JP2023028427A - Inkjet recording device and inkjet recording method - Google Patents

Abstract

To solve such the problem that there is a concern when a vicinity of the center of a bar code part becomes a boundary of recording scanning which may affect bar code reading accuracy.SOLUTION: When a length of a bar code part is longer than a length recorded by one scanning operation and shorter than twice the length, transportation of a recording medium is controlled so as to record the bar code part with three scanning operations.SELECTED DRAWING: Figure 8

Description

The present invention relates to an inkjet recording apparatus and an inkjet recording method for recording an image on a recording medium.

2. Description of the Related Art In recent years, there has been known an inkjet printing apparatus that performs so-called multi-pass printing, in which an image is printed by scanning a unit area multiple times. Such an inkjet printing apparatus prints an image on a printing medium by repeatedly controlling the conveyance of the printing medium and scanning the carriage on which the printing head is mounted.

Patent Literature 1 describes a recording system for recording barcodes. A barcode recorded on a recording medium is expected to be optically read, and a highly accurate barcode image is required to be recorded.

Japanese Patent Application Laid-Open No. 2002-150211

On the other hand, in an inkjet printing apparatus, when one bar code is printed by two or more print scans, there is a possibility that conveyance control will be performed between print scans. At this time, if the transport accuracy for transporting the recording medium is low, an error may occur in the transport amount, and variations in the line widths of the bars that make up the barcode, jaggedness of the lines, white spots, etc. may occur. There is

Such deterioration in barcode quality may affect the reading of the barcode recorded on the recording medium. In general, the vicinity of the center of the bar of the barcode is easily read, and if the vicinity of the center of the bar is jolted, it is conceivable that it cannot be read accurately or that it takes a long time to read.

SUMMARY OF THE INVENTION In view of such problems, it is an object of the present invention to provide a printing apparatus capable of suppressing deterioration in image quality in the vicinity of the bar center of a bar code, and suppressing the influence during reading due to conveyance of the printing medium. .

According to the present invention, a conveying means for conveying a recording medium in a first direction; and a nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction. recording means for recording an image on the recording medium conveyed by the conveying means by scanning in a second intersecting direction; A recording apparatus comprising: a control unit for controlling the conveying unit and the recording unit so as to record an image on the recording medium by performing a conveying operation for conveying a medium and a recording operation by scanning the recording unit. wherein the length of the bar code portion recorded on the recording medium in the first direction is the length of the area recorded in one scan by the recording means in the first direction. so that the barcode portion is recorded by three scans by the recording means, if longer than a first length that is the length in and shorter than twice the first length, It is characterized by controlling the conveyance of the recording medium by the conveying means.

The present invention can suppress deterioration in image quality in the vicinity of the center of a bar in a bar code, and can suppress the influence during reading due to conveyance of a recording medium.

A diagram schematically showing an inkjet printer Schematic diagram when the print head 303 is observed from the nozzle forming surface. Block diagram of control configuration of IJ recording system Block diagram of the system of record overview Flow chart of image data processing performed by the image processing device Schematic diagram showing a connecting portion during barcode recording, which is a problem of the present invention. Perspective view of barcode reader Schematic diagram showing a connecting portion during barcode recording in Embodiment 1. FIG. FIG. 10 is a flowchart for adjusting the conveying amount in the first embodiment; Schematic diagram showing the feed amount and band data when adjusting the feed amount Schematic diagram showing a connecting portion at the time of barcode recording in a modified example of the first embodiment. Schematic diagram showing a connecting portion during barcode recording in the second embodiment. Schematic diagram showing a connecting portion during barcode recording in Embodiment 3 Explanatory diagram of the multi-pass printing method

(First embodiment)
An embodiment of the present invention will be described below with reference to the drawings.

The first embodiment will be described below. Note that the following description assumes image processing inside the printer main body, but this is merely an example of one embodiment, and the present embodiment is not limited to the following. .

(Explanation of inkjet recording device)
FIG. 1 is a diagram for explaining the printing apparatus of this embodiment. The printing apparatus of the present embodiment is a so-called serial printing type inkjet printer, and executes multi-pass printing in which the printing of an image on a unit area is completed by a plurality of relative scans of the printing head 303 on the printing medium P. FIG.

The recording medium P fed to the recording unit is moved in the direction of arrow Y ( hereinafter also referred to as the transport direction).

The platen 103 is provided at a position facing the ejection port surface on which the ejection ports (hereinafter also referred to as nozzles) of the print head 303 are formed. By supporting the back surface of the recording medium P from below, the distance between the front surface of the recording medium P and the ejection surface of the recording head 303 is kept constant.

The recording medium P on which an image has been recorded is conveyed in the Y direction as the discharge roller 105 rotates while being nipped between the discharge roller 105 and the spur 106 driven by the discharge roller 105 , and discharged to the paper discharge tray 107 . The discharge roller 105 and the spur 106 form the constituent elements of the second conveying means on the downstream side in the conveying direction of the recording medium.

