JP2001091238A - Measuring method for paper transport amount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method for transport amount for properly and effectively measuring the paper feed accuracy. SOLUTION: In this paper transport amount measuring method in a printer, while a paper sheet on which a measurement pattern is printed by designated print pitch is fed in a inspection object printer 100, the measurement pattern is measured, and the obtained measurement value is corrected by reference measurement data to measure the paper feed amount. In creating a paper sheet where a measurement pattern is printed, to print a measurement pattern while the paper sheet is fed by measured pitch, the moving amount of the paper sheet is used as a correction value to measure the printer pattern position. Thus, the paper transport amount can be measured without the factor of a print head, so as to improve the accuracy of measuring the paper feed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for measuring the amount of feeding or the amount of conveyance of a sheet medium, such as in the case of paper conveyance of an ink jet printer.

[0002]

2. Description of the Related Art For example, in a paper conveying system of an ink jet printer, printing is performed while intermittently feeding a sheet at a predetermined pitch every time one line is printed. If the precision of the paper feed pitch is poor, problems such as white lines and overlapping occur in connecting lines. In particular, due to high definition printing, a one-pitch feed dimensional accuracy in intermittent feed of paper has been required. Accordingly, a method of measuring the paper feed amount has become an important item for evaluating the paper feed amount of the printer.

In the conventional paper feed amount measurement, a print pattern for pitch measurement is printed while the paper is fed by a print head of a printer to be measured. The printed paper is then measured while moving after performing image processing of the print pattern and the like.

[0004]

However, in the prior art, in addition to the feed pitch error of the print head paper, a variation factor of dots printed from the nozzles is included.
It is impossible to separate the error factors of the paper transport system from the ejection direction characteristics of the nozzles. For this reason, there is a problem that the measurement and evaluation of only the paper feed amount cannot be correctly performed. Therefore, it is desirable to use a measurement method that does not include the landing position error due to the print head characteristics, particularly the variation in the ejection direction.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for measuring a paper transport amount capable of properly and effectively measuring paper transport accuracy.

[0006]

A paper transport amount measuring method according to the present invention is a method for measuring a paper transport amount in a printer, wherein paper on which a measurement pattern is printed at a predetermined print pitch is fed by a printer to be inspected. The paper feed amount is measured by measuring the measurement pattern and correcting the obtained measurement value with reference measurement data.

In the method for measuring the amount of paper transported according to the present invention,
When creating a sheet on which a measurement pattern is printed, in order to print the measurement pattern while feeding the sheet at the pitch to be measured, the measurement of the print pattern position is performed using the movement amount of the sheet as a correction value. .

Further, in the method for measuring the amount of paper conveyed according to the present invention,
When the measurement pattern is printed and the print pitch is measured, the same measurement system as the measurement system for the pattern position used in the printer to be inspected is used.

Further, the method for measuring the amount of paper conveyed according to the present invention comprises:
When the measurement paper on which the measurement pattern is printed at a pitch substantially equal to the paper feed pitch is passed through a printer to be inspected and the position of the measurement pattern printed on the paper is measured in the middle of the paper transport path, the measurement pattern is converted into a two-dimensional image. As a video,
It is characterized in that the pattern position is measured based on the video information.

In the method for measuring the amount of paper conveyed according to the present invention, the pattern measuring unit measures a reference pattern position and a pitch which have been calibrated in advance, and obtains a shift amount of the measured pattern from these reference positions to obtain a pattern position. Is measured.

According to the present invention, while the paper on which the measurement pattern is printed at a predetermined print pitch is fed by the printer to be inspected, the measurement pattern is measured, and the obtained measurement value is corrected by the reference measurement data. . As a result, the paper transport amount can be measured excluding the factors of the print head, and the measurement accuracy of the paper feed amount is improved.

Further, in order to print a measurement pattern while feeding the paper at a desired pitch, the movement amount of the paper is used as a correction value. Then, by creating an inspection sheet in which the error of the print pattern position and the error of the feed amount are separated, the accuracy of the feed amount measurement in the inspection target printer is improved.

[0013]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram that best illustrates the features of the present invention. In the figure, reference numeral 100 denotes a printer to be inspected. In this example, a printer having an intermittent feed mechanism such as an ink jet printer is targeted. 101
Reference numeral denotes an inspection pattern printing sheet intermittently fed by the inspection target printer 100, and reference numeral 102 denotes a sheet for manufacturing the inspection pattern printing sheet 101.

