Inkjet recording apparatus and inkjet recording method

Abstract

The present invention relates to an inkjet recording device and an inkjet recording method. The inkjet recording device includes a recording unit, an acquisition unit, a scanning unit and a control unit. In the recording unit, a plurality of nozzles supplied with ink from a common liquid chamber are arranged along a first direction. The acquisition unit is configured to acquire image data. The scanning unit is configured to perform relative scanning with a recording medium along a second direction intersecting the first direction. The control unit is configured to control the ink ejection operation of the recording unit. In a predetermined relative scan, for an edge area of ​​a barcode including a plurality of strips whose length in the first direction is longer than that in the second direction, the control unit uses a first nozzle and does not use a second nozzle adjacent to the first nozzle in the first direction.

Description

Technical Field

[0001] One disclosed aspect of the present embodiment relates to an inkjet recording apparatus and an inkjet recording method for recording an image on a recording medium. Background Art

[0002] In recent years, some inkjet recording apparatuses that perform multi-pass recording by multiple scanning on a unit area to record an image have become available. Such inkjet recording apparatuses record images on recording media by performing control to repeat conveyance control of recording media and scanning using a carriage including a recording unit.

[0003] Japanese Patent Laid-Open No. 2002-150211 discusses a recording device that records a barcode on a recording medium. It is expected that the barcode recorded on the recording medium is optically read. Therefore, it is expected that the barcode is recorded with high accuracy. Summary of the invention

[0004] An aspect of the embodiment is directed to an inkjet recording apparatus capable of performing recording so that a recorded article has a strip forming a barcode having a width desired by a user.

[0005] According to one aspect of the embodiment, an inkjet recording device includes: one or more processors; and one or more memories coupled to the processors, which store instructions, which, when executed by the processors, cause the processors to function as: a recording unit, an acquisition unit, a scanning unit, and a control unit. In the recording unit, a plurality of nozzles supplied with ink from a common liquid chamber are arranged along a first direction. The acquisition unit is configured to acquire image data. The scanning unit is configured to perform relative scanning with a recording medium along a second direction intersecting the first direction. The control unit is configured to control the ink ejection operation of the recording unit. In a predetermined relative scan, for an edge area of ​​a barcode including a plurality of strips whose length in the first direction is longer than that in the second direction, the control unit uses a first nozzle and does not use a second nozzle adjacent to the first nozzle in the first direction.

[0006] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a diagram schematically showing an inkjet printer.

[0008] Figure 2 This is a schematic diagram when the recording head is viewed from the nozzle formation surface.

[0009] Figure 3 is a block diagram showing a control configuration of an inkjet recording system.

[0010] Figure 4 is a block diagram showing a recording system.

[0011] Figure 5 is a flowchart of image data processing performed by an image processing device.

[0012] Figure 6 It is a cross-sectional view of an ink flow path showing the flow of ink in the recording head.

[0013] Fig. 7A is a diagram showing a situation where ink droplets land at an ideal position, and Figure 7B It is a figure which shows the barcode in the case where the ink landing accuracy is reduced.

[0014] Fig. 8A and Figure 8B are diagrams each showing an example of the number of ink droplets applied to binary data.

[0015] Fig. 9 is a flowchart illustrating a process for improving ejection stability according to the first exemplary embodiment.

[0016] Fig.10 is a diagram showing a barcode with improved ink landing accuracy according to the first exemplary embodiment.

[0017] Fig.11A and Fig. 11B is a diagram showing an example of a pass mask in the case where a barcode is divided and recorded.

[0018] Fig.12 is a flowchart illustrating a process for improving ejection stability according to the second exemplary embodiment.

[0019] Fig.13 This is a schematic diagram when the recording head is viewed from the nozzle formation surface.

[0020] Fig.14 is a diagram showing an example of a recording operation of multi-pass scanning. DETAILED DESCRIPTION

[0021] Some exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings. Hereinafter, the term "unit" may refer to a software association, a hardware association, or a combination of software and hardware associations. In software association, the term "unit" refers to a utility, application, software module, function, routine, instruction set, or program that can be executed by a programmable processor such as a microprocessor, a central processing unit (CPU), or a specially designed programmable device or controller. The memory contains instructions or programs that, when executed by the CPU, cause the CPU to perform operations corresponding to the unit or function. In hardware association, the term "unit" refers to a hardware element, circuit, component, physical structure, system, module, or subsystem. A unit may include a mechanical component, an optical component, or an electronic component, or any combination thereof. A unit may include an active (e.g., a transistor) or a passive (e.g., a capacitor) component. A unit may include a semiconductor device having a substrate and other material layers having various concentrations of conductivity. A unit may include a CPU or a programmable processor capable of executing a program stored in a memory to perform a specific function. A unit may include a logic element (e.g., AND, OR) implemented by a transistor circuit or any other switching circuit. In the context of a combination of software and hardware, the term "unit" refers to any combination of software and hardware as described above.

[0022] A first exemplary embodiment will be described below. The following description is provided assuming image processing within a printer main body; however, this is merely an example of an exemplary embodiment, and the present disclosure is not limited to the following exemplary embodiments.

[0023] (Description of Inkjet Recording Apparatus)

[0024] Figure 1 30 is a diagram showing a recording apparatus according to the present exemplary embodiment. The recording apparatus is a serial recording inkjet printer, and performs multi-pass recording in which image recording for a unit area is completed by performing a plurality of relative scans of a recording medium P by a recording head 303 .