The print head 303 is detachably mounted on the carriage 108 with the ejection port surface facing the platen 103 or the print medium P. FIG. The carriage 108 reciprocates in the X direction along two guide rails 109 and 110 by the driving force of the carriage motor. In the course of the movement, the print head 303 executes an ejection operation of ejecting ink from ejection openings according to a print signal, and applies ink onto the print medium.

FIG. 2 is a schematic diagram of the print head 303 viewed from the ejection port surface. In this embodiment, the cyan nozzle row 21, the magenta nozzle row 22, the yellow nozzle row 23, and the black nozzle row 24 are arranged in parallel in the X direction as shown. In each nozzle row, ejection openings (nozzles) for ejecting ink are arranged at regular intervals in the Y direction.

A printing element (not shown) is provided inside each ejection port, and thermal energy is generated by driving the printing element with electrical energy. This thermal energy causes the ink to bubble, and the ink is ejected as droplets from the ejection port. In the following description, for the sake of simplification, a row in which a plurality of ejection openings for ejecting the same color and the same amount of ink are lined up is referred to as a nozzle row. The present embodiment is not limited to the above-described thermal ink jet recording head, and may be provided with a piezo ink jet recording head.

The X direction in which the carriage 108 moves is a direction intersecting with the Y direction in which the print medium is conveyed, and is called a scanning direction. By alternately repeating the main scanning movement of the carriage 108 and the print head 303, which accompanies printing, and the conveyance of the print medium, multi-pass printing is performed in which an image is formed on the print medium P in stages.

FIG. 14 is a diagram for explaining the relationship between the print medium P during multi-pass printing and ejection openings (nozzles) used for image printing. Here, the black nozzle row 24 will be described as an example, but the same applies to other nozzle rows.

First, in the first scan, while moving the print head 303 together with the carriage 108 in the +X direction (forward direction), all nozzles are used to print an image in the area A1. After the first scan, the recording medium P is conveyed in the +Y direction. The transport amount at this time is the length corresponding to all the nozzles arranged in the print head 303 . After returning the print head 303 together with the carriage 108 in the -X direction (return direction), forward printing is performed in the forward direction by the second scan. In the second scan, the print head 303 is again moved in the +X direction together with the carriage 108, and an image is printed in area A2 using all the nozzles. After the second scan, the recording medium P is conveyed in the +Y direction. The transport amount at this time is also the length corresponding to all the nozzles. After that, the recording medium P is ejected in the +Y direction, and the recording operation ends.

As described above, the printing method in this embodiment is a one-pass unidirectional printing method in which an image in a predetermined area (A1, A2) on the printing medium is completed by one-time scanning of the printing head 303 in one direction. The conveying amount per time is equal to the nozzle length. That is, the length in the Y direction of the area printed in one printing scan is the nozzle length.

In the above example, after the first scan in the +X direction, the print head 303 was returned by scanning in the -X direction without printing, and the second scan in the +X direction was performed. It is also possible to perform the printing operation by reciprocating scanning, in which the scanning of the second scanning is the second scanning accompanied by the printing operation. That is, after the first scan, the carriage 108 and print head 303 are not returned in the -X direction, and the print medium P is conveyed in the +Y direction by the length of all the nozzles. After that, in the second scan in the -X direction, all nozzles may be used to record an image in the area A2.

FIG. 3 is a block diagram for explaining the control configuration of the inkjet printing system of this embodiment. A printing apparatus main control unit 301 controls the printing apparatus as a whole and includes a CPU, a ROM, a RAM, and the like. A print buffer 302 stores image data before being transferred to the print head 303 as raster data. The print head 303 is an inkjet print type print head having a plurality of nozzles capable of ejecting ink droplets, and ejects ink from each nozzle according to the image data stored in the print buffer 302 . A paper feed/discharge motor control unit 304 controls conveyance and paper feed/discharge of a recording medium. An interface (I/F) 305 is connected to the image processing apparatus via an I/F signal line 313 and exchanges data signals. A data buffer 306 temporarily stores image data received from the image processing apparatus. A system bus 307 is a bus that connects each function of the printing apparatus.

An image processing apparatus main control unit 308 mainly controls image creation and image data control in the image processing apparatus, and includes a CPU, a ROM, a RAM, and the like. An interface (I/F) 309 exchanges data signals with the recording apparatus. The display unit 310 displays various information to the user, and can apply an LCD, for example. An operation unit 311 is an operation unit for receiving an operation/instruction from a user, and can be a keyboard or a mouse, for example. A system bus 312 is a bus that connects the image processing apparatus main control unit 308 and each function.

(Overview of recording system)
FIG. 4 is a block diagram for explaining the outline of the recording system of this embodiment. The printing system shown in this figure includes a PC 401 serving as a host, and a printing apparatus (printer) 407 that prints an image based on print data transmitted from the PC 401 . The PC 401 is composed of an application 402 , an OS 403 , a printer driver 404 and a print data transmission unit 406 . In this embodiment, print data sent to the printer 407 is print data including a bar code image.