Reference numeral 1 denotes a paper moving mechanism for moving the paper 102 to create the test pattern printing paper 101. Reference numeral 2 denotes a printing mechanism for printing the test pattern on the test pattern printing paper 101. Used. Reference numeral 3 denotes a print pattern measuring mechanism for measuring a pattern position printed on the inspection pattern printing paper 101, and includes a microscope optical system, a two-dimensional sensor, and the like. Reference numeral 4 denotes a moving unit of the print pattern measuring mechanism 3 for moving and positioning the print pattern measuring mechanism 3, and 5 denotes a measurement for measuring the moving direction and position of the paper 102 and the paper moving mechanism 1 moved by the paper moving mechanism 1. It is a long mechanism.

Next, the operation will be described. First, FIG.
The inspection pattern is printed, and the paper 101 whose correction data is known is fed by the inspection target printer 100. The pitch at which the paper is fed intermittently at this time is measured by measuring the measurement pattern by the measurement unit that has moved the print pattern measurement mechanism 3 to a predetermined position by the moving unit 4.

FIG. 2 schematically shows this state.
101 is the outer shape of the paper, in which 201, 20
2. . . A pattern to be measured is printed like 203. These patterns are printed at a pitch substantially corresponding to the feed pitch to be measured by the printer to be inspected.
204, 205. . . 206 is the pattern 20 to be measured
1,202. . . 203 represents the feed direction position of each measurement pattern.

Reference numeral 207 denotes a measurement area observed by the print pattern measurement mechanism 3, and FIG. 3 is an enlarged view of the measurement area. Reference numeral 207 denotes a measurement area. 201 is a measurement pattern, 208 is a feed direction position of the measurement pattern 201 measured by the print pattern measurement mechanism 3,
This position is calculated from the position of the center of gravity by performing image processing on the captured image using a two-dimensional sensor or the like. 209
Indicates the position when the pitch was correct, the position of the previous measurement pattern repeated every time a predetermined pitch is sent,
This is the position of the result calculated from the value calculated from the data that the measurement paper has as the correction data. Reference numeral 210 denotes a shift amount at one pitch as a result of intermittent feeding of the printer to be inspected.

In FIG. 2, the paper feeding direction will be described as an arrow direction. The measurement paper 101 is put into the printer 100 to be inspected, and the measurement pattern 201 is measured first. The position 204 is measured first, and the measured position is used as data corrected by the correction data of the measurement pattern sheet for correcting the target position to be measured next time.

Next, when one pitch is fed, the position of the measurement pattern 202 is measured. In this case, the position when the position of the measurement pattern 201 was measured last time and the measurement pattern 2
The target position 209 is set based on the correction data of 01 and the correction data of the measurement pattern 202 to be measured this time. The deviation 210 between the target position 209 and the position 208 measured by the measurement mechanism is determined by the measurement pattern 20.
This is the feed pitch error when one pitch of 1 and 202 is sent. When measuring the measurement pattern 202, an operation for setting a measurement target for the next measurement is performed again.
By repeating this for the number of times the sheet is to be measured, it is possible to measure the feed error for each feed pitch.

Next, a method of generating a measurement pattern correction value will be described. As described above, in the method of creating the correction data on the measurement paper 101 used for the measurement of the inspection target printer, first, the moving unit 4 uses the print pattern measurement mechanism 3.
Is moved to a position above the paper moving mechanism 1. The paper 102 on which the measurement pattern is printed at the pitch to be measured by the inspection target printer 100 is measured while being fed by the paper moving mechanism 1 in this case.

The operation at this time will be described with reference to FIGS. First, the paper is moved using the paper moving mechanism 1 so as to be at the position of the measurement pattern 201 of the printing paper 101. At this time, the position 204 of the measurement pattern 201 and the position of the paper moving mechanism 1 at that time are measured by the length measuring mechanism 5. Next, the paper moving mechanism 1 is moved to measure the measurement pattern 202 and the measurement pattern 20 is measured.
The position 2 and the position of the paper moving mechanism 1 at that time are similarly measured by the length measuring mechanism 5.

This is repeated the required number of times, and the length of the measurement pattern in the measurement area of the print pattern measurement mechanism 3 and the position of the paper moving mechanism 1 when the measurement pattern is measured are measured by the length measurement mechanism 5. From the data, measurement pattern correction data is generated. That is, the pitch between the measurement pattern and the position of the measurement pattern is measured, the pitch error between the measurement patterns is stored as a correction value, and when the feed pitch in the inspection target printer is measured using the corresponding measurement paper. In addition, a correction value generated in combination with a sheet is always used.