[0025] The recording medium P fed to the recording unit or circuit passes through a roller nip portion formed by a conveying roller 101 arranged in a conveying path and a pinch roller 102 following the conveying roller 101, and as the conveying roller 101 rotates, the recording medium P is Figure 1104. The recording medium P is transported in the Y direction (sub-scanning direction) indicated by the arrow in FIG. 105. The platen 103 is disposed at a position facing the ejection port face of the recording head 303 of the inkjet recording method where ejection ports (nozzles) are formed. The platen 103 supports the rear surface of the recording medium P from below to maintain a constant distance between the front surface of the recording medium P and the ejection port face of the recording head 303. The recording medium P on which an image has been recorded is transported in the Y direction as the ejection roller 105 rotates while being clamped by the ejection roller 105 and the ratchet 106 following the ejection roller 105, and is ejected to the ejection tray 107.

[0026] The recording head 303 is detachably mounted on the carriage 108 in a posture where the ejection ports face the platen 103 or the recording medium P. The carriage 108 reciprocates in the X direction along two guide rails 109 and 110 by the driving force of the carriage motor. During the reciprocating motion, the recording head 303 performs an ejection operation in response to a recording signal to eject ink droplets from the ejection ports, thereby applying ink to the recording medium P.

[0027] Figure 2 is a schematic diagram of a case where the recording head 303 is viewed from the ejection port surface side. Figure 2 As shown, the cyan nozzle array 21, magenta nozzle array 22, yellow nozzle array 23, and black nozzle array 24 are arranged in parallel in the X direction. In each nozzle array, ejection ports (nozzles) ejecting ink are arranged at equal intervals in the Y direction.

[0028] A recording element (not shown) is provided in each ejection port, and generates thermal energy when the recording element is driven by electric energy. The thermal energy is used to foam the ink so that the ink is ejected from the ejection port as droplets. In the following description, an array in which a plurality of ejection ports for ejecting ink of the same color in the same amount is arranged is referred to as a nozzle array.

[0029] The X direction in which the carriage 108 moves intersects with the Y direction in which the recording medium P is conveyed, and is referred to as a main scanning direction. The Y direction in which the recording medium P is conveyed is referred to as a sub-scanning direction. Multi-pass recording for forming an image on the recording medium P in a step-by-step manner is performed by alternately repeating the movement of the carriage 108 and the recording head 303 accompanying recording (as a main scanning) and the conveyance of the recording medium P (as a sub-scanning).

[0030] Fig.14 2 is a diagram showing the relationship between the recording medium P and nozzles (ejection openings) used for image recording during multi-pass recording. The black nozzle array 24 will be described as an example, and the other nozzle arrays operate in a similar manner.

[0031] In the first scan, forward recording is performed, in which an image is recorded in area A1 by using all nozzles while the carriage 108 and the recording head 303 move in the +X direction (forward direction). After the first scan, the recording medium P is transported in the +Y direction. The transport amount at this time is the length corresponding to all nozzles. After the carriage 108 and the recording head 303 return in the -X direction, forward recording using the second scan is performed. In the second scan, the carriage 108 and the recording head 303 move in the +X direction again, and an image is recorded in area A2 by using all nozzles. After the second scan, the recording medium P is transported in the +Y direction. The transport amount at this time is also the length corresponding to all nozzles. Thereafter, the recording medium P is discharged in the +Y direction, and the recording operation ends.

[0032] As described above, the recording method in the present exemplary embodiment is a one-pass unidirectional recording method in which images in respective predetermined areas ( A1 and A2 ) on the recording medium are completed by a single scan of the recording head 303 in a single direction.

[0033] In the above example, after the first scan in the +X direction, the recording head 303 is returned by scanning in the -X direction without performing the recording operation, and then the second scan in the +X direction is performed. Alternatively, the scan in the -X direction may be performed as the second scan accompanying the recording operation. In other words, after the first scan, the recording medium P is conveyed in the +Y direction by a length corresponding to all the nozzles without returning the carriage 108 and the recording head 303 in the -X direction. Thereafter, in the second scan in the -X direction, an image can be recorded in the area A2 by using all the nozzles.

[0034] Figure 3 301 is a block diagram showing a control configuration of an inkjet recording system according to the present exemplary embodiment. A recording device main control unit or circuit 301 controls the entire recording device, and includes a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM). A recording buffer 302 stores image data before being transferred to a recording head 303 as raster data. The recording head 303 is a recording head of an inkjet recording method including a plurality of nozzles capable of ejecting ink droplets, and ejects ink from each nozzle based on the image data stored in the recording buffer 302. A sheet feed / ejection motor control unit or circuit 304 controls the conveying, feeding, and ejection of a recording medium. A recording device interface (I / F) 305 is connected to an image processing device via an I / F signal line 313, and sends and receives data signals. A data buffer 306 temporarily stores image data received from an image processing device. A system bus 307 is used to connect functional units of a recording device.

[0035] The image processing device main control unit 308 mainly performs the creation of images and the control of image data in the image processing device, and includes a CPU, a ROM, and a RAM. The image processing device I / F 309 sends data signals to / receives data signals from the recording device. The display unit or circuit 310 displays various types of information to the user, and may include, for example, a liquid crystal display (LCD). The operation unit or circuit 311 receives operations and instructions from the user, and may include a keyboard and a mouse. The system bus 312 is a bus that connects the image processing device main control unit or circuit 308 and the functional unit.

