JP2005074698A - Ejection inspecting device, ejection inspecting method, and printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a pattern for an ejection inspection by eliminating influence, for example, of an error of mounting of a sensor. <P>SOLUTION: The ejection inspecting device is equipped with a plurality of ink ejection parts for performing recording on a medium by using ink, and the sensor for detecting the pattern which is formed by the ink ejection parts. The ejection inspection for the ink ejection parts is performed according to the result of detection by the sensor when a detecting position of the sensor and the pattern for the inspection are relatively moved in the first direction. Before the ejection inspection, the ink ejection parts form a pattern for adjustment on the medium; the detecting position of the sensor and the pattern for the adjustment are relatively moved in the second direction; and a second-direction adjusted value is acquired according to the result of the detection by the sensor in this case. The ink ejection parts form the pattern for the adjustment on the medium. The detecting position of the sensor and the pattern for the adjustment are relatively moved in the first direction, and a first-direction adjusted value is acquired according to the result of the detection by the sensor in this case. The ejection inspection is performed by means of the acquired first-direction and second-direction adjusted values. Relative movement speeds of the detecting position of the sensor and the pattern for the adjustment when the second adjusted value is acquired are lower than relative movement speeds when the first adjusted value is acquired. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge inspection apparatus, a discharge inspection method, and a printing system.

Inkjet printers are known as printing apparatuses that perform printing by discharging ink onto various media such as paper, cloth, and film. This inkjet printer performs printing by ejecting ink from nozzles to form dots on a medium.
However, the nozzle may be clogged due to ink sticking or the like, and the ink may not be ejected from the nozzle. If there are nozzles that cannot eject ink, the image quality of the printed image will deteriorate.
Therefore, in order to detect the presence or absence of ink that cannot be ejected, a test pattern is formed by a nozzle, the test pattern is detected by a sensor, and a nozzle ejection test is performed.
JP-A-11-240191

However, the detection accuracy of the inspection pattern may decrease due to the influence of the sensor mounting error and the like.
Accordingly, an object of the present invention is to remove the influence of a sensor mounting error or the like and to accurately detect a discharge inspection pattern.

  A main invention for achieving the above object includes: a plurality of ink ejection portions that perform recording on a medium using ink; and a sensor that detects a pattern formed by the ink ejection portion, and a detection position of the sensor. The present invention relates to a discharge inspection apparatus that performs a discharge inspection of the ink discharge portion based on a detection result of a sensor when the inspection pattern is relatively moved in a first direction. Before the ejection inspection, the ink ejection unit forms an adjustment pattern on the medium, and the detection position of the sensor and the adjustment pattern are moved relative to each other in the second direction. Based on the detection result, a second adjustment value is acquired, and the detection position of the sensor and the adjustment pattern are moved relative to each other in the first direction. Based on the detection result of the sensor at this time, the first adjustment is performed. In the discharge inspection apparatus that performs the discharge inspection using the acquired first adjustment value and the second adjustment value, the detection position of the sensor and the adjustment when acquiring the second adjustment value The relative movement speed with respect to the pattern for use is slower than the relative movement speed when the first adjustment value is acquired.

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

  According to the present invention, it is possible to remove the influence of a sensor mounting error and the like, and to accurately detect a discharge inspection pattern.

=== Summary of disclosure ===
At least the following matters will become clear from the description of the present specification and the accompanying drawings.
A plurality of ink ejection units that perform recording on a medium using ink;
A sensor for detecting a pattern formed by the ink ejection unit;
With
A discharge inspection apparatus that performs a discharge inspection of the ink discharge unit based on a detection result of the sensor when the detection position of the sensor and the inspection pattern are relatively moved in a first direction;
Before the discharge inspection,
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
In the discharge inspection apparatus that performs the discharge inspection using the acquired first direction adjustment value and the second direction adjustment value,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A discharge inspection apparatus characterized by that.
According to such a discharge inspection apparatus, the discharge inspection can be performed with high accuracy. Moreover, since the moving speed of the detection spot can be increased when acquiring the first direction adjustment value, the time required for acquiring the adjustment value can be shortened.

  In this discharge inspection apparatus, the relative movement speed between the detection position of the sensor when acquiring the first direction adjustment value and the adjustment pattern is the detection position of the sensor during the discharge inspection. It is desirable that the speed is the same as the relative movement speed of the inspection pattern. Thereby, during the ejection inspection, the influence of the mounting error and the influence other than the mounting error (for example, the influence of the delay of the output signal) can be removed together using the scanning direction adjustment value. As a result, the ejection inspection pattern can be detected with high accuracy.

  In such a discharge inspection apparatus, it is preferable that the sensor has a low-pass filter. Thus, noise can be removed, and the influence of the mounting error and the influence of the delay of the output signal can be removed together, so that the discharge inspection can be performed with high accuracy.

  In this discharge inspection apparatus, it is preferable that the first direction adjustment value is acquired by adjusting the positions of the sensor and the adjustment pattern based on the acquired second direction adjustment value. As a result, the adjustment process can be performed under the same conditions as in the ejection inspection, and the ejection inspection can be performed with high accuracy.

  The discharge inspection apparatus further includes a transport unit that transports the medium in the second direction, and the second direction is based on a detection result of the sensor when the transport unit is transporting the medium. It is desirable to obtain an adjustment value. Accordingly, when the transport unit transports the paper, the detection position of the downstream optical sensor 55 moves in the transport direction relative to the paper, so that the downstream optical when the detection spot SP passes through the blank pattern 751 is detected. The second direction adjustment value can be acquired based on the detection result of the sensor. Further, it is preferable that the transport unit is controlled during the ejection inspection based on the second direction adjustment value. Thereby, the discharge inspection can be performed with high accuracy. Further, it is preferable that a transport amount from when the ink ejection unit forms the test pattern to when the sensor detects the test pattern is controlled based on the second direction adjustment value. Thereby, the discharge inspection can be performed with high accuracy.

  In this discharge inspection apparatus, it is preferable that the non-discharge nozzle is specified based on the detection result of the sensor that has detected the inspection pattern and the first direction adjustment value. Thereby, a non-ejection nozzle can be specified accurately.

  In this ejection inspection apparatus, it is preferable that the adjustment pattern is a pattern having the same configuration as the inspection pattern. Thereby, the discharge inspection can be performed with high accuracy. Further, the adjustment pattern is preferably a pattern created without ejecting ink from a predetermined ink ejection portion of the plurality of ink ejection portions. As a result, the adjustment process is performed with a pattern having the same configuration as the pattern for ejection inspection when the non-ejection nozzles actually exist, so that the ejection inspection can be performed with high accuracy. Further, the inspection pattern is a pattern in which a predetermined area of the medium is filled with the ink, and the adjustment pattern is a pattern in which a blank pattern is formed in a predetermined area of the inspection pattern. preferable. As a result, the adjustment process is performed with a pattern having the same configuration as the pattern for ejection inspection when the non-ejection nozzles actually exist, so that the ejection inspection can be performed with high accuracy. Further, the inspection pattern is a pattern in which the plurality of ink discharge portions respectively form pattern pieces on the medium, and the adjustment pattern is a pattern in which a predetermined pattern piece of the inspection pattern is omitted. Is preferred. As a result, the adjustment process is performed with a pattern having the same configuration as the pattern for ejection inspection when the non-ejection nozzles actually exist, so that the ejection inspection can be performed with high accuracy.

A test pattern is formed on a medium by a plurality of ink ejection portions,
A discharge method for performing a discharge inspection of the ink discharge unit based on a detection result of the sensor when a detection position of the sensor and a test pattern are relatively moved in a first direction,
Before the discharge inspection,
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
In the ejection inspection method for performing the ejection inspection using the acquired first direction adjustment value and the second direction adjustment value,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A discharge inspection method characterized by the above.
According to such a discharge inspection method, the discharge inspection can be performed with high accuracy. Moreover, since the moving speed of the detection spot can be increased when acquiring the first direction adjustment value, the time required for acquiring the adjustment value can be shortened.

A printing system comprising a computer and a printing device,
The printing apparatus includes:
A plurality of ink ejection units that perform recording on a medium using ink;
A sensor for detecting a pattern formed by the ink ejection unit;
With
A printing apparatus that performs a discharge inspection of the ink discharge unit based on a detection result of the sensor when the detection position of the sensor and a test pattern are relatively moved in a first direction,
Before the ejection inspection, the printing device
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
Using the acquired first direction adjustment value and the second direction adjustment value, the discharge inspection is performed,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A printing system characterized by that.
According to such a printing system, the discharge inspection can be performed with high accuracy. Moreover, since the moving speed of the detection spot can be increased when acquiring the first direction adjustment value, the time required for acquiring the adjustment value can be shortened.

=== Configuration of Printing System ===
Next, an embodiment of a printing system (computer system) will be described with reference to the drawings. However, the description of the following embodiments includes embodiments relating to a computer program and a recording medium on which the computer program is recorded.

  FIG. 1 is an explanatory diagram showing an external configuration of a printing system. The printing system 100 includes a printer 1, a computer 110, a display device 120, an input device 130, and a recording / reproducing device 140. The printer 1 is a printing apparatus that prints an image on a medium such as paper, cloth, or film. The computer 110 is electrically connected to the printer 1 and outputs print data corresponding to the image to be printed to the printer 1 in order to cause the printer 1 to print an image. The display device 120 has a display and displays a user interface such as an application program or a printer driver. The input device 130 is, for example, a keyboard 130A or a mouse 130B, and is used for operating an application program, setting a printer driver, or the like along a user interface displayed on the display device 120. As the recording / reproducing device 140, for example, a flexible disk drive device 140A or a CD-ROM drive device 140B is used.

  A printer driver is installed in the computer 110. The printer driver is a program for realizing the function of displaying the user interface on the display device 120 and the function of converting the image data output from the application program into print data. This printer driver is recorded on a recording medium (computer-readable recording medium) such as a flexible disk FD or a CD-ROM. Alternatively, the printer driver can be downloaded to the computer 110 via the Internet. In addition, this program is comprised from the code | cord | chord for implement | achieving various functions.