Here, a pattern printing mechanism for generating a pattern to be printed on the test pattern printing paper is provided at a position where the print pattern measuring mechanism enters the measurement area along the moving direction of the paper moving mechanism, and , The correction data of the test pattern printing paper can be generated.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram that best illustrates the features of this embodiment. In the figure, reference numeral 100 denotes a printer to be inspected,
In particular, its outer shape is shown. Reference numeral 101 denotes an inspection pattern printing paper, and 100a denotes a paper feeding mechanism of the inspection target printer 100, which conveys a predetermined amount of paper using friction by a motor driven roller.

In this embodiment, a measuring device substantially the same as that of the above-described embodiment is provided, and the print pattern measuring mechanism 3 includes a microscope optical system, a two-dimensional sensor, and the like. Is imaged, and the position of the measurement pattern in the paper feed direction is measured. In this example, the reference pattern position measurement unit and the pitch measurement unit are configured.

FIG. 5 shows the measurement pattern printed on the inspection pattern printing paper 101 and the print pattern measurement mechanism 3.
FIG. Reference numerals 211 to 214 denote measurement patterns, which are printed side by side at a substantially necessary paper conveyance pitch. Reference numerals 215 and 216 denote measurement areas of the pattern measurement mechanism 3, 215 denotes a measurement area of the pitch measurement unit, and 216 denotes a measurement area of the reference pattern position measurement unit.

FIG. 6 is an enlarged view of the processing area of the pattern measuring section of FIG. FIG. 6A shows a measurement area 216 of the reference pattern position measurement unit. 212 is a measurement pattern, and 217 is a reference position, which represents a paper feed direction position calibrated in advance. 218 is a measurement position of the measurement pattern 212 in the paper feed direction, and 219 is a difference between the reference position 217 and the measurement position 218. Similarly, FIG. 6B shows a measurement area 215 of the pitch measurement unit. 211 is a measurement pattern, and 220 is a reference position, which represents a paper feed direction position calibrated in advance. 221 is a measurement position of the measurement pattern 211 in the paper feeding direction, and 222 is a difference between the reference position 220 and the measurement position 221.

Next, the operation of the measuring method will be described. FIG. 7 is a flowchart illustrating this operation. First, prior to the start of measurement, the reference position 217 of the reference pattern position measurement unit in FIG. 6A and the reference position 220 of the pitch measurement unit in FIG. 6B are measured in advance by using a calibration chart or the like. Is determined as the reference position.

Specifically, a calibration chart 30 as shown in FIG.
1, the reference pattern position measurement and the pitch measurement of the pattern measuring mechanism 3 are performed. At this time, the calibration chart 30
In 1, calibration patterns 302 and 303 are patterns used as references for a reference pattern measurement unit and a pitch measurement unit, respectively. In the reference pattern measurement unit, the position 305 of the calibration pattern 302 in the measurement area 304 is set, and in the pitch measurement unit, the calibration pattern 30 in the measurement area 306 is set.
The position 307 of No. 3 is stored. At the time of actual measurement, the position 217 in the reference pattern measurement unit of FIG.
In the pitch measuring section of FIG. 6B, the position 220 corresponds to each.

After the calibration of the reference pattern measuring unit and the pitch measuring unit has been completed as described above, the test pattern printing paper 101 is placed on the printer 100 to be inspected. In FIG. 5, the first pattern 211 of the measurement pattern is sent to the measurement area 216 of the reference pattern measurement unit (FIG. 7, step S
2), a measurement pattern is measured and set as a reference position (FIG. 7,
Step S3).

Referring to FIG. 6, the position of the measurement pattern 212 is measured in FIG. 6A, and the deviation from the reference position 217 at that time is measured and stored. At this time, the measurement pattern is not yet in the measurement area in the pitch measurement section in FIG. Next, in the inspection target printer 100, the inspection pattern printing paper 101 is shifted by a predetermined pitch.
Is sent (step S4). If the pitch feed and the measurement are repeated a predetermined number of times on the paper and the measurement is completed, the measurement is completed. If the measurement still remains, the measurement is repeated (step S5).

When the measurement is repeated, the measurement pattern 211 measured in step S4 is within the measurement area of the pitch measurement section at this stage. In this state, the measurement pattern 211 of FIG. 6B is measured, and the position 221 is measured. From the displacement amount 219 from the reference position measured in step S3 and the displacement amount 222 from the reference measured this time, the actual paper transport amount can be measured (step S6).

