ink is not ejected from the nozzles during the printing process.

(2) When the power is turned on When the power is turned on, the ink discharge detection process is executed. When the power is turned on, there is a possibility that ink has not been ejected from the nozzles for a while. In such a case, ink in the nozzles may dry and ink may not be ejected from the nozzles. Further, since the printer 1 may be turned on to perform printing from now on, the ink ejection detection process of the nozzles # 1 to # 180 is executed as one of the processes at the initialization process of the printer 1. By executing the ink ejection detection process at such timing, it is possible to eject a good image by ejecting ink from the nozzles # 1 to # 180.

(3) At the time of paper feeding An operation for feeding the paper S to a predetermined position for printing, that is, an ink discharge detection process is executed at the time of paper feeding. At this timing, when the paper S is fed to print an image, it is possible to detect whether or not the ink is normally ejected. Each time the paper S is fed, an ink ejection detection process is performed. Ink discharge detection processing may be executed every time a predetermined number of sheets are printed at an appropriate interval.

(4) At the time of acquisition of print data The ink discharge detection process is executed when the printer 1 receives the print data from the connected computer 110 such as a personal computer. That is, when printing data is received from the computer 110 and printing is to be executed from now on, it is checked whether or not ink is normally ejected. By executing the ink ejection detection process at such timing, it is possible to eject a good image by ejecting ink from the nozzles # 1 to # 180.

  Note that the ink discharge detection process in the present invention is not necessarily performed at the timings (1) to (4) described above, and the ink discharge detection is performed at a timing other than (1) to (4). Processing may be executed.

<Ink ejection detection process>
The printing system 100 as the liquid ejection apparatus according to the present embodiment allows the cleaning of the nozzles according to the detection result when the nozzles that have not ejected the ink are detected by detecting the ink ejection status. It is possible for the user to set in advance whether or not to do this as information. That is, the user satisfies the conditions by specifying the conditions such as the number of nozzles detected as not ejecting ink and the color of the ink from the input screen as the information input unit displayed by the computer 110. In this case, it is possible to set in advance whether to allow the cleaning to be performed, or to display the detected result on the display device 120 without allowing the cleaning to be performed. is there.

  FIG. 13 is a diagram for explaining an example of a screen for setting conditions in the ink ejection detection process.

  The conditions for the ink discharge detection process are set on the utility screen 94 set on the user interface screen of the printer driver 111. On the utility screen 94, for example, a process selection for selecting whether to perform cleaning as it is or to notify the user when a nozzle that has not ejected ink is detected in the ink ejection detection process. A unit 95 and a condition setting unit 96 for setting a standard condition when selecting whether to perform cleaning or to notify the user are provided. That is, it is possible to set so that neither cleaning nor notification to the user is executed even if a nozzle that does not eject ink is detected when the ink ejection status is detected. This is because, even if there are nozzles that do not eject ink, the image may have little or no effect on the image. This is realized by setting a desired value at an allowable level. Here, when a nozzle that has not ejected ink is detected, the criterion for determining whether to perform cleaning as it is or to notify the user is determined that the ink is not ejected in association with the print mode. It is possible to set the number of nozzles used as a threshold value.

  Specifically, as the process selection unit 95, when the set threshold value is reached, the radio button 95a is associated with each of two items “clean the nozzle” and “notify the detection result”. The user can select the associated process by clicking one of the radio buttons 95a.

  The condition setting unit 96 includes a dialog box 96a for selecting items to be set as conditions, such as the print mode and ink color, and a threshold value for setting the classification for each condition classification corresponding to the selected item. A threshold value input box 96b is arranged.

  Here, when the threshold value is reached, the user clicks the radio button 95a associated with “clean nozzle” and selects the print mode from the dialog box 96a as an item to be set as a condition. A screen on which threshold value input boxes 96b associated with the three categories of “draft mode”, “fast mode”, and “beautiful mode” are arranged is displayed on the display device 120. The user inputs a desired value in the threshold value input box 96b associated with the classification. For example, “10” is input to the threshold value input box 96b associated with “draft mode”, “3” is input to the threshold value input box 96b associated with “fast mode”, It is assumed that “1” is input to the threshold value input box 96b associated with “clean mode”. In this case, when the code indicating the print mode included in the print data is a code indicating “draft mode”, if the number of nozzles that did not eject ink is 9 or less, the nozzle is not cleaned. The printing process is executed or the standby state is entered. In addition, when the code indicating the print mode included in the print data is a code indicating “fast mode”, if the number of nozzles that have not ejected ink is two or less, the print processing is performed without cleaning the nozzles. Is executed or enters a standby state. Further, when the code indicating the print mode included in the print data is a code indicating “clean mode”, if there is even one nozzle that has not ejected ink, the nozzle is set to be cleaned.