[0036] (Description of the summary of the recording system)

[0037] Figure 4 is a block diagram showing an overview of a recording system according to the present exemplary embodiment. Figure 4 The recording system shown includes a personal computer (PC) 401 serving as a host and a recording device (printer) 407 that records an image based on recording data sent from the PC 401. The PC 401 includes an application 402, an operating system (OS) 403, a printer driver 404, and a recording data sending unit 406. In the present exemplary embodiment, the recording data to be sent to the printer 407 includes a barcode image.

[0038] The application 402 can insert the barcode data into the image. In response to an instruction from the printer driver 404, the function for image processing provided by the OS 403 and the data obtained from the application 402 are combined and converted into recording data.

[0039] The printer driver 404 causes the rasterization unit 405 to rasterize (bitmap) the received recording data into an image having a resolution corresponding to the recording head, thereby converting the recording data into recording data receivable by the printer 407. The converted recording data is sent to the recording data transmission unit 406 and then sent to the printer 407.

[0040] Now, the processing until a predetermined character string is sent as barcode data to a printer in a recording system according to the present exemplary embodiment will be described. The barcode data is image data including a barcode, wherein the barcode includes a combination of bars and spaces. The barcode image is generated by converting the predetermined character string into a format including bars and spaces in a barcode font.

[0041] When a character string is input to the application 402, the printer driver 404 is called via the OS 403. Thereafter, the barcode font information stored in the printer driver 404 is requested, and the barcode font designated by the user is set.

[0042] The barcode font information includes information about a barcode font name selected from a plurality of types of barcodes previously registered and information such as the height and width of the barcode font. Examples of the barcode font information include Japanese Article Number (JAN) code, code (CODE) 39, and CODE 128. The setting value and image data of the barcode font are sent from the application 402 to the printer driver 404 via the OS 403.

[0043] Thereafter, the rasterization unit 405 rasterizes the image data into barcode data including a combination of one-dimensional stripes and spaces by using a designated barcode font. The rasterized data is converted into recording data receivable by the printer 407, and the recording data is sent to the printer 407 via the recording data sending unit 406.

[0044] In the present exemplary embodiment, a configuration has been described in which an application program calls a barcode font stored in a printer driver via an OS; however, the configuration is not limited thereto.

[0045] (A brief description of the entire process)

[0046] Figure 5 is a flowchart illustrating image data processing performed by the image processing apparatus according to the present exemplary embodiment. Figure 5 The illustrated processing may be performed by the PC 401 serving as a host, may be performed by the printer 407 , or may be partially shared by the PC 401 and the printer 407 .

[0047] In step S501, image data is input, and the image data to be input may be vector data or bitmap data.

[0048] In step S502, the input image data is drawn and the vector data is rasterized. At this time, mapping and paging corresponding to the size of the recording medium on which the image is to be recorded are performed in some cases.

[0049] Image data corresponding to pixels arranged in a row in a predetermined direction among pixels arranged in a matrix is ​​called raster data. Data corresponding to a plurality of such aligned rows is called band data. In the case where the printer 407 performs image processing on these data, the image processing is performed with a small ROM capacity and a small RAM capacity in some cases, and the band data is processed sequentially in most cases.

[0050] In step S503, the barcode detection unit detects the barcode area. At this time, the position of the detected barcode is acquired. The barcode data may be formed by rasterizing from a barcode font, or may be formed as bitmap data or vector data from the beginning. Therefore, the barcode information may be acquired in the drawing in step S502, or may be detected from edge information or the like after bitmapping. The user may specify the barcode information on the panel or the host, and the method is not limited to the present exemplary embodiment.

[0051] In step S504, the edge detection unit detects edge information related to the strip included in the barcode. At this time, as edge information, information related to pixels corresponding to the edge area of ​​the strip and information related to pixels corresponding to the non-edge area as the area within the edge are detected. The control of the edge area of ​​the barcode described below is performed by using the position information of the barcode acquired in step S503 and the detected edge information. The edge detection process can be performed by a known method such as a Sobel filter or a Laplacian filter. The edge detection process can be performed on the entire area of ​​the input image data, or the edge detection process can be performed only on the detected barcode area.

[0052] In step S505, image processing is performed for converting the image data into image data in a format recordable by the printer 407. At this time, the image data generated in step S504 is converted into image data corresponding to the color reproduction range of the printer 407.

[0053] In the present exemplary embodiment, the input image data represents color coordinates (R, G, B) in a color space coordinate such as the sRGB color space of the monitor for expressing colors. The 8-bit input image data R, G, B is converted into image data (R', G', B') in the color reproduction domain of the printer by known methods such as matrix calculation processing and processing using a three-dimensional lookup table (LUT).

[0054] Next, the 8-bit image data R', G', B' are converted into image data including color signal data corresponding to the ink color used in the printer 407. The printer 407 according to the present exemplary embodiment records an image by using black (K), cyan (C), magenta (M) and yellow (Y) inks. Therefore, the image data of the RGB signal is converted into image data including 8-bit color signals K, C, M, Y. This color conversion is performed by using a three-dimensional LUT and an interpolation calculation together. As another conversion method, a method such as matrix calculation processing can be used as in the case described above. The ink color is not limited to the four colors K, C, M, Y. Low-concentration light cyan (Lc), light magenta (Lm) and gray (Gy) inks, transparent inks, special color inks, and other types of inks can also be used.

[0055] Next, a process for correcting the 8-bit image data to adjust the number of dots to be recorded on the recording medium is performed. The relationship between the number of dots to be applied to the recording medium and the optical density reproduced on the recording medium by the number of dots is not linear. Therefore, an adjustment is performed to establish a linear relationship. In the adjustment process, a one-dimensional LUT can be used to convert input data into output data.