  The “printing apparatus” means the printer 1 in a narrow sense, but means a system of the printer 1 and the computer 110 in a broad sense.

=== Printer driver ===
<About the printer driver>
FIG. 2 is a schematic explanatory diagram of basic processing performed by the printer driver. The components already described are given the same reference numerals, and the description thereof is omitted.
In the computer 110, computer programs such as a video driver 112, an application program 114, and a printer driver 116 operate under an operating system installed in the computer. The video driver 112 has a function of displaying, for example, a user interface on the display device 120 in accordance with display commands from the application program 114 and the printer driver 116. The application program 114 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 114 via the user interface of the application program 114. Upon receiving a print instruction, the application program 114 outputs image data to the printer driver 116.

  The printer driver 116 receives image data from the application program 114, converts the image data into print data, and outputs the print data to the printer. Here, the print data is data in a format that can be interpreted by the printer 1, and is data having various command data and pixel data. Here, the command data is data for instructing the printer 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 formed at positions on the paper corresponding to a certain pixel (such as dot color and size). Data).

  The printer driver 116 performs resolution conversion processing, color conversion processing, halftone processing, rasterization processing, and the like in order to convert image data output from the application program 114 into print data. The resolution conversion process is a process for converting image data (text data, image data, etc.) output from the application program 114 into a resolution for printing on paper. The color conversion process is a process for converting RGB data into CMYK data represented by a CMYK color space. The halftone process is a process for converting high gradation number data into gradation number data that can be formed by a printer. The rasterization process is a process of changing matrix image data in the order of data to be transferred to the printer. The rasterized data is output to the printer as pixel data included in the print data.

<About printer driver settings>
FIG. 3 is an explanatory diagram of the user interface of the printer driver. The user interface of this printer driver is displayed on the display device via the video driver 112. The user can make various settings of the printer driver using the input device 130.

The user can select a print mode from this screen. For example, the user can select the high-speed print mode or the fine print mode as the print mode. Then, the printer driver converts the image data into print data so as to have a format corresponding to the selected print mode.
Further, the user can select the printing resolution (dot interval when printing) from this screen. For example, the user can select 720 dpi or 360 dpi as the print resolution from this screen. Then, the printer driver performs resolution conversion processing according to the selected resolution, and converts the image data into print data.

  Further, the user can select a printing paper used for printing from this screen. For example, the user can select plain paper or glossy paper as the printing paper. If the paper type (paper type) is different, the ink bleeding and drying methods are also different, so the ink amount suitable for printing also differs. Therefore, the printer driver converts the image data into print data according to the selected paper type. Note that “plain paper” is paper that does not have a coating layer on its surface and is made of only a base material (base). On the other hand, “glossy paper” is paper in which a coating layer is provided on the surface of a substrate. When ink lands on the glossy paper, the ink appropriately penetrates into the coat layer, so that high-quality image quality can be obtained by printing a photograph on the glossy paper.

  As described above, the printer driver converts the image data into print data according to the conditions set via the user interface. The user can make various settings of the printer driver from this screen, and can also know the remaining amount of ink in the cartridge.

=== Configuration of Printer ===
<Inkjet printer configuration>
FIG. 4 is a block diagram of the overall configuration of the printer of this embodiment. FIG. 5 is a schematic diagram of the overall configuration of the printer of this embodiment. FIG. 6 is a cross-sectional view of the overall configuration of the printer of this embodiment. Hereinafter, the basic configuration of the printer of this embodiment will be described.

  The printer of this embodiment 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 forms an image on paper. 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 that receives the detection result from the detector group 50 controls each unit based on the detection result.

  The transport unit 20 is for feeding a medium (for example, the paper S) to a printable position and transporting the paper by a predetermined transport amount in a predetermined direction (hereinafter referred to as a transport direction) during printing. That is, the transport unit 20 functions as a transport mechanism (transport means) that transports paper. 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. However, in order for the transport unit 20 to function as a transport mechanism, all of these components are not necessarily required. The paper feed roller 21 is a roller for automatically feeding the paper inserted into the paper insertion slot into the printer. The paper feed roller 21 has a D-shaped cross section, and the length of the circumferential portion is set to be longer than the transport distance to the transport roller 23. 23 can be conveyed. The transport motor 22 is a motor for transporting paper in the transport direction, and is constituted by a DC motor. The transport roller 23 is a roller that transports the paper S fed by the paper feed roller 21 to a printable area, and is driven by the transport motor 22. The platen 24 supports the paper S being printed. The paper discharge roller 25 is a roller for discharging the printed paper S to the outside of the printer. The paper discharge roller 25 rotates in synchronization with the transport roller 23.

  The carriage unit 30 is for moving (scanning) the head in a predetermined direction (hereinafter referred to as a scanning 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 in the scanning direction. (Thus, the head moves along the scanning direction.) 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 scanning direction, and is constituted by a DC motor.

  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 that are ink discharge portions, and discharges ink intermittently from each nozzle. The head 41 is provided on the carriage 31. Therefore, when the carriage 31 moves in the scanning direction, the head 41 also moves in the scanning direction. Then, when the head 41 is intermittently ejected while moving in the scanning direction, dot lines (raster lines) along the scanning direction are formed on the paper.

  The detector group 50 includes a linear encoder 51, a rotary encoder 52, a paper detection sensor 53, an upstream optical sensor 54, and the like. The linear encoder 51 is for detecting the position of the carriage 31 in the scanning 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 paper detection sensor 53 is provided at a position where the position of the leading edge of the paper can be detected while the paper feed roller 21 feeds the paper toward the transport roller 23. The paper detection sensor 53 is a mechanical sensor that detects the leading edge of the paper by a mechanical mechanism. More specifically, the paper detection sensor 53 has a lever that can rotate in the transport direction, and this lever is disposed so as to protrude into the paper transport path. For this reason, since the leading edge of the paper comes into contact with the lever and the lever is rotated, the paper detection sensor 53 detects the position of the leading edge of the paper by detecting the movement of the lever. The upstream optical sensor 54 is attached to the carriage 31. The upstream optical sensor 54 detects the presence or absence of paper by the light receiving unit detecting reflected light of the light emitted from the light emitting unit to the paper. The upstream optical sensor 54 detects the position of the edge of the paper while being moved by the carriage 41. The upstream optical sensor 54 optically detects the edge of the paper, and therefore has higher detection accuracy than the mechanical paper detection sensor 53.

  In the present embodiment, the detector group 50 includes a downstream optical sensor 55. The downstream optical sensor 55 is attached to the carriage 31. The downstream optical sensor 55 detects the pattern formed on the paper when the light receiving unit detects the reflected light of the light irradiated on the paper from the light emitting unit. The configuration of the downstream optical sensor 55 will be described in detail later.

  The controller 60 is a control unit (control means) 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 the program of the CPU 62, a work area, and the like, and has storage means 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.

<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.

  The controller 60 receives a print command from the computer 110 via the interface unit 61 (S001). This print command is included in the header of print data transmitted from the computer 110. Then, the controller 60 analyzes the contents of various commands included in the received print data, and performs the following paper feed processing, transport processing, ink ejection processing, and the like using each unit.

  First, the controller 60 performs a paper feed process (S002). The paper feed process is a process of 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 sends the paper to be printed to the transport roller 23. The controller 60 rotates the transport roller 23 to position the paper fed from the paper feed roller 21 at the print start position. When the paper is positioned at the print start position, at least some of the nozzles of the head 41 are opposed to the paper.

  Next, the controller 60 performs dot formation processing (S003). The dot formation process is a process for forming dots on paper by intermittently ejecting ink from a head that moves in the scanning direction. The controller 60 drives the carriage motor 32 to move the carriage 31 in the scanning direction. Then, the controller 60 ejects ink from the head based on the print data while the carriage 31 is moving. When ink droplets ejected from the head land on the paper, dots are formed on the paper.

  Next, the controller 60 performs a conveyance process (S004). The conveyance process is a process of moving the paper relative to the head along the conveyance direction. The controller 60 drives the carry motor and rotates the carry roller to carry the paper in the carrying direction. By this carrying process, the head 41 can form dots at positions different from the positions of the dots formed by the previous dot formation process.

  Next, the controller 60 determines whether or not to discharge the paper being printed (S005). If there is still data to be printed 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 data to be printed, and gradually prints an image composed of dots on paper. When there is no more data for printing on the paper being printed, the controller 60 discharges the paper. The controller 60 discharges the printed paper to the outside 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.

  Next, the controller 60 determines whether or not to continue printing (S006). If printing is to be performed on the next paper, printing is continued and the paper feeding process for the next paper is started. If printing is not performed on the next paper, the printing operation is terminated.

<About nozzle>
FIG. 8 is an explanatory diagram of the configuration of the lower surface of the carriage. A head 41, an upstream optical sensor 54, and a downstream optical sensor 55 are provided on the lower surface of the carriage.

  On the lower surface of the head 41, a yellow ink nozzle group Y, a magenta ink nozzle group M, a cyan ink nozzle group C, a matte black ink nozzle group MBk, a photo black ink nozzle group PBk, and a red ink nozzle group R A violet ink nozzle group V and a clear ink nozzle group CL are formed. Each nozzle group includes a plurality (180 in this embodiment) of nozzles that are ejection openings for ejecting each ink.

  The plurality of nozzles of each nozzle group are aligned at a constant interval (nozzle pitch: k · D) along the transport direction. Here, D is the minimum dot pitch in the carrying direction (that is, the interval at the highest resolution of dots formed on the 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), k = 4.

  The nozzles in each nozzle group are assigned a lower number in the downstream nozzle (# 1 to # 180). That is, the nozzle # 1 is located downstream of the nozzle # 180 in the transport direction. Each nozzle is provided with a piezo element (not shown) as a drive element for driving each nozzle to eject ink droplets.

