JP2010012741A - Printer and method for correcting width of bar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an adequate correction amount when correcting a barcode. <P>SOLUTION: A test pattern 90 including a plurality of segment patterns 91 to 95 in which intervals between adjacent segments are sequentially differentiated is printed and scanned with a sensor. On the basis of the result obtained by determining a threshold of the read waveform, an interval of bars of a discrimination limit, by which adjacent bars are not discriminated from each other, is determined. A width of a bar of the barcode is corrected in accordance with the interval of bars of the determined discrimination limit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing apparatus that prints a barcode and a bar width correction method thereof.

  Bar code printing is often printed by a printing apparatus using thermal transfer or thermal recording. Recently, printing on a printing apparatus using an ink jet recording technique has increased. The barcode includes a one-dimensional barcode and a two-dimensional barcode, and there are a plurality of formats.

  In an inkjet printing apparatus, the main drop for forming an image is ejected, and at the same time, extra small droplets called satellites are simultaneously ejected from the nozzles, and the barcode bar also has a predetermined width. May be thicker.

  In addition, when barcode printing is performed on a recording medium with an ink jet printing apparatus, the bars constituting the barcode may be thicker than a predetermined width even if the ink spreads through the fibers of the recording medium.

  In the case of the thermal method or thermal transfer method, tailing may occur due to excessive heat of the print head or unevenness of heat distribution, and may become thick.

  FIG. 6A shows an ideal printing result of the bar. Due to the above factors, the width of the bar becomes thick as shown in FIG. 6B. In this example, the boundary of the bar is expanded downstream in the head relative movement direction due to the influence of the satellite. As a result of bleeding, the bar width can increase on both sides. In order to prevent the bar width of the barcode when printed in this way from increasing, the indication value of the bar width of the barcode is reduced in advance, and correction is performed so that the desired thickness is obtained when printed. May be taken.

For example, in the “barcode printing method using a thermal printer” described in Patent Document 1, since there is an increase due to tail coloring, correction is performed so that the original image is uniformly thinned.
JP 2003-011433 A

  According to the technique described in Patent Document 1, the print result when the correction data is printed on the corrected original data as shown in FIG. 7A is as shown in FIG. Become.

  Even in an ink jet printing apparatus, the bar width of a bar code becomes thick due to the influence of satellite, paper bleeding, a drop amount due to head temperature distribution, and the like. Therefore, application of the technique of Patent Document 1 is conceivable.

  However, if the increase is uniformly determined, it is difficult to cope with head, environment, aging, and the like.

  That is, if the bar code thickness is reduced by a certain amount, it may not be able to properly cope with actual printing environment conditions (such as the type of recording medium and head variations). Further, since the amount of thickening may vary as shown in FIG. 8, it is not easy to determine the correction amount.

  In recent years, the length of the head has been increased both in the ink jet head and in the thermal head for thermal and thermal transfer. In the long head, characteristics such as heat distribution may be different from place to place, so that the amount of fat in the nozzle row may not be constant as shown in FIG.

  The present invention has been made in such a background, and an object of the present invention is to provide a printing apparatus and a bar width correction method capable of determining an appropriate correction amount when performing barcode correction.

  According to the printing apparatus of the present invention, in a printing apparatus capable of printing a barcode, a bar interval identification limit determining unit that determines a bar interval of an identification limit in an actual printing environment and a bar interval of the obtained identification limit Correction means for determining a correction value of the bar width.

  The bar interval at the identification limit is an index of how much the bar interval (size) of adjacent bars cannot be identified in an actual printing environment. Therefore, by determining the bar interval of such an identification limit, it is possible to recognize the extent of actual bar width thickening. Therefore, an appropriate correction value of the bar width can be obtained according to the determined bar interval of the identification limit.

