Inkjet recording device, and method of outputting nozzle check pattern

Abstract

To solve the problem that, as the number of nozzles comprised in recording heads increases due to higher densities of nozzle arrangements resulting from the need to improve recording image quality, the number of lines to be drawn using nozzle check patterns increases so that the lines are congested, thereby resulting in the difficulty to specify a non-discharge nozzle according to a user's visual inspection.SOLUTION: A first pattern enabling discrimination of whether a prescribed nozzle of a recording head is discharging, is outputted onto a recording medium. Then, superposed on the first pattern outputted onto the recording medium, a second pattern is outputted to enable a non-discharge nozzle to be specified, thereby facilitating specification of a non-discharge nozzle.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus. [Background technology]

[0002] In an inkjet printing device that uses a print head equipped with multiple nozzles that eject ink, when a non-ejecting nozzle that cannot eject ink normally occurs, there is a non-ejection interpolation technology that uses other nozzles to form the pixels that would have been formed by the non-ejecting nozzle instead, thereby preventing a decrease in output image quality.

[0003] To perform non-discharge interpolation, it is necessary to identify the position (nozzle number) of the non-discharge nozzle. One known method for identifying non-discharge nozzles is to output a stepped pattern called a nozzle check pattern, which discharges ink from each nozzle one by one, and identify the position of the non-discharge nozzles that are not discharging, as in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-64223 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the need for improved print quality has led to a denser nozzle arrangement and an increased number of nozzles in print heads. As the number of nozzles increases, the number of 1-dot lines that must be drawn in one nozzle check pattern increases, and the 1-dot lines become more densely packed, making it difficult for users to visually identify non-firing nozzles.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an inkjet recording apparatus and a method for outputting a nozzle check pattern that allows a user to easily identify non-ejecting nozzles visually. [Means for solving the problem]

[0007] In order to achieve the above object, an image forming apparatus according to one aspect of the present invention comprises the following configuration: a conveying unit that conveys a recording medium in a predetermined conveying direction, a recording head that has a plurality of nozzles that eject ink and that performs recording on the recording medium conveyed by the conveying unit, an operation unit that accepts user operations, and control unit that outputs a first pattern onto the recording medium in response to the user's operation, which allows the user to determine whether a predetermined nozzle of the recording head is ejecting ink, and then, in response to the user's operation, backfeeds the recording medium in a direction opposite to the predetermined conveying direction, and then outputs a second pattern that is superimposed on the first pattern output onto the recording medium and allows the user to identify which of the predetermined nozzles is not ejecting ink. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an inkjet recording apparatus capable of outputting a nozzle check pattern that makes it easy to identify non-ejecting nozzles.

[0009] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals. [Brief explanation of the drawings]

[0010] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a printing system including an image forming apparatus and a host computer according to a first embodiment. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a block diagram illustrating the configuration of a control unit that controls the main body of the image forming apparatus according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a conventional nozzle check pattern. [Figure 5] FIG. 10 is an explanatory diagram of a first pattern and a second pattern. [Figure 6] 10A to 10C are diagrams illustrating a procedure for identifying a non-discharge nozzle. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] First, the terms used in this embodiment are defined as follows. "Formation" In this specification, "formation" does not only refer to the formation of meaningful information such as characters or figures. It does not matter whether it is meaningful or insignificant, and whether it is manifested in a way that can be perceived by humans visually. It also broadly refers to the formation of images, designs, patterns, etc. on a recording medium, or the processing of a medium. Furthermore, "formation" does not matter whether it is manifested in a way that can be perceived by humans visually. "Recording Media" Recording media refers not only to the paper used in general image forming devices, but also to a wide range of materials that can accept ink, such as cloth, plastic film, metal plates, glass, ceramics, wood, and leather. "Ink" should be interpreted broadly, as with the definition of "formation" above, and refers to a medium containing a recording material that can be applied to a recording medium to form an image, design, pattern, etc., or to process the recording medium, or to treat the ink. It is liquid in physical properties. The ink treatment mentioned above refers, for example, to the solidification or insolubilization of the coloring material in the ink applied to the recording medium. "Nozzle": Unless otherwise specified, the term "nozzle" refers to an ejection port. Inside the nozzle there is a communicating liquid path and an element that generates the energy used to eject ink.

