JP3729140B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inkjet printer, and more particularly to an inkjet printer having an alignment adjustment function in a printer body.
[0002]
[Prior art]
An ink jet printer interested in the present invention is disclosed in, for example, Japanese Patent Laid-Open No. 10-217479.
[0003]
According to the publication, when the host computer launches an application for each print quality adjustment pattern, the ink jet printer receives the ink jet printer control command and print data transmitted from the host computer, and the print quality is correspondingly received. An ink jet printer print quality adjustment method and apparatus are disclosed in which an adjustment pattern image is created and a host computer sets an appropriate adjustment value for each print quality adjustment pattern. According to the publication, since the print quality adjustment is automatically performed by the host computer, the operator can easily maintain the print quality without performing an erroneous operation.
[0004]
[Problems to be solved by the invention]
The alignment adjustment for adjusting the print quality in the conventional ink jet printer has been performed as described above. Although the print quality adjustment pattern is automatically recognized, there is a problem that the host computer performs the print quality adjustment, and the print quality cannot be adjusted without the host computer.
[0005]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ink jet printer capable of adjusting print quality with a single printer such as an ink jet printer.
[0008]
[Means for Solving the Problems]
The inkjet printer according to the present invention moves relative to a sheet in a first direction and a second direction intersecting with the sheet, and prints the first pattern by moving in the first direction. Printing means for printing on the paper a second pattern different from the first pattern by moving in a direction opposite to the first direction on the print band of the first pattern, and the first direction or the first direction. The reading means for reading the print result of the first pattern and the second pattern on the paper by the printing means , and the plurality of first patterns based on the reading result by the reading means. Using the value up to the adjacent second pattern and the values from the plurality of second patterns to the adjacent first pattern, the average interval between the adjacent first pattern and the second pattern Proportionally Calculating means for calculating a value as an alignment adjustment value, using the alignment adjusted by operating means, and a regulating means for alignment of the printing means. This ink jet printer is characterized by adjusting the alignment of the printing means alone.
[0009]
Since the ink jet printer itself adjusts the alignment of the printing means based on the reading result of the reading means, the print quality can be adjusted by the ink jet printer alone.
[0010]
The alignment adjustment by the ink jet printer alone is performed at a predetermined timing such as an instruction from the host or replacement of the ink cartridge.
[0013]
Preferably, the ink jet printer includes storage means for storing the alignment adjustment value. Since the alignment adjustment value is stored in the storage means, reference from an external host is also possible as necessary.
[0015]
More preferably, the adjusting means uses the first pattern depending on the second direction printed on the paper by the printing means and the alignment adjustment value obtained by the calculating means based on the second pattern . After adjusting the alignment in one direction, the calculation means obtains the first pattern and the second pattern that are printed on the paper by the printing means and that depends on both the first direction and the second direction. the alignment of the second direction is adjusted by using the obtained alignment values.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 is a schematic diagram (A) showing a schematic configuration of a main part of an ink jet printer according to an embodiment of the present invention, and a diagram (B) showing a front view as viewed from the direction of arrow 1B in (A). .
[0018]
Referring to FIG. 1, an ink jet printer 10 includes a carrier 11 that is driven to reciprocate in a drawing direction that intersects a sheet 40 that is conveyed in the direction of an arrow indicated by 1B in the drawing. The carrier 11 includes a print head 12 for printing on the paper 40 and an ink cartridge 13 that supplies ink to the print head 12. The carrier 11 is attached to a belt 19 moved in the drawing direction, and printing is performed in the main scanning direction of the paper 40 by reciprocating the belt 19 with a carrier motor (not shown). The ink cartridge 13 includes a black cartridge 13a for monochrome printing and a color cartridge 13b for color printing, and a corresponding print head 12 is provided.
[0019]
Referring to FIG. 1B, an alignment sensor 17 for detecting a printing result is attached to the carrier 11. The position of the carrier 11 is specified by the encoder 14.
[0020]
Since the alignment sensor 17 is attached to the side surface of the carrier 11, a series of operations from reading the pattern by the print head 12 to reading the printing result requires complicated mechanisms and operations for reading the alignment sensor 17. It is continuously performed when feeding one sheet without adding.