  More specifically, a means for printing a plurality of line segment patterns in which intervals between adjacent line segments are sequentially different as a test pattern, and scanning a sensor in a direction orthogonal to the line segments of the printed test pattern. Detection means for obtaining a sensor output, and the bar interval identification limit determination means can determine the bar interval of the identification limit based on the sensor output. By using such a test pattern, it is not necessary to actually measure the width and bar interval of each bar, and the bar interval at the discrimination limit can be confirmed by the threshold judgment of the sensor output.

  The correction means includes, for example, a correction value table in which a correction value for a bar width of a barcode to be recorded is determined in advance for each identification limit bar interval value determined based on the test pattern. The correction value can be determined with reference to FIG. By using such a correction value table, it is possible to select an appropriate correction corresponding to individual conditions of individual printing environments.

  The correction of the bar width can be performed by at least one of correction of original data of a barcode to be printed and correction of a heat pulse width.

  The sensor can be fixedly arranged with respect to a print head having a nozzle array. Accordingly, the test pattern can be read by the sensor by the same relative movement operation as the relative movement of the print head for printing with respect to the recording medium. Here, "fixed" means that the relative positional relationship between the sensor and the print head does not change, and it does not matter whether or not the two are physically integrated.

  In this case, the sensor is preferably arranged on the downstream side of the nozzle row in the relative movement direction of the print head with respect to the recording medium. Thereby, in the relative movement of the print head for printing the test pattern with respect to the recording medium, the test pattern immediately after printing can be read by the sensor. As a result, the correction value can be determined quickly.

  A plurality of the sensors may be provided and arranged at a plurality of positions in the longitudinal direction of the nozzle row. Thereby, even when the thickness of the bar is different in different portions of the nozzle row, the correction can be performed individually for each portion.

  The present invention is more useful when the orientation of the bar code is an orientation in which each bar extends in a direction perpendicular to the relative movement direction of the print head with respect to the recording medium.

  A single sensor may be provided, and the test pattern may be read by sequentially moving to a plurality of positions in the longitudinal direction of the nozzle row. In this case, it is possible to individually perform correction for each different part of the nozzle row without increasing the number of sensors.

  The sensor includes a light emitting element for irradiating the recording medium with light and a light receiving element for receiving the light emitted from the light emitting element and reflected from the recording medium, and receives the reflected light in the printed test pattern. It is detected by an element, and the bar interval of the identification limit can be determined based on the detection signal.

  A bar width correction method according to the present invention is a bar width correction method for correcting the bar width of a barcode printed by a printing apparatus, and a plurality of line segment patterns in which intervals between adjacent line segments are sequentially changed are test patterns. A step of scanning the sensor in a direction orthogonal to a line segment of the printed test pattern to obtain a sensor output, and a step of determining an identification limit bar interval based on the sensor output; And a step of correcting the bar width according to the obtained bar interval of the identification limit.

  Other configurations and operational effects of the present invention are as described below.

  According to the present invention, when printing a barcode, it is possible to correct an appropriate barcode bar width in accordance with an actual printing environment. In addition, by determining the bar interval of the identification limit, it is possible to recognize the extent of the actual width of the bar, so there is no need to measure the actual bar thickness or bar interval, and the test pattern And a simple sensor configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, an inkjet barcode printer that prints barcodes will be described as an example of the printing apparatus of the present invention.

  FIG. 1 is a diagram showing a schematic configuration of a main part of a barcode printer 1 according to the present embodiment.

  A sheet 20 as a recording medium is conveyed in one direction by a conveyance roller rotated by a conveyance motor (sub-scanning motor) 8. Further, the carriage 2 reciprocates in the direction orthogonal to the paper transport direction by the rotation of the belt driven by the carriage mode (main scanning motor) 7. A print head 3 is mounted on the carriage 2. A plurality of nozzles are formed in a row on the print head 3. Ink droplets are ejected from the nozzles according to the image data, and an image is formed on the paper 20. At this time, the sheet 20 is conveyed intermittently and synchronized with the left and right movement of the carriage, thereby forming an image on the sheet. The nozzles may be in multiple rows or single rows.