  An ink ejection detection process executed in the printing system set as described above will be described. FIG. 14 is a flowchart for explaining an example of the ink ejection detection process.

  In the present embodiment, the nozzle rows 411 (K), 411 (C), 411 (M), and 411 (Y) for four colors can be made to face the sensing unit 71 at the same time. In order to detect which nozzle has not ejected ink, the ink ejection status is individually detected for each nozzle in each nozzle row 411 (K), 411 (C), 411 (M), and 411 (Y). To do. Here, the ink ejection status is detected in the order of black ink nozzle row 411 (K) → cyan ink nozzle row 411 (C) → magenta ink nozzle row 411 (M) → yellow ink nozzle row 411 (Y).

  First, the ink discharge status is sequentially detected from the black ink nozzle row 411 (K) to the yellow ink nozzle row 411 (Y) (S202). The method for detecting the ink discharge status with respect to each color nozzle row is the same, and the method for detecting the ink discharge status will be described in detail later.

  The controller 60 acquires conditions set in advance by the user from the memory (S204), and determines whether or not the detection results satisfy the set conditions (S206). At this time, if the detection result does not satisfy the set condition, that is, if the number of nozzles detected as not discharging ink is smaller than the threshold value, the printer enters a standby state or print processing is performed. Execute (S220). At this time, if the timing of executing the detection process is when the power is turned on, it enters a standby state, and the detection process was executed while trying to execute the print process, such as during print processing, paper feed, or when acquiring print data. In this case, the printing process is executed.

  On the other hand, if the detection result satisfies the set condition, that is, if the number of nozzles detected not to eject ink is equal to or greater than a threshold value, information on cleaning preset by the user Is acquired (S208). If the acquired information is information indicating that cleaning is permitted based on the result of detecting the ink discharge status (S210), the nozzle is cleaned (S212). The cleaning executed at this time may be set in association with the number of nozzles detected as having not ejected ink among cleaning methods such as flushing, wiping, and suction. For example, when the user reaches the threshold value from the process selection unit 95 of the utility screen 94, the user clicks the radio button 95a associated with “clean nozzle” to set the cleaning method. A cleaning method setting screen 97 is displayed, and the nozzles may be cleaned based on the cleaning method set by the user from the cleaning method setting screen 97.

  FIG. 15 is a diagram illustrating an example of the cleaning method setting screen. As shown in the figure, for example, dialog boxes 97a and 97b for setting the number of detected nozzles and the cleaning method are associated with each other. The user sets the number of nozzles to be detected and the cleaning method in association with each other. In this example, flushing is performed when the number of detected nozzles is 1 to 5, wiping is performed when the number is 6 to 20, and suction is performed when the number is 21 or more. Is set to

  After the nozzles are cleaned, the ink discharge status is detected again (S216). If the result of detecting the ink ejection status indicates that the number of nozzles detected as not ejecting ink is smaller than the threshold value (S218), the printer enters a standby state or print processing is executed (S220). As a result of detecting the ink discharge status for the second time, if the number of nozzles detected not to discharge ink is equal to or greater than the threshold value (S218), the nozzles are further cleaned (S212). As described above, after cleaning once, the ink discharge state is detected until the number of nozzles detected not to discharge ink becomes smaller than the threshold value (S216), and then the nozzles are cleaned (S212). Will be repeated.

  On the other hand, if the acquired information is information indicating that the nozzle is not allowed to be cleaned even when a nozzle that has not ejected ink is detected when the ink ejection status is detected, the nozzle is The detection result is notified to the display device 120 without cleaning (S216).