[0021]
FIG. 2 is a block diagram showing the overall configuration of the inkjet printer 10 shown in FIG. Referring to FIG. 2, the inkjet printer 10 includes a digital ASIC (Application Specific Integrated Circuit) 20, a carrier 11 connected to the digital ASIC 20, a plurality of sensors, and a carrier motor 27 connected via an analog ASIC 26. A paper feed motor 28 and an operation panel 31 are included.
[0022]
The digital ASIC 20 is connected to the CPU 21 that controls the entire inkjet printer 10, the user logic block 22 connected to the CPU 21, the RAM 23, and a host 30 such as a personal computer provided via the USB interface 29. USB block 24. A nonvolatile NVRAM (Non-Volatile Random Access Memory) 25 is connected to the user logic block 22. The user logic block 22 controls access to a memory such as the NVRAM 25, data input / output, input / output port control and signal input / output such as the USB interface 29, interrupt signal processing and generation, and communication control of the data. .
[0023]
The sensor group is connected to the user logic block 22, and includes an encoder 14 that specifies the position of the carrier 11, a cover sensor 15 that detects opening and closing of a cover (not shown) of the inkjet printer, and a paper sensor 16 that detects the presence or absence of the paper 40. And an alignment sensor 17 for detecting the alignment of the print pattern printed on the paper 40 and an alignment LED 18 for detecting by the alignment sensor 17.
[0024]
The user logic block 22 is connected to the carrier motor 27 via the analog ASIC to move the carrier 11 in the drawing direction crossing the arrow in FIG. 1A and to feed the paper 40 in the arrow direction. Yes.
[0025]
Next, the operation of the inkjet printer 10 will be described based on the flowchart shown in FIG. Referring to FIG. 3, ink jet printer 10 prints an alignment adjustment pattern based on an alignment adjustment command sent from host 30, and reads the print result with alignment sensor 17. Several types of alignment adjustment patterns are prepared on the inkjet printer 10 side, and the patterns are printed based on command instructions sent from the host 30 according to the adjustment purpose. The print result is scanned by the alignment sensor 17, and the result is stored in the NVRAM 25 that can be referred to from the host. The inkjet printer 10 performs processing from command reception / analysis to creation / printing of an alignment pattern and reading / calculation / saving of a print result.
[0026]
More specifically, the paper 40 is fed to the printing unit of the ink jet printer in response to a signal from the host 30 (step S10, the following steps are omitted). Next, the first pattern printing (S11), the second pattern printing (S12), and the pattern reading (S13) are performed. Then, a predetermined calculation is performed (S14), and the result is recorded in the NVRAM 25 (S15). Next, the paper 40 is fed in accordance with the determination of the ink jet printer driver, and paper feeding (S17) or paper discharge for further pattern printing is performed (S18).
[0027]
In the present invention, the inkjet printer 10 can perform all the processes of S11 to S15 described above independently.
[0028]
Since the alignment adjustment pattern data and the alignment adjustment sequence are provided on the ink jet printer 10 side, alignment adjustment can be automatically performed only by the ink jet printer 10 alone.
[0029]
The pattern for preparing the alignment may be printed by an instruction from the operation panel 31 of the ink jet printer, or may be automatically performed at a predetermined time such as when the cartridge is replaced. .
[0030]
Next, reading of the pattern shown in S13 will be described. After printing the alignment pattern, light from the light emitting part of the alignment sensor 17 is applied to the printed alignment pattern while moving the carrier 11 and reflected on the paper. The reflected light is interrupted at the place where the pattern is present, and the reflected light is received by the light receiving portion at the place where there is no pattern (white background), and a pulse corresponding to the presence or absence of the pattern can be obtained. Patterns to be printed are shown in FIGS.
[0031]
FIG. 4 is a diagram showing a printing result of a printing adjustment pattern for bidirectional printing (horizontal direction) in color (white in the drawing) and black ink (with hatching in the drawing).
[0032]
FIG. 5 is a diagram (A) showing a vertical adjustment pattern in color and black ink, and a diagram (B) showing the detection principle, which are performed after the horizontal adjustment shown in FIG. 4 is completed. The vertical adjustment pattern is printed in an oblique direction as shown in FIG. 5, and the intervals between the adjacent color and black ink are shown as B1 to B8.