  The print head 3 is connected to a control board (not shown) via a cable, and signals, power, and the like for controlling the head are supplied from the control board. Image data, a print timing signal, and the like are transferred from the control board in synchronization with the transfer CLK. Ink droplets are ejected from the nozzles in accordance with the print timing signal.

  As an example, the linear scale 6 is installed along the scanning direction of the carriage 2, the slit of the linear scale 6 is optically detected by the encoder sensor 5 mounted on the carriage 2, and an encoder signal is output. Based on the encoder signal from the encoder sensor 5, the carriage motor 7 is controlled to scan the carriage 2 left and right. A signal for generating the print timing is also generated based on this encoder signal.

  FIG. 2 is a block diagram showing a schematic hardware configuration of the barcode printer 1.

  It has a controller 10, which is a control unit, a carriage 2, a carriage motor 7, a transport motor 8, and an encoder sensor 8a. The encoder sensor 8a is an element constituting a rotary encoder described later.

  As described above, the print head 3, the optical sensor 4, and the encoder sensor 5 are mounted on the carriage 2. The optical sensor 4 and the encoder sensor 5 are fixedly arranged with respect to the print head 3 having a nozzle row.

  The controller 10 is connected to other parts and controls the entire barcode printer 1. The controller 10 includes a CPU 11, ROM 12, RAM 13, EEPROM 14, I / O port 15, ASIC 16, carriage motor control unit 17, transport motor control unit 18, and connection unit 20.

  The CPU 11 is a processor that performs overall control of the barcode printer 1 and predetermined processing by reading and executing a program stored in the ROM 12.

  The ROM 12 is a read-only memory that stores various control programs that define the operation of the barcode printer 1, a program that executes necessary processes, and necessary fixed data.

  The RAM 13 is a volatile memory used as a work area or a temporary storage area by the CPU 11.

  The EEPROM 14 is a rewritable nonvolatile memory that stores additional programs and various data that need to be stored in a nonvolatile manner. A flash memory can also be used as such a memory.

  The I / O port 15 is a port that connects the detection signal of the optical sensor 4 to the CPU 11.

  The ASIC 16 is an application specific integrated circuit that constitutes a control circuit for controlling the print head 3.

  The carriage motor control unit 17 includes a control circuit that controls the carriage motor 7 based on the output of the encoder sensor 5.

  The carry motor control unit 18 includes a control circuit that controls the carry motor 8 based on the output of the encoder sensor 8a.

  The connection unit 20 is a part for connecting an element outside the controller 10 inside the controller 10. In addition, although not shown, an operation panel having a display unit such as an LCD connected to the CPU 11 and an input unit such as operation keys may be provided.

  The “bar interval identification limit determining means” of the present invention is realized by the CPU 11 executing a predetermined process based on the sensor output of the optical sensor 4. The “correction means” is also realized by the CPU 11 executing a predetermined process using a correction value table described later.

  FIG. 3 shows a configuration example of the optical sensor 4. The optical sensor 4 is configured by a combination of a light emitting element 41 and a light receiving element 42. As the light emitting element 41, for example, an infrared LED (light emitting diode) can be used, and as the light receiving element 42, for example, a phototransistor can be used. The light emitting element 41 irradiates the surface of the paper 20 with light, and the reflected light of the irradiated light is detected by the light receiving element 42. Based on this detection signal, the bar distance of the identification limit in the actual printing environment is obtained. Here, the printing environment includes a printing apparatus to be used, a print head, ink, a type of recording medium, a change with time of the print head and ink, and the like. The output voltage of the light receiving element 42 is connected to an input terminal of a comparator (not shown), and a reference voltage is set to the input terminal of the other comparator (comparator). The reference voltage can be set by a D / A converter (not shown) as an example.

  FIG. 4 shows a barcode printer 30 having another configuration according to the present embodiment. The paper 20 is continuously transported by a transport mechanism (not shown). The print head 31 is a line type print head having a long nozzle row 32 extending over the width direction of the paper 20. The print head 31 is stationary in the apparatus during printing, and the nozzle rows 32 are arranged in a direction orthogonal to the paper transport direction. In accordance with the conveyance of the paper 20, ink droplets are ejected from the print head 31 according to the image data, and an image is formed on the paper 20. The nozzle row 32 may be a plurality of rows or a single row.