Application 402 is an application that can insert barcode data into an image. According to an instruction from the printer driver 404, the functions required for image processing provided by the OS 403 and data obtained from the application 402 are combined and converted into print data.

The printer driver 404 rasterizes (bitmaps) the received print data in a rasterization unit 405 and converts it into print data in a form that can be received by the printer. The converted print data is sent to the print data transmission unit 406 and transmitted to the printer 407 .

Next, in the recording system of this embodiment, the process of sending a predetermined character string as bar code data to the printer will be described.

Barcode data is image data containing a so-called barcode, which is composed of a combination of one-dimensional bars and spaces. In this specification, the black bars forming the barcode are called "bars" and the white bars are called "spaces". A plurality of bars forming a barcode are arranged in parallel. The bars and spaces are rectangles, the length of the long side of which is called the "length of the bar (or space)" and the length of the short side of which is called the "width of the bar (or space)". A barcode image is generated by converting a predefined character string into a form consisting of bars and spaces according to the barcode font.

The width of the bars and spaces varies depending on the type of barcode. For example, a binary-level barcode consists of two levels of width, and a multi-level barcode consists of multiple levels of width, such as four levels. In general, multi-level barcodes have more width variations than binary-level barcodes. For this reason, multi-level barcodes have a narrower tolerance for width variations and require higher recording accuracy.

When a character string is input to the application 402 , the printer driver 404 is called via the OS 403 . Then, the barcode font information stored in the printer driver 404 is requested, and the user sets the specified barcode font.

The barcode font information includes information such as the barcode font name selected from a plurality of barcode types registered in advance, and the height and width of the barcode font. For example, JAN code, CODE39, CODE128, and the like. Then, the application 402 sends the setting values and the image data together to the printer driver 404 via the OS 403 .

After that, the rasterization unit 405 rasterizes the data into barcode data consisting of a combination of one-dimensional bars and spaces using a designated barcode font. The rasterized data is converted into print data in a format that the printer 407 can receive, and is transmitted to the printer 407 via the print data transmission unit 406 .

Note that in the present embodiment, a configuration in which the barcode font of the printer driver is called from the application via the OS has been described, but the present invention is not limited to this.

(Outline explanation of overall flow)
FIG. 5 is a flowchart for explaining image processing performed in the image processing apparatus of this embodiment. The processing shown in this figure may be performed by the PC 301 serving as a host, may be performed within the printer 307, or may be partially shared and executed.

In step S501, image data of an image including a barcode portion is input. The input image data may be vector data or bitmap data.

In step S502, the input image data is rendered. At this time, vector data is rasterized. Here, mapping, imposition, etc. may be performed in accordance with the size of the recording medium on which the image is recorded. Among the pixels arranged on the matrix, pixel data corresponding to one row of pixels arranged in a predetermined direction is called raster data. A plurality of such columns are called band data. If the capacity of the ROM or RAM in the printer 407 is small, the image data for one page is divided into band data and sequentially processed.

In step S503, the barcode portion is detected by the barcode detection unit. Here, information indicating the position and size of the barcode included in the image data is acquired. Although the details will be described later, when barcode data is formed from a barcode font, barcode information may be acquired during rendering in step S502, and the barcode is detected from edge information after bitmapping. You can Alternatively, the barcode may be acquired by a method such as the user specifying the position of the barcode on the panel or on the host side.

In step S504, image processing is performed to convert the image data into a printable format in the printer 407. FIG. First, the image data output in step S503 is converted into image data corresponding to the color gamut of the printer.

The image data input in step S501 is data indicating color coordinates (R, G, B) in color space coordinates such as sRGB, which are colors expressed on a monitor. Each 8-bit R, G, B input image data is converted into image data (R', G', B') in the color gamut of the printer by a known method such as matrix operation processing or processing using a three-dimensional LUT. ).

Next, the 8-bit image data for each of R′, G′, and B′ are converted into image data based on ink color signal data used by the printer 407 . The printer 407 of this embodiment prints an image using black (K), cyan (C), magenta (M), and yellow (Y) inks. Therefore, the RGB signal image data is converted into image data consisting of 8-bit color signals for each of the K, C, M, and Y ink colors. This color conversion is also performed using both a three-dimensional lookup table and an interpolation calculation. Note that, as another conversion method, a method such as matrix calculation processing may be used as described above. In addition, the number of ink colors is not limited to the four colors of K, C, M, and Y, and light cyan (Lc), light magenta (Lm), gray (Gy) ink, transparent ink, and special color ink. It may further have inks of other colors.