  FIG. 16 is a diagram illustrating an example of a screen for notifying a user or the like of a detection result. As shown in the drawing, the detection result display screen 98 displays, for example, how many nozzles of which color have been detected, the number of detected nozzles for each color, and a cleaning process when the user clicks. A “cleaning” button 98a and an “end” button 98b for closing the detection result display screen and ending the ink discharge detection process. The user can arbitrarily clean the nozzle by referring to the displayed detection result and clicking the “cleaning” button 98a as necessary.

  When the “cleaning” button 98a is clicked (S222), the nozzle is cleaned (S212). After cleaning the nozzles, the ink discharge status is detected again (S216). If the number of nozzles detected not to eject ink is smaller than the threshold value as a result of detecting the ink ejection status (S218), the printer enters a standby state or print processing is executed (S220). If the number of nozzles detected not to eject ink is equal to or greater than the threshold value as a result of detecting the ink ejection status for the second time (S218), cleaning after detecting the ink ejection status Regardless of whether or not is allowed, the nozzle is further cleaned (S212). That is, also in this case, after cleaning once, the ink discharge status is detected until the number of nozzles detected not discharging ink becomes smaller than the threshold value (S216), and then the nozzles are cleaned (S212). ) Is repeated.

<Method of detecting ink discharge status>
FIG. 17 is a flowchart for explaining a method of detecting the ink discharge status.

  When detecting the ink ejection status, the controller 60 first clears a counter assigned to a predetermined area in the memory and sets “N = 0” (S302). Next, after adding “1” to the value N of the counter (S304), an operation of ejecting one ink droplet with the first nozzle is executed (S306). At this time, the controller 60 monitors the output of the detection circuit 80, and determines whether or not a signal indicating that ink has been ejected from the detection circuit 80 is detected within a predetermined time (S308).

  When a signal indicating that ink has been ejected is detected, it is determined whether the counter value N has reached 180 (S310). If the counter value N is less than 180, the counter After adding “1” to the value (S304), an operation of ejecting one drop of ink from the next nozzle (here, the second nozzle) is executed (S306), and ink is ejected from the detection circuit 80. It is determined whether a signal indicating this is detected (S308). In this manner, the process of monitoring the output from the detection circuit 80 is repeated while sequentially changing the nozzles that perform the operation of ejecting ink. If the counter value N has reached 180, processing for acquiring the setting condition is executed (S204 in FIG. 14).

  On the other hand, if a signal indicating that ink has been ejected from the detection circuit 80 within a predetermined time is not detected, the counter value N at this time is stored in the area set as the non-ejection nozzle storage area of the memory 63. This is stored for each ink color (S312). Thereafter, it is determined whether or not the counter value N has reached 180 (S310). If the counter value N is less than 180, “1” is added to the counter value (S304), and then The operation of ejecting one ink droplet from the nozzle is executed (S306), and the process of determining whether or not a signal indicating that ink has been ejected from the detection circuit 80 has been detected (S308) is repeated. If the counter value N has reached 180, processing for acquiring the setting condition is executed (S204 in FIG. 14). That is, the operation for ejecting ink droplets is periodically executed while sequentially changing the nozzles, and the ink droplets are ejected at the next nozzle after the operation of ejecting the ink droplets at a certain nozzle is performed. Whether or not ink is ejected from the certain nozzle is determined based on whether or not the controller 60 detects a signal from the detection circuit 80 within the time before the operation (the predetermined time). In this manner, ink discharge detection is sequentially performed on the black ink nozzle row 411 (K), the cyan ink nozzle row 411 (C), the magenta ink nozzle row 411 (M), and the yellow ink nozzle row 411 (Y).

  That is, the controller 60 acquires the information stored in the non-ejection nozzle storage area, thereby detecting the number of nozzles detected that ink has not been ejected, the ink color, the total number of nozzles from which ink has not been ejected, and the like. It is possible to acquire the information.

  According to the printing system 100 of the present embodiment, when the ink discharge state is detected and it is detected that the ink is not discharged, the information indicating whether or not cleaning is permitted is set in advance. Based on this, it is determined whether or not to clean the nozzle. For this reason, when it is detected that the ink is not ejected, whether or not to clean the nozzles can be set in advance as desired by the user or the like. At this time, if the user is set not to clean the nozzle, unnecessary cleaning that the user does not want is not performed. For this reason, it is possible to prevent waste of ink due to unnecessary cleaning. In addition, since unnecessary cleaning is not performed, it is possible to prevent wasting time.

