JPH03226609A - Measuring method of width of sheet material - Google Patents

Abstract

PURPOSE:To measure the width of a sheet material with good accuracy by a method wherein the scattering lights from both edges in a widthwise direction of the sheet material are photographed by a pickup camera, and the width of the sheet material is measured by the image signal. CONSTITUTION:The image signals of a section including front and rear ends in a width wise direction of a transparent film obtained by first and second TV cameras 41, 42 are input to first and second image input circuits 51, 52, where the signals are amplified, wave-shaped and kept for a predetermined time. Then, the image signal selectively taken out from the circuits 51, 52 by an input image switching circuit 53 is output to a binary circuit 54 to be converted to an image data of dark and bright two values. The image data is written into an image memory 55. Binary coding and writing into the memory 55 are controlled by a CPU 56. Moreover, a threshold value for the binary coding of the circuit 54 is set by the CPU 56. The image data processed in the circuit 54 is converted to a video signal by an image output circuit 57 and output to a monitor TV 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the width of a sheet material, such as a film, for optically detecting the width dimension of a sheet material.

Conventionally, in one conventional example of a method for measuring the width of this type of sheet material, a long cylindrical film (manufactured in a cylindrical shape, then
A laser measuring device is placed above the cylindrical film that is transported in a crushed state, and the laser beam irradiated by the laser measuring device is scanned in the width direction of the cylindrical film to detect the reflected light from the film surface. There is a method of measuring the width dimension of a cylindrical film.

However, when using the above conventional method, the detection sensitivity depends on the quality of the reflection from the film surface.
In cases where the film is transparent, the amount of detected light remains insufficient, and accurate measurements cannot be performed. Therefore, the current situation is that the operator has no choice but to rely on visual measurements.

The present invention has been made in view of the current situation, and it is an object of the present invention to provide a method for measuring the width of a sheet material that can accurately detect the width dimension even if the sheet material is transparent.

1. The present invention aims to irradiate the sorting material with light from a light source, and capture the scattered light from both ends of the sheet material in the width direction using an imaging device arranged in the width direction of the sheet material. The detected image signal is detected by
The converted image data is converted into a value and temporarily stored in the storage unit, and then the stored image data is read out, and from this image data, the image sensor number, the two positions of the imaging field of view edge and the width direction edge of the sheet material are determined. The feature is that the distance between the seat and the seat is calculated, and the width of the sheet wood is measured based on the calculation result.

The end of the sheet material corresponds to the boundary between the sheet material and the sky W when viewed from the light source. Therefore, when light is irradiated, scattering occurs at the ends of the C2 sheet material. In the present invention, C: This scattered light is detected by an imager to determine the position of the edge of the sheet material, and the widthwise dimension of the material to be sorted is determined.

The method for determining the width direction dimension of the sheet material is to set in advance the distance C (distance between points D and E shown in Figure 7) between the two outermost positions corresponding to the edge of the I image field of the t1 imager. Then, from this distance, the sum A+B of the distances MA and B between the outermost two position points and the SE point and both ends F and G in the width direction of the sheet material is subtracted.

Note that one imager may be used that has a detection field of view on the width plate of the sheet material, but two cameras that have a detection field of view near the widthwise edge of the sheet material may be installed side by side. It can also be used as

Back - Ship - ■ An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic perspective view showing the implementation state of the method of the present invention.

An extrusion molding machine (not shown) for molding a transparent cylindrical film 2 is provided on the left side of the nip roller I in the drawing. A transparent cylindrical film 2 formed by an extrusion molding machine is crushed in the vertical direction by a nip roller 1, and becomes a sheet-like transparent film 20. transparent film 2
o is conveyed toward the downstream side indicated by the arrow and wound up on a storage roll (not shown).

Two lights a3.3 are provided in the transport area of the transparent film 20 in its width direction. The light source 3.3 is made of, for example, a high-frequency fluorescent lamp, and irradiates light toward both ends of the transparent film 20 in the width direction.

As shown in FIG. 7, a predetermined area including each edge of the transparent film 200 in the width direction is set as an imaging field of view above the transport area of the transparent film 20 in a position where direct light from the light a3.3 does not enter. 1st TV (television) camera 41, 2nd TV
A camera 42 is provided.