[0056] Next, the 8-bit 256-value image data for each ink color is quantized. Through the quantization process, 1-bit binary data representing recording "1" or non-recording "0" is generated for each pixel. The output of the quantization process can be the number of ink droplets per specific unit area, and is not limited to 1-bit binary data representing recording "1" or non-recording "0". The image data can be quantized into multi-value data of 2 bits or more. The error diffusion method and the dithering method are known as methods for the quantization process, but any method is applicable.

[0057] Ink is applied based on the image data generated in step S505, thereby recording an image on a recording medium.

[0058] (Description of the barcode)

[0059] The barcode includes a combination of strips and spaces, and the strips and spaces are parallel to each other and each has a rectangular shape. The minimum width unit of each strip and space is called the basic module width or the minimum element width, and the strips and spaces are configured based on the width. The width of each strip and space has a characteristic depending on the type of the barcode. For a binary-level barcode, each strip and space has one of two levels of width (up to twice the reference). For a multi-level barcode, each strip and space has any one of a plurality of widths, such as four levels of width (up to four times the reference). Compared with a binary-level barcode, a multi-level barcode generally includes multiple types of strip widths. Therefore, for a multi-level barcode, the allowable variation range of the width is narrow, and a higher recording accuracy is required.

[0060] A blank space called a quiet zone is provided in each of the left and right areas of the barcode.

[0061] Depending on the type of barcode, the required size of the blank space is different. If the size of the blank space is smaller than the required size, the barcode may not be read.

[0062] The barcode reader uses a red light source. Light is applied from the light source to the barcode, and the reflected light is read. Therefore, in order to properly read the barcode, the color of the area of ​​the stripes should be a color that absorbs wavelengths of red light, and the color of the area of ​​the spaces should be a color that reflects wavelengths of red light. In many cases, the barcode typically includes black stripes and white spaces; however, the stripes can be formed of a color that absorbs wavelengths of red light, such as blue or green, and the spaces can be formed of a color that reflects wavelengths of red light, such as red or yellow.

[0063] In order for a barcode reader to be able to properly read a barcode, elements required for the quality of a recorded barcode are standardized by International Organization for Standardization / International Electrotechnical Commission (ISO / IEC) 15416 as follows.

[0064] The minimum reflectivity is the minimum reflectivity in the entire barcode. When the minimum reflectivity is 50% or less, the barcode is readable.

[0065] Symbol contrast is the difference between the maximum and minimum reflectivity across the barcode.

[0066] The symbol contrast is represented by the value obtained by subtracting the darkest reflectivity of the strip from the brightest reflectivity of the interval. The larger the value, the higher the readability of the barcode.

[0067] The minimum edge contrast is the minimum of the differences in reflectivity between a space and its adjacent (one or more) stripes. When the minimum difference is 15% or greater, the barcode is readable.

[0068] Modulation is the ratio of the minimum edge contrast to the symbol contrast.The readability of the barcode increases as the difference in reflectivity between a space and its adjacent (one or more) stripes increases.

[0069] Defects are gaps (vacancies) in any stripe and dirt (spots) in any space. When uneven reflectivity valleys appear relative to one ridge corresponding to the maximum reflectivity in each space, the readability of the barcode increases as the difference between the maximum reflectivity at the ridge and the reflectivity at the valley is smaller. For stripes, the ridges and valleys are the opposite of the ridges and valleys for each space.

[0070] Decodability is the margin in determining the value based on the decoding rules defined for each barcode. The readability of a barcode increases as the actual measured values ​​of the width of the bars and spaces get closer to the ideal width.

[0071] (Barcode reading)

[0072] Among the above factors, modulation is a problem in inkjet recording devices. In inkjet recording devices, ejecting ink droplets from a large number of nozzles simultaneously may reduce the ejection stability of the ink. The reduction in ejection stability may cause the ink landing accuracy on the recording medium to decrease, so that the ink may land at a position deviating from the expected landing position. As a result, the width of the strip forming the barcode may vary due to the deviation of the landing position, which may have an impact on the reading result. The details of the ejection stability of the recording head will be described below.

[0073] Figure 6 6 is a schematic cross-sectional view of an ink flow path showing the flow of ink as a liquid in the recording head 303. Ink is supplied from an ink reservoir (not shown) to the common liquid chamber 62 through an ink supply port 61. The ink supplied to the common liquid chamber 62 is filled into the nozzle 64a through the flow path. When a voltage is applied to a heater 63 as a recording element provided above the nozzle 64a, the ink is foamed and ink droplets are ejected from the nozzle 64a.

[0074] Most of the energy generated by bubbling is converted into the ejection of ink droplets, but part of the energy propagates from the nozzle 64a to the common liquid chamber 62. The propagated energy causes the ink in the common liquid chamber 62 to vibrate, and has an influence on the meniscus vibration of the ink filled in the nozzle 64b adjacent to the nozzle 64a. In this way, in the head configuration in which ink is supplied from the common liquid chamber 62 to the nozzle 64a and the nozzle 64b adjacent to the nozzle 64a, the ejection operation of the ink droplets of the nozzle 64a causes the ink in the nozzle 64b to vibrate. As a result, the operation of ejecting ink from the nozzle 64b becomes unstable.

[0075] Fig. 7A and Figure 7B1 is a diagram showing a situation where the ink landing position on the recording medium is deviated due to such a decrease in ejection stability. Fig. 7A Shows the ink droplets landing at the ideal position. Figure 7B The figure shows the situation where the landing position of the ink droplet is deviated due to the influence of the ejection operation of the adjacent nozzle. Figure 7B In the case where each interval between two stripes is represented by a blank space to which ink is not applied, the width of the stripes constituting the barcode is wider than the width of the stripes in the image data due to the deviation of the landing position. Fig. 7A The ink droplets shown land at different ideal positions, and the intervals are as follows: Figure 7B Shown narrowed by thick bands.