Next, by correcting the 8-bit image data for each color, a process for adjusting the number of dots to be recorded on the recording medium is performed. One dot is formed by applying one ink droplet to the recording medium, but in general, the relationship between the number of dots formed on the recording medium and the optical density represented by the number of dots is not linear. . Therefore, the number of dots to be applied is adjusted so that the optical density has a linear relationship with the number of dots. A one-dimensional lookup table (LUT) is used as a method of converting input data into output data in this adjustment process.

Next, each 8-bit 256-value ink color image data is quantized to generate 1-bit binary data of "1" indicating printing or "0" indicating non-printing. The output of the quantization process may be the number of ink drops per unit area, and is not limited to 1-bit binary data consisting of a printed "1" or a non-printed "0". It may be quantized into multilevel data of 2 bits or more. Also, although the error diffusion method and the dither method are known as methods of quantization processing, any method may be used.

Then, in step S505, an image is printed based on the image data generated in step S504. At this time, the transport amount is adjusted based on the position and size of the barcode detected in step S503.

Here, the method of adjusting the transport amount in step S505 will be described in detail. In a printer that prints an image on a print medium by a so-called multi-pass printing method, print operation conditions are determined in consideration of the performance of the print head 303, output image quality, print speed, and the like. For example, when plain paper is used, productivity is often required, so so-called 1-pass printing is adopted in which printing of an image is completed by one printing scan for a unit area on a printing medium. . Even in the case of 1-pass printing, a technique is known in which an area printed in one printing scan overlaps a part of an area printed in the next printing scan to increase robustness against variations in conveyance accuracy. However, the narrower the overlapping area (joint part), the lower the effect of improving the robustness, and the wider the overlapping area, the higher the number of printing scans and the lower the productivity.

FIG. 6 is a diagram showing printing scans and their boundaries (joints) when printing an image including a bar code. Here, an example in which the barcode 603 is printed on the printing medium P using black ink using only the black nozzle array 24 in the printing head 303 will be described.

FIG. 6A is a schematic diagram when printing the barcode 603 by scanning the print head 303 twice. A position 601 indicates the Y-direction position of the print head 303 with respect to the print medium in the first print scan. At this position 601 , the print head 303 scans in the X direction, ink is ejected from the black nozzle array 24 , and the upper portion of the bar code 603 is printed.

After the first printing scan, the printing medium P is conveyed in the +Y direction. A position 602 indicates the Y-direction position of the print head 303 with respect to the transported print medium. At this position 602, the print head 303 performs the second printing scan, and the lower portion of the bar code 603 is printed.

FIG. 6B is an enlarged view of a border (joint) between scans in a bar code 603 printed by two print scans at positions 601 and 602 of the print head 303. A landing state of an ink droplet 604 is shown. In the figure, (x) is a diagram showing a case where the conveyance amount of the recording medium P between the first and second times is ideal. Similarly, (y) is a diagram showing a case where the conveying amount is insufficient, and (z) is a diagram showing a case where the conveying amount is large.

Reference numeral 605 denotes a grid of 600 dpi, in which a grid of 1200 dpi per cell is arranged in a matrix of 2 pixels vertically by 2 pixels horizontally. Here, two dots are formed on a 600 dpi grid. As described above, the print head 303 has nozzles arranged at intervals of 1200 dpi. In reality, the ink spreads widely on the recording medium, so that the color of the recording medium P (paper white) cannot be seen.

In FIG. 6B, (x) is the case where the transport amount in the transport operation performed between two printing scans is an ideal amount, and no error occurs. Therefore, the ink droplets land at ideal positions, and the quality of the barcode is maintained.

On the other hand, (y) is a case where the conveying amount is insufficient, and the dots formed by the printing scan at the position 601 and the dots formed by the printing scan at the position 602 are overlapped, and the ink droplets are concentrated in the connecting portion. ing. In this way, the ink droplets are concentrated in a narrow area with a short time lag, and the ink bleeds and the line width of the bar code becomes thicker.

Also, (z) is a case where the transport amount is too large, and a large gap is formed between the dots formed by the printing scan at the position 601 and the dots formed at the position 602, and the ink droplets at the joint are insufficient. do. As a result, the color of the print medium (paper white) can be seen, or the ink at both ends of the joint bleeds, reducing the density of the joint and narrowing the width of the bar.

In this way, when a barcode is printed by a plurality of printing scans, there is a possibility that the width of the bar will not be constant due to an error in the conveying amount.

Devices for optically reading barcodes (barcode readers) include contact and non-contact systems. A person brings the barcode reader close to the barcode, and the barcode is read by being irradiated with red light from the reading window. At that time, it is highly likely that the barcode reader will be directed to the center of the bar for reading.

FIG. 7 is a diagram for explaining an example of a CCD scanning barcode reader. In the CCD scanning method, the bar code 702 is uniformly illuminated with light from the red LED 701 . The barcode image is refracted by a mirror 703 and projected onto a CCD sensor 705 by a lens 704 . The CCD sensor 705 is a line sensor in which 1000 to 2000 optical sensors are arranged in a row, and outputs electric signals in order from the end. Since less light is reflected from the bar area of the bar code, the output electrical signal is smaller. On the other hand, since the area of the space reflects a large amount of light, a large electric signal is output.