[0013] [Embodiment 1] First, the schematic configuration of an image forming apparatus 100 according to the first embodiment will be described with reference to FIGS.

[0014] FIG. 1 is a diagram showing an example of the configuration of a printing system including an image forming apparatus 100 and a host computer 104 according to the first embodiment.

[0015] The image forming apparatus 100 includes an apparatus main body 101 provided with a touch panel 102 and a feed unit 103 that loads and feeds a roll sheet, which is a recording medium, wound into a roll. The image forming apparatus 100 prints image data received from a host computer 104 on a label attached to the roll sheet while transporting the roll sheet using a transport unit. As shown in FIG. 1, the image forming apparatus 100 and the host computer 104 are connected via a printer cable 105. While the first embodiment illustrates a configuration in which the image forming apparatus 100 and the host computer 104 are connected via the printer cable 105, they may also be connected via wireless communication using Wi-Fi (registered trademark) or Bluetooth (registered trademark). The image forming apparatus 100 starts up in normal mode by briefly pressing a power button 106. The method for starting up in normal mode is described in the user's manual.

[0016] The operation unit 102 displays software keys on an LCD (liquid crystal display) panel 102A (FIG. 3) and can accept information input by contact (touch operation) with a touch operation unit 102B (FIG. 3). That is, the operation unit 102 displays software keys and can input information by detecting that the software keys have been touched. The panel size of the operation unit 102 according to the first embodiment is 480 pixels by 272 pixels. The touch operation unit 102B may be a resistive type, a capacitive type, or an optical type such as infrared. Note that, although the explanation has been given here using an example in which the touch panel module and the liquid crystal module are separate, they may be integrated as long as the settings of the image forming apparatus 100 can be changed by input via touch operation. In this embodiment, the touch panel refers to a device including both the touch panel module and the liquid crystal module. Furthermore, in this embodiment, "displaying on the touch panel" also includes displaying on the liquid crystal module in a structure in which the touch panel module and the liquid crystal module are provided separately.

[0017] Furthermore, in this embodiment, the operation unit 102 is a touch panel, but the operation unit where the user operates to change the settings of the image forming apparatus 100 and the display unit that displays information may be located in separate positions. In this case, cursor movement keys, a decision key, a cancel key, etc. are located as the operation unit, and a display panel such as a liquid crystal module is located in a position separate from the operation unit as the display unit. The user presses the cursor movement keys to move the cursor displayed on the display panel, and then presses the decision button to select the item selected by the cursor keys.

[0018] FIG. 2 is a schematic cross-sectional view illustrating the configuration of the image forming apparatus 100 according to this embodiment.

[0019] The roll sheet may be a marked roll sheet with a plurality of marks regularly provided in the conveyance direction of the sheet as a recording medium, a continuous roll sheet with no marks, or a label sheet with labels laminated on a roll sheet as a backing. In the following, the image forming apparatus 100 according to the first embodiment will be described taking as an example a case where a roll sheet with marks regularly provided is used as a recording medium.

[0020] As shown in FIG. 2, the image forming apparatus 100 includes an image forming apparatus main body 101 and a feeding unit 103. The feeding unit 103 includes a rolled sheet holder 10A and a pair of rolled sheet conveying rollers 10B. A rolled sheet M mounted in the rolled sheet holder 10A is placed on the pair of rolled sheet conveying rollers 10B and is supplied to the apparatus main body 101 by the rotation of the rolled sheet conveying rollers 10B. The apparatus main body 101 includes a conveying unit 20 that conveys the rolled sheet M, an image forming unit 30 that forms an image on a label on the rolled sheet, a discharge unit 40 that discharges the rolled sheet, and a control unit 50 (see FIG. 3) that controls the image forming apparatus 100. The apparatus main body 101 also includes a sheet detection sensor 70A and a post-processing sheet detection sensor 80A.

[0021] The conveying unit 20 conveys the roll sheet M fed from the feeding unit 10 to the image forming unit 30 and then to the discharge unit 40. The image forming unit 30 forms an image on the fed roll sheet M. The discharge unit 40 cuts the roll sheet M conveyed from the image forming unit 30 by the conveying unit 20 and discharges it outside the apparatus. The control unit 50 controls the operation of each unit of the image forming apparatus 100, such as the feeding unit 10, the conveying unit 20, the image forming unit 30, and the discharge unit 40. The configuration of each unit will be described in detail below.