  In addition, when information indicating that cleaning is not permitted is set, the display device 120 is notified of an event in which ink is not ejected from the nozzle after a nozzle that has not ejected ink is detected. Therefore, the user can recognize that there is a nozzle that does not eject ink. Further, since the number of nozzles detected for each ink color is displayed on the detection result display screen 98 for notifying the detection result, the user can obtain more detailed information, and the cleaning can be performed. It is possible to appropriately determine whether or not it is necessary to do so. Further, since the detection result display screen 98 includes a “cleaning” button 98a for cleaning the nozzle when the user clicks, the user refers to the displayed detection result, and displays “ By clicking the “clean” button 98a, it is possible to arbitrarily clean the nozzle.

  In addition, since information indicating whether or not to allow cleaning of nozzles after detection of nozzles that have not ejected ink is input from the input screen of the computer 110 by the user, nozzles that have not ejected ink The user can set and change whether or not to perform nozzle cleaning after the detection is detected. In addition, since information indicating whether or not cleaning is permitted is input from the input screen of the computer 110, the user can easily set the information.

  Furthermore, since it is determined whether or not ink has been ejected from the nozzle based on the detection result by the ink ejection detection unit 70 and the threshold value for a predetermined condition set in advance, the condition and threshold value to be set are determined. Depending on the setting, it is possible to set the detected level differently. For example, even when there are nozzles that are detected as not ejecting ink to an allowable level, the printing process is set to be executed in the same manner as when there are no nozzles that do not eject ink. It is possible. For this reason, it is possible to set so that the nozzles are not cleaned even when there are nozzles that are detected not to eject ink to an allowable level. Furthermore, since the threshold value to be set can be arbitrarily set, it is possible to set the cleaning according to the user's desire. In other words, it is possible to make a setting with a degree of freedom for an allowable level of a nozzle that is detected as not discharging ink.

  In addition, immediately after cleaning the nozzle, the ink discharge status is detected. When a nozzle that does not discharge ink is detected, the nozzle is cleaned regardless of the set information. After that, it is possible to prevent ink from being ejected from more nozzles than the number allowed by the user. In particular, since cleaning is performed to eject ink from nozzles that did not eject ink, the number of nozzles that do not eject ink after cleaning should be smaller than a set number. For this reason, it is possible to improve the reliability of cleaning by repeating the cleaning of the nozzles based on the set conditions. At this time, by setting the threshold value of the nozzle detected that ink is not ejected to “1”, it is possible to return to ensure that ink is ejected from all nozzles that have not ejected ink. It is.

  Furthermore, the cleaning performed when a nozzle to which ink is not ejected is detected is set to an arbitrary cleaning method among a plurality of types of cleaning methods according to the detection result of the ink ejection detection unit 70. Since it is possible, it is possible to set a cleaning method according to the occurrence state of nozzles that do not eject ink. For this reason, it is possible to clean appropriately according to the generation situation of the nozzle which does not discharge ink.

  FIG. 18 is a diagram illustrating an example of a screen displayed on the display device 120 when the user inputs a command to execute the ink ejection detection process. FIG. 18A shows an example of a screen displayed when the nozzle check for detecting the ink discharge state is executed and the nozzle is set to be cleaned when a nozzle that does not discharge ink is detected. 18B is a diagram showing an example of a screen that is displayed when the execution button is clicked on the screen of FIG. 18A. FIG. 18C is a nozzle check that is performed and a nozzle that has not ejected ink is detected. It is a figure which shows an example of the screen displayed when it sets so that a nozzle may not be automatically cleaned at the time.