  Also in this configuration, the print head 31 is connected to the control board via a cable, and signals, power, and the like for controlling the head are supplied from the control board. Image data, a print timing signal, and the like are transferred from the control board in synchronization with the transfer CLK. Ink droplets are ejected from the nozzles in accordance with the print timing signal.

  FIG. 5 is a schematic diagram for explaining the configuration of paper conveyance in the printer 30 of FIG. For example, a rotary encoder can be used as position detecting means for grasping the printing position in the paper transport direction. The rotary encoder can be configured such that the encoder sensor 8a detects a slit printed on the circumferential portion of the code wheel 51 installed on the shaft of the transport roller 52 and outputs an encoder signal. In synchronization with the encoder signal from the encoder sensor 8a, the transport motor is driven, and the transport roller 52 rotates, whereby the paper is fed from the roll paper 54. A signal for determining printing timing is also generated based on the encoder signal.

  Hereinafter, the configuration of the test pattern and the barcode correction using the test pattern according to the present invention will be described in detail. In the present invention, a plurality of line segment patterns in which intervals between adjacent line segments are sequentially changed are printed on a recording medium such as paper as a test pattern for correcting the barcode width. Further, the printed line segment pattern is read by the optical sensor, and the print data is corrected based on the read result.

  FIG. 9 shows a configuration example of the test pattern in the present embodiment. It is assumed that the test pattern data is stored in the above-described ROM 12 or EEPROM 14 in the barcode printer 1.

  FIG. 9A shows a configuration example of a test pattern in the present embodiment. The test pattern 90 includes line segment patterns 91 to 95. Each of the line segment patterns 91 to 95 is composed of three parallel line segments. The interval between adjacent line segments is varied depending on the line segment patterns 91-95. In this example, the line segment intervals of the line segment patterns 91 to 95 are d, 2d, 3d, 4d, and 5d, respectively. In this example, the line segment interval has been shown to be a natural number multiple, but is not necessarily a natural number multiple.

  When the barcode is printed ideally, when the optical sensor 4 is scanned in the direction orthogonal to each line segment with respect to the test pattern 90, an output signal having a waveform as shown in FIG. 9B is obtained. . However, actually, as shown in FIG. 10A, the thickened portion fills the white background (paper background color) of the line segment interval, so the line segment interval becomes narrower than the default value. As a result, the output of the optical sensor 4 has a waveform as shown in FIG. The output voltage value corresponding to the peak value of the white background portion of the waveform is compared with a reference voltage v as a predetermined threshold value, and whether or not the bar interval identification limit has been reached is determined depending on whether the output voltage value is equal to or lower than the reference voltage v. I understand. In order to cope with the case where the color of the recording medium is other than white or the color of the ink is other than black, the amplitude value from the lowest level of the waveform to the peak value of the white background portion between the bars, or the ratio to the maximum amplitude, You may make it compare with a predetermined threshold value.

  When the output voltage value becomes equal to or lower than the reference voltage v, it is determined that the bar interval identification limit has been reached for the line segment pattern, and the bar interval is confirmed. When there are a plurality of bar intervals having an amplitude value equal to or less than the threshold value v, the maximum bar interval is set as the bar interval to be obtained.

  FIG. 11 shows an example of the contents of the correction value table 110 used in the present embodiment. In the correction value table 110, a correction value for the line width of the barcode to be recorded (width of the black bar to be printed) is determined in advance for each bar distance value of the identification limit determined based on the test pattern as described above. It is a data table. In this example, the corrected bar width is determined for each bar width instruction value to be printed as the correction value. For example, when the identification limit value of the bar interval is 0.4 mm, the bar width of the barcode having the indication value of 1.2 mm is corrected to 1.18 mm, and the barcode width of the barcode having the indication value of 1.4 mm is set to 1. It is corrected to 38 mm. Such correction values under the individual conditions in the correction value table 110 can be obtained experimentally. The reason why the correction value changes due to the difference in the bar width indication value even with the same bar interval identification limit value is generally attributed to the fact that the larger the bar width, the larger the bar width. It is done. That is, it is presumed that the influence of satellites and blurring is larger when the bar width is larger.