Since the light from the red LED 701 is irradiated only on a part of the barcode, if the width of the bar in the irradiated part is not the intended width, there is a problem that accurate reading cannot be performed. be. A plurality of evaluation values are known as evaluation values for barcode readers to read barcodes, but the above-mentioned problems affect modulation and defects.

Modulation is the ratio of minimum edge contrast to symbol contrast. The larger the difference between the reflectance of a space and the reflectance of a bar adjacent to it, the easier it is to read as a barcode.

Defects are voids in bars and spots in spaces. When an opposite trough which becomes non-uniform occurs for one ridge having the maximum reflectance in the space, the smaller the difference between the maximum reflectance of the ridge and the reflectance of the trough, the more It is evaluated as easy to read as a barcode. For bars, the crests and troughs of the space are reversed.

In this way, the deterioration of the quality of the bar affects the readability of the bar code. In order to solve such a problem, in the present embodiment, by adjusting the conveying amount of the print medium so that the joining portion during print scanning is positioned at the end rather than the center of the bar code, the barcode can be read. suppresses the deterioration of the quality of the bar in the high-strength area.

Here, the length of the barcode to be recorded in the Y direction (length of the long side of the bar, also referred to as the height of the barcode) is longer than the length of the nozzle array of the recording head 303, and the length of the nozzle array is A recording operation when the length is shorter than twice the length will be described.

FIG. 8A shows positions 801 and 802 when the bar length of the bar code 803 is approximately 1.5 times the length of the nozzle array of the print head 303 (hereinafter referred to as nozzle length). 2 is a diagram showing a case where printing is performed by two printing scans in . A dashed line indicates the position of the boundary of the area printed by each printing scan. A recording scan boundary is located near the center of the plurality of bars forming the barcode 803 .

If the length of the bar code is longer than the nozzle length, the bar code will be printed by a plurality of printing scans. For this reason, the smaller the number of boundaries, the better. However, if the number of boundary portions is reduced to one by performing two recording scans as shown in FIG. 8A, the position of the boundary portion will be near the center of the bar code, which may affect the reading result. .

On the other hand, in FIG. 8B, when printing a bar code 803 whose bar length is about 1.5 times the nozzle length of the print head 303, printing is performed three times from position 804 to position 806. It is the figure which showed about the case where it does. Similarly, dashed lines indicate the location of boundaries.

By printing the barcode in three printing scans, all the nozzles of the print head 303 are used in the second printing scan at the position 805 . That is, since the area including the center of the barcode is printed by scanning the position 805, the position of the boundary can be kept away from the vicinity of the center of the barcode.

Thus, when the height of the bar code (the length of the long side of the bar) is longer than the nozzle length and shorter than twice the nozzle length, the bar code is printed by three printing scans. This avoids the position of the recording scan boundary in the center in the length direction of the bar. As a result, deterioration in recording quality of the bar near the center of the bar, which is likely to be irradiated with light when the barcode is read, can be suppressed. To be particularly effective when the direction in which the long side of a bar forming a bar code extends coincides with the conveying direction of a recording medium. can be done.

FIG. 9 is a flow chart showing recording control in this embodiment. In step S901, image data of an image including a barcode is input, and in step S902, the barcode portion in the input image data is detected.

In step S903, the length of the detected barcode in the conveying direction of the recording medium (barcode length B_Len) and the barcode start position Y on the recording medium are obtained. For the bar code start position, at least the Y coordinate with respect to the transport direction should be acquired. Also, the end position may be calculated by adding the barcode length B_Len to the barcode start position B_Ys, or may be obtained from the image data. Alternatively, the barcode length B_Len may be calculated by obtaining the barcode start position B_Ys and the end position B_Ye.

In step S904, the default nozzle length N_Len stored in the memory is obtained. Then, in step S905, B_Len and N_Len are compared to determine whether Expression 1 below is satisfied.

N_Len×2 > B_Len > N_Len (Formula 1)
In step S905, it is determined whether or not the barcode length B_Len is longer than the nozzle length N_Len and shorter than twice the nozzle length N_Len according to Equation 1 above. If Expression 1 is satisfied, the conveying amount is adjusted so that the barcode portion is printed by three printing scans. If Expression 1 is not satisfied, the conveying amount of the printing medium is adjusted so that the number of printing scans required for printing the barcode portion is minimized.

If Expression 1 is not satisfied, it means that N_Len is longer than the barcode length B_Len, or that the barcode length B_Len is N_Len×2 or more. It explains in a form.

FIG. 10 is a diagram illustrating a method of adjusting the conveying amount so that printing is performed by three printing scans when it is determined in step S905 that Expression 1 is satisfied.