  Whether the user performs a so-called nozzle check command to detect the ink discharge status, performs a nozzle check, and automatically performs cleaning when a nozzle that has not discharged ink is detected A cleaning confirmation screen 150 for confirmation may be displayed on the display device 120. If the printer 1 is set with information that allows the nozzle to be cleaned when a nozzle that has not ejected ink is detected, the nozzle is automatically selected after the nozzle check, as shown in FIG. 18A. Notify cleaning. At this time, an “execution” button 150a for executing the nozzle check is arranged on the cleaning confirmation screen 150. When the user allows automatic cleaning after the nozzle check, the user performs an “execute” button. By clicking 150a, the nozzle check is started. At this time, when the user clicks the “execute” button 150a, a condition setting screen 151 as shown in FIG. 18B is displayed, and the user inputs a predetermined value into the condition input box 151a arranged on the condition setting screen 151. After that, the nozzle check may be started by clicking the “execute” button 151b arranged on the condition setting screen 151.

  On the other hand, in the cleaning confirmation screen 150 and the condition setting screen 151, “end” buttons 150b and 151c for canceling the nozzle check are arranged, and when the user does not allow the automatic cleaning after the nozzle check, When the user clicks the “end” buttons 150b and 151c, the cleaning confirmation screen 150 or the condition setting screen 151 is closed and returns to the standby state.

  If the printer 1 is set with information that does not allow the nozzle to be cleaned when a nozzle that has not ejected ink is detected, only the nozzle check is executed as shown in FIG. 18C. Is notified on the nozzle check execution screen 152. In this case, the nozzle check is started by clicking the “execute” button 152a arranged on the nozzle check execution screen 152, and the nozzle check execution screen 152 is closed and waited by clicking the “end” button 152b. Return to state.

=== Other Embodiments ===
The above-described embodiment is mainly described with respect to a printing system, but it is needless to say that the disclosure includes the printer 1, the liquid ejection device, the nozzle cleaning method, and the like. That is, in the above-described embodiment, the liquid ejecting apparatus has been described as a printing system including the ink jet printer 1. However, the ink jet printer 1 determines whether the ink jet is ejected, a notification unit capable of reporting a detection result, for example. If an information input unit or the like capable of inputting information such as conditions for detection is provided, this can be realized even with a single printer. For example, the notification unit is a liquid crystal display provided in a printer, and the information input unit corresponds to an input button or a touch panel provided in the printer.

  In the present embodiment, part or all of the configuration realized by hardware may be replaced by software, and conversely, part of the configuration realized by software may be replaced by hardware.

  In addition, a part of the processing performed on the liquid ejection apparatus (inkjet printer 1) side may be performed on the host computer 110 side, and a dedicated process is performed between the liquid ejection apparatus (inkjet printer 1) and the host computer 110. A part of the processing may be performed by this processing apparatus via an apparatus.

  Moreover, although the printing system etc. as one embodiment were demonstrated, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About the printer>
In the above-described embodiment, the printer 1 has been described as an apparatus for ejecting liquid. However, the present invention is not limited to this. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, liquid vaporizer, organic EL manufacturing apparatus (particularly polymer EL manufacturing apparatus), display manufacturing apparatus, film formation The same technique as that of the present embodiment may be applied to various recording apparatuses to which an ink jet technique is applied such as an apparatus and a DNA chip manufacturing apparatus. These methods and manufacturing methods are also within the scope of application.

<About liquid>
In the above embodiment, the case where ink is used as the liquid has been described as an example. However, the liquid ejection apparatus according to the present invention is not limited to ink, but other liquids such as metal materials and organic materials. Various liquids such as a polymer material (for example, a polymer material), a magnetic material, a conductive material, a wiring material, a film forming material, electronic ink, various processing liquids, and a gene solution may be used instead of the ink.

<About nozzle>
In the above embodiment, ink is ejected using a piezoelectric element. However, the method of ejecting ink is not limited to this. For example, other methods such as a method of generating bubbles in the nozzle by heat may be used.

<About ink>
In the above embodiment, dye ink or pigment ink is ejected from the nozzles of the printer 1 from the nozzles. However, the ink ejected from the nozzle is not limited to such ink.

<Ink colors used for printing>
In the above-described embodiment, multicolor printing in which dots are formed by ejecting four colors of ink of cyan (C), magenta (M), yellow (Y), and black (K) onto the paper S has been described as an example. However, the ink color is not limited to this. For example, in addition to these ink colors, ink such as light cyan (light cyan, LC) and light magenta (light magenta, LM) may be used.
Conversely, monochrome printing may be performed using only one of the four ink colors. <About the carriage moving direction for ejecting ink>
In the above-described embodiment, unidirectional printing in which ink is ejected only when the carriage 31 moves in the forward direction has been described as an example. However, the present invention is not limited to this, and so-called ink ejection is performed when the carriage 31 reciprocates in both directions. Bidirectional printing may be performed.