[0076] The barcode image includes a plurality of stripes and a plurality of spaces, and there are a variety of stripe widths and space widths. In particular, when the above-mentioned landing deviation occurs to a stripe adjacent to a space having a narrow width, the space is squeezed and a sufficient reflectivity cannot be obtained. The reduction in the reflectivity of the space causes the difference in reflectivity with the adjacent stripe to decrease, and the modulation decreases. Therefore, the barcode cannot be read correctly. The characteristic configuration for solving such a problem according to the present exemplary embodiment will be described below.

[0077] (Description of record control)

[0078] Fig. 8A is a diagram showing the number of ink droplets to be applied per unit area when 1-bit binary data indicating recording "1" or non-recording "0" is input. Fig. 8A As shown, pattern A and pattern B are prepared. It is specified that when binary data indicates recording "1", one dot is recorded to each non-edge area of ​​the strip of the bar code image in both pattern A and pattern B. It is specified that when binary data indicates recording "1", one dot is recorded to each edge area of ​​the strip of the bar code in one of the patterns, and zero dot is recorded (i.e., no recording is performed) to each edge area of ​​the strip of the bar code in the other pattern.

[0079] Figure 8B The pattern assigned to the input image data is shown. The pattern can be used to control which of pattern A and pattern B is assigned to the input value. In the present exemplary embodiment, control can be performed by synchronizing the spacing between the pattern and the nozzle so that two adjacent nozzles do not eject ink to the object area at the same time. In this example, ink is not ejected to the pixel in pattern B even when the binary data indicates recording "1". In other words, control is performed so that ink is ejected only from the odd-numbered nozzles to the edge area, and ink is not ejected from the even-numbered nozzles.

[0080] Fig. 9 is a flowchart showing the processing of recording device main control unit or circuit 301 to record image data.

[0081] In step S901 , image data in a binary data format and information indicating a detected edge region of a barcode are input.

[0082] In step S902 , it is determined for each pixel whether the pixel corresponds to the detected edge region of the barcode.

[0083] In steps S903 and S904, Fig. 8A and Figure 8B The recording pattern is allocated as shown, and the number of ink droplets to be applied per unit area is determined. As a result, in the non-edge area of ​​the bar code, one dot is applied to each pixel having a value "1" indicating recording, while in the edge area of ​​the bar code, even for each pixel having a value "1" indicating recording, a pixel to which no dot is applied is generated.

[0084] Finally, in step S905, recording based on the number of applied ink droplets is performed, and ink is applied.

[0085] Fig.10 FIG. 1 is a diagram showing the dot arrangement of a bar code recorded on a recording medium. Fig.10 In the embodiment of the present invention, two nozzles adjacent in the vertical direction do not eject ink to the edge areas of the stripe area 1001 and the stripe area 1003 at the same time. When viewed by human eyes, if the vertical straightness is lost in the edge area of ​​the stripe, the human eye perceives the stripe as if the reading accuracy of the bar code is reduced. However, for the bar code, the vertical straightness of the edge area is unnecessary. Therefore, even if such processing is performed, the reading accuracy will not be reduced.

[0086] As described above, in the case where two adjacent nozzles eject ink simultaneously in an inkjet recording device, the ejection becomes unstable and the landing accuracy decreases. In contrast, limiting the simultaneous ejection from two adjacent nozzles enables stable ejection, thereby preventing the reduction in landing accuracy. In this way, preventing the landing deviation of the edge areas of the strips on both sides enables the reflectivity of the spacing area 1002 adjacent to the strips to be prevented from being reduced. In the present exemplary embodiment, control is performed so as not to restrict the simultaneous ejection from two adjacent nozzles for areas other than the edge areas of the strips. This is because, in the modulation, which is one of the elements required for the bar code, it is expected that the difference in reflectivity between the spacing and the strips adjacent thereto is large. For areas other than the edge areas of the strips, simultaneous ejection from two adjacent nozzles enables the reflectivity of the strip area to be reduced, thereby preventing the degradation of the modulation when the bar code is read.

[0087] In the present exemplary embodiment, in order to limit the simultaneous ejection from two adjacent nozzles, the binary recording data indicating whether ink is applied is changed; however, a similar effect can be produced by other methods. For example, in the case where the number of dots to be recorded on the recording medium is adjusted by using a one-dimensional LUT in step S505, the LUT can be changed to a LUT having a different adjusted value based on information indicating whether a pixel corresponds to an edge area of ​​a barcode. Quantization processing can be performed based on the information whether a pixel corresponds to an edge area of ​​a barcode so that the value of a pixel corresponding to one of any two adjacent nozzles becomes non-recorded "0".

[0088] In the present exemplary embodiment, the edge area and the non-edge area are detected as edge information related to the barcode. For the area other than the barcode, it is desirable to perform a process similar to that performed on the non-edge area of ​​the barcode. In other words, simultaneous ejection from two adjacent nozzles may be restricted only for the edge area of ​​the barcode, and simultaneous ejection may not be restricted for other areas.