FIGS. 10A and 10B show band data obtained by dividing the area printed by one printing scan with a broken line for page data of one page. In the example of this figure, printing is performed by nine printing scans.

When the image processing in the printing apparatus is performed as shown in FIG. 10A, the barcode portion is printed by two printing scans, the seventh printing scan and the eighth printing scan. However, as described above, it is necessary to adjust the transport amount so as to avoid the position of the recording scan boundary near the center of the long side of the bar. FIG. 10(b) shows the band data after adjustment, and the bar code portion is printed by three printing scans. In this example, the eighth printing scan corresponds to the second printing scan among the three printing scans for printing the barcode portion. In this eighth recording scan, the center position B_Yc of the long side of the bar in the barcode portion is calculated or obtained. Then, a print scan start position is calculated such that the center position B_Yc is not printed by the end nozzles among the nozzles used for printing.

The calculation method will be described below with examples of numerical values. Let 0 be the coordinate position on the upstream side (upper side in the figure) of the print medium in the conveying direction. Assuming that the conveying amount for one time and the nozzle length N_len are 30, the starting position of the second printing scan is 30, and the starting position of the seventh printing scan is 180.

Here, assume that the barcode length B_Len is 50, the barcode start position B_Ys is 190, and the barcode end position B_Ye is 240. At this time, the barcode center position B_Yc is 215 . Therefore, in order for the center position of the nozzle length 30 to match the coordinates 215, which is the center position of the bar code, it is necessary to control the coordinates of the start position of the eighth printing scan to be 200. FIG. FIG. 10B is a diagram showing the state after adjustment.

In order to set the coordinates of the start position of the eighth print scan to 200, it is necessary to change the start positions of the print scans before the eighth print scan. If the coordinates of the start position of the sixth print scan are set to 150 without changing the state of FIG. 10A, the coordinates of the start position of the seventh print scan are set to 170. In that case, the band data for the sixth printing scan is set as shown in FIG. 10(c).

FIG. 10(c) is a diagram showing band data with a height of 30. Image data is held in the top 20 areas, and image data is held in the lower 10 areas. Therefore, white data that is not recorded is assigned. As a result, the height of the band data can always be kept constant, and adjustments can be made by changing the transport amount without imposing a load on image processing. Note that the sixth print scan may be performed in the same manner as in FIG. 10A, and the same processing may be performed with the coordinates of the start position of the seventh print scan set to 180. FIG.

On the other hand, if the height of the band data is variable, it is possible to adjust by making the feed amount and the feed start position the same as the height of the band data without adding white data where no image is printed. be.

The adjustment of the transport amount can be controlled by changing the transport amount transmitted to the paper feed/discharge motor control unit 304 . Also, in the image data, if there is no image before the band data including the barcode portion, white data, which is data that is not printed, is added, or out of the three printing scans for printing the barcode portion. It suffices to carry the sheet to the start position of the first printing scan.

In this way, when the relationship between the nozzle length N_Len and the barcode length B_Len satisfies the condition of Equation 1 above, the print scan is performed from the center of the barcode portion by adjusting the conveying amount so that printing is performed in three print scans. It is possible to shift the boundaries of As a result, it is possible to suppress the influence at the time of reading due to deterioration in barcode recording quality due to conveyance error of the recording medium.

In this embodiment, the length in the Y direction of the area printed in one printing scan is the nozzle length. That is, although all the nozzles arranged in the nozzle row are used for printing scanning, the present invention is not limited to this. The range of nozzles used in one recording scan may be shorter than the nozzle length. In that case, the amount of print medium conveyed between print scans may also be adjusted to the range of nozzles used, and N_Len to be compared in Equation 1 above also corresponds to the range of nozzles used. length.

(Modification of the first embodiment)
In the first embodiment, when the relationship between the nozzle length N_Len and the barcode length B_Len satisfies the condition of Expression 1, a method of adjusting the barcode portion to be printed by three printing scans has been described. In this modified example, a method of printing with two printing scans will be described. Even when the barcode is printed by two printing scans, the boundary between the printing scans can be shifted from the center position of the barcode portion.

As in the first embodiment, the coordinates of the center position B_Yc of the barcode portion are calculated based on the position information of the barcode. If the nozzle length N_Len is within the range of the bar code in the recording scan including the center position B_Yc, the boundary part can be prevented from touching the bar code center position.

FIG. 11 is a diagram showing an adjustment method for printing the barcode 1103 in two printing scans when the nozzle length N_Len is 30 and the barcode height B_Len is 40. As shown in FIG. In the Y direction, which is the print medium conveying direction, the center position B_Yc of the barcode 1103 is included within the range of the first printing scan 1101, and the nozzle length N_Len is all within the range of the barcode 1103 in the Y direction. ing. That is, the start position of the first print scan among the print scans for printing the barcode 1103 is the same position as the start position B_Ys of the barcode portion.

