JPH09178423A - Travel amount measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure travel amount of sheetlike medium to be measured accurately by measuring at which position of read-out picture element of a CCD camera the center of horizontal rule of the medium to be measured is and moving the medium to be measured by one pitch. SOLUTION: A horizontal rule is recorded on paper 8 by a printer 4, and the paper is conveyed until this record reaches a paper guide face 7A and is stopped. Next, a CCD camera 17 is moved together with a length measuring machine 12 by driving a motor 13 to a position where horizontal rule of the paper 8 can be visually checked through an ocular lens 18 of the CCD camera 17. When horizontal rule can be visually checked on the paper 8, the motor 13 is stopped, the horizontal rule on the paper 8 is photographed by the camera 17, and the horizontal rule which is photographed is image-processed by a control means 24. Then, the paper is conveyed by one pitch to photograph the horizontal rule again. Consequently, since two coordinates of the horizontal rule before and after the paper 8 is conveyed by one pitch are detected, it is possible to calculate the actual conveyance amount of the paper 8 by subtracting it by the control means 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving amount measuring device, and more particularly to a moving amount measuring device suitable for measuring the amount of paper conveyed by a printer.

[0002]

2. Description of the Related Art Generally, in a printer, a sheet is conveyed by driving a step motor or the like. By design, the step motor is driven by a set number of steps to convey a sheet of one pitch. However, the paper may not be accurately conveyed by one pitch due to backlash of gears or bending of the rotation axis of the conveyance roller. Then, recording may be partially overlapped, or an unnecessary gap may be formed between recordings.

Therefore, conventionally, the actual amount of paper transported in the printer is measured by using a movement amount measuring device to transport the paper by a predetermined amount.

By the way, there is a reflection type photo sensor as a conventionally known movement amount measuring device, and this photo sensor is installed on an extension of the front or rear in the moving direction of the medium to be measured. The amount of movement of the medium to be measured is measured by irradiating the medium to be measured with light and changing the time until the light is reflected by the surface of the medium to be measured and returns.

[0005]

However, according to the movement amount measuring device such as the photo sensor described above, the movement amount can be accurately measured if the medium to be measured has a shape capable of stably reflecting light. However, in the case of thin measurement media such as paper, the light cannot be stably reflected at the end surface of the measurement media, so the amount of movement of the measurement medium must be accurately measured. I couldn't.

For this reason, conventionally, the measurement of the sheet conveyance amount in the printer has been performed by applying a ruler to the sheet.

However, if the ruler is directly applied to the sheet to measure the sheet conveyance amount as described above, the work efficiency is very poor, and it takes a lot of time to measure the sheet conveyance amount in many printers. I was there.

In view of the above points, the present invention is a movement amount measuring method capable of accurately measuring the movement amount of a sheet-shaped medium to be measured such as the movement amount of a sheet discharged by a printer. The purpose is to provide a device.

[0009]

In order to achieve the above-mentioned object, a feature of the present invention as set forth in claim 1 is that a ruled line recorded on a medium to be measured is arranged so as to face a medium guide portion to be measured. A CCD camera capable of photographing, measuring means for measuring the central portion of the ruled line on the medium to be measured photographed by the CCD camera, and a moving amount of the central portion of the ruled line before and after the medium to be measured is calculated. And a calculation means. By adopting such a configuration, first, the ruled line of the medium to be measured is set within the image reading range of the CCD camera, and the center of the ruled line is located at which position of the read pixel of the CCD camera. To measure. Next, the medium to be measured is moved, the medium to be measured is moved by one pitch, and the center of the ruled line is measured in the same manner as described above. Then, by calculating the number of read pixels of the CCD camera for the center of the ruled line after the movement of the medium to be measured and before the movement, based on the pitch of the read pixels,
It is possible to measure the actual amount of movement of the medium to be measured during the movement of the medium to be measured by one pitch.