  The correction value can also be changed depending on the type of recording medium used. To solve this problem, print a test pattern on a predetermined reference recording medium to determine the bar code interval identification limit, and add a predetermined correction value or multiply the correction coefficient according to the recording medium to be used. It is possible to cope by doing. Therefore, a data table in which a correction value or a correction coefficient is defined for each type of recording medium is prepared.

  Of course, a test pattern may be printed on a recording medium actually used for barcode printing, and a correction value table may be provided for each type of recording medium.

  The bar width can also be changed by the direction of the bar code (the direction of the bar relative to the head relative movement direction). (The effect of the satellite described above appears prominently when the direction of the bar is perpendicular to the head relative movement direction.) In the present embodiment, the present invention is applied only to a bar code having a direction in which the influence of the satellite is significant. You may make it do. Alternatively, a separate test pattern and correction value table may be provided for each barcode direction.

  FIG. 12 is a flowchart illustrating an example of a process procedure for determining a barcode correction value in the present embodiment. This process is realized by the CPU 11 (FIG. 2) reading and executing the program in the ROM 12. The execution time of this process can be performed, for example, before barcode printing. In addition, it is possible to cope with changes in printing conditions over time by performing the printing after a predetermined number of barcodes are printed or after a predetermined time has elapsed. Further, it may be performed in accordance with a user instruction at an arbitrary time.

  First, test pattern data is read out and printing of the test pattern is started (S11). Next, the printed test pattern is read by the optical sensor 4 (S12). At this time, the position of each bar of the test pattern detected by the encoder signal can be managed as necessary. That is, it is possible to grasp the position where each line segment pattern is detected by counting the encoder pulse from the time when the front end of the sheet passes through the optical sensor 4.

  Based on the test pattern reading result, that is, the sensor output, the bar interval serving as the discrimination limit is determined (S13). If such a bar interval does not exist (S14, No), it is determined that correction is unnecessary (S16), and this process is terminated.

  If there is a bar interval that becomes an identification limit (S14, Yes), a correction value for the bar width is determined with reference to the correction value table 110 (S15). The obtained correction value is temporarily stored as necessary. Thereafter, the barcode is corrected according to the correction value when the barcode is printed.

  In the present embodiment, correction of the barcode, that is, correction of the bar width, is performed by correcting the original data of the barcode to be printed, that is, correcting the data so that the bar width matches the correction value in the original data. Instead of this, the heat pulse width given to the print head during printing of the bar to be corrected may be corrected (reducing the pulse width) according to the correction value.

  As described above, in the present embodiment, a plurality of line segment patterns having different line segment intervals are prepared as test patterns, and whether or not the bar interval can be identified for each line segment pattern (that is, the gap between the bars is different). The line segment interval at which the bar interval cannot be identified is determined based on whether or not it can be detected. This eliminates the need to measure the actual bar width and bar spacing.

  As a modification of the present embodiment, a plurality of optical sensors 4a, 4b, 4c may be provided as shown in FIG. In particular, when the line-type print head 31 as shown in FIG. 4 is used, the bar width may differ depending on the nozzle row portion. In such a case, if a plurality of optical sensors are used, the nozzle array 32 of the print head can be divided into several blocks and the test pattern can be scanned simultaneously. As a result, finer correction can be performed. In the example shown in the figure, it is divided into three parts, the center and both ends.