[0022] The conveying section 20 has a conveying roller 20A, an endless conveying belt 20B stretched over the conveying roller 20A, and a conveying motor 20C (see FIG. 3) that drives the conveying belt 20B, and is configured to convey the rolled sheet M by the conveying belt 20B. An image forming section 30 is provided at a position facing the conveying surface of the conveying belt 20B that conveys the rolled sheet. A sheet detection sensor 70A is also provided upstream of the image forming section 30 in the sheet conveying direction. The image forming section 30 has a recording head unit 30A and ink cartridges 30B.

[0023] The recording head unit 30A internally holds recording heads 30A1, 30A2, 30A3, and 30A4 of each color, each having a plurality of nozzles (6,000 in the first embodiment). The recording heads 30A1, 30A2, 30A3, and 30A4 incorporate a heating element (not shown) that heats the ink, causing it to be ejected from the nozzles. The ink cartridges 30B1, 30B2, 30B3, and 30B4 are disposed below the conveyor belt 20B in the device main body 101. The ink cartridges 30B1, 30B2, 30B3, and 30B4 are connected to the corresponding recording heads 30A1, 30A2, 30A3, and 30A4 by flexible tubes (not shown) or the like, respectively, to supply ink of each color. The maintenance cartridge 30C stores excess ink ejected during printing, recovery operations, and other operations.

[0024] The recording head unit 30A is configured as an inkjet recording head unit that performs line recording. When performing line recording on a recording medium, the recording head is fixed at the recording position, and the recording medium is transported below it. The recording head unit 30A forms an image by ejecting ink onto the roll sheet M that is transported below.

[0025] The sheet detection sensor 70A is capable of detecting the leading edge of the rolled sheet M in the transport direction. This sheet detection sensor 70A detects the leading edge of the rolled sheet M in the transport direction before image formation by the recording head unit 30A. For this reason, it is disposed at a position upstream of the recording head unit 30A in the transport direction. In the case of the first embodiment, the sheet detection sensor 70A is a transmission type sensor that has a light emitting unit and a light receiving unit that are disposed so as to sandwich the rolled sheet M transported by the transport belt 20B, and receives light emitted from the light emitting unit and transmitted through the rolled sheet with the light receiving unit.

[0026] The discharge section 40 also has a cutter unit 40A and a cutting motor 40B (FIG. 3) that drives the cutter unit 40A. The cutter unit 40A has a cutter 40A1 that can cut the roll sheet M and an elevator mechanism (not shown) that can raise and lower the cutter 40A1 in the vertical direction, and is located downstream in the conveyance direction from the recording head unit 30A. The cutting motor 40B also drives the elevator mechanism to raise and lower the cutter 40A1 in the vertical direction. When the control section 50 (described later) drives the cutting motor 40B, the elevator mechanism raises and lowers the cutter 40A1, and the roll sheet M can be cut at a position set by the control section 50 or between any images specified by the user.

[0027] The post-processing sheet detection sensor 80A is located upstream of the cutter unit 40A in the conveying direction, and like the sheet detection sensor 70A, is a reflective sensor that is used to detect the leading edge of the roll sheet M in the conveying direction and the presence or absence of marks on the roll sheet M. The control unit 50 can determine the cutting position by the cutter unit 40A based on the result of sheet detection by the post-processing sheet detection sensor 80A.

[0028] Next, the control unit 50 will be described with reference to FIG.

[0029] FIG. 3 is a block diagram illustrating the configuration of the control unit 50 that controls the apparatus main body 101 of the image forming apparatus 100 according to the first embodiment.

[0030] The control unit 50 includes a main controller 50A, a driver controller 50B, a ROM 50C, a RAM 50D, an image buffer memory 50E, a head drive circuit 50F, a drive circuit 50G, and a sensor circuit 50H.