The features of the present invention according to claim 2 are as follows:
A CCD which is arranged so as to face the medium-to-be-measured medium and is capable of photographing a ruled line recorded on the medium-to-be-measured, and which is movable in the moving direction of the medium-to-be-measured which is moved along the medium-measuring-guide portion to be measured. A camera, a measuring means for measuring the center of the ruled line on the medium to be measured photographed by the CCD camera, a moving means for moving the CCD camera by a predetermined distance, and a moving means before and after moving the medium to be measured. It has a calculation means for calculating the movement amount of the central portion of the ruled line based on the movement distance of the CCD camera and the movement amount of the ruled line in the CCD camera. By adopting such a configuration, the moving distance of the CCD camera is previously determined to be constant, and the CCD camera is moved by this distance.
It is not necessary to measure again the moving distance of the CCD camera before and after moving the medium to be measured by one pitch by moving the camera. After that, measure how much the ruled line is deviated in the reading pixels of the CCD camera. , CC
By correcting the shift amount with respect to the value of the moving distance of the D camera, it is possible to measure the actual amount of movement of the medium to be measured in one pitch of movement of the medium to be measured.

Next, a feature of the present invention described in claim 3 is that it has a length measuring device for measuring the moving amount of the CCD camera by the moving means. By adopting such a configuration, the amount of movement of the CCD camera is measured by the length measuring device to measure the actual amount of movement of the medium to be measured in one pitch of movement of the medium to be measured. You can

Further, a feature of the present invention described in claim 4 is that it has a manual operation means for manually operating the drive of the moving means. By adopting such a configuration, the ruled line on the medium to be measured can be easily captured by the manual operation means.

Further, a feature of the present invention according to claim 5 is that the medium to be measured is a recording sheet to be recorded / conveyed by the printer, and the computing means and the paper feed control section of the printer are connected. . By adopting such a configuration, by feeding back the calculation result of the movement amount to the paper feed control unit of the printer, the motor for conveying the recording paper of the printer is based on the actually measured movement amount of the medium to be measured. It is possible to accurately set the conveyance amount of one pitch of the medium to be measured by changing the number of driving steps of.

[0014]

1 to 3 show an embodiment of a movement amount measuring apparatus according to the present invention. This movement amount measuring apparatus 1 has a base 2. A printer installation section 3 having a flat plate shape and extending in the horizontal direction is formed on the base 2, and a printer 4 is installed on the printer installation section 3.
Stoppers 5 and 5 for fixing are arranged. A printer 4 is installed on the printer installation unit 3, and a flat plate shape is formed horizontally on the base 2 of the movement amount measuring device 1 so as to face the paper discharge unit 6 of the printer 4. An extending paper guide portion 7 is formed. Therefore,
The paper 8 as the medium to be measured discharged from the paper discharge unit 6 of the printer 4 is moved along the paper guide surface 7A on the upper surface of the paper guide unit 7.

On the other hand, substantially above the paper guide portion 7, a fixing plate 10 supported by the base 2 via a plurality of columns 9, 9 is arranged so as to extend in the horizontal direction. Has been done. On the fixed plate 10, a guide rod 11 extending in parallel with the moving direction of the sheet is supported.
A length measuring device 12 is supported on the guide rod 11 so as to be movable along the guide rod 11. The operation of this length measuring device 12 will be described later, but this length measuring device 12
A motor 13 for reciprocating the length measuring device 12 along the guide rod 11 is provided near the position. Further, a manual operation means 14 for manually operating to stop the length measuring device 12 at a predetermined position is provided. Further, a holding arm 15 is fixed to the length measuring device 12, and a housing 16 is supported by the holding arm 15 so as to move integrally with the length measuring device 12.

A CCD camera 17 extending in the vertical direction and having a front end facing the paper guide surface 7A is supported on the housing 16. At the upper end of the CCD camera 17, an eyepiece lens 18 for observing the sheet 8 positioned on the sheet guide portion 7 through the CCD camera 17 is arranged. A focus adjusting micrometer 19 is provided. Further, the CCD camera 17 is connected with an interface 20 for outputting an image of the paper 8 taken by the CCD camera 17. In the vicinity of the lower end of the CCD camera 17, a pair of light sources 21 and 21 for illuminating the paper directly below the CCD camera 17 on the paper guide portion 7 are supported, and each of these light sources 21 is turned on. A switch 22 for performing an off control is arranged on the fixed plate 10.

Further, in the vicinity of the lower end of the CCD camera 17, a pair of air nozzles 23, 23 for bringing the paper on the paper guide surface 7A into close contact with the paper guide surface 7A are arranged. Each air nozzle 23 is connected to an air supply source (not shown), and each air nozzle 23 moves in the moving direction of the paper 8 in order to bring the paper 8 along the paper guide surface 7A of the paper guide portion 7 into close contact with the paper guide surface 7A by wind force. The sheets are arranged so as to be obliquely downward on the downstream side in the moving direction of the paper so as to be extended to each other.