  The upstream optical sensor 54 is provided at substantially the same position as the most upstream nozzle # 180 with respect to the position in the transport direction. On the other hand, the downstream optical sensor 55 is provided further downstream than the most downstream nozzle # 1 with respect to the position in the transport direction.

<Color ink and clear ink>
Here, the color inks are yellow (Y), magenta (M), cyan (C), black (a general term for matte black (MBk) and photo black (PBk)), red (R), violet (V, “ Colored non-transparent ink such as “blue”. These color inks are composed of dye ink, pigment ink, and the like.

  Clear ink is generally colorless and transparent ink as opposed to colored ink. Here, it is not limited to such colorless and transparent, but widely refers to inks that are difficult to detect using diffuse reflected light when ejected onto a medium, even if they are colored and transparent or colored and non-transparent. That is, colored non-transparent color inks such as yellow (Y), magenta (M), cyan (C), and black (Bk) described above use an optical sensor when diffusely reflected light is used when attached to a medium. On the other hand, when the clear ink is attached to the medium, it is extremely difficult to specify whether or not the clear ink is attached even if diffuse reflected light is used. When this clear ink is attached to glossy paper, it has an effect of increasing the glossiness of the attached portion. However, even if this clear ink is attached to plain paper, the glossiness of the attached portion is not so improved.

=== Configuration of Optical Sensor ===
<Upstream optical sensor>
FIG. 9 is an explanatory diagram of the configuration of the upstream optical sensor 54. The horizontal direction in the figure is the transport direction, and the direction perpendicular to the paper surface in the figure is the scanning direction.
The upstream optical sensor 54 is a reflective optical sensor having a light emitting unit 541 and a light receiving unit 542. The light emitting unit 541 has, for example, an infrared LED (light emitting diode), and irradiates the paper with light. The light receiving unit 542 includes, for example, a phototransistor, and detects reflected light of light irradiated on the paper from the light emitting unit.
The light emitting unit 541 of the upstream optical sensor 54 irradiates the paper S with light obliquely. The light receiving unit 542 of the upstream optical sensor 54 is provided at a position perpendicular to the paper S. Therefore, the light receiving unit 542 receives the diffuse reflected light of the light emitted from the light emitting unit 541 onto the paper.
When there is no paper S in the region where the light emitting unit 541 emits light, the amount of reflected light received by the light receiving unit 542 decreases. When the paper S is in an area where the light emitting unit 541 emits light, the amount of reflected light received by the light receiving unit 542 increases. That is, since the amount of light received by the light receiving unit 542 varies depending on the presence or absence of paper, the controller can detect the presence or absence of paper based on the signal output from the light receiving unit 542.

<About downstream optical sensors>
FIG. 10 is an explanatory diagram of the configuration of the downstream optical sensor 55. The horizontal direction in the figure is the scanning direction, and the direction perpendicular to the paper surface in the figure is the transport direction.
The downstream optical sensor 55 is a sensor for detecting a pattern formed on the paper. The pattern detection using the downstream optical sensor 55 will be described later.

The downstream optical sensor 55 is a reflective optical sensor having a light emitting unit 551, a first light receiving unit 552, and a second light receiving unit 553. The light emitting unit 551 has, for example, a white LED (light emitting diode), and irradiates paper with light. The first light receiving unit 552 and the second light receiving unit 553 have, for example, phototransistors, and detect reflected light of light irradiated on the paper from the light emitting unit.
The light emitting unit 551 of the downstream optical sensor 55 irradiates the paper S with light obliquely. Further, the first light receiving unit 552 of the downstream optical sensor 55 is provided at a position perpendicular to the paper S. Therefore, the first light receiving unit 552 receives the diffuse reflected light of the light irradiated on the paper from the light emitting unit, like the light receiving unit 542 of the upstream optical sensor 54 described above. On the other hand, the second light receiving unit 553 of the downstream optical sensor 55 is provided at a position symmetrical to the light emitting unit 553, and receives light emitted obliquely from the paper. Therefore, the second light receiving unit 553 receives specularly reflected light emitted from the light emitting unit 551 onto the paper.

When there is a dark pattern at the position of the detection spot of the downstream optical sensor 55 (the area on the paper irradiated with light from the light emitting unit 551), the amount of light received by the first light receiving unit 552 is reduced. On the other hand, when there is a light-density pattern at the position of the detection spot of the downstream optical sensor 55 (including the case where no pattern is formed), the amount of light received by the first light receiving unit 552 increases. That is, since the amount of light received by the first light receiving unit 552 varies depending on the density of the pattern, the controller determines the density of the pattern in the detection spot (or the presence / absence of the pattern) based on the signal output from the first light receiving unit 552. Can be detected. In addition, since the light emission part 551 of a downstream optical sensor is irradiating the light by white LED on paper, it can detect the pattern of a different color.
In addition, when there is an object with low gloss at the position of the detection spot of the downstream optical sensor 55, the amount of light received by the second light receiving unit 553 decreases. On the other hand, when the position of the detection spot of the downstream optical sensor 55 is highly glossy, the amount of light received by the second light receiving unit 553 increases. That is, since the amount of light received by the second light receiving unit 553 varies depending on the level of glossiness, the controller detects the level of glossiness in the detection spot based on the signal output from the second light receiving unit 553. Can do.

=== Discharge Inspection Procedure ===
The ink jet printer 1 can inspect whether the color ink and the clear ink of each color described above are properly ejected from the nozzles. In this ejection inspection, color ink and clear ink are actually ejected from the nozzles to form a predetermined inspection pattern on the paper. Then, as a result of the inspection, when a discharge failure such as clogging is found in the nozzle, a process for cleaning the nozzle is executed.

FIG. 11 shows an example of a discharge inspection procedure.
First, the type of paper on which the test pattern is printed is determined. In this embodiment, it is determined whether the paper type is plain paper or glossy paper. The paper on which the test pattern is printed is preferably equal to the type of paper printed after the test. The method for determining the paper type will be described in detail later. In the case of clear ink ejection inspection, ejection inspection is performed according to the type of paper. However, in the case of color ink ejection inspection, the same ejection inspection processing is performed regardless of the type of paper. In the present embodiment, a discharge inspection in the case of color ink will be described.

Next, color ink or clear ink is ejected toward the medium to form a predetermined inspection pattern (S102). The inspection pattern formed here will be described in detail later.
Next, the formed inspection pattern is inspected (S103). This inspection is performed using the downstream optical sensor 55 mounted on the carriage. The inspection pattern inspection using the downstream optical sensor 55 will be described in detail later.
After checking in this way, the presence or absence of ejection failure of color ink or clear ink is determined based on the detection result from the downstream optical sensor 55 (S104). If it is determined that there is a discharge failure, nozzle cleaning is executed (S105). This nozzle cleaning will be described in detail later. On the other hand, if no discharge failure is found, the process ends.

=== Distinguishing method of paper type ===
The following two types are conceivable as methods for determining the type of paper. However, the method for determining the paper type is not limited to these, and other methods may be used. In short, when the printer prints the test pattern on paper, it is only necessary to acquire information on the type of the paper.

<About the method of acquiring paper type information from an external device>
As described in the printer driver setting described above, the user can select the printing paper used for printing from the printer driver setting screen. If the user has selected plain paper when setting the printer driver, the type of paper fed by the printer is usually plain paper. If the user selects glossy paper when setting the printer driver, the type of paper fed by the printer is normally glossy paper. Information regarding the paper type (paper type information) set by the printer driver is transmitted together with the print data when the print data is transmitted from the computer to the printer. The printer can acquire the paper type information based on the information transmitted from the computer.

<How the optical sensor determines the paper type>
Different paper types have different light reflectivities. For example, the amount of reflected light differs between plain paper and glossy paper even if the same amount of light is incident on the surface. Therefore, the printer transports the paper to the position of the upstream optical sensor 54 or the downstream optical sensor 55 and uses the upstream optical sensor 54 or the downstream optical sensor 55 to determine the amount of reflected light reflected on the paper. Thus, the type of paper can be determined. In this case, the printer stores in advance a reference table indicating the relationship between the output result of the upstream optical sensor 54 or the downstream optical sensor 55 and the paper type, and refers to the reference table using the output result of the optical sensor as a key. And discriminate the type of paper.

=== Method for Forming Color Ink Inspection Pattern ===
<About inspection pattern>
FIG. 12 is an overall conceptual diagram of an inspection pattern group 70 used for ejection inspection of nozzles that eject color ink. FIG. 13A is an explanatory diagram of the inspection pattern 71 constituting the inspection pattern group 70. FIG. 13B is an example of an inspection pattern when there are nozzles that do not eject color ink. FIG. 14 is an explanatory diagram of the configuration of the color ink test pattern 71. FIG. 15 is an explanatory diagram of the block pattern BL constituting the inspection pattern 71.
The inspection pattern group 70 includes a plurality of inspection patterns 71. The plurality of inspection patterns 71 are formed adjacent to each other along the scanning direction. Each inspection pattern is divided for each color ink. For example, the test pattern 71 described as “Y” in FIG. 12 is composed of only yellow ink. That is, in the drawing, the test pattern 71 described as “Y” is formed by nozzles that discharge yellow ink. As will be described later, the test pattern 71 is used for discharge inspection of nozzles that discharge yellow ink. The test patterns 71 of other colors are configured in the same manner.