  When printing a barcode using most of the longitudinal direction of the nozzle row 32 of the print head 31, as shown in FIG. 14, each of the portions of the test pattern 90 (with the three optical sensors 4a, 4b, 4c) Read the center and both ends of the bar. For example, as shown in FIG. 15B, in the case where the central portion of the bar after printing is the thickest and the amount of thickness decreases toward the end, the output from the optical sensors 4a, 4b, and 4c. The voltage (detected waveform) is as shown in FIG. Therefore, the discrimination limit bar interval at the center is larger than the discrimination limit bar interval at the end. This means that due to a temperature change in the longitudinal direction of the print head 31, the bar is thicker in the central portion and reaches the identification limit at a larger bar interval. Therefore, the central portion becomes larger, and correction is performed to make the central portion thinner than the end portion.

  As a result, as shown in FIG. 16, when printing a bar having a width as shown in FIG. 16 (a), not only reducing the width of the bars on both ends as shown in FIG. The central portion is made smaller than the width at both ends. As a result, as shown in FIG. 3C, the variation in the bar width at the center and the end of the bar is reduced after printing. In addition, the quality can be improved even when printing other images by adjusting discharge conditions according to not only the quality of the barcode but also the position of the nozzle row.

  As a modification of the correction method of the bar width correction, in the configuration of FIG. 16, the original data is corrected for the entire bar of the barcode to be printed, and the nozzle group of the print head that prints the central portion of the bar However, the heat pulse width given to the print head only may be corrected (the pulse width is reduced) according to the correction value.

  In the serial type printer, as shown in FIG. 17, when the carriage 2a having the nozzle rows 32a arranged in the direction orthogonal to the scan direction (head relative movement direction) of the print head 3a is moving in the main scanning direction. A test pattern 90 (a direction in which each bar is orthogonal to the head relative movement direction) as shown in FIG. 9A is printed, and a line printed by the optical sensor 4 provided on the carriage 2 is printed. Minute patterns can be detected. This printing and detection can be performed by the same scanning (scanning). However, the present invention does not exclude the case where printing and detection are performed in separate scans.

  As shown in FIG. 18, when a serial type print head 3b having a long nozzle row 32b is used, the correction amount may be changed depending on the nozzle position. In such a case, correction according to each position can be performed by detecting the line segment pattern by sequentially scanning the carriage 2b at a plurality of locations in the nozzle row direction with respect to the printed test pattern. . Therefore, after printing the test pattern 90, the first detection is performed for one end of the bar as it is, and then the test pattern paper is conveyed by a predetermined amount so that the optical sensor 4 is positioned at the center of the nozzle row. A second test pattern scan is performed. Further, a predetermined amount of paper is conveyed so that the optical sensor 4 is positioned at the lower end of the nozzle row, and the third test pattern is scanned on the other end of the bar. In this way, the number of optical sensors 4 can be single by reading the test patterns by sequential separate scanning with different test pattern detection positions.

  Even when a line-type print head is used, if a mechanism capable of moving and arranging the optical sensors 4 in the nozzle row direction is provided, a single optical sensor 4 is used to sequentially sequentially at a plurality of locations in the nozzle row direction. It is also possible to scan.

  The preferred embodiments of the present invention have been described above, but various modifications and changes other than those mentioned above can be made.

  For example, the barcode correction value table is stored in the printer and the correction value is determined by the printer. However, the correction value is transmitted to an external device that instructs to print the barcode, such as an external device such as a host PC. A table may be held, test pattern detection result data may be acquired from a printer (or upon receiving data input by a user), and a correction value may be determined by the external device.

  Further, the test pattern data may be stored in a storage device in the host PC, and the data may be sent to a printer for printing when necessary.

  Although a printer using an inkjet head has been described, the present invention is also applicable to a printer using a thermal head.