The length measuring device 12, the motor 13, the manual operation means 14, the interface 20 of the CCD camera 17 and the like are connected to the control means 24 which is the arithmetic means of the movement amount measuring device 1. Further, the control means 24 is connected to the paper feed control means 25 of the printer 4, and the printer 4
The feed amount of the sheet 8 in the above can be feedback-controlled.

Next, the operation of this embodiment having the above-mentioned structure will be described.

In the present embodiment, in order to measure the carry amount of the paper 8 in the printer 4, the printer 4 is installed in the printer installation unit 3, and the printer 4 installed in the printer installation unit 3 forms a ruled line on the paper 8. After recording, the sheet 8 is conveyed by the sheet conveying unit (not shown) of the printer 4 until the recording on the sheet 8 reaches the sheet guide surface 7A of the sheet guide unit 7, and the movement of the sheet 8 is stopped. When the sheet 8 is stopped, the motor 13 is driven by the manual operation means 14 to the position where the ruled line on the sheet 8 can be seen through the eyepiece lens 18 of the CCD camera 17 or a monitor such as a display (not shown), and the CCD camera 17 is driven. Is moved together with the length measuring device 12 which is integrated. In addition, this CCD
The ruled line image photographed by the camera 17 may be directly viewed through the eyepiece lens, but it is possible to make the image easier to see by enlarging it on a monitor such as a display.

The ruled line on the paper 8 is the eyepiece lens 18.
When it becomes visible at the center of the
After the driving of No. 3 is stopped, the CCD camera 17 photographs the ruled lines on the paper 8, and the photographed ruled lines are image-processed by the control means 24. At this time, the paper guide portion 7
The paper 8 placed on the paper guide surface 7A is in close contact with the paper guide surface 7A by the wind force of the air jetted obliquely downward from the air nozzle 23.

FIG. 4 shows the illuminance distribution in the width direction of the ruled line which has been image-processed as described above. In the control means 24, the threshold value A of illuminance shown by the line segment in FIG. 4 is set. The coordinates of the intermediate point in the length direction of the line segment in the portion where the illuminance is reduced by setting and corresponding to the ruled line are the coordinates of the central part of the ruled line, and these coordinates are output from the length measuring device 12. The signal is detected and stored in the memory (not shown) of the control means 24.

Next, the sheet conveying section of the printer 4 is re-driven to convey the sheet 8 again by one pitch. Then, the ruled line of the sheet 8 advances by about 1 pitch on the sheet guide surface 7A of the sheet guide portion 7. Therefore, with the paper 8 stopped, the CCD camera 17
The motor 13 is driven by the manual operation means 14 to a position where the ruled line on the paper 8 can be seen through the eyepiece lens 18 of
The CD camera 17 moves together with the integrated length measuring device 12. When the ruled line on the sheet 8 becomes visible at the center of the eyepiece lens 18, the motor 13
After stopping the driving, the CCD camera 17 photographs the ruled line on the sheet 8 again, the photographed ruled line is image-processed by the control means 24, and the coordinates of the central portion of the ruled line are processed in the same manner as described above. To detect again. In this way, two coordinates of the ruled line on the sheet 8 before and after the conveyance of the sheet 8 by one pitch by the conveying section of the printer 4 are detected, and the control means 24 subtracts these two coordinates. By doing so, it is possible to calculate the actual transport amount of the sheet 8 by the transport unit of the printer 4.

As described above, according to the movement amount measuring apparatus 1 of this embodiment, the CCD camera 17 photographs the ruled lines on the paper 8 before and after the movement, and the image processing of the photographed image of the ruled lines is performed. Since the actual movement amount of the paper 8 is measured by detecting the coordinates before and after the movement of the central portion of the ruled line, the actual movement amount of the paper 8 can be accurately measured. Therefore, if the control means 24 of the movement amount measuring device 1 is connected to the paper feed control means 25 of the printer 4,
It is also possible to perform feedback control of the conveyance of the paper 8 by the conveyance unit of the printer 4 such that the set amount of paper is conveyed by adjusting the number of driving steps of the step motor, and stitching of recording on the paper 8 or the like. And good recording can be performed.

If the amount of movement of the paper 8 as the medium to be measured in one pitch is within the reading pixel range of the CCD camera 17, the CCD camera 17 is not moved.
It is possible to calculate the amount of movement of the center of the ruled line from the pitch of the reading pixels and measure the amount of movement of the paper 8 in one pitch.