  One inspection pattern 71 includes an inspection target area 72 and a non-inspection target area 73. The inspection target area 72 includes nine block patterns BL in the scanning direction and twenty block patterns BL in the transport direction, and is configured by a total of 180 block patterns BL. As will be described later, one block pattern BL corresponds to one nozzle. Therefore, the 180 block patterns BL in the inspection target area 72 are patterns for inspecting 180 nozzles. The non-inspection target area 73 is formed so as to surround the inspection target area 72. The non-inspection target area 73 includes a transport direction upper inspection margin 731, a transport direction lower inspection margin 732, a scanning direction left part inspection margin 733, and a scanning direction right part inspection margin 734. Each inspection margin is provided in order to prevent erroneous detection when the downstream optical sensor 55 detects the block pattern BL in the inspection target region 72. That is, when there is no non-inspection target region around the inspection target region 72, a block pattern formed inside the inspection target region and surrounded by another block pattern, and another block pattern formed at the outer edge of the inspection target region Since the detection result is different from the block pattern not surrounded by the block pattern, the block pattern is also formed outside the detection target region 72.

  Each block pattern BL is a rectangular pattern composed of 56 dots at 1/720 inch intervals along the scanning direction and 18 dots at 1/360 inch intervals along the transport direction. Dots in the same block pattern BL are formed by ink droplets ejected from the same nozzle. For example, the block pattern BL described as “# 1” in FIG. 14 is formed only by ink droplets ejected from the nozzle # 1. Thus, each block pattern BL is associated with a nozzle that forms the block pattern BL. If there are ink non-ejection nozzles (no nozzles that do not eject ink), a rectangular blank pattern is generated in the test pattern 71 as shown in FIG. 13B. That is, by detecting the presence or absence of a blank pattern, it is possible to inspect whether or not there is an ink non-ejection nozzle. Further, if the position of the blank pattern can be detected, the ink non-ejection nozzle can be specified.

<Regarding the method for forming the inspection pattern>
FIG. 16 is an explanatory diagram of a method for forming eleven block patterns in the first row of the inspection pattern 71. This figure shows dot rows (56 dot rows arranged in the scanning direction of FIG. 15) formed by a single dot formation process (S003: see FIG. 7). Further, the numbers on the left side of the figure indicate nozzle numbers, and the positions of the nozzle numbers indicate the positions of the nozzles with respect to the block pattern BL.

  First, the paper is fed so that the tip position on the downstream side in the transport direction of the inspection target region 72 faces the nozzle # 9. Thereafter, the printer executes a first dot formation process and intermittently ejects ink from nozzle # 9 at a position where the carriage 31 reaches a predetermined position. As a result, a dot row is formed at a downstream position of the block pattern corresponding to the nozzle # 9.

  Next, the printer transports the paper by the transport unit by half the nozzle pitch (1/360 inch). The printer then executes the second dot formation process and intermittently ejects ink from nozzle # 9 at the position where the carriage has reached a predetermined position. Thereby, a dot row is formed adjacent to the upstream side in the transport direction of the dot row formed by the first dot formation process.

  Next, the printer transports the paper by the transport unit by half the nozzle pitch. Then, the printer executes a third dot formation process. In the third dot formation process, the printer intermittently ejects ink from nozzle # 9 and nozzle # 8. A dot row is formed by the ink ejected from the nozzle # 9 adjacent to the upstream side in the transport direction of the dot row formed by the second dot formation process. In addition, a dot row is formed at a downstream position of the block pattern BL corresponding to the nozzle # 8 by the ink ejected from the nozzle # 8.

  Next, the printer transports the paper by the transport unit by half the nozzle pitch. Then, the printer executes a fourth dot formation process. Even in the fourth dot formation process, the printer intermittently ejects ink from nozzle # 9 and nozzle # 8, and is adjacent to the upstream side in the transport direction of the dot row formed by the third dot formation process. A row is formed. In this way, the dot formation process and the conveyance process are executed to form the dot row twice, and the nozzles for ejecting ink are increased one by one from the upstream side in the conveyance direction every two dot formation processes.

In the 18th dot formation process, a block pattern corresponding to nozzle # 9 is completed. Therefore, in the 19th dot formation process, the ejection of ink from the nozzle # 9 is stopped. Thereafter, the ink ejection is stopped one by one from the nozzle located upstream in the transport direction every two dot formation processes.
In the 34th dot formation process, 11 block patterns in the first row of the inspection target area 72 are completed.

In the description so far, the method of forming 11 block patterns in the first row located on the most downstream side in the transport direction of the inspection target region 72 has been described. However, 11 block patterns in the first row are formed. In the meantime, 11 block patterns in other rows are formed at the same time. That is, the 180 nozzles from nozzle # 1 to nozzle # 180 are set to 20 nozzle groups each consisting of 9 consecutive nozzles, and 11 block patterns for each nozzle group follow the same procedure. Is formed. For example, when a dot row is formed by nozzle # 9, ink is ejected from nozzle # 9N (N is an integer) at the same timing.
An interval between adjacent block patterns is equal to a dot interval of a dot row constituting each block pattern. Therefore, if there is no non-ejection nozzle, the density in the test pattern 71 becomes uniform, and it is difficult to recognize individual block patterns from the test pattern 71 with the naked eye.

=== Inspection of Inspection Pattern ===
Inspection of the inspection pattern (color ink inspection pattern 71) is performed by moving the carriage 31 in the scanning direction to scan the detection spot of the downstream optical sensor in the scanning direction. Then, the controller alternately repeats the process of scanning the detection spot of the downstream optical sensor and the process of conveying the paper for one block in the conveyance direction until the inspection of all the inspection areas of the inspection pattern is completed. Then, by detecting the presence or absence of a block pattern (block pattern BL) corresponding to each nozzle, the ejection inspection of each nozzle is performed.

  Hereinafter, inspection of each inspection pattern will be described.

<About inspection of color ink inspection pattern>
FIG. 17A is an explanatory diagram of the inspection of the color ink inspection pattern 71. FIG. 17B is an explanatory diagram of the inspection result of the downstream optical sensor 55 when there is no non-ejection nozzle. FIG. 17C is an explanatory diagram of the inspection result of the downstream optical sensor 55 when there is a non-ejection nozzle. A circle SP in the figure indicates a detection spot of the downstream optical sensor 55.

In the inspection of the color ink inspection pattern 71, the inspection is performed based on the output of the first light receiving unit 552 of the downstream optical sensor 55. That is, in the inspection of the color ink inspection pattern, the inspection is performed based on the amount of diffuse reflected light.
The first light receiving unit 552 of the downstream optical sensor 55 outputs a higher voltage as the amount of received light increases, and outputs a lower voltage when the amount of received light is small.
Since inspection is performed with diffuse reflected light using the first light receiving unit 552 of the downstream optical sensor 55, the first light receiving unit 552 receives light when a pattern formed of color ink exists in the detection spot SP. The amount of light decreases, and the output voltage of the downstream optical sensor 55 decreases. On the other hand, when there is no pattern formed of color ink in the detection spot SP, the amount of light received by the first light receiving unit 552 increases, and the output voltage of the downstream optical sensor 55 increases.

  When the controller inspects the inspection pattern, the detection spot SP moves in the scanning direction and crosses the inspection pattern 71. If there is no blank pattern in the locus of the detection spot SP, the downstream optical sensor 55 outputs a low voltage while the detection spot SP crosses the inspection pattern 71. That is, if there is no non-ejection nozzle, the downstream optical sensor 55 outputs a low voltage while the detection spot SP crosses the inspection pattern 71 (see FIG. 17B).

  On the other hand, if there is a blank pattern in the locus of the detection spot SP, the downstream optical sensor 55 outputs a relatively high voltage when the detection spot SP is positioned on the blank pattern. In other words, if there is a non-ejection nozzle, the downstream optical sensor 55 outputs a relatively high voltage when the detection spot is located on the block pattern BL corresponding to the non-ejection nozzle (FIG. 17C).

  Therefore, the controller sets the predetermined threshold value V1 in advance, and whether the output voltage of the downstream optical sensor 55 exceeds the threshold value V1 during the inspection of the inspection pattern 71 (while the detection spot SP crosses the inspection pattern 71). If this can be detected, the presence of a non-ejection nozzle can be detected. Information regarding the threshold value V1 is stored in advance in the memory. Further, by counting how many times the output voltage of the downstream optical sensor 55 exceeds the threshold value V1, it is possible to detect how many non-ejection nozzles are present.

  Further, the controller can specify the non-ejection nozzle based on the position of the detection spot SP when the output voltage of the downstream optical sensor 55 exceeds V1. Note that the position of the detection spot SP in the scanning direction can be detected based on the output of the linear encoder 51. Further, the position of the detection spot SP in the transport direction can be detected based on the output of the rotary encoder 52. For example, the controller can specify that the non-ejection nozzle is nozzle # 112 based on the detection result of the downstream optical sensor 55 as shown in FIG. 17C. In this case, information in which the position of each block pattern BL is associated with the nozzle number is stored in advance in the memory.

=== Nozzle cleaning ===
If there is a non-ejection nozzle as a result of the inspection pattern inspection, the controller executes a cleaning process in order to eliminate the ejection failure. Here, the following two types of cleaning processes executed by the controller can be considered. However, the cleaning process is not limited to these, and other methods may be used. In short, any process that eliminates clogging of nozzles that are defective in ejection may be used.

<About nozzle suction>
Nozzle suction is a process for forcibly sucking ink from the nozzles to eliminate ejection defects such as nozzle clogging. When the carriage 31 is in the standby position, the head 41 is covered with the cap. In this state, the controller makes a negative pressure in the cap by the pump, and sucks out the ink in the nozzle.

<About flushing>
Flushing is a process for forcibly ejecting ink from nozzles and eliminating ejection defects such as nozzle clogging. The controller drives the piezo element outside the printing area and ejects ink from the nozzle. Unlike ink ejection during printing, ink ejected during flushing does not land on the paper but is collected by a collection mechanism (not shown). If a non-ejection nozzle is specified, only that nozzle may be used for ejecting ink. In this way, waste of ink can be avoided.

=== Adjustment of sensor ===
<About the effects of mounting errors>
In the printer manufacturing process, it is difficult to mount the downstream optical sensor 55 as designed. Therefore, the downstream optical sensor 55 is mounted on the carriage 31 in a state where there is a relative displacement between the nozzles in the transport direction and the scanning direction. However, if there is an attachment error between the downstream optical sensor 55 and the nozzle, the accuracy of the discharge inspection is lowered. Hereinafter, the influence of the mounting error in the transport direction and the mounting error in the scanning direction will be described.