In this state, since the next measurement pattern 212 is in the measurement area in FIG. 6A of the reference pattern measurement unit, the position 218 of the measurement pattern 212 is measured, and the deviation from the reference position 210 is measured. The quantity 219 is obtained (step S7). Next, returning to step S4, the measurement paper is fed by one pitch, and the next measurement is repeated. The paper conveyance amount for each pitch can be measured by a series of these measurements.

Here, the reference pattern position measuring unit and the pitch measuring unit, which are constituent elements of the pattern measuring unit, are each composed of two two-dimensional sensors, and if the pitch is short, the reference pattern is composed of one two-dimensional sensor. Both measurement and pitch measurement can be performed in the same field of view. Further, the measurement pattern is described as a circle in the figure, but is not limited to this. Further, the position measurement in the pattern position measurement can also be obtained from the position of the center of gravity of the two-dimensional image of the measurement pattern or the edge position of the pattern.

The measurement position of the printer 100 to be inspected is in the middle of the paper transport path, but may be the position where the paper is discharged from the paper discharge unit. Further, the relative position between the inspection target printer 100 and the pattern measurement unit may be adjusted by an adjustment mechanism so that the measurement pattern of the measurement sheet enters the measurable area of the pattern measurement unit. This is an optical characteristic of the arrangement and the pattern measuring unit in consideration of the deviation for each sheet.

In the above-described embodiment, the measurement pattern is measured by using a sheet on which the measurement pattern is printed in advance. However, the measurement is performed by marking on the paper conveyance path of the printer to be inspected before the measurement by the reference pattern measurement unit. A mechanism for printing a pattern may be provided. In this case, the marking position is marked at a position where the measurement pattern enters the measurement area of the pattern measurement unit when the pitch is fed. This eliminates the need to prepare a sheet on which the measurement pattern is printed in advance.

[0037]

As described above, according to the present invention, paper feed accuracy is measured in paper feed amount measurement of this type of printer, excluding the error factor of the print head. In addition, it is possible to extract data obtained by separating the printhead error factors from the printing paper including the printhead error factors, and to reduce the position measurement error factors when measuring the print pattern. As a result, the accuracy of paper feed measurement of a printer having an intermittent feed mechanism such as an ink jet printer can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a sheet measurement pattern according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a measurement pattern of a measurement mechanism according to the first embodiment of the present invention.

FIG. 4 is a schematic perspective view of a measuring device according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a sheet measurement pattern according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a measurement pattern of a measurement mechanism according to a second embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation example according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating a pitch calibration method according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper moving mechanism 2 printing mechanism 3 print pattern measuring mechanism 4 moving section of print pattern measuring mechanism 5 length measuring mechanism 100 printer to be inspected 101 inspection pattern printing paper 102 paper 201, 202, 203 pattern to be measured 204, 205, 206 measurement pattern Feed direction position 207 Measurement area 208 Feed direction position

Claims (5)

[Claims] 1. A method for measuring the amount of paper transported by a printer, comprising: measuring a measurement pattern while feeding the paper on which the measurement pattern is printed at a predetermined print pitch by a printer to be inspected; A paper transport amount measuring method, wherein a paper feed amount is measured by correcting a value with reference measurement data. 2. The method according to claim 1, wherein, when creating a sheet on which the measurement pattern is printed, moving the sheet to print the measurement pattern while feeding the sheet at a desired pitch. A paper transport amount measuring method, wherein a print pattern position is measured using an amount as a correction value. 3. The method according to claim 1, wherein the same measurement system as the pattern position measurement system used in the inspection target printer is used when the measurement pattern is printed and the print pitch is measured. A method for measuring the amount of paper transported, characterized in that it is used. 4. A method for measuring a paper transport amount in a printer, comprising: passing a measurement paper on which a measurement pattern is printed at a pitch substantially equal to a paper feed pitch through a printer to be inspected, and printing the paper on the paper along the paper transport path. When measuring the position of the measured pattern, the measured pattern is visualized as a two-dimensional image,
A method for measuring the amount of paper transported, comprising measuring a pattern position based on the video information. 5. The pattern position is measured by measuring a reference pattern position and a pitch that have been calibrated in advance in a pattern measuring section, and calculating a shift amount of a measured pattern from the reference position. 4. The method for measuring the amount of paper transported according to item 4.