[0031] The main controller 50A controls the entire image forming apparatus 100 and has functions such as storing data in ROM 50C, controlling data, and functioning as a setting unit that changes the operation of the main body based on setting data. The main controller 50A is connected to the host computer 104 and can exchange signals with the host computer 104. The ROM 50C is connected to the main controller 50A and is a memory that stores control programs and the like. The CPU 300 operates as the main controller 50A using the RAM 50D as working memory. The main controller 50A is also connected to the touch panel 102, and the user can access functions of the image forming apparatus 100 using the touch operation unit 102B, which can input information by recognizing touches on software keys displayed on the liquid crystal panel 102A.

[0032] The image buffer memory 50E, which serves as a storage means for print data, includes image buffer memories 50E1, 50E2, 50E3, and 50E4 for the colors Bk (black), C (cyan), M (magenta), and Y (yellow). The image buffer memory 50E stores bitmap image data for each color transmitted from the host computer 104. The head drive circuit 50F drives the heating elements (not shown) built into the print heads 30A1, 30A2, 30A3, and 30A4 of each color. The print heads 30A1, 30A2, 30A3, and 30A4 eject inks of Bk (black), C (cyan), M (magenta), and Y (yellow). The control unit 50 uses these components to form an image using the print head unit 30A. Specifically, a driver controller 50B connected to the main controller 50A records an image by controlling the driving of the recording head unit 30A via a head driving circuit 50F based on image data stored in an image buffer memory 50E.

[0033] The drive circuit 50G can drive the aforementioned conveyance motor 20C and cutting motor 40B, and is controlled by the main controller 50A. The sensor circuit 50H includes a sheet detection sensor 70A and a post-processing sheet detection sensor 80A, and the main controller 50A can control the image forming operation, the cutting operation of the roll sheet M, and the like, based on signals input from the sensor circuit 50H.

[0034] Figure 4 shows an example of a conventional nozzle check pattern. The nozzle check pattern is a stepped print of one-dot lines (vertical lines) aligned in the transport direction for each nozzle. Printing horizontal lines at the boundaries of each nozzle's one-dot line makes it easier to determine the drawing range for each nozzle. Each nozzle in the Bk head 30A1 is ejected at a time to form one-dot lines in the nozzle check pattern. If there is a non-discharging nozzle, the one-dot line that was supposed to be drawn by the non-discharging nozzle will be missing, making it possible to determine whether or not there is a non-discharging nozzle. 41 in Figure 4 indicates the area where the one-dot line was not drawn due to the non-discharging nozzle.

[0035] Furthermore, by adding numbers to the nozzle check pattern, it is possible to identify the location of the non-discharge nozzle, i.e., the nozzle number. In Figure 4, 41 is located in the second row, fourth column of the nozzle check pattern. If the number of nozzles in Bk head 30A1 is 64, it can be determined that the non-discharge nozzle is nozzle number 12. The user can input the number of the determined non-discharge nozzle into the recording device 100 using the operation unit 102, and this can be used to control non-discharge interpolation, which distributes the data discharged by nozzle number 12 to another nozzle.

[0036] However, when a nozzle check pattern is output using a head with a large number of nozzles arranged at high density, the number of 1-dot lines that must be drawn in one nozzle check pattern increases, and the 1-dot lines and the numbers used to identify non-firing nozzles become crowded together, making it difficult to identify non-firing nozzles.

[0037] 5 shows a portion of the nozzle check pattern of this embodiment. The nozzle check pattern of this embodiment is output twice on one label: a first pattern that draws a one-dot line with each nozzle, and a second pattern that identifies the numbers of non-discharge nozzles.

[0038] Figure 6 shows the procedure for identifying the numbers of non-ejecting nozzles using a nozzle check pattern. When a user operates touch panel 102 to instruct recording device 100 to print a nozzle check pattern, recording device 100 outputs a first pattern to a loaded sheet (Figure 6(1)). At this time, recording device 100 prints the first pattern at a predetermined position on the label based on the detection results of sheet detection sensor 70A. After printing the first pattern, recording device 100 displays on touch panel 102, which also serves as a display unit, a message prompting the user to mark the position of the non-ejecting nozzle, and a button to instruct printing of a second pattern.

[0039] With the label attached to the recording device 100, the user visually checks the first pattern and marks the non-ejection area with a pen (FIG. 6(2)). When the user then touches a button to instruct printing of the second pattern, the recording device 100 prints the second pattern. At this time, the recording device 100 backfeeds the label and then prints the second pattern based on the detection results of the sheet detection sensor 70A, in a position that matches the position of the first pattern on the label. The second pattern may be printed in black, or each row may be printed in a different color to make it easier to distinguish between them.