Alternatively, the method may be such that the center position B_Yc of the barcode is printed in the second printing scan 1102 . In that case, the coordinates of the position B_Ye of the lower end of the bar code portion should be the coordinates of the start position of the second recording scan plus the nozzle length N_Len. As a result, it is possible to prevent the joining portion, which is the boundary between the printing scans, from coming near the center of the bar code portion. It should be noted that the method of adjusting the transport amount is the same as in the above-described first embodiment.

Even when the barcode portion is printed by two printing scans in this way, it is possible to keep the joining portion of the printing scans away from the center position of the barcode, thereby suppressing the deterioration of the barcode printing quality. can be done.

(Second embodiment)
In the second embodiment, the case where the condition of formula 1 of the first embodiment is not satisfied will be described. In other words, the following two cases are cases where the formula 1 [N_Len×2>B_Len>N_Len] is not satisfied.
・When the barcode height is shorter than the nozzle length N_Len > B_Len (Formula 2)
・When the barcode height is longer than twice the nozzle length N_Len × 2 < B_Len (Equation 3)
First, when Expression 2 is satisfied, that is, when the barcode height is shorter than the nozzle length, it is possible to print the barcode with one printing scan. If printing can be performed in one printing scan, it is possible to print without generating a joint in the bar code. Therefore, by adjusting the conveying amount so that the number of recording scans required for recording the barcode portion is one, the deterioration of the recording quality of the barcode portion can be suppressed.

Next, the case where Expression 3 is satisfied, that is, the case where the barcode height is longer than twice the nozzle length will be described. For example, suppose the height of the barcode is 2.5 times the length of the nozzle. FIG. 12 shows an example in which the conveying amount is not adjusted, and the bar code portion 1203 is printed by four printing scans 1201 to 1204 . In this case, there are three recording scan joints within the range of the bar code portion. On the other hand, by printing the barcode portion 1203, which is 2.5 times longer than the nozzle length, with three times, which is the minimum number of printing scans, the joint portion can be reduced to two locations. As a result, the vicinity of the center of the bar code portion can be prevented from being recorded at the ends of the nozzle length. The method of adjusting the transport amount is the same as in the first embodiment.

(Third embodiment)
In the above-described first and second embodiments, the printing medium is conveyed so as to keep the print scan joint away from the vicinity of the center of the barcode by not printing the center position of the barcode at the end of the nozzle length. described how to adjust the In this embodiment, a method of obtaining the same effect by adjusting the position of the barcode in the image data without adjusting the conveying amount of the recording medium will be described.

The processing up to the determination based on the height of the barcode and the nozzle length in step S905 in FIG. 9 is the same as in the above-described embodiment. As a result of the determination, if the condition is satisfied, the coordinates of the barcode position in the image are adjusted so that the barcode portion is recorded by three recording scans. Adjust the barcode position in the image so that

Processing when the condition of Expression 1 is satisfied will be described with reference to FIG. 13 . In FIG. 13(a), it is assumed that the one-time transport amount and the nozzle length N_len are 30. In FIG. Let 30 be the coordinates of the start position of the second print scan, and 180 be the coordinates of the start position of the seventh print scan. Assuming that the barcode B_Len is 50, the barcode start position B_Ys is 190, and the barcode end position B_Ye is 240, the coordinates of the barcode center position B_Yc are 215.

Since the center position of the barcode is positioned at the center of the band of the second recording scan among the three recording scans for recording the barcode, as shown in FIG. do. Since the coordinates of the center of the eighth recording scan are 225, the coordinates of the center position B_Yc of the bar code should be set to 225. For that purpose, the position of the barcode portion in the image data should be moved +10 in the Y direction. The seventh printing scan may be the second printing scan for printing the barcode, but there is a possibility that the image will overlap with the image upstream of the barcode. Therefore, when moving the position of the barcode portion, it is preferable to determine the positions of the surrounding images and move in a direction in which the images do not overlap. It can be realized by checking the presence or absence of an image in the band data. Similarly, for the processing when the conditions are not satisfied, it is preferable to calculate the amount of movement of the barcode portion so that the number of joints between print scans is minimized.

Next, a method for moving an image will be described. When moving an image, there are methods such as when rasterizing raster data, using rasterized BMP data (RGB data), and using dot data after quantization. When performing rasterization, it is possible to move by calculating the coordinate calculation position at the time of a drawing command and correcting the Y coordinate. When using BMP data or quantized data, after the image of the barcode portion is stored in memory once, the pixels at the position of the barcode portion are changed to white pixels, and the pixel data of the destination is changed to the data of the barcode portion. This can be done by copying the .

In this way, by moving the image of the bar code portion in consideration of the transfer joints, it is possible to reduce the number of joints, which are boundaries between recording scans in the bar code, and to move the image away from the center of the bar code portion. .