[0089] In this exemplary embodiment, although the edge area of ​​the barcode is extracted by using an edge detection filter or the like, and the simultaneous ejection from two adjacent nozzles is restricted for the edge area, this restriction does not need to be performed on all edge areas. The problem to be solved is ink leakage in the edge area extending along the Y direction, which is the arrangement direction of the plurality of nozzles. Therefore, only the edge area and the interval of the barcode including the strip extending along the Y direction (i.e., the strip whose length in the Y direction is longer than the length in the X direction) can be detected. At the edge in the X direction, there will be no reading problem due to leakage. Therefore, only the strip extending along the Y direction (i.e., the strip whose length in the Y direction is longer than the length in the X direction) can be detected. Fig. 7A and 7B The side edges of the strips extending in the up and down directions (in the image) are detected as edge areas.

[0090] The barcode has a configuration for reading reflected light at a portion where light is applied, and is sufficient to limit simultaneous ejection from adjacent nozzles in most edge regions of the barcode. For example, even when simultaneous ejection from adjacent nozzles is performed on a portion of the edge region, the beneficial effects of this exemplary embodiment can be achieved.

[0091] exist Fig. 8A and Figure 8BIn the example shown, control is performed so that ink is ejected from the odd nozzles assigned with pattern A and ink is not ejected from the even nozzles assigned with pattern B. Therefore, in the case where the amount of ink ejected from all nozzles simultaneously is 100%, the ratio of ink ejected from the odd nozzles is 100%, and the ratio of ink ejected from the even nozzles is 0%. As described above, when the influence of simultaneous ejection can be controlled, the ratio of ink from one of the even nozzles and the odd nozzles may not be 0%. Ink may be ejected from the even nozzles. In this exemplary embodiment, for the non-edge area, the ratio of ink ejected from the odd nozzles is 100%, for the non-edge area, the ratio of ink ejected from the even nozzles is 100%, and the difference therebetween is 0%. On the other hand, for the edge area, the ratio of ink ejected from the odd nozzles is 100%, for the edge area, the ratio of ink ejected from the even nozzles is 0%, and the difference therebetween is 100%. It is expected that the difference between the ratios of ink ejected from two adjacent nozzles for the edge area is greater than the difference between the ratios of ink ejected from two adjacent nozzles for the non-edge area. The relationship between the odd-numbered nozzles and the even-numbered nozzles may be reversed, and the ratio of ink ejected from the even-numbered nozzles may be large for the edge area.

[0092] In the present exemplary embodiment, although the form of quantizing 8-bit 256-value image data into binary data representing recording "1" or non-recording "0" has been described, the image data may be quantized into multi-value data of 3 or more values. In the case where the image data is quantized into multi-value data, binary recording data may be generated by further converting one pixel of the multi-value data into multiple pixels using an index. For example, data representing recording or non-recording of four pixels including two pixels in the vertical direction and two pixels in the lateral direction is generated from one pixel of the multi-value data. When performing index expansion, an index that is not used for simultaneous ejection in the edge area of ​​the barcode may be used. For example, for recording data of four pixels including two pixels in the vertical direction and two pixels in the lateral direction, an index that is used to generate the following data may be used, in which ink is ejected from only one of two adjacent nozzles and ink is not ejected from the other nozzle. In other words, simultaneous ejection may be limited by using the following index, in which data for indicating that ink is ejected only to the upper two pixels or the lower two pixels is applied using the index.

[0093] A second exemplary embodiment will be described below. In this exemplary embodiment, components different from those in the first exemplary embodiment will be described. Components similar to those in the first exemplary embodiment are represented by the same reference numerals, detailed description of the components is omitted, and only different components are described in detail.

[0094] In the first exemplary embodiment, the edge area of ​​the barcode is detected, the jetting stability is enhanced by limiting the ink jetting of two adjacent nozzles at the same time in one scan, and the recording of the barcode image is completed by one scan. This is called one-pass recording. In the present exemplary embodiment, a configuration for completing the recording of the barcode image by multi-pass recording will be described. In the multi-pass recording, a plurality of image data corresponding to each of the multiple scans are generated based on the input image data, and the image is recorded by the multiple scans.

[0095] Fig.11A and Fig. 11B is a diagram showing a pass mask used for dividing image data when the image data is divided and recorded by two scans. Fig.11A shows a pass mask for non-edge areas of the barcode, and Fig. 11B The mask for the edge area of ​​the barcode is shown. The pixels shown by the oblique lines are recording pixels that allow ink to be applied during scanning, and the white pixels are non-recording pixels that do not allow ink to be applied. The two masks have a mutually exclusive relationship, and all pixels are recorded by two scans.

[0096] exist Fig.11A In the embodiment, during the first scan for the non-edge area of ​​the barcode, recording is performed based on the recording data generated by using the mask 1101, and during the second scan, recording is performed based on the recording data generated by using the mask 1102. Fig. 11B 1104. In the embodiment of the present invention, during the first scan for the edge area of ​​the barcode, recording is performed based on the recording data generated by using the mask 1103, and during the second scan, recording is performed based on the recording data generated by using the mask 1104. The recording pixels and non-recording pixels of the respective masks are arranged so that simultaneous ejection from two adjacent nozzles is not performed in the recording performed by each scan of the edge area.

[0097] Fig.12 : is a flowchart illustrating a process of recording image data according to the present exemplary embodiment.

[0098] In step S1201, image data in a binary data format and information indicating a detected edge region of a barcode are input.

[0099] In step S1202, the number of ink drops to be applied per unit area is determined. In the present exemplary embodiment, one dot is applied to a pixel having a value indicating recording "1", regardless of whether the pixel corresponds to an edge region or a non-edge region of the barcode.

[0100] In step S1203, it is determined for each pixel whether the pixel corresponds to an edge area of ​​the barcode.