FIG. 18A is an explanatory diagram of inspection in the case where the downstream optical sensor 55 is provided shifted in the transport direction. Compared with the state of inspection in the normal case (see FIG. 17A), the downstream optical sensor 55 is mounted shifted in the transport direction, so that the detection spot SP does not pass through the middle of the blank pattern and is blank. It passes through the edge of the pattern.
When the detection spot SP passes through the middle of the blank pattern, the ratio of the blank pattern in the detection spot is large (see FIG. 17C). On the other hand, when the detection spot SP passes through the edge of the blank pattern, the ratio of the blank pattern in the detection spot is small (the ratio of the pattern formed by the color ink is large). Since the detection spot SP passes through the edge of the blank pattern, the output voltage of the downstream optical sensor 55 is lower than when the detection spot SP passes through the middle of the blank pattern.
As a result, even if a blank pattern exists in the inspection pattern 71, the output voltage of the downstream optical sensor 55 does not exceed the threshold value V1, and therefore the presence of a non-ejection nozzle cannot be detected. In other words, if the downstream optical sensor 55 is attached while being displaced in the transport direction, the accuracy of the discharge inspection may be reduced.

  FIG. 19A is an explanatory diagram showing the inspection start position of the detection spot SP when the downstream optical sensor 55 is normally attached, and the inspection start position of the detection spot SP ′ when the optical sensor 55 is attached so as to be shifted in the scanning direction. It is. As shown in the figure, when there is an attachment error in the scanning direction, the distance from the inspection start position of the detection spot SP to the blank pattern changes. In this description, due to the mounting error, the distance from the inspection start position of the detection spot SP to the blank pattern is longer than the normal distance.

  FIG. 19B is an explanatory diagram of inspection results when the downstream optical sensor 55 is normally attached. The distance from the inspection start position to the blank pattern can be detected based on the output of the linear encoder 51. When the downstream optical sensor 55 is normally attached, the controller determines that the non-ejection nozzle is # 112 based on the output of the linear encoder 51 when the output voltage of the downstream optical sensor 55 exceeds the threshold value V1. Is identified.

  FIG. 19C is an explanatory diagram of an inspection result when the downstream optical sensor 55 is attached while being shifted in the scanning direction. In this description, as described above, the distance from the inspection start position of the detection spot SP to the blank pattern is longer than the normal distance. Therefore, the moving distance until the detection spot SP reaches the blank pattern is longer than the normal moving distance.

  As a result, when the downstream optical sensor 55 is mounted shifted in the scanning direction, the controller forms a pattern next to the nozzle # 112 pattern even though the nozzle # 112 is actually a non-ejection nozzle. Nozzle # 113 is identified as a non-ejection nozzle. In other words, if the downstream optical sensor 55 is attached while being displaced in the scanning direction, the accuracy of the discharge inspection may be reduced.

As can be seen from the above description, if there is an attachment error between the downstream optical sensor 55 and the nozzle, the accuracy of the discharge inspection is lowered. However, if the downstream optical sensor 55 is to be mounted as designed, excessive precision is required in the printer manufacturing process.
Therefore, in the present embodiment, in the printer manufacturing process, an adjustment value for adjusting the relative positional relationship between the downstream optical sensor 55 and the nozzle is acquired, and a discharge inspection is performed based on the adjustment value. . Below, the flow of the adjustment process of an attachment error is demonstrated.

<Outline of adjustment process>
FIG. 20 is an explanatory diagram of the adjustment processing of the present embodiment. This adjustment processing is performed in the manufacturing process before shipping the printer. In the following description, operations performed by the printer are realized by the controller controlling each unit in accordance with a program stored in a memory in the printer. This program has a code for controlling each unit.

  First, the printer forms an inspection pattern 71 (S201). Since the configuration and creation method of the test pattern 71 are the same as those of the test pattern 71 described above, the description thereof is omitted.

Next, the inspector checks the presence / absence of a non-ejection nozzle using the inspection pattern 71 (202). If there is a non-ejection nozzle, a blank pattern is formed in the inspection pattern 71, so that the presence or absence of the non-ejection nozzle can be visually inspected (see FIG. 13B). However, at this time, it is not necessary to determine which nozzle is a non-ejection nozzle. Here, the downstream optical sensor 55 is not used as in the above-described ejection inspection.
If there is a non-ejection nozzle (YES in S202), a cleaning process is performed (S203). As a result, the nozzle clogging is recovered. If there is no non-ejection nozzle (NO in S202), the process proceeds to the next S204. That is, when proceeding to S204, ink is ejected from all nozzles.

  Next, the printer forms an adjustment pattern (S204). The adjustment pattern formed here will be described in detail later.

  Next, a conveyance direction adjustment process is performed. This process is a process for detecting the relative position in the transport direction between the downstream optical sensor 55 and the nozzle and adjusting the relative positional relationship. This process will be described later in detail.

  Next, scanning direction adjustment processing is performed. This process is a process for adjusting the signal shift due to the influence of the mounting error of the downstream optical sensor 55 and the like. This process will be described later in detail.

  When the printer finishes the above processing, the relative positional relationship between the downstream optical sensor 55 and the nozzle can be detected. Based on the detected positional relationship, the printer adjusts the detection result of the downstream optical sensor at the time of a discharge inspection process performed by the user thereafter, and prevents a decrease in detection accuracy due to the above-described mounting error.

<(S204) Creation of Adjustment Pattern>
FIG. 21 is an explanatory diagram of an adjustment pattern. The adjustment pattern 75 has substantially the same configuration as the above-described inspection pattern 71, and is formed on paper by the same creation method. That is, the adjustment pattern 75 is composed of a plurality of block patterns corresponding to each nozzle.
Unlike the above-described inspection pattern, the adjustment pattern 75 is formed without ejecting ink from the nozzle # 47 to the nozzle # 53 and the nozzle # 142. Therefore, the adjustment pattern 75 includes a blank pattern 751 that is long in the scanning direction and a blank pattern 752 that is one block pattern in size. Since the adjustment pattern 75 is formed after the non-ejection nozzle is visually checked (S202), there is no blank pattern other than the blank pattern 751 and the blank pattern 752.

<(S205, S206)) Conveyance direction and scanning direction adjustment processing>
FIG. 22 is an explanatory diagram of adjustment processing in the transport direction and the scanning direction. In the figure, the components already described are given the same reference numerals and the description thereof is omitted. In addition, the round mark in a figure shows the position on the paper of the detection spot of the downstream optical sensor 55. FIG. When the transport unit 20 transports the paper in the transport direction, the detection spot SP moves to the upstream side in the transport direction with respect to the paper. The detection spot SP moves in the scanning direction with respect to the paper when the carriage moves in the scanning direction.

  The movement operation of the detection spot SP described below is realized by the controller controlling each unit in the printer. The controller controls each unit according to a program stored in the memory.

  First, in order to perform the conveyance direction adjustment process (S205), the printer positions the detection spot of the downstream optical sensor 55 at the detection spot SP1 in the drawing with respect to the paper. This position is almost the position of the block pattern (see FIG. 14) formed by the nozzle # 23. However, due to an installation error, a positional deviation occurs between the downstream optical sensor 55 and the nozzle within a design tolerance range. However, the amount of this positional deviation is sufficiently smaller than the length of the blank pattern 751 in the scanning direction. Therefore, even if there is an attachment error of the downstream optical sensor 55, the detection spot SP1 is located at least on the downstream side in the transport direction of the blank pattern 751.

  Next, the printer positions the detection spot of the downstream optical sensor 55 at the detection spot SP2 in the drawing with respect to the paper. This position is almost the position of the block pattern (see FIG. 14) formed by the nozzle # 77. That is, the printer transports the paper by the transport unit 20 and moves the detection spot of the downstream optical sensor 55 to the upstream side in the transport direction with respect to the paper. The moving speed of the detection spot at this time is sufficiently slower than the moving speed of the detection spot in the scanning direction when the ejection inspection is actually performed (see FIG. 17A).

  FIG. 23 is an explanatory diagram of the output voltage of the downstream optical sensor 55 while the detection spot moves from SP1 to SP2. Since the detection spot of the downstream optical sensor 55 passes through the blank pattern 751, the output voltage of the downstream optical sensor 55 exceeds the threshold value V1 on the way. Since the position of the blank pattern 751 of the adjustment pattern 75 is determined in advance, the position exceeding the threshold value V1 when there is no attachment error is determined by design. However, when the downstream optical sensor 55 is attached to the nozzle so as to be displaced in the transport direction, the position where the detected output signal exceeds the threshold value V1 shifts. Therefore, the relative positional relationship in the transport direction between the downstream optical sensor 55 and the nozzle can be detected by comparing the position determined by design with the detected position for the position exceeding the threshold value V1.

  For example, in the present embodiment, with respect to the detected output signal, the position exceeding the threshold value V1 is detected earlier than the designed position by the distance α. In this case, the downstream optical sensor 55 is provided at a distance α from the designed mounting position toward the nozzle # 180. That is, the downstream optical sensor 55 is provided so as to be shifted upstream in the transport direction by a distance α with respect to the nozzle.

  The controller stores in the memory information related to the attachment error in the transport direction (information related to the distance α). The distance α is calculated based on the detection result of the rotary encoder. This information is used for future processing (scanning direction adjustment processing and ejection inspection) as an offset value (conveyance direction adjustment value) in the conveyance direction. The process so far is the conveyance direction adjustment process.

