KR100561412B1 - Method for alignment of printer head and apparatus thereof - Google Patents

Abstract

The present invention discloses a method and an apparatus for aligning a head of a printer.

According to the present invention, in the method for aligning a head in a printer device, a predetermined test pattern is printed, a position of a printed test pattern is detected, and a distance for aligning the head at the time of printing from the position of the detected pattern. If the alignment value is less than or equal to a predetermined value in a partial section of the boundary of the test pattern, the alignment value obtained above is determined as the final alignment value, and the alignment value is detected through a carriage scan in the corresponding alignment pattern. In this case, error cases can be reduced by filtering and removing a wrong value detected as a noise component due to an electric factor or an external environmental factor within an allowable range.

In addition, by reducing the use of incorrectly detected values within the allowable range as the alignment value, the alignment value is preferably adjusted through the corresponding alignment pattern to improve the print quality by performing the head alignment and bidirectional alignment correctly through the automatic alignment. You can.

As a result, there is no need to add a separate electric filter component to eliminate the noise effect caused by electrical factors, and the use of software filtering and elimination methods eliminates the cost increase in product development and production.

Description

Method and alignment of printer head and apparatus

1 shows the flow of a method for aligning a head of a printer according to the present invention.

2 is a block diagram showing the configuration of an apparatus for aligning a head of a printer according to the present invention.

3 shows a detailed flow of an example of a method of aligning a head of a printer according to the present invention.

4 is a diagram illustrating an example of obtaining an alignment value of a printer header and determining it as a final value according to the present invention.

The present invention relates to a printer, and to a method and apparatus for removing the influence of noise in automatic alignment of a printer.

For inkjet printers and multifunction printers, head alignment between mono heads and color heads with multiple heads and bidirectional alignment by bidirectional printing are the major factors that determine print quality. By adjusting the above two alignment factors before printing, the desirable print quality can be obtained.

In particular, there are manual sorting and automatic sorting methods to adjust the sorting factors, and among the two methods, the automatic sorting method is used to automatically adjust the factors that reduce the print quality by using the automatic sorting method. It is a recent trend. In this case, when the automatic alignment method is used in performing head alignment and bidirectional alignment to improve the print quality, undesirable alignment values are generated due to noise components caused by electrical factors and other external environmental factors. Often not obtained.

Automatic alignment of a conventional inkjet printer is performed as follows.

Calibration is first performed on the automatic alignment sensor to perform automatic alignment. The head is newly mounted or replaced, or the user is instructed to perform an automatic alignment. At this time, in order to perform the calibration of the automatic alignment sensor, paper is first fed and transported, and sensor calibration (white calibration) is performed on the margin of the transferred paper and checked. Next, a calibration pattern is printed on the paper and scanned over the printed pattern at the corresponding speed to perform a threshold calibration (black calibration) and confirm.

Check whether the sensor calibration (white calibration) and threshold calibration (black calibration) were performed correctly, that is, the error of the automatic alignment sensor. If a problem with the automatic alignment sensor is identified, the user is notified of the error through the host to handle the automatic alignment error. If normal, proceed to the next step.

After printing the alignment pattern prepared for head alignment and bidirectional alignment, the printed pattern is scanned at the corresponding speed to detect the alignment value for the case. Check whether the edge detection value that can be detected in the alignment pattern is correct. If the edge detection value is not correct, the host computer notifies the user for automatic alignment error handling. If normal, proceeds to the next step.

The alignment value is obtained through the alignment pattern, and the value is stored in a storage medium for use in printing. After checking whether the sorting is completed, if the completion of the automatic sorting is completed, and if it is not completed, the above process is repeated for the next corresponding sorting pattern.

When the automatic alignment is completed normally, the alignment values for head alignment and bidirectional alignment are obtained, and the values are reflected in printing and used to improve the print quality.

In such a case, an incorrect value may be detected by a noise component of an electrical factor or an external environmental factor during a carriage scan for edge detection in a corresponding alignment pattern.

If the alignment value is obtained from the wrongly detected value, the print quality may be degraded because the alignment to be adjusted through the corresponding alignment pattern may not be performed correctly. In this case, there is a problem in that the cost increases when a filter component for removing noise components is added by an electronic method in order to eliminate the influence of noise components due to electrical factors.

However, even in such a case, there is no problem in the actual use of the printer, but minute noise that may be detected and interpreted as an error situation may continue to occur. And cost.