[0040] The user reads the numbers printed in the second pattern on the marked areas as shown in Figure 6(3) and identifies the numbers of the non-discharge nozzles. The user inputs the identified non-discharge nozzle numbers into the recording device 100, causing the main controller 50A to perform non-discharge interpolation processing.

[0041] The first pattern is not limited to a single dot line, but can be anything that can determine whether or not ink is being ejected from each nozzle, such as a dotted line pattern or a dot pattern in which multiple drops of ink are deposited onto one pixel. The second pattern is not limited to numbers, and can be anything that can individually identify non-ejecting nozzles, such as letters or symbols.

[0042] Furthermore, the first pattern need only be configured to be ejected from at least the nozzles that can be used for printing, and does not have to be ejected from all the nozzles provided in each print head, including the Bk head 30A1. Also, if the first pattern is printed in yellow, it is difficult to determine which nozzles are non-ejecting, so the determination in yellow may be omitted.

[0043] In this embodiment, after printing the first pattern, the recording device 100 backfeeds the label and prints the second pattern. However, it is also possible to prompt the user to remove and reset the label, and then print the second pattern on the reset label after printing the first pattern.

[0044] In addition, in this embodiment, the nozzle check pattern is printed as the first pattern using the Bk head 30A1, but the nozzle check pattern may also be printed using a head of an ink color specified by the user by operating the touch panel 102.

[0045] Furthermore, in this embodiment, the first pattern and the second pattern are printed by the user operating the touch panel 102, but the recording device 100 may also print the first pattern and the second pattern by the user operating the host computer 104 connected to the recording device 100.

[0046] Furthermore, in this embodiment, the numbers of the non-discharge nozzles are input to the recording device 100, but it is also possible to input the numbers of the non-discharge nozzles to the host computer 104, perform non-discharge interpolation processing when creating image data in the host computer 104, and send the image data that has undergone non-discharge interpolation processing from the host computer 104 to the recording device 100.

[0047] As explained above, in the inkjet recording device according to this embodiment, the nozzle check pattern is output in two parts: a first pattern that ejects ink from each nozzle, and a second pattern that prints a number to identify non-ejecting nozzles, making it easy to identify the non-ejecting nozzle numbers.

Claims

1. a conveying means for conveying the recording medium in a predetermined conveying direction; a recording head having a plurality of nozzles for ejecting ink and for recording on the recording medium conveyed by the conveying means; an operation unit that accepts user operations; a control means for outputting, in response to a user's operation, a first pattern onto a recording medium, which allows the user to determine whether or not a predetermined nozzle of the recording head is ejecting ink, and then, in response to a user's operation, backfeeding the recording medium in a direction opposite to the predetermined transport direction, and then outputting a second pattern superimposed on the first pattern output onto the recording medium, which allows the user to identify a nozzle among the predetermined nozzles that is not ejecting ink; An inkjet recording apparatus comprising:

2. 2. The inkjet recording apparatus according to claim 1, wherein the nozzle number pattern is drawn at a position adjacent to the one-dot line of the nozzle check pattern.

3. 2. The inkjet recording apparatus according to claim 1, further comprising a processing unit that performs non-ejection interpolation processing to allocate image data to be recorded to each nozzle based on information specifying the nozzles input by a user operating the operation unit.

4. 1. A method for outputting a nozzle check pattern in an inkjet recording apparatus that performs recording on a recording medium transported in a predetermined transport direction using an inkjet recording head having a plurality of nozzles that eject ink, comprising: a receiving step of receiving a user operation; a first output step of outputting, in response to a user's operation, a first pattern onto the recording medium being transported in the predetermined transport direction, for the user to determine whether or not a predetermined nozzle of the recording head is ejecting ink; a backfeeding step of backfeeding the recording medium in a direction opposite to the predetermined transport direction in response to a user operation after the first output step; a second output step of conveying the recording medium that has been backfed in the backfeed step in the predetermined conveyance direction, and outputting a second pattern that is superimposed on the first pattern output on the recording medium and allows a user to specify the predetermined nozzle; An output method comprising:

Images