  Next, in order to perform the scanning direction adjustment process (S206), the printer positions the detection spot of the downstream optical sensor 55 at the detection spot SP3 in the drawing with respect to the paper. This position is almost the position of the block pattern (see FIG. 14) formed by the nozzle # 136. However, due to a mounting error in the scanning direction, a positional deviation in the scanning direction occurs between the downstream optical sensor 55 and the nozzle within a design tolerance range. However, in the present embodiment, when the detection spot is moved to the position SP3 in the drawing, the transport unit adjustment processing is offset using the transport direction adjustment value described above. Therefore, at the position of the detection spot SP3, there is no influence of the mounting error in the transport direction.

  Next, the printer positions the detection spot of the downstream optical sensor 55 at the detection spot SP4 in the drawing with respect to the paper. This position is almost the position of the block pattern (see FIG. 14) formed by the nozzle # 144. That is, the printer moves the carriage 31 in the scanning direction by the carriage unit 30 and moves the downstream optical sensor 55 in the scanning direction. In addition, the moving speed of the detection spot at this time is the same speed as the moving speed of the detection spot (see FIG. 17A) when the ejection inspection is actually performed.

  If the detection spot SP3 is moved in the scanning direction, the attachment error in the transport direction has already been adjusted, so the detection spot passes through the middle of the blank pattern 752. Since the detection spot passes through the middle of the blank pattern 752, the output voltage of the downstream optical sensor 55 exceeds V1 when the detection spot reaches the blank pattern. Since the nozzle # 142 does not eject ink when the adjustment pattern 75 is formed, the nozzle corresponding to the blank pattern 752 is naturally the nozzle # 142. However, the position where the detected output signal exceeds V1 is shifted due to the influence of an attachment error or the like (errors other than the attachment error will be described later). Therefore, if the position of the blank pattern 752 is compared with the detected position for the position exceeding the threshold value V1, the relative positional relationship between the downstream optical sensor 55 and the nozzle in the scanning direction can be adjusted.

  When the detection spot moves from SP3 to SP4, the controller stores the detection result of the linear encoder when the output voltage of the downstream optical sensor 55 exceeds the threshold value V1 in the memory. This information is used for future processing (ejection inspection) as an offset value (scanning direction adjustment value) in the scanning direction. The process so far is the scanning direction adjustment process.

<About movement speed during adjustment processing>
In this embodiment, the movement speed of the detection spot during the conveyance direction adjustment process is slower than the movement speed of the detection spot during the actual ejection inspection. Further, the movement speed of the detection spot during the adjustment process in the scanning direction is the same as the movement speed of the detection spot during the actual ejection inspection. The reason for this will be described below.

FIG. 24A is an explanatory diagram of a configuration of the light receiving unit 552 of the downstream optical sensor 55. FIG. 24B is an explanatory diagram for explaining the relationship between the moving speed of the detection spot and the output voltage.
When the transistor of the light receiving unit 552 of the downstream optical sensor 55 receives the reflected light, the voltage Vout is output. In the light receiving unit 552, a capacitor is provided in parallel with the transistor, and noise is removed by the effect of a low-pass filter.
When the detection spot of the downstream optical sensor 55 passes through the blank pattern 752, the output voltage of the downstream optical sensor 55 exceeds the threshold value V1. However, the output signal is delayed due to the influence of the low-pass filter of the light receiving unit 552 of the downstream optical sensor 55 (see FIG. 24A), and when the detection spot SP reaches a blank pattern and when the output signal exceeds the threshold value V1. Deviation occurs between That is, even if the downstream optical sensor 55 is attached in a state where there is no attachment error, if the detection spot moving speed (relative movement speed between the downstream optical sensor 55 and the paper) is high, the downstream optical sensor 55. Deviation occurs in the output signal. And this deviation | shift amount will shift | deviate large, so that the moving speed of detection spot SP is quick (refer FIG. 24B).

  For example, when the moving speed of the detection spot SP is sufficiently low as in the above-described conveyance direction adjustment processing, the amount of deviation due to the low-pass filter is small, and thus the detection is performed when the output voltage Vout exceeds the threshold value V1. The spot SP is at the position of the blank pattern. Therefore, in the above-described transport direction adjustment process, the controller moves the detection spot SP at a sufficiently slow speed and accurately detects the position where the detection spot SP has reached a blank pattern. Thereby, in the above-mentioned conveyance direction adjustment process, the relative positional relationship in the conveyance direction between the downstream optical sensor 55 and the nozzle can be directly detected, and the influence of the attachment error can be eliminated.

  On the other hand, if the moving speed of the detection spot SP is high as in the above-described scanning direction adjustment process, for example, when the output voltage Vout exceeds the threshold value V1 due to the low-pass filter, the detection spot SP has already been detected. It passes a blank pattern by a distance β. However, if the moving speed of the detection spot SP is constant, the deviation amount is the same. Therefore, the controller moves the detection spot SP at the same speed as the movement speed of the detection spot when the actual ejection inspection is performed, and the linear encoder detects when the output voltage of the downstream optical sensor 55 exceeds the threshold value V1. If the result is set to the offset value, the influence of the mounting error of the downstream optical sensor 55 and the influence of the signal delay can be removed together.

  In the scanning direction adjustment process, unlike the above-described conveyance direction adjustment process, it is not possible to individually detect the influence of the attachment error or the signal delay. However, if the moving speed is the same, the influence of the signal delay is the same, and therefore the amount of deviation combining the influence of the mounting error and the influence of the signal delay is the same. Therefore, in the scanning direction adjustment process, the influence of the mounting error of the downstream optical sensor 55 and the influence of the signal delay are removed together.

<Detection of a plurality of adjustment patterns>
FIG. 25 is an explanatory diagram of detection of a plurality of detection patterns. In the above description, the detection of one detection pattern has been described for the sake of simplification. However, when an adjustment pattern is created in actual adjustment processing, each nozzle group uses a plurality of inks. The adjustment pattern is formed.
The plurality of adjustment patterns are formed adjacent to each other along the scanning direction. Further, the plurality of adjustment patterns are arranged in the same order as the inspection pattern group 70 described above. Therefore, the configuration is the same as that of the above-described inspection pattern group 70 except that a blank pattern is formed.

First, the transport direction adjustment process described above is performed using an adjustment pattern formed by black (matt black (MBk)) ink formed fourth from the left. The reason why the conveyance direction adjustment processing is performed using the black adjustment pattern instead of the other color adjustment patterns is that the output signal of the downstream optical sensor of the filled pattern and the downstream optical sensor of the blank pattern This is because the accuracy of the conveyance direction adjustment processing is increased because the difference from the output signal is large.
Next, scanning direction adjustment processing is performed by detecting each blank pattern 752 of the plurality of adjustment patterns. Since the blank patterns of the plurality of adjustment patterns can be detected by moving the detection spot SP once, the scanning direction adjustment process can be performed in a short time.

In the above description, the conveyance direction adjustment process is performed using only one adjustment pattern. This is because the transport direction adjustment process detects the influence of the mounting error of the downstream optical sensor 55 in the transport direction, but the mounting error of the downstream optical sensor 55 is common to each nozzle group. is there.
On the other hand, in the above description, the scanning direction adjustment paper is performed using a plurality of adjustment patterns. This is because the threshold value set for detecting a blank pattern is different for each nozzle group (for each ink color), and if the threshold value is different, the amount of deviation in the output signal of the downstream optical sensor 55 This is because they are different. The reason why the threshold value differs for each nozzle group is that the difference between the output signal of the downstream optical sensor of the filled pattern and the output signal of the downstream optical sensor of the blank pattern is different for each ink color. is there.

=== Other Embodiments ===
The above embodiment is mainly described for a printer, but it is needless to say that the disclosure includes a discharge inspection apparatus that performs nozzle discharge inspection, a nozzle discharge inspection method, a printing system, and the like. .

  Moreover, although the printer 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 has been described. However, the present invention is not limited to this. For example, a technique similar to that of the present embodiment may be applied to an apparatus that performs a dedicated nozzle discharge inspection.

<About nozzle>
In the above-described embodiment, ink is ejected using a piezoelectric element. However, the method for discharging the liquid 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 color ink>
In the above-described embodiment, yellow (Y), magenta (M), cyan (C), black (a general term for matte black (MBk) and photo black (PBk)), red (R), violet (V) ) Was used. However, the color ink used is not limited to this. For example, color inks such as light magenta, light cyan, and dark yellow may be used.

<About media>
In the above-described embodiment, plain paper or glossy paper is used as the medium. However, the medium for forming the inspection pattern is not limited to these. For example, inspection patterns can be formed on various media as shown in FIG. The printer forms an inspection pattern corresponding to the type of medium so that the downstream optical sensor can detect the inspection pattern.

=== Summary ===
(1) Conventionally, it is movable in the scanning direction (moving direction), and can be moved together with a plurality of nozzles (ink ejection units) that perform printing (recording) on paper (medium) using ink, A printer including a downstream optical sensor 55 (sensor) that detects a pattern formed by nozzles is known. The printer (which is also a discharge inspection apparatus) has a plurality of nozzles based on the detection result of the downstream optical sensor when the downstream optical sensor and the inspection pattern are relatively moved in the first direction. A discharge inspection can be performed.

However, if there is a deviation in the output of the sensor due to the influence of the mounting error or the like of the downstream optical sensor 55, the detection accuracy of the inspection pattern decreases.
For example, when the downstream optical sensor 55 is mounted so as to be shifted in the transport direction, the detection spot SP cannot pass through the middle of the blank pattern of the inspection pattern 71, which may reduce the accuracy of the discharge inspection (FIG. 18A). FIG. 18B). Further, for example, when the downstream optical sensor 55 is attached while being shifted in the scanning direction, the adjacent nozzle may be erroneously specified as a non-ejection nozzle, and the accuracy of ejection inspection may be reduced (see FIGS. 19A to 19C). ). Moreover, there is a possibility that the accuracy of the discharge inspection may be reduced due to the influence of the output delay of the downstream optical sensor 55 (see FIG. 24B).