In addition, the false alignment value that may be caused by the self-alignment sensor itself failure can not be processed in the production process of the failure can increase the production cost due to the failure.

As a result, undesirable alignment values were often detected by noise components in the early stages of the automatic alignment development process. In the process of solving the problem, there is a problem in that development cost and development time can be lost. have.

The technical problem to be solved by the present invention, in order to solve the above problems, when obtaining the alignment value required for automatic alignment in the range that does not interfere with printing when the alignment value is changed due to various factors causing various errors in various environments. The present invention provides a method and an apparatus for aligning a head of a printer that can obtain an alignment value of a print header even when an error occurs.

According to the present invention for solving the above technical problem, the method of aligning the head of the printer, (a) printing a predetermined test pattern by printing a detailed pattern that already knows a plurality of print positions of the same shape ; (b) scanning the printed pattern at predetermined intervals to detect the position, spacing and printed border of each actual printed detail pattern to detect the position of the test pattern; (c) an alignment for comparing the position and spacing of the detailed patterns to be printed with the position and spacing of the actual printed detail patterns detected in the step (b) to align the head at the time of printing for each of the detailed patterns. Obtaining values; And (d) a detailed pattern boundary corresponding to the alignment values of each sub-pattern that is substantially non-zero in step (c) is within a predetermined ratio compared to the area of the area where the sub-pattern is printed or the area of the gap between the patterns. In the case of obtaining a plurality in the range of the step of ignoring the plurality of alignment values as 0 to determine the final alignment value; characterized in that it comprises a.

The apparatus for aligning the head of the printer according to the present invention for solving the above other technical problem, the pattern printing unit for printing a predetermined test pattern by printing the detailed patterns that already know a plurality of positions to be printed of the same shape ; A pattern position detection unit scanning the printed pattern at a predetermined period to detect the position, spacing, and printed boundary of each actual printed detail pattern to detect a position of a test pattern; Alignment is a distance for aligning the head at the time of printing for each of the detailed patterns by comparing the position and spacing of the detailed patterns to be printed in the pattern printing unit and the position and spacing of the actual printed detailed patterns detected by the pattern position detecting unit. An alignment value obtaining unit obtaining values; And when a plurality of detailed pattern boundaries corresponding to each of the sub-pattern alignment values that are substantially non-zero are obtained in a range within a predetermined ratio in comparison with the area of the area where the detail pattern is printed or the area of the gap between the patterns. And a sorting value determining unit determining the final sorting value by ignoring the plurality of sorting values as 0 and ignoring the sorting values.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows the flow of a method for aligning a head of a printer according to the present invention. The predetermined test pattern is printed (step 100), and the position of the printed test pattern is detected (step 110). And an alignment value, which is a distance for aligning the head during printing, from the position of the pattern detected in step 110 (step 120), and when the alignment value obtained is less than or equal to a predetermined value in a partial section of the boundary of the test pattern. The alignment value obtained in step 120 is determined as the final alignment value (step 130).

In this case, the test pattern is printed by printing a plurality of detailed patterns having the same shape at regular intervals at positions 100 in step 100, and the positions, intervals, and printed information of the respective patterns are scanned by scanning the printed patterns at predetermined intervals in step 110. The boundary is detected, and the alignment values are calculated for each subpattern by comparing the position to be printed, the interval with the detected position, and the interval in step 120, and the alignment values for each subpattern that are substantially non-zero correspond to the detail in step 130. When a plurality of pieces are obtained within a predetermined range of the pattern boundary, the plurality of alignment values are regarded as 0 and ignored.

In operation 130, if the alignment values for each sub-pattern that are not substantially zero do not fall within a predetermined range based on the corresponding sub-pattern boundary, and are within the boundary of the neighboring sub-pattern, the final alignment value may not be obtained. I think that.

The test pattern of 100 steps may include a pattern for aligning a plurality of headers, a pattern for aligning vertical and horizontal heads, an alignment pattern for bidirectional mono printing according to print speeds for each print mode, and a print speed for each print mode. Including the alignment pattern for bidirectional color printing, after printing each test pattern and performing steps 110 to 130, if another test pattern is to be printed, the print pattern is alternately printed at a predetermined interval from the printed test pattern. Repeat steps 130 to 130 to obtain alignment values for each pattern type.