It is a figure for demonstrating the structure of a printing system. FIG. 3 is a schematic explanatory diagram of basic processing performed by a printer driver. 3 is an explanatory diagram of a user interface of a printer driver. FIG. 1 is a block diagram of an overall configuration of a printer. FIG. 5A is a schematic diagram of the overall configuration of the printer. FIG. 5B is a longitudinal sectional view of the overall configuration of the printer. It is explanatory drawing which shows the arrangement | sequence of the nozzle in the lower surface of a head. It is a flowchart of the process at the time of printing. It is a figure for demonstrating the structure of a liquid discharge detection part. It is explanatory drawing for demonstrating the detection principle of a liquid discharge detection part. It is a figure for demonstrating the installation position of the sensing part of this embodiment. It is a top view of the sensing part of this embodiment. It is a figure for demonstrating an ink collection | recovery part. FIG. 6 is a diagram for explaining an example of a screen for setting conditions in ink discharge detection processing. 6 is a flowchart for explaining an example of ink discharge detection processing; It is a figure which shows an example of the cleaning method setting screen. It is a figure which shows an example of the screen for alert | reporting a detection result to a user. 6 is a flowchart for explaining a method of detecting an ink discharge state. FIG. 18A is a diagram illustrating an example of a cleaning confirmation screen. FIG. 18B is a diagram illustrating an example of a condition setting screen. FIG. 18C is a diagram illustrating an example of a nozzle check execution screen.

Explanation of symbols

1 printer (inkjet printer), 20 transport unit, 21 paper feed roller,
22 transport motor, 23 transport roller, 24 platen, 25 discharge roller,
30 Carriage unit, 31 Carriage, 32 Carriage motor,
40 head units, 41 heads, 41a lower surface of the head, 50 detector groups,
51 Linear encoder, 52 Rotary encoder, 53 Paper detection sensor,
54 optical sensor, 60 controller, 61 interface section,
62 CPU, 63 memory, 64 unit control circuit, 70 ink ejection detection unit,
71 sensing part, 71a foam member, 71b wire, 72 substrate, 74 opening,
76 fixing member, 80 detection circuit, 82, 83, 84 circuit element,
90 ink collection unit, 92 absorber, 94 utility screen,
95 process selection part, 95a radio button,
96 condition setting section, 96a dialog box, 96b threshold value input box,
97 Method setting screen, 97a dialog box, 98 detection result display screen,
98a “clean” button, 98b “end” button, 100 printing system,
110 computer, 111 printer driver, 112 resolution conversion processing unit,
114 color conversion processing unit, 116 halftone processing unit, 118 rasterization processing unit,
120 display device, 130 input device, 140 recording / reproducing device,
150 cleaning confirmation screen, 150a “execute” button, 150b “end” button,
151 condition setting screen, 151a input box, 151b “execute” button,
151c “End” button, 152 nozzle check execution screen,
152a “Execute” button, 152b “End” button, 411 nozzle row,
411 (K) black ink nozzle row, 411 (M) magenta ink nozzle row,
411 (C) cyan ink nozzle row, 411 (Y) yellow ink nozzle row,
Ap printing area, An non-printing area, Ip ink drop, R1 protection resistance,
R2 input resistance, R3 feedback resistance, Amp operational amplifier

Claims (13)