  Therefore, before performing the ejection inspection, the nozzle (ink ejection unit) forms the adjustment pattern 75 on the paper (medium), and the detection spot (detection position of the sensor) and the adjustment pattern 75 are moved in the transport direction (second direction). ), The conveyance direction adjustment value (second direction adjustment value) is acquired based on the detection result of the downstream optical sensor (sensor) at this time, and the detection spot and the adjustment pattern 75 are scanned. The scanning direction adjustment value (first direction adjustment value) was acquired based on the detection result of the downstream optical sensor at this time. Then, the printer (discharge inspection apparatus) performs discharge inspection using the acquired scanning direction adjustment value and transport direction adjustment value. For example, the printer controls the transport unit based on the transport direction adjustment value, and the downstream optical sensor 55 and the paper so that the detection spot SP passes through the middle of the block pattern of the test pattern 71 during the ejection test. Adjust the relative position with. Further, for example, the printer identifies the nozzle corresponding to the detection result peak (see 19C) in the ejection inspection based on the scanning direction adjustment value.

  On the other hand, when the moving speed of the detection spot SP is fast, an effect other than the attachment error (for example, the effect of delay of the output signal) may be included in the adjustment value (see FIG. 24B). However, this effect is considered to be the same if the moving speed of the detection spot SP is constant.

Therefore, in the above-described embodiment, the relative movement speed (movement speed from SP1 to SP2 in FIG. 22) between the detection spot (sensor detection position) and the adjustment pattern 75 when acquiring the conveyance direction adjustment value is as follows. The moving speed when acquiring the scanning direction adjustment value (the moving speed from SP3 to SP4 in FIG. 22) is assumed to be slower.
For example, in the above-described embodiment, the moving speed of the detection spot when acquiring the scanning direction adjustment value is the actual moving speed. On the other hand, the movement speed of the detection spot when acquiring the adjustment value in the conveyance direction is slower than the movement speed of the detection spot during the ejection inspection.

  Thereby, since the moving speed of the detection spot when acquiring the conveyance direction adjustment value is slow, the conveyance direction adjustment value is not affected by influences other than the mounting error (for example, the influence of the delay of the output signal). The influence of the mounting error of the downstream optical sensor can be eliminated. On the other hand, the movement speed of the detection spot when acquiring the scanning direction adjustment value is fast, and the scanning direction adjustment value includes effects other than the attachment error (for example, the influence of delay of the output signal). However, since the movement direction of the detection spot when acquiring the scanning direction adjustment value is the same direction as the movement direction of the detection spot when detecting the inspection pattern, the scanning direction adjustment value includes effects other than mounting errors. However, there is no problem as long as it is affected by other than the mounting error in the same manner during the discharge inspection.

  If the ejection inspection is performed using the scanning direction adjustment value and the conveyance direction adjustment value acquired in this manner, the ejection inspection can be performed with high accuracy. Moreover, since the moving speed of the detection spot can be increased when acquiring the scanning direction adjustment value, the time required for acquiring the adjustment value can be reduced.

(2) In the above-described embodiment, the moving speed of the detection spot SP when acquiring the scanning direction adjustment value (the moving speed from SP3 to SP4 in FIG. 22) is the moving speed of the detection spot when actually discharging ( (See FIG. 17A).
Thereby, during the ejection inspection, the influence of the mounting error and the influence other than the mounting error (for example, the influence of the delay of the output signal) can be removed together using the scanning direction adjustment value. As a result, the ejection inspection pattern can be detected with high accuracy.

(3) In the above-described embodiment, the downstream optical sensor 55 (sensor) has a low-pass filter. Thereby, a signal having a predetermined frequency or higher can be removed.
However, even if the downstream optical sensor 55 is attached with no attachment error, if the moving speed of the detection spot is high due to the influence of the low-pass filter, the output signal of the downstream optical sensor may be shifted.
However, in the above-described embodiment, the movement speed of the detection spot in the transport direction when detecting the adjustment pattern is slow, so the influence of the mounting error is not included in the transport direction adjustment value (second direction adjustment value).

(4) In the above-described embodiment, after adjusting the positions of the downstream optical sensor 55 (sensor) and the adjustment pattern 75 based on the acquired conveyance direction adjustment value (second direction adjustment value), the scanning direction adjustment value is adjusted. Is getting.
When the positions of the downstream optical sensor 55 and the adjustment pattern 75 in the transport direction are not adjusted, the detection spot SP does not pass through the center of the blank pattern 752 as shown in FIG. I can't.
On the other hand, according to the above-described embodiment, when the scan direction adjustment value is acquired, the detection spot SP passes through the center of the blank pattern 752 (see FIG. 22), so that the scan direction adjustment value can be acquired with high accuracy. it can.

(5) In the above-described embodiment, a transport unit that transports paper (medium) in the transport direction (second direction) is provided, and based on the detection result of the downstream optical sensor 55 when the transport unit is transporting paper. The conveyance direction adjustment value was acquired.
If the transport unit transports the paper, the detection position of the downstream optical sensor 55 moves in the transport direction relative to the paper, so that the detection of the downstream optical sensor when the detection spot SP passes through the blank pattern 751. Based on the result, the conveyance direction adjustment value can be acquired.

(6) In the above-described embodiment, the transport unit is controlled during the discharge inspection based on the transport direction adjustment value.
If the above-described transport direction adjustment processing (see S205) is not performed, the detection spot SP cannot pass through the middle of the blank pattern of the inspection pattern 71, and the accuracy of the discharge inspection may be reduced (FIG. 18A, (See FIG. 18B).
On the other hand, according to the above-described embodiment, when the ejection unit is controlled by controlling the transport unit 20 using the transport direction adjustment value obtained by the transport direction adjustment process (the downstream optical sensor 55 is a pattern for ejection inspection) When detecting 71), the detection spot SP can pass through the middle of the block pattern. Thereby, the discharge inspection can be performed with high accuracy.

(7) In the above-described embodiment, the downstream optical sensor 55 detects the ejection test pattern 71 after the nozzle (ink ejection unit) forms the ejection test pattern 71 based on the transport direction adjustment value (S102). The carry amount until (S103) is controlled.
For example, in the above-described embodiment, when the transport direction adjustment value indicates that “the downstream optical sensor 55 is provided to be shifted to the upstream side in the transport direction by the distance α with respect to the nozzle”, the nozzle performs ejection inspection. An offset corresponding to the distance α is applied to the transport amount from the formation of the pattern 71 for use until the downstream optical sensor 55 detects the ejection test pattern 71. Thereby, when performing the ejection inspection (when the downstream optical sensor 55 detects the ejection inspection pattern 71), the detection spot SP can pass through the middle of the block pattern, so that the ejection inspection is performed with high accuracy. Can do.

(8) In the above-described embodiment, the non-ejection nozzle is specified based on the detection result of the downstream optical sensor that has detected the inspection pattern and the scanning direction adjustment value.
If the above-described scanning direction adjustment processing (S206) is not performed, the influence of the attachment error (the influence of the inspection start position of the detection spot SP when performing the discharge inspection is shifted (see FIGS. 19A to 19C)) or the downstream side Due to the delay of the output signal of the optical sensor 55, there is a possibility that the nozzle that normally ejects ink is identified as a non-ejection nozzle.
On the other hand, according to the above-described embodiment, by using the scanning direction adjustment value, the influence of the mounting error of the downstream optical sensor 55 and the influence of the signal delay can be removed together, and the non-ejecting nozzle can be accurately removed. Can be identified.

(9) In the above-described embodiment, the adjustment pattern 75 is a pattern having the same configuration as the inspection pattern 71.
As a result, even if a non-ejection nozzle exists and the inspection pattern 71 has a blank pattern, the blank pattern can be detected with high accuracy.

(10) In the above-described embodiment, the adjustment pattern receives ink from nozzle # 47 to nozzle # 53 and nozzle # 142 (predetermined ink ejection unit) among nozzle # 1 to nozzle # 180 (a plurality of nozzles). It is a pattern created without discharging.
As a result, a blank pattern is formed in a pattern having the same configuration as the ejection inspection pattern 71 (see FIG. 21). In the above-described embodiment, the conveyance direction adjustment value and the scanning direction adjustment value are acquired using the adjustment pattern formed in this way. That is, the adjustment process is performed by the adjustment pattern 75 having the same configuration as the inspection pattern 71 (see FIG. 13B) when the non-ejection nozzle actually exists. Therefore, the ejection inspection can be performed with high accuracy using the conveyance direction adjustment value and the scanning direction adjustment value.

(11) In the above-described embodiment, the ejection inspection pattern 71 is a pattern in which a predetermined area of paper (medium) is filled with ink, and the adjustment pattern 75 is blank in the predetermined area of the ejection inspection pattern. It is the pattern which formed the pattern.
Thereby, the adjustment process can be performed by the adjustment pattern 75 having the same configuration as the inspection pattern 71 (FIG. 13B) when the non-ejection nozzle actually exists. For this reason, it is possible to accurately perform the ejection inspection using the conveyance direction adjustment value and the scanning direction adjustment value.

(12) In the above-described embodiment, the ejection test pattern 71 is a pattern in which a plurality of nozzles (ink ejection portions) are respectively formed on the paper (medium) with the block pattern BL (pattern piece) (see FIG. 14), the adjustment pattern 75 (another pattern) is a pattern in which a predetermined pattern piece of the ejection test pattern 71 is missing.
As a result, a blank pattern is formed in a pattern having the same configuration as the ejection inspection pattern 71 (see FIG. 21). In the above-described embodiment, the conveyance direction adjustment value and the scanning direction adjustment value are acquired using the adjustment pattern formed in this way. That is, the adjustment process is performed by the adjustment pattern 75 having the same configuration as the inspection pattern 71 (FIG. 13B) when the non-ejection nozzle actually exists. Therefore, it is possible to accurately perform the ejection inspection using the conveyance direction adjustment value and the scanning direction adjustment value.