[0033]
Referring to FIG. 5B, since the adjustment in the horizontal direction has been completed, if there is no deviation in the vertical direction (indicated by a solid line in FIG. B), D0 should be a predetermined value. If there is a deviation (indicated by a dotted line in FIG. B), it becomes D1 and does not become the predetermined value D0. Therefore, it is possible to detect a vertical shift.
[0034]
FIG. 6 is a diagram showing a pattern printing sample for alignment preparation. Four bands shown in (A) are prints for nozzle cleaning of black and YMC three color ink cartridges, and a short band in (B) is a print for checking the operation of the alignment sensor 17. As described above, the arrangement of patterns is determined by the host 30 or the like such as a personal computer, and commands for paper feed, pattern selection, paper feed, and paper discharge are sent to the inkjet printer 10.
[0035]
6C is a horizontal alignment adjustment pattern for color bidirectional printing, FIG. 6D is a horizontal alignment adjustment pattern for bidirectional printing with black ink, and FIG. 6E is a pattern for color and black ink. This is a horizontal alignment adjustment pattern for bidirectional printing, and (F) is a vertical alignment adjustment pattern for bidirectional printing of color and black ink.
[0036]
Each time (D) to (F) in FIG. 6 are printed one step, the result is read by the alignment sensor 17 provided on the side surface of the carrier 11. An example of the process from printing to reading will be described with reference to FIG.
[0037]
FIG. 7A is a diagram showing a first pattern drawing result in the pattern drawing shown in FIG. The drawing direction (carrier movement direction) is the direction indicated by the arrows in the figure. A second pattern drawing example is shown in FIG. The second drawing direction is opposite to the first drawing direction as indicated by an arrow in the figure.
[0038]
Drawing is performed over the entire width of the paper 40 as shown in FIG. After that, without performing line feed, the second pattern is drawn by moving the carrier 11 in the direction of the arrow in the same manner in (B). In these two drawing operations, a pattern as shown in (C) is printed on this print line. This pattern corresponds to the pattern of FIG. When the pattern drawing is completed, the pattern is read by the alignment sensor 17 in the direction of the arrow (C). Even during this reading, line feed is not performed, and reading is performed by moving the carrier in the direction of the arrow.
[0039]
The alignment sensor 17 scans the adjustment pattern in the direction indicated by the arrow in the drawing, thereby detecting the printing intervals indicated by A1 to A16 and B1 to B16 in the drawing.
[0040]
Next, a specific method for obtaining the alignment value will be described. Referring to FIG. 7, basically, a value obtained by dividing the distance An from the small block to the large block by subtracting the distance Bn from the large block to the small block by 2 is obtained, and the average value of these values is obtained. Alignment value.
[0041]
The processing procedure is as follows.
1) Print the alignment pattern as described above.
[0042]
2) While moving the carrier at 6 ips (inch per second, 152.4 mm / second), the alignment sensor scans the print result and counts A1 to A16 and B1 to B16 which are blank areas. However, this counter is incremented by 1 in 100 μsec. After the count is completed up to B16, the carrier is returned to scan from A1 again. Since this scan is repeated a total of three times, the data acquired as a result is three each of A1 to A16 and B1 to B16, for a total of 96 data. When this scan is performed, a process of counting up from the start edge of A1 at the first small block end to the end edge of B16 in units of 100 μs is also performed at the same time. This is done for each scan and averaged when the three scans are completed. This value is later used as a count number (Speed Samp Count) required for the distance movement.
[0043]
3) In the calculation procedure, first, the sum of all the data of A1 to A16 (48) is set as count A, and the sum of all of the data of B1 to B16 (48) is set as count B. Then, a value (AVG_count) in which the alignment value is indicated by the count number is obtained by the following equation.
[0044]
AVG_count = (countA-countB) / (2 * 48)
4) Since AVG_count indicates the alignment value by the count value of the counter, it is necessary to convert this into a dot number of 1/1200 dp (dot per inch). Since the print data is fixed, the distance from the start edge of A1 to the end edge of B16 is determined to be 6.1417 inches (about 156 mm). In 2), the count number (Speed Samp Count) required for the movement of this distance is acquired. Accordingly, the number of inches per count can be obtained from 6.1417 inches / Speed Samp Count. Therefore, the dot number alignment value (AAV) can be obtained by the following equation.