[0101] In steps S1204 and S1205, a pass mask is assigned to binary data. Through this process, a pass mask set not to perform simultaneous ejection from two adjacent nozzles in the same scan is assigned to the edge area of ​​the barcode.

[0102] Finally, in step S1206 , an image is recorded based on each recording data corresponding to two scans.

[0103] In the present exemplary embodiment, for the edge area of ​​the barcode, a pass mask is used in which recording pixels and non-recording pixels are arranged so as not to perform simultaneous ejection from two adjacent nozzles in one scan. Restriction is performed so that simultaneous ejection from two adjacent nozzles is not performed, which stabilizes the ink ejection operation of each nozzle, thereby preventing a decrease in landing accuracy.

[0104] In the case of segmenting and recording image data by multiple scans, the total number of dots supplied to the recording medium can be maintained even if restrictions are imposed on simultaneous ejection from two adjacent nozzles. Therefore, for modulation, which is one of the elements required for a barcode, the reflectivity of the spacer area can be increased while keeping the reflectivity of the stripe area low. This makes it possible to maintain reading accuracy.

[0105] In the present exemplary embodiment, a configuration has been described in which the image data is divided and an image including a barcode is recorded by two scans. The present exemplary embodiment is similarly applicable to a configuration in which the image data is divided and an image including a barcode is recorded by three or more scans. In other words, by controlling simultaneous ejection from two adjacent nozzles in one scan, a barcode image with high image quality can be obtained while achieving ink ejection stability.

[0106] (Other embodiments)

[0107] In the above exemplary embodiments, a method for maintaining ejection stability by limiting the simultaneous ejection of two adjacent nozzles has been described. Depending on the nozzle interval of the recording head and the flow path length to the liquid chamber, the vibration of the ink via the common liquid chamber may have an influence on the ejection operation of the nozzles separating two or more nozzles. In the present disclosure, the simultaneous ejection of the nozzles within the range where the ejection operation is affected can be limited.

[0108] In the above exemplary embodiment, restrictions are made so that simultaneous ejection from two adjacent nozzles is not performed. The ejection of ink from pixels arranged in the same row (in the same column) along the nozzle arrangement direction (Y direction in the figure) on the recording medium is defined as simultaneous ejection. Depending on the driving frequency of the recording head and the composition of the ink, the degree of influence of the vibration of the ink from the adjacent nozzles is different. Therefore, the problem may not be solved by only restricting the ejection of adjacent nozzles for recording one pixel in the X direction. Therefore, simultaneous ejection for an area including two or more pixels continuous in the X direction can be restricted.

[0109] Similar problems may arise in configurations where multiple nozzle arrays are connected to a common fluid chamber. Fig.13 As shown, the present disclosure is also applicable to a recording head having the following configuration, wherein a nozzle array including an even number of nozzles and a nozzle array including an odd number of nozzles are connected to a common liquid chamber, and these nozzle arrays are arranged while being offset in the X direction. At this time, the simultaneous ejection of ink may affect the ink ejection operation of two adjacent nozzles using the common liquid chamber. For example, in the case of supplying ink from a common liquid chamber to two nozzle arrays included in the nozzle group 1321, the ejection operation of nozzle 1321a may affect the ejection operation of nozzle 1321b. In other words, in the case of supplying ink from the same common liquid chamber to multiple nozzle arrays, the simultaneous operation of two nozzles (in the figure, nozzle 1321a and nozzle 1321b) located adjacent to each other in the Y direction in the figure is limited.

[0110] Although a thermal recording head using an electrothermal conversion element as a recording element for ejecting ink has been described in the above exemplary embodiments, the recording head may be a piezoelectric recording head that ejects ink by applying a voltage to a piezoelectric element to change the volume.

[0111] In the above-described exemplary embodiments, a serial recording inkjet recording apparatus has been described that records an image by scanning a recording head including a plurality of arranged nozzles in a direction intersecting the nozzle arrangement direction. The present disclosure is applicable to a form in which an image is recorded by relative scanning of a recording medium and a recording head. For example, the present disclosure may be applied to a full-width multi-inkjet recording apparatus in which a recording medium is conveyed in a direction intersecting the nozzle arrangement direction, and an image is recorded by using a line head capable of recording an image over the entire width of the recording medium by a single scan. Even in the case of a full-width multi-inkjet recording apparatus, it is desirable to apply the above-described configuration to a barcode in which a strip extends in the nozzle arrangement direction.

[0112] Although the width of each edge region of the barcode is described as one pixel in the above exemplary embodiment, the number of pixels to be detected as edge regions may be two or more. In this case, it is desirable to restrict simultaneous ejection of two adjacent nozzles in an area having a width of one pixel along the nozzle arrangement direction. In other words, it is desirable that the difference between the ratios of ink ejected from two adjacent nozzles for the edge region is greater than the difference between the ratios of ink ejected from two adjacent nozzles for the non-edge region.

[0113] The present disclosure can be implemented by combining the configuration according to the first exemplary embodiment and the configuration according to the second exemplary embodiment.

[0114] According to an exemplary embodiment of the present disclosure, it is possible to record a record item in which stripes constituting a barcode each have a width desired by a user.

[0115] Other embodiments

[0116] The disclosed embodiments may also be implemented by providing software (program) for performing the functions of the above embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0117] While the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An inkjet recording device, comprising: one or more processors; as well as One or more memories coupled to the processor storing instructions that, when executed by the processor, cause the processor to: a recording unit in which a plurality of nozzles supplied with ink from a common liquid chamber are arranged in a first direction; an acquisition unit configured to acquire image data; a scanning unit configured to perform relative scanning with respect to the recording medium along a second direction intersecting with the first direction; as well as a control unit configured to control an ink ejection operation of the recording unit, In which, in a predetermined relative scan, for an edge area of ​​a barcode including multiple strips whose length in the first direction is longer than that in the second direction, the control unit uses a first nozzle instead of a second nozzle adjacent to the first nozzle in the first direction to spray ink onto the edge area.