(A) a nozzle for discharging liquid;
(B) a liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle;
(C) a cleaning mechanism for cleaning the nozzle;
(D) To determine whether or not the nozzle is to be cleaned by the cleaning mechanism based on preset information when the nozzle that is not discharging liquid is detected by the liquid discharge detection unit. With the controller
A liquid ejecting apparatus comprising (e). The liquid ejection apparatus according to claim 1,
The liquid ejection apparatus according to claim 1, wherein the information is information indicating whether or not the nozzle is allowed to be cleaned after the nozzle that has not ejected the liquid is detected. The liquid ejection apparatus according to claim 2, wherein
In the case where the information is information indicating that the cleaning is not permitted, the nozzle is not cleaned by the cleaning mechanism after the nozzle that is not ejecting the liquid is detected. apparatus. In the liquid ejection device according to claim 2 or 3,
When an event to be notified occurs, it has a notification unit for notifying the event,
In the case where the information is information indicating that the cleaning is not permitted, an event that the liquid is not discharged from the nozzle is detected in the notification unit after the nozzle that is not discharging the liquid is detected. A liquid ejecting apparatus characterized by notifying. The liquid ejection apparatus according to any one of claims 1 to 4,
An information input unit for inputting the information;
The liquid ejecting apparatus according to claim 1, wherein the information is set when the user inputs the information from the information input unit. The liquid ejection apparatus according to any one of claims 1 to 5,
Whether or not the liquid is discharged from the nozzle is determined based on a detection result by the liquid discharge detection unit and a predetermined threshold set in advance for a predetermined condition. Discharge device. The liquid ejection apparatus according to claim 6, wherein
The liquid discharge apparatus according to claim 1, wherein the threshold value can be arbitrarily set. The liquid ejection apparatus according to any one of claims 1 to 7,
Immediately after cleaning the nozzle, it is detected whether or not liquid is ejected from the nozzle. When the nozzle that is not ejecting liquid is detected, the nozzle is cleaned regardless of the set information. A liquid discharge apparatus characterized by: The liquid ejection apparatus according to any one of claims 1 to 8,
The cleaning mechanism can clean the nozzle by a plurality of types of cleaning methods,
The cleaning that is performed when the nozzle that is not ejecting liquid is detected can be set to any cleaning method among the plurality of types of cleaning methods according to the detection result of the liquid ejection detection unit. A liquid ejecting apparatus comprising: The liquid ejection device according to any one of claims 1 to 9,
The liquid ejecting apparatus, wherein the liquid is ink. (A) a nozzle for discharging liquid;
(B) a liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle;
(C) a cleaning mechanism for cleaning the nozzle;
(D) To determine whether or not the nozzle is to be cleaned by the cleaning mechanism based on preset information when the nozzle that is not discharging liquid is detected by the liquid discharge detection unit. A controller, and
(E) The information is information indicating whether or not to allow the nozzle to be cleaned after the nozzle that is not ejecting liquid is detected;
(F) In the case where the information is information indicating that the cleaning is not permitted, the nozzle is not cleaned by the cleaning mechanism after the nozzle that is not ejecting liquid is detected;
(G) When an event to be notified occurs, it has a notification unit for notifying the event,
In the case where the information is information indicating that the cleaning is not permitted, an event that the liquid is not discharged from the nozzle is detected in the notification unit after the nozzle that is not discharging the liquid is detected. Inform,
(H) having an information input unit for inputting the information;
When the user inputs the information from the information input unit, the information is set,
(I) Whether or not the liquid is discharged from the nozzle is determined based on a detection result by the liquid discharge detection unit and a predetermined threshold value set in advance for a predetermined condition,
(J) The threshold value can be arbitrarily set;
(K) Immediately after cleaning the nozzle, it is detected whether or not liquid is ejected from the nozzle. When the nozzle that is not ejecting liquid is detected, the nozzle is not related to the set information. Clean the nozzle,
(L) The cleaning mechanism can clean the nozzle by a plurality of types of cleaning methods.
The cleaning that is performed when the nozzle that is not ejecting liquid is detected can be set to any cleaning method among the plurality of types of cleaning methods according to the detection result of the liquid ejection detection unit. Yes,
(M) The liquid ejection apparatus, wherein the liquid is ink. A nozzle for discharging liquid;
A liquid discharge detection unit for detecting whether or not liquid is discharged from the nozzle;
A liquid ejection device having a cleaning mechanism for cleaning the nozzle,
Implementing a function of determining whether or not to clean the nozzle by the cleaning mechanism based on preset information when the nozzle from which no liquid is discharged is detected by the liquid discharge detection unit. Computer program for. Detecting whether or not liquid has been discharged from a nozzle for discharging liquid;
Determining whether to clean the nozzles based on preset information when the nozzles that are not ejecting liquid are detected;
A nozzle cleaning method characterized by comprising:

Images