[0045]
AAV = AVG_count * 6.1417 / Speed Samp Count * 1200
Here, 6.1417 / Speed Samp Count * 1200 is called an alignment constant.
[0046]
The AAV is obtained as described above, and the value finally stored in the NVRAM 25 is obtained using a predetermined formula. The formula used is shown in FIG. The meaning of each variable in the figure is as follows.
[0047]
MONO_BIDI_NOMINAL = 20. This is the most ideal value when manual black alignment is performed manually.
[0048]
COLOR_BIDI_NOMINAL = 10, which is the most ideal value when color normal alignment is performed manually.
[0049]
CMYK_HORIZONTAL_NOMINAL = 7, and this value is the most ideal value when the horizontal alignment is performed manually.
[0050]
CMIK_VERTICAL_NOMINAL = 7, and this value is the most ideal value when the vertical alignment is performed manually.
[0051]
The alignment adjustment value obtained as described above is stored in the NVRAM 25. When the host 30 performs printing, the print data is corrected by reading the value.
[0052]
When the storage is completed, the inkjet printer 10 supplies the next sheet and performs the next alignment adjustment in accordance with a command from the host 30, or discharges the sheet and ends the alignment adjustment.
[0053]
Next, the details of the auto-alignment processing procedure shown in FIG. 3 will be described with reference to FIGS. 8 to 10 are diagrams showing operation procedures performed by the host 30, the inkjet printer 10, and the user for the automatic alignment adjustment processing.
[0054]
When the user opens a cover (not shown) for replacement of the ink cartridge 13 or the like (S61), the inkjet printer 10 recognizes that using the cover sensor 15 and starts sampling of the cartridge 13 (S21). When the user removes and attaches the cartridge 13 (S62, S63), the inkjet printer 10 recognizes replacement of the cartridge 13 (S22). Next, when the user closes the cover (S64), the inkjet printer 10 recognizes that the cover is closed, and sets cartridge replacement information (S23). That is, the cartridge replacement information is set by opening the cover of the inkjet printer 10 and replacing the cartridge 13.
[0055]
Next, the user starts printing (S65). The host 30 performs a print start process (S41), and requests information from the inkjet printer 10. The inkjet printer 10 transmits cartridge replacement information (S25). In response to this, the host 30 recognizes replacement of the cartridge 13 (S42). If the cartridge replacement is not recognized, the alignment process is not performed.
[0056]
Next, the host 30 issues a paper feed and paper feed command (S43). In response to this, the inkjet printer 10 feeds paper and feeds paper (S26). Next, a check command from the alignment sensor is issued from the host 30 (S44). In response to this, the inkjet printer 10 starts a maintenance operation. The carrier 11 is moved to the print start area, and the color cartridge 13b prints the band in the state where all nozzles are ejected, and then performs line feed. Next, the carrier 11 is sent to the print start area, and the band is printed by the black cartridge 13a in the state where all nozzles are ejected (S16). Next, line feed is performed, the carrier 11 is moved to the printing start area, and the band for checking the auto alignment sensor is printed. The print result is read by moving to the carrier reading start area, turning on the alignment LED 18 and moving the carrier 11 (alignment sensor 17). The analysis of the reading result and the result are stored (S27). This storage is performed in the NVRAM 25.
[0057]
If the input from the alignment sensor 17 cannot be obtained due to damage of the alignment sensor 17 or the like, the alignment operation is not performed via an error with respect to the host 30 in the subsequent alignment adjustment.
[0058]
Next, in response to a line feed command (S45) from the host 30, the inkjet printer 10 performs line feed (S28).
[0059]
Referring to FIG. 9, in response to an arbitrary pattern execution command (S46) from host 30, inkjet printer 10 starts a maintenance operation. A pattern is created, the carrier 11 is moved to the printing area, and the pattern is printed. The position is moved to the sampling start position, and 100 μs interruption for sampling is started. The alignment LED 18 is turned on, the carrier 11 (alignment sensor) is moved, and the detection data is read. The position of the carrier 11 is moved to the sampling start position, the carrier 11 (alignment sensor) is moved, and the detection result of the alignment sensor 17 is read. The position of the carrier 11 is moved to the sampling start position, the alignment sensor 17 is moved, and the detection result of the alignment sensor 17 is read. Thereafter, the carrier 11 is moved to a predetermined initial position (home position) (S29).