1 is a diagram showing a schematic configuration of a main part of a barcode printer according to an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic hardware configuration of the barcode printer shown in FIG. 1. It is a figure which shows the structural example of the optical sensor shown in FIG. It is the figure which showed the barcode printer of the other structure by embodiment of this invention. FIG. 5 is a schematic diagram for explaining a configuration of paper conveyance in the printer of FIG. 4. It is explanatory drawing of the problem concerning the printing of the conventional barcode. It is explanatory drawing of the correction method of the conventional barcode. It is explanatory drawing of the further problem which concerns on the printing of the conventional barcode. It is a figure which shows the example of a structure of the test pattern in embodiment of this invention, and an example of the read waveform. It is a figure which shows the example of a structure of the test pattern in embodiment of this invention, and the other example of the read waveform. It is a figure which shows the example of the content of the correction value table used in embodiment of this invention. It is the flowchart which showed the example of the procedure of the process for determining the correction value of barcode in embodiment of this invention. It is explanatory drawing of the modification of embodiment of this invention. It is a figure which shows the relationship between the some optical sensor and test pattern in the modification of FIG. It is a figure which shows the example of the output waveform of the some optical sensor in the structure of FIG. It is a figure which shows the correction | amendment state of the bar in the structure of FIG. 13 based on the detection result of the output waveform of the some optical sensor of FIG. It is explanatory drawing of operation | movement of this Embodiment in a serial type printer. It is explanatory drawing of the modification of a structure and operation | movement of FIG.

Explanation of symbols

2, 2a, 2b ... carriage 3, 3a, 3b ... print heads 4, 4a, 4b, 4c ... optical sensor 5 ... encoder sensor 6 ... linear scale 7 ... carriage motor 8 ... transport motor 8a ... encoder sensor 10 ... control unit 20 ... paper (recording medium)
30 ... Barcode printer 31 ... Print heads 32, 32a, 32b ... Nozzle array 51 ... Code wheel 52 ... Conveying roller 90 ... Test pattern 110 ... Correction value table

Claims (11)

In a printing apparatus capable of printing a barcode,
A bar interval identification limit determining means for determining an identification limit bar interval in an actual printing environment;
And a correction unit that determines a correction value of the bar width according to the bar interval of the identification limit. Means for printing, as a test pattern, a plurality of line segment patterns in which intervals between adjacent line segments are sequentially different;
Detecting means for obtaining a sensor output by scanning the sensor in a direction orthogonal to a line segment of the printed test pattern;
The printing apparatus according to claim 1, wherein the bar interval identification limit determination unit determines a bar interval of an identification limit based on the sensor output.   The correction means has a correction value table in which a correction value for the bar width of the barcode to be recorded is predetermined for each bar width value of the identification limit determined based on the test pattern. Refer to the correction value table. The printing apparatus according to claim 1, wherein the correction value is determined.   The printing apparatus according to claim 1, wherein the correction of the bar width is performed by at least one of correction of original data of a barcode to be printed and correction of a heat pulse width.   The printing apparatus according to claim 2, wherein the sensor is fixedly arranged with respect to a print head having a nozzle row.   The printing apparatus according to claim 5, wherein the sensor is disposed on the downstream side of the nozzle row in a relative movement direction of the print head with respect to a recording medium.   The printing apparatus according to claim 2, 5 or 6, wherein a plurality of the sensors are provided and arranged at a plurality of positions in a longitudinal direction of the nozzle row.   The printing apparatus according to claim 1, wherein the direction of the bar code is a direction in which each bar extends in a direction orthogonal to a relative movement direction of the print head with respect to a recording medium.   The printing apparatus according to claim 2, wherein the test pattern is read by providing a single sensor and sequentially moving and arranging the sensor at a plurality of positions in the longitudinal direction of the nozzle row.   The sensor includes a light emitting element for irradiating light onto a recording medium, and a light receiving element that receives light reflected from the recording medium and irradiated from the light emitting element, and reflects reflected light in the printed test pattern. The printing apparatus according to claim 2, wherein detection is performed by a light receiving element, and the bar interval of the identification limit is determined based on the detection signal. A bar width correction method for correcting a bar width of a barcode printed by a printing apparatus,
Printing a plurality of line segment patterns in which intervals between adjacent line segments are sequentially different as a test pattern;
Scanning the sensor in a direction perpendicular to the line segment of the printed test pattern to obtain a sensor output;
Determining an identification limit bar spacing based on the sensor output;
And correcting the bar width in accordance with the determined bar interval of the identification limit.