Further, since the movement amount of one pitch of the medium to be measured can be predicted in advance, the movement amount of the CCD camera 17 is set to a distance substantially equal to the movement amount of one pitch, and thus the CCD is set. It is not necessary to measure the moving amount of the camera one by one, and the moving amount of the center of the ruled line in the reading pixel of the CCD camera 17 and the preset C
It is also possible to measure the amount of movement of the medium to be measured for one pitch by calculation from the amount of movement of the CD camera 17.

The present invention is not limited to the above-described embodiment, but various modifications can be made if necessary. For example, the medium to be measured whose movement amount is measured is not limited to paper.

[0028]

As described above, according to the present invention, the movement amount of a sheet-shaped medium can be accurately measured. Further, if the printer prints the ruled line on the medium to be measured for detecting the coordinates for measuring the movement amount, it is not necessary to record the record on the medium to be measured in advance. By connecting to the paper feed control unit, the paper feed of the printer can be feedback-controlled to carry an accurate amount of paper.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a movement amount measuring device according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a right side view of FIG. 1;

FIG. 4 is a graph showing an image-processed illuminance distribution of a ruled line of a sheet in the embodiment of FIGS. 1 to 3;

[Explanation of symbols]

 1 Moving amount measuring device 3 Printer installation section 4 Printer 7 Paper guide section 7A Paper guide surface 8 Paper 12 Length measuring machine 13 Motor 14 Manual operation means 17 CCD camera 18 Eyepiece 19 Micrometer 20 Interface 21 Light source 22 Switch 23 Air nozzle 24 Moving Control means of quantity measuring device 25 Paper feed control means of printer 4

Claims (5)

[Claims] 1. A medium to be measured guide portion having a flat guide surface for guiding the medium to be measured, and a ruled line recorded on the medium to be measured and arranged so as to face the medium medium guide portion to be measured. A CCD camera capable of photographing, measuring means for measuring the central portion of the ruled line on the medium to be measured photographed by the CCD camera, and the movement amount of the central portion of the ruled line before and after the movement of the medium to be measured. A movement amount measuring device comprising: an arithmetic unit for performing an arithmetic operation. 2. A measured medium guide portion having a flat guide surface for guiding the measured medium, and a ruled line recorded on the measured medium arranged so as to face the measured medium guide portion. A CCD camera that can be photographed and is movable in the moving direction of the medium to be measured that moves along the medium to be measured guide section, and a central portion of the ruled line on the medium to be measured photographed by the CCD camera. A measuring means for measuring; a moving means for moving the CCD camera by a predetermined distance; and a moving amount of the center portion of the ruled line before and after moving the medium to be measured in the moving distance of the CCD camera and in the CCD camera. A moving amount measuring device, comprising: a calculating unit that calculates based on a moving amount of a ruled line. 3. A medium-to-be-measured guide portion having a flat guide surface for guiding the medium-to-be-measured, and a ruled line which is arranged so as to face the medium-to-be-measured medium and is recorded on the medium to be measured. A CCD camera that can be photographed and is movable in the moving direction of the medium to be measured that moves along the medium to be measured guide section, and a central portion of the ruled line on the medium to be measured photographed by the CCD camera. Measuring means for measuring, moving means for moving the CCD camera by a predetermined distance, length measuring device for measuring the moving amount of the CCD camera by the moving means, center of ruled lines before and after moving the medium to be measured A moving amount measuring device, comprising: a calculating unit that calculates the moving amount of the portion based on the moving amount of the length measuring device. 4. A medium-to-be-measured guide portion having a planar guide surface for guiding the medium-to-be-measured, and a ruled line recorded on the medium-to-be-measured which is arranged so as to face the medium-to-be-measured medium guide portion. A CCD camera that can be photographed and is movable in the moving direction of the medium to be measured that moves along the medium to be measured guide section, and a central portion of the ruled line on the medium to be measured photographed by the CCD camera. Measuring means for measuring, moving means for moving the CCD camera by a predetermined distance, length measuring device for measuring the moving amount of the CCD camera by the moving means, and manual operation means for manually operating the driving of the moving means. A moving amount measuring device, comprising: a calculating unit that calculates a moving amount of a central portion of a ruled line before and after moving the medium to be measured based on a moving amount of the length measuring device. 5. The medium to be measured is a recording paper to be recorded / conveyed by a printer, and the arithmetic means and the paper feed control unit of the printer are connected to each other. The movement amount measuring device according to any one of items.