301 recording apparatus main control section 303 recording head 304 sheet feed/discharge motor control section 308 image processing apparatus main control section

Claims (11)

a conveying means for conveying the recording medium in a first direction;
A nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction is scanned in a second direction intersecting the first direction, so that the ink is transported by the transport means. a recording means for recording an image on a recording medium;
An image is recorded on a recording medium by performing a conveying operation for conveying the recording medium and a recording operation by scanning the recording means based on the image data of the image including the bar code portion formed by a plurality of bars. a control means for controlling the conveying means and the recording means such that
A recording device comprising
The control means determines that the length in the first direction of the barcode portion recorded on the recording medium is the length in the first direction of the area recorded in one scan by the recording means. longer than a first length and shorter than twice the first length, the bar code portion is moved by the conveying means so as to be recorded by three scans by the recording means; A recording apparatus that controls the conveyance of a recording medium. The control means controls that the length of the barcode portion recorded on the recording medium in the first direction is longer than the first length and shorter than twice the first length. 2. A recording apparatus according to claim 1, further comprising determination means for determining whether or not the following condition is satisfied. 3. A printing apparatus according to claim 1, wherein said first length is a nozzle length in which a plurality of nozzles are arranged in said nozzle row. 4. The method according to any one of claims 1 to 3, wherein the amount of transport of the recording medium performed by said transport means between two scans of said recording means is said first length. recording device. 5. A recording apparatus according to claim 1, wherein said recording means reciprocates in said second direction. The three scans for recording the barcode portion are scans in the forward direction in the first direction, and the control means ejects ink during the three scans for recording the barcode portion. 6. A recording apparatus according to any one of claims 1 to 5, wherein scanning is performed in the reverse direction. 7. A center position of the barcode portion in the first direction is recorded in a second scan out of three scans for recording the barcode portion. The recording device described in . a conveying means for conveying the recording medium in a first direction;
A nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction is scanned in a second direction intersecting the first direction, so that the ink is transported by the transport means. a recording means for recording an image on a recording medium;
An image is recorded on a recording medium by performing a conveying operation for conveying the recording medium and a recording operation by scanning the recording means based on the image data of the image including the bar code portion formed by a plurality of bars. a control means for controlling the conveying means and the recording means such that
A recording device comprising
The control means determines that the length in the first direction of the barcode portion recorded on the recording medium is the length in the first direction of the area recorded in one scan by the recording means. When longer than a certain first length and shorter than twice the first length, a boundary between multiple scans by the recording means is near the center of the barcode portion in the first direction. A recording apparatus, wherein the transport of the recording medium by the transport means is controlled so that the recording medium does not move. a conveying means for conveying the recording medium in a first direction;
A nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction is scanned in a second direction intersecting the first direction, so that the ink is transported by the transport means. a recording means for recording an image on a recording medium;
An image is recorded on a recording medium by performing a conveying operation for conveying the recording medium and a recording operation by scanning the recording means based on the image data of the image including the bar code portion formed by a plurality of bars. a control means for controlling the conveying means and the recording means such that
A recording device comprising
The control means determines that the length in the first direction of the barcode portion recorded on the recording medium is the length in the first direction of the area recorded in one scan by the recording means. longer than a first length and shorter than twice the first length, complete the recording of the bar code portion in three scans; and A printing apparatus, wherein the conveyance of the recording medium by the conveying means is controlled so that the second scan for recording the center position in the direction of (1) is included in the bar code portion. a conveying means for conveying the recording medium in a first direction;
A nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction is scanned in a second direction intersecting the first direction, so that the ink is transported by the transport means. a recording means for recording an image on a recording medium;
An image is recorded on a recording medium by performing a conveying operation for conveying the recording medium and a recording operation by scanning the recording means based on the image data of the image including the bar code portion formed by a plurality of bars. a control means for controlling the conveying means and the recording means such that
A recording device comprising
The control means determines that the length in the first direction of the barcode portion recorded on the recording medium is the length in the first direction of the area recorded in one scan by the recording means. longer than a first length and shorter than twice the first length, the bar code portion is moved by the conveying means so as to be recorded by three scans by the recording means; A recording apparatus that controls the conveyance of a recording medium. a conveying means for conveying the recording medium in a first direction;
A nozzle row in which a plurality of nozzles for ejecting ink are arranged along the first direction is scanned in a second direction intersecting the first direction, so that the ink is transported by the transport means. a recording means for recording an image on a recording medium;
A control method for a recording apparatus comprising: a conveying operation for conveying a recording medium based on image data of an image including a bar code portion formed by a plurality of bars; and a recording operation by scanning the recording means; The conveying means and the recording means are controlled so as to record an image on the recording medium by performing
A first length in which the length in the first direction of the barcode portion recorded on the recording medium is the length in the first direction of the area recorded in one scan by the recording means and shorter than twice the first length, the recording medium is conveyed by the conveying means so that the barcode portion is recorded by scanning three times by the recording means. A control method characterized by controlling.

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