2 is a block diagram showing the configuration of an apparatus for aligning a head of a printer according to the present invention. The apparatus is a pattern printing unit 200 for printing a predetermined test pattern by printing a plurality of detailed patterns of the same shape at regular intervals for each position, the position, spacing and The pattern position detection unit 210 detects the printed boundary and detects the position of the test pattern, and the position, spacing of the detailed patterns to be printed in the pattern printing unit 200, and the position and interval detected by the pattern position detection unit 210. By comparison, the alignment value acquisition unit 220 which obtains alignment values which are distances for aligning the heads at the time of printing for each detailed pattern, and the alignment values for each detailed pattern which is substantially non-zero are within a predetermined range of the corresponding detailed pattern boundary. In the case of obtaining a plurality of, the alignment value determination unit 230 determines the final alignment value by ignoring the plurality of alignment values as 0 and ignoring the plurality of alignment values.

At this time, the alignment value determination unit 230 is the final alignment value when the alignment values for each sub-pattern that are not substantially zero do not fall within a predetermined range based on the corresponding sub-pattern boundary and are within the boundary of the neighboring sub-pattern. In this case, the apparatus according to the present invention further includes an error notification unit 240 for notifying the user when the final value of the alignment cannot be obtained. do.

3 shows a detailed flow of an example of a method of aligning a head of a printer according to the present invention.

When the head of the printer is newly mounted or replaced, or when the user is instructed to perform the head auto alignment, the paper is first fed and transported to perform the calibration of the automatic alignment sensor as in the conventional alignment method. Perform sensor calibration (white calibration) on the margins and check. Then, the calibration pattern is printed on the paper, and the printed pattern is scanned on the printed pattern or at a corresponding speed to be tested separately to perform and check threshold calibration (black calibration) (step 300).

The sensor calibration (white calibration) and the threshold calibration (black calibration) is performed correctly, that is, whether the alignment sensor is checked (step 310). If a problem with the alignment sensor is confirmed, an automatic alignment error is reported to the user (step 380). At this time, the error notification unit 240 informs the user that the automatic alignment is not possible because the automatic alignment sensor is abnormal. In this case, the error notification unit 240 may display an error message through a display means such as an LCD window attached to the printer, or may flash a lamp prepared for an error, or an error in a host computer connected to the printer. The situation may be notified and displayed to the user.

The pattern printing unit 200 prints a test alignment pattern prepared for head alignment and bidirectional alignment (step 320). The alignment pattern may be in various forms, but in order to easily obtain the alignment value, the test pattern may be printed by printing a plurality of detailed patterns having the same shape at regular intervals for each position.

4 is a diagram illustrating an example of obtaining an alignment value of a printer header and determining it as a final value according to the present invention. Pattern 400 shows an example of an alignment pattern.

The detailed pattern of this pattern is composed of rectangular shapes and gaps therebetween, n rectangles M1, M2, ... are the same shape, and n-1 gaps S1, S2, ...) is also the same.

The pattern position detector 210 scans the printed pattern at predetermined intervals to detect the position, spacing, and printed boundary of each detailed pattern (step 330).

DIN 410 is a waveform resulting from scanning the pattern and detecting the edge of the pattern. For example, when the pattern 400 is scanned from left to right, the gray level is 0 (full white) before M1, and the gray level is 255 (full black) from the boundary of M1. Will be. Alternatively, before the detailed pattern of M1, the output of 0 volts is regarded as the output of 5 volts from the boundary of M1. If the detailed pattern includes a color, it may be a method of easily determining the boundaries of the detailed patterns by indicating the change in the voltage value rather than the gray level.

Each edge is marked on ED 420. Each arrow indicates the position of the edge. In other words, when DIN 410 represents a voltage, the edge that changes from 0 volts to 5 volts or from 5 volts to 0 volts becomes the edge.

SP 430 is a sampling period. The lengths of regions of the patterns of M1, S1, M2, and S2 may be obtained with time values such as MC1, SC1, MC2, and SC2, which are sampling periods, respectively. Such time values may be represented by the horizontal length of the region shown in the drawing, or when the counter element is used for sampling, it may be represented as an output value of a count output during each time of MC1, SC1, MC2, and SC2. have.