[0060]
Next, the sampling result is analyzed, and an alignment value is calculated (S30). The result is stored in the NVRAM 25 (S30).
[0061]
Next, line feed is performed by a line field command (S47) from the host 30 (S31). In response to an arbitrary pattern execution command (S48) from the host 30, alignment measurement is performed with a pattern b different from the previous pattern a (S32). This alignment measurement is the same as S29 described above.
[0062]
Next, a line feed command from the host 30 (line feed is performed according to S49 (S33), and an alignment measurement is performed with a pattern c different from the above pattern according to an arbitrary pattern execution command (S50) from the host 30 ( S34) The contents of this alignment measurement are also the same as S29 described above.
[0063]
Both alignment measurement results are stored in the NVRAM 25.
Referring to FIG. 10, alignment measurement is performed using pattern d in response to a further arbitrary pattern execution command (S 51) from host 30 (S 35). The contents of this alignment measurement are the same as the contents of S29 described above. The result is stored in the NVRAM 25.
[0064]
In response to the paper discharge command (S52), the inkjet printer 10 discharges paper (S36), and ends the auto-alignment process (S37). Thereafter, the user re-executes printing in response to an instruction to execute printing again from the host 30 (S53) (S65). In response to this, the host 30 and the inkjet printer 10 start the printing process, and the host 30 requests alignment information from the inkjet printer 10 and performs predetermined printing according to the alignment information (S38, 39 and S54, 55). ).
[0065]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of an ink jet printer according to the present invention.
FIG. 2 is a block diagram showing a main part of the ink jet printer according to the present invention.
FIG. 3 is a flowchart showing a basic procedure of alignment adjustment.
FIG. 4 is a diagram showing a horizontal adjustment pattern in color black bidirectional printing.
FIG. 5 is a diagram illustrating an adjustment pattern in a vertical direction in color black bidirectional printing.
FIG. 6 is a diagram showing an example of alignment pattern printing.
FIG. 7 is a diagram illustrating a procedure from pattern drawing to reading.
FIG. 8 is a flowchart showing a detailed processing procedure of alignment adjustment.
FIG. 9 is a flowchart showing a detailed processing procedure of alignment adjustment.
FIG. 10 is a flowchart showing a detailed processing procedure of alignment adjustment.
FIG. 11 is a diagram illustrating an example of data stored in NVRAM.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Inkjet printer, 11 Carrier, 12 Print head, 13 Ink cartridge, 14 Encoder, 15 Cover sensor, 16 Paper sensor, 17 Alignment sensor, 18 Alignment LED, 20 Digital ASIC, 21 CPU, 22 User logic block, 25 NVRAM, 30 host.

Claims (1)

It moves relative to the paper in the scanning direction and the sub-scanning direction that is orthogonal to the scanning direction, and moves the scanning direction in the first direction to print a first pattern at a predetermined interval. The second pattern having a print position different from the first pattern at the same interval as the predetermined interval by moving the scanning direction in a second direction that is opposite to the first direction . Printing means for printing on the paper so as to overlap the printing band of one pattern;
Reading means for reading the printing result of the first pattern and the second pattern on the paper by the printing means by moving the scanning direction in the first direction or the second direction ;
Based on the reading result by the reading means, a value from a plurality of the first patterns to the second pattern adjacent to the first pattern, and a plurality of the second patterns to the second pattern Using the value up to the adjacent first pattern, the distance from the first pattern to the second pattern next to the first pattern, and the second pattern to the second pattern Calculating means for calculating an average value of a difference from the distance to the first pattern next to the first pattern as an alignment adjustment value;
Storage means for storing the alignment adjustment value;
Using the alignment adjustment value by the calculation means, and an adjustment means for adjusting the alignment of the printing means,
The adjusting means is based on the first pattern and the second pattern printed on the paper by the printing means and having a length in the sub-scanning direction and not forming an angle with respect to the sub-scanning direction. after adjustment of the scanning direction of alignment using the alignment adjustment value obtained in the calculating means, are printed on the paper by the printing means, an angle in both directions between the sub-scanning direction and the scanning direction the An ink jet printer that adjusts the alignment in the sub-scanning direction using the alignment adjustment value obtained in the calculation unit based on the first pattern and the second pattern.

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