It is explanatory drawing of the whole structure of a printing system. FIG. 10 is an explanatory diagram of 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. 1 is a schematic diagram of an overall configuration of a printer. 1 is a cross-sectional view of the overall configuration of a printer. It is a flowchart of the process at the time of printing. It is explanatory drawing which shows the arrangement | sequence of a nozzle. It is explanatory drawing of a structure of an upstream optical sensor. It is explanatory drawing of a structure of a downstream optical sensor. It is a flowchart of a discharge inspection procedure. FIG. 3 is an overall conceptual diagram of an inspection pattern group used for ejection inspection of nozzles that eject color ink. FIG. 13A is an explanatory diagram of inspection patterns constituting the inspection pattern group. FIG. 13B is an example of an inspection pattern when there are nozzles that do not eject color ink. It is explanatory drawing of the structure of the test pattern for color ink. It is explanatory drawing of the block pattern which comprises the pattern for a test | inspection. It is explanatory drawing of the formation method of 11 block patterns. FIG. 17A is an explanatory diagram of the inspection of the color ink inspection pattern. FIG. 17B is an explanatory diagram of the inspection result of the downstream optical sensor when there is no non-ejection nozzle. FIG. 17C is an explanatory diagram of the inspection result of the downstream optical sensor when there is a non-ejection nozzle. FIG. 18A is an explanatory diagram of inspection in the case where the downstream optical sensor 55 is provided shifted in the transport direction. FIG. 18B is an explanatory diagram of an inspection result when there is a non-ejection nozzle when the downstream optical sensor 55 is provided shifted in the transport direction. FIG. 19A is an explanatory diagram showing the inspection start position of the detection spot SP when the downstream optical sensor 55 is normally attached, and the inspection start position of the detection spot SP ′ when the optical sensor 55 is attached so as to be shifted in the scanning direction. It is. FIG. 19B is an explanatory diagram of inspection results when the downstream optical sensor 55 is normally attached. FIG. 19C is an explanatory diagram of an inspection result when the downstream optical sensor 55 is attached while being shifted in the scanning direction. It is explanatory drawing of the adjustment process of this embodiment. It is explanatory drawing of the pattern for adjustment. It is explanatory drawing of the adjustment process of a conveyance direction and a scanning direction. It is explanatory drawing of the output voltage of the downstream optical sensor 55 during a detection spot moving from SP1 to SP2. FIG. 24A is an explanatory diagram of a configuration of the light receiving unit 552 of the downstream optical sensor 55. FIG. 24B is an explanatory diagram for explaining the relationship between the moving speed of the detection spot and the output voltage. It is explanatory drawing of the detection of the several pattern for a detection.

Explanation of symbols

1 printer,
20 transport unit, 21 paper feed roller, 22 transport motor (PF motor),
23 transport roller, 24 platen, 25 discharge roller,
30 carriage unit, 31 carriage,
32 Carriage motor (CR motor),
40 head units, 41 heads,
50 detector groups, 51 linear encoder, 52 rotary encoder,
53 paper detection sensor, 54 upstream optical sensor, 55 downstream optical sensor,
60 controller, 61 interface unit, 62 CPU,
63 memory, 64 unit control circuit 70 inspection pattern group, 71 inspection pattern (for color ink),
72 inspection area, 73 non-inspection area,
731 Transport direction upper inspection margin, 732 Transport direction lower inspection margin,
733 Scanning direction left part inspection margin, 734 Scanning direction right part inspection margin,
BL block pattern,
75 Adjustment pattern,
100 printing system,
110 computers,
120 display device,
130 input device, 130A keyboard, 130B mouse,
140 recording / reproducing apparatus,
140A flexible disk drive device,
140B CD-ROM drive device,
112 video drivers,
114 application programs,
116 Printer Driver

Claims (15)

A plurality of ink ejection units that perform recording on a medium using ink;
A sensor for detecting a pattern formed by the ink ejection unit;
With
A discharge inspection apparatus that performs a discharge inspection of the ink discharge unit based on a detection result of the sensor when the detection position of the sensor and the inspection pattern are relatively moved in a first direction;
Before the discharge inspection,
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
In the discharge inspection apparatus that performs the discharge inspection using the acquired first direction adjustment value and the second direction adjustment value,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A discharge inspection apparatus characterized by that. The discharge inspection apparatus according to claim 1,
The relative moving speed of the detection position of the sensor and the adjustment pattern when acquiring the first direction adjustment value is relative to the detection position of the sensor and the inspection pattern during the ejection inspection. Discharge inspection apparatus characterized by having the same speed as a typical moving speed. The discharge inspection apparatus according to claim 1 or 2,
The sensor has a low-pass filter. The discharge inspection apparatus according to any one of claims 1 to 3,
Based on the acquired second direction adjustment value, adjust the position of the sensor and the adjustment pattern,
The discharge inspection apparatus characterized by acquiring the first direction adjustment value. A discharge inspection apparatus according to any one of claims 1 to 4,
A transport unit for transporting the medium in the second direction;
The discharge inspection apparatus according to claim 1, wherein the second direction adjustment value is acquired based on a detection result of the sensor when the transport unit is transporting the medium. The discharge inspection apparatus according to claim 5,
The discharge inspection apparatus, wherein the transport unit is controlled in the discharge inspection based on the second direction adjustment value. The discharge inspection apparatus according to claim 5 or 6,
Ejection characterized in that, based on the second direction adjustment value, a transport amount from when the ink ejection unit forms the test pattern to when the sensor detects the test pattern is controlled. Inspection device. A discharge inspection apparatus according to any one of claims 1 to 7,
An ejection inspection apparatus, wherein a non-ejection nozzle is specified based on a detection result of the sensor that detects the inspection pattern and the first direction adjustment value. A discharge inspection apparatus according to any one of claims 1 to 8,
The ejection inspection apparatus, wherein the adjustment pattern is a pattern having the same configuration as the inspection pattern. The discharge inspection apparatus according to claim 9,
The ejection inspection apparatus, wherein the adjustment pattern is a pattern created without ejecting ink from a predetermined ink ejection section of the plurality of ink ejection sections. The discharge inspection apparatus according to claim 9 or 10,
The inspection pattern is a pattern in which a predetermined area of the medium is filled with the ink,
The ejection inspection apparatus, wherein the adjustment pattern is a pattern in which a blank pattern is formed in a predetermined region of the inspection pattern. The discharge inspection apparatus according to any one of claims 9 to 11,
The test pattern is a pattern in which the plurality of ink ejection portions respectively form pattern pieces on the medium,
The ejection inspection apparatus, wherein the adjustment pattern is a pattern in which a predetermined pattern piece of the inspection pattern is missing. A plurality of ink ejection units that perform recording on a medium using ink;
A sensor for detecting a pattern formed by the ink ejection unit;
With
A discharge inspection apparatus that performs a discharge inspection of the ink discharge unit based on a detection result of the sensor when the detection position of the sensor and the inspection pattern are relatively moved in a first direction;
Before the discharge inspection,
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
In the discharge inspection apparatus that performs the discharge inspection using the acquired first direction adjustment value and the second direction adjustment value,
The relative movement speed of the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. ,
The relative moving speed of the detection position of the sensor and the adjustment pattern when acquiring the first direction adjustment value is relative to the detection position of the sensor and the inspection pattern during the ejection inspection. The same speed as the typical movement speed,
The sensor has a low pass filter;
Based on the acquired second direction adjustment value, the position of the sensor and the adjustment pattern is adjusted, the first direction adjustment value is acquired,
A transport unit for transporting the medium in the second direction;
Based on the detection result of the sensor when the transport unit is transporting the medium, the second direction adjustment value is acquired,
Based on the second direction adjustment value, the transport unit is controlled during the ejection inspection,
Based on the second direction adjustment value, a transport amount from when the ink ejection unit forms the inspection pattern to when the sensor detects the inspection pattern is controlled,
Based on the detection result of the sensor that has detected the inspection pattern and the first direction adjustment value, the non-ejection nozzle is identified,
The adjustment pattern is a pattern having the same configuration as the inspection pattern,
The adjustment pattern is a pattern created without discharging ink from a predetermined ink discharge portion of the plurality of ink discharge portions,
The inspection pattern is a pattern in which a predetermined area of the medium is filled with the ink, and the adjustment pattern is a pattern in which a blank pattern is formed in a predetermined area of the inspection pattern,
The inspection pattern is a pattern in which the plurality of ink discharge portions respectively form pattern pieces on the medium, and the adjustment pattern is a pattern in which a predetermined pattern piece of the inspection pattern is missing. Discharge inspection device. A test pattern is formed on a medium by a plurality of ink ejection portions,
A discharge method for performing a discharge inspection of the ink discharge unit based on a detection result of the sensor when a detection position of the sensor and a test pattern are relatively moved in a first direction,
Before the discharge inspection,
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
In the ejection inspection method for performing the ejection inspection using the acquired first direction adjustment value and the second direction adjustment value,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A discharge inspection method characterized by the above. A printing system comprising a computer and a printing device,
The printing apparatus includes:
A plurality of ink ejection units that perform recording on a medium using ink;
A sensor for detecting a pattern formed by the ink ejection unit;
With
A printing apparatus that performs a discharge inspection of the ink discharge unit based on a detection result of the sensor when the detection position of the sensor and a test pattern are relatively moved in a first direction,
Before the ejection inspection, the printing device
The ink discharge part forms an adjustment pattern on the medium;
The detection position of the sensor and the adjustment pattern are relatively moved in the second direction, and based on the detection result of the sensor at this time, a second direction adjustment value is acquired,
The detection position of the sensor and the adjustment pattern are relatively moved in the first direction, and based on the detection result of the sensor at this time, a first direction adjustment value is obtained,
Using the acquired first direction adjustment value and the second direction adjustment value, the discharge inspection is performed,
The relative movement speed between the detection position of the sensor and the adjustment pattern when acquiring the second direction adjustment value is slower than the relative movement speed when acquiring the first direction adjustment value. A printing system characterized by that.