Since the printed pre-prepared pattern has already determined the position and / or spacing of each detail pattern (or coordinates to be printed on paper), the alignment value obtaining unit 220 may know the position and spacing of the detail patterns to be printed. In addition, since the pattern position detection unit 210 obtained the position and the interval of each detailed pattern from the pattern 400 as described above, the pattern prepared in advance is aligned, and the alignment value acquisition unit 220 determines the position where each detailed pattern should be printed. By using the difference between the position and the actual printed position can be obtained (step 340).

In this case, if each detail pattern is printed in place to be printed, the alignment value of each detail pattern will be substantially zero. However, if the boundary of all the detail patterns is moved by + a more than the position to be printed, the value of each detail pattern will be -a.

However, if the alignment value is different for each detailed pattern, this cannot be used as the alignment value (step 350), and since this cannot be solved through the head alignment, the error notification unit 240 may have the same method as described above. This is reported to the user as an error (step 380).

However, if the other edge portions are normal as shown in FIG. 4 and the alignment values obtained using the edges are the same, but several edges appear locally as shown by the reference numeral 440, the edges cannot be properly processed in the conventional case. In this case, the alignment value determination unit 230 considers the plurality of alignment values as 0 when a plurality of alignment values for each sub-pattern that are not substantially 0 are obtained within a predetermined range of a corresponding sub-pattern boundary. Ignore it. This is explained.

4 is an enlarged view of a portion of 440. Such multiple detection of the edges locally may be an external environmental factor or may occur due to electrical noise.

Because of the noise generated at 450, a plurality of edges are detected in the SCex 460, which is a noise influence period. Increasing the sampling period sufficiently can detect edges due to noise generated in a short time or in a very small area. Therefore, the alignment value due to noise can be obtained from the obtained edges. As shown in Fig. 4, these alignment values are concentrated near the boundary between the subregions S1 and M2. That is, the plurality of edges due to this negligible noise are concentrated in a constant area EDex 470 around the boundary of the detailed pattern. That is, in this case, the measured edges are edges generated by negligible noise, so the alignment value obtained from such edges will be relatively small and can be ignored.

However, if an area such as 440 occurs in the middle of the MC2 480 instead of the edge, it is not a negligible noise and cannot be ignored. This is because it cannot be solved by automatic alignment. (Step 350). In this case, an error report is also reported to the user (step 380).

To this end, the alignment value determination unit 230 may have a final alignment when the alignment values for each sub-pattern that are not substantially 0 are large enough to fall within a predetermined range based on the corresponding sub-pattern boundary and are within the boundary of the neighboring sub-pattern. It is desirable to judge that the value is not available. In this case, the area SCex 460 where the edges are detected by the noise is too large in this case, which is a noise that cannot be ignored.

The constant area centered on the boundary of the detailed pattern that can ignore the alignment value obtained by the noise as described above may be determined by a relative position such as, for example, within 1% of the value of M1 or S1 or on the head of the printer. It is an area that can be narrowed further depending on the required precision. Or it can be determined by design precision or user definition.

As described above, if a certain area that can ignore edges due to noise is obtained from Mc1, Sc1, ..., etc., such as reference numeral 430, from the edge generated due to the noise, and the magnitude of the values is smaller than a predetermined value, It can also be defined as the region where. In this case, the noise is considered to be negligible. That is to say, the unwanted edges generated by the noise have only a negligible effect, so the noise is ignored. Similarly, the predetermined value at this time may also be determined within 1% or the like as described above.

The alignment value determination unit 230 detects only substantially the same values except for the negligible values among the alignment values obtained by the alignment value acquisition unit 220 through the above method (step 360). That is, a plurality of alignment values are obtained, but they are all the same value, which is an alignment value according to the alignment pattern. This alignment value is stored in predetermined storage means for use in printing.

The pattern 400 of FIG. 4, which is printed in step 320, includes a pattern for aligning a plurality of headers, a pattern for aligning vertical and horizontal heads, an alignment pattern for bidirectional mono printing according to the printing speed, and a printing mode for each printing mode. It includes alignment patterns for bidirectional color printing according to the printing speed for each mode. Therefore, if it is determined that the alignment value corresponding to the pattern is obtained through the same process as described above for each pattern and stored, and then the alignment value is obtained from another pattern (step 370), at a predetermined interval from the test pattern printed first. The next pattern is printed by changing the lines, and the operations of steps 320 to 370 are continued to obtain and store alignment values for all the patterns needed or desired by the user. In printing, a corresponding alignment value is extracted according to the printing mode, and the alignment value is applied to control the head to provide improved print quality.