2. The inkjet recording apparatus according to claim 1, wherein In the predetermined one relative scanning, the control unit ejects ink to a non-edge area of ​​the barcode using the first nozzle and the second nozzle.

3. The inkjet recording apparatus according to claim 1, wherein In the predetermined one relative scan, the control unit ejects ink to the edge area using one type of nozzles of odd-numbered nozzles and even-numbered nozzles without using the other type of nozzles, wherein the odd-numbered nozzles and the even-numbered nozzles are arranged along the first direction. 4 . The inkjet recording apparatus according to claim 1 , further comprising a detection unit configured to detect an edge region and a non-edge region from the image data.

5. The inkjet recording apparatus according to claim 4, wherein The detection unit detects only the sides of the plurality of strips extending along the first direction as edge areas.

6. The inkjet recording apparatus according to claim 1, wherein The control unit completes recording of the edge area through the predetermined one relative scanning.

7. The inkjet recording apparatus according to claim 1, wherein The control unit completes recording for the edge area through a plurality of relative scans including the predetermined one relative scan.

8. The inkjet recording apparatus according to claim 7, in, The control unit generates recording data corresponding to each relative scan of the plurality of relative scans by dividing the image data using a pass mask corresponding to the plurality of relative scans, and Here, for the edge region, a pass mask is used which is set to allow recording for pixels corresponding to the first nozzle and not allow recording for pixels corresponding to the second nozzle.

9. The inkjet recording apparatus according to claim 1, wherein The first nozzle and the second nozzle are arranged while being offset from each other in the second direction. 10 . The inkjet recording apparatus according to claim 1 , further comprising a carriage configured to move the recording unit in the second direction relative to the recording medium.

11. An inkjet recording device comprising: one or more processors; as well as One or more memories coupled to the processor storing instructions that, when executed by the processor, cause the processor to: a recording unit in which a plurality of nozzles supplied with ink from a common liquid chamber are arranged in a first direction; an acquisition unit configured to acquire image data; a scanning unit configured to perform relative scanning with respect to the recording medium along a second direction intersecting with the first direction; as well as a control unit configured to control an ejection operation of ink from the recording unit, wherein, in a predetermined one relative scan, for an edge region of a barcode including a plurality of strips whose length in the first direction is longer than that in the second direction, the control unit controls so that a difference between a ratio of ink ejected from a first nozzle and a ratio of ink ejected from a second nozzle adjacent to the first nozzle in the first direction becomes a first value, and Wherein, in the predetermined relative scan, the control unit controls the non-edge area of ​​the barcode so that the difference between the ratio of ink ejected from the first nozzle and the ratio of ink ejected from the second nozzle becomes a second value smaller than the first value.

12. An inkjet recording method, using a recording unit and a scanning unit, in which a plurality of nozzles supplied with ink from a common liquid chamber are arranged along a first direction, and the scanning unit is configured to perform relative scanning with respect to a recording medium along a second direction intersecting the first direction, the inkjet recording method comprising: Get image data; as well as controlling the ink ejection operation of the recording unit, In which, in a predetermined relative scan, in recording an edge area of ​​a barcode including multiple strips whose length in the first direction is longer than that in the second direction, ink is ejected to the edge area using a first nozzle instead of a second nozzle adjacent to the first nozzle in the first direction.

13. The inkjet recording method according to claim 12, wherein: In the predetermined one relative scanning, in recording for a non-edge area of ​​the barcode, ink is ejected to the non-edge area using the first nozzle and the second nozzle.

14. The inkjet recording method according to claim 12, wherein: In the predetermined one relative scan, in recording for an edge area, ink is ejected to the edge area using one of odd-numbered nozzles and even-numbered nozzles without using the other nozzle, wherein the odd-numbered nozzles and the even-numbered nozzles are arranged along the first direction.

15. The inkjet recording method according to claim 12, further comprising: An edge region and a non-edge region are detected from the image data.

16. The inkjet recording method according to claim 15, wherein In the detection, edge regions are detected only from sides of the plurality of strips extending along the first direction.

17. The inkjet recording method according to claim 12, wherein: The recording of the edge area is completed by the predetermined one relative scanning.

18. The inkjet recording method according to claim 12, wherein: The recording for the edge area is completed by a plurality of relative scans including the predetermined one relative scan.

19. An inkjet recording method, using a recording unit and a scanning unit, wherein a plurality of nozzles supplied with ink from a common liquid chamber are arranged along a first direction in the recording unit, and the scanning unit is configured to perform relative scanning with respect to a recording medium along a second direction intersecting the first direction, the inkjet recording method comprising: Get image data; as well as controlling the ink ejection operation of the recording unit, wherein, in a predetermined one relative scan, in recording for an edge region of a barcode including a plurality of strips whose length in the first direction is longer than that in the second direction, a difference between a ratio of ink ejected from a first nozzle and a ratio of ink ejected from a second nozzle adjacent to the first nozzle in the first direction is a first value, and wherein, in the predetermined one relative scan, in the record for the non-edge area of ​​the barcode, the difference between the ratio of ink ejected from the first nozzle and the ratio of ink ejected from the second nozzle is a second value smaller than the first value.

Images