Through the above process, the present invention provides a software filtering function within an allowable range for designing an alignment value that may be wrong by noise in the process of obtaining an alignment value corresponding to each pattern in addition to the conventional alignment method.

According to the present invention, in the method for aligning a head in a printer device, a predetermined test pattern is printed, a position of a printed test pattern is detected, and a distance for aligning the head at the time of printing from the position of the detected pattern. If the alignment value is less than or equal to a predetermined value in a partial section of the boundary of the test pattern, the alignment value obtained above is determined as the final alignment value, and the alignment value is detected through a carriage scan in the corresponding alignment pattern. In this case, error cases can be reduced by filtering and removing a wrong value detected as a noise component due to electric or external environmental factors within the allowable range.

In addition, by reducing the use of incorrectly detected values within the allowable range as the alignment value, the alignment value is preferably adjusted through the corresponding alignment pattern to improve the print quality by performing the head alignment and bidirectional alignment correctly through the automatic alignment. You can.

As a result, there is no need to add a separate electric filter component to eliminate the noise effect caused by electrical factors, and the use of software filtering and elimination methods eliminates the cost increase in product development and production.

Claims (7)

delete In the method of aligning the head in the printer device, (a) printing a predetermined test pattern by printing detailed patterns already knowing a plurality of positions to be printed of the same shape; (b) scanning the printed pattern at predetermined intervals to detect the position, spacing and printed border of each actual printed detail pattern to detect the position of the test pattern; (c) an alignment for comparing the position and spacing of the detailed patterns to be printed with the position and spacing of the actual printed detail patterns detected in the step (b) to align the head at the time of printing for each of the detailed patterns. Obtaining values; And (d) The detailed pattern boundary corresponding to the alignment values for each sub-pattern that is substantially non-zero in step (c) is within a certain ratio compared with the area of the area where the sub-pattern is printed or the area of the gap between the patterns. And determining a final alignment value by ignoring the plurality of alignment values as 0 when the plurality of alignment values are obtained in a range. The method of claim 2, wherein in step (d), The detailed pattern boundary to which the alignment values of the respective sub-patterns, which are substantially non-zero, correspond, does not fall within a predetermined ratio compared to the area of the area where the subpattern is printed or the area of the gap between the patterns and neighboring subpatterns. If it is located within the boundary of the method of aligning the head of the printer, it is determined that the final alignment value is not available. The method according to claim 2 or 3, The test pattern of step (a) is a pattern for aligning a plurality of headers, a pattern for aligning vertical and horizontal heads, an alignment pattern for bidirectional mono printing according to the printing speed for each printing mode, and a printing speed for each printing mode. Including alignment pattern for bi-directional color printing according to After printing each test pattern and performing the above steps (b) to (d), when another test pattern is printed, lines are printed at a predetermined interval from the printed test pattern and the above (b) to (d) are printed. Repeating the steps to obtain an alignment value for each pattern type. An apparatus for aligning a print head, A pattern printing unit for printing a predetermined test pattern by printing detailed patterns already knowing a plurality of print positions of the same shape; A pattern position detection unit scanning the printed pattern at a predetermined period to detect the position, spacing, and printed boundary of each actual printed detail pattern to detect a position of a test pattern; Alignment is a distance for aligning the head at the time of printing for each of the detailed patterns by comparing the position and spacing of the detailed patterns to be printed in the pattern printing unit and the position and spacing of the actual printed detailed patterns detected by the pattern position detecting unit. An alignment value obtaining unit obtaining values; And When a plurality of detailed pattern boundaries corresponding to the alignment values for each sub-pattern that are substantially non-zero are obtained in a range within a predetermined ratio compared to the area of the area where the subpattern is printed or the area of the gap between the patterns, the subpattern And an alignment value determination unit for ignoring the number of alignment values as 0 and determining final alignment values. The method of claim 5, wherein the alignment value determination unit, The detailed pattern boundary to which the alignment values of the respective sub-patterns, which are substantially non-zero, correspond, does not fall within a predetermined ratio compared to the area of the area where the subpattern is printed or the area of the gap between the patterns and neighboring subpatterns. If it is located within the boundary of the device for aligning the head of the printer, it is determined that the final alignment value can not be determined. The method according to claim 5 or 6, And an error notification unit for notifying a user when the alignment value determination unit cannot obtain a final alignment value.

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