The image signals captured by the first TV camera 41 and the second TV camera 42 are input to the width dimension measuring device 5, where the arithmetic processing described later is executed, and the width dimension of the transparent film 20 (folded state) is diameter) is measured. The measurement results of the width dimension measuring device 5 are fed back to the extrusion molding machine in order to maintain the width dimension of the transparent film 20 at a desired value.

In addition, the measurement results of the width measurement device 5 are displayed on the front of the width measurement device 5 for use by the operator.
(See Figure 2). The state of binarization of the image signal by the width measurement device 5 is displayed on the monitor TV 6.

Next, the configuration of the width dimension measuring device 5 will be explained with reference to FIG. However, FIG. 2 is a block diagram showing the overall configuration of the width dimension measuring device 5. As shown in FIG.

Transparent film 20 imaged by first TV camera 41
The image signal of the area including the front end in the width direction is input to the first image input circuit 51, and after being amplified, waveform shaped, etc., is held for a predetermined period of time. On the other hand, the image signal of the area including the rear end in the width direction of the transparent film 20 captured by the second TV camera 42 is input to the second image input circuit 52, and is similarly amplified and
After the waveform is shaped, etc., it is held for a predetermined period of time.

Here, each TV camera 41, 42 has a transparent film 20
Since the light source 3.3 is arranged to measure scattered light rather than transmitted light or reflected light from the TV camera 41.42, the image signal captured by the TV camera 41.42
Only the edge portion of the image is bright, and the other background portions and the center of the transparent film have a dark contrast signal.

The first image input circuit 51 and the second image input circuit 52 include
An input image switching circuit 53 for selectively extracting image signals that have been amplified, waveform-shaped, etc., is connected thereto. The selection timing of the input image switching circuit 53, that is, the switching operation is C.
This is performed by a switching command signal from the PU 56. CPU5
6 is a control center of the width dimension measuring device 5;
The width dimension of the transparent film 20 is measured by executing calculation processing described below.

The image signal selectively extracted by the input image switching circuit 53 is output to the binarization circuit 54, where it is converted into light and dark binary (
The image data is converted into black-and-white binary image data in which both edges in the width direction of the scattered and shining transparent film 20 are white pixels, and the other background portions are black pixels, and is written into the image memory 55. Such binarization processing and writing operation to the image memory 55 are controlled by the CPtJ56. In addition, the CPU 56 has 2
A dark value required for binarization by the digitization circuit 54 is set.

Furthermore, the image data processed by the binarization circuit 54 is
The signal is input to the image output circuit 57, where it is converted into a video signal and output to the monitor TV 6.

As shown in the figure, a set value necessary for width measurement, that is, a distance C shown in FIG. 7, is input to the CPU 5 through an operation setting means not shown, and Width data after measurement is output.

Next, details of the width measurement process of the transparent film 20 will be explained according to the flowcharts shown in FIGS. 3 to 5. However, FIG. 3 is a flowchart showing the main flow of the width measurement process, and FIGS. 4 and 5 are flowcharts showing subroutines for calculating width measurement data, respectively.

When the built-in control program for measuring the width dimension starts, the CPU 56 first initializes the image memo I755 (Sl) and then calculates the calculation parameter for calculating the width dimension, that is, the value of the distance C shown in FIG. Set. This setting operation is performed by the aforementioned operation setting means.

Next, the CPU 56 sets the dark value of the binarization circuit 54 (S3), and when this is completed, it issues a switching command signal to the input image switching circuit 53, and changes the image signal captured by the first TV camera 41 to the binarization circuit 54. Then, the binarized image data is written into the image memory 55 (S4).

Next, the CPU 56 proceeds to step S5 and calculates the distance, %[A
Perform the calculation. This step S5 is a subroutine shown in FIG. The procedure for calculating the distance A between the front end F in the width direction of the transparent film 20 and the above-mentioned point will be explained below with reference to FIG.

First, the CPU 56 designates a vertical address V (0, 1...) in the image memory 55 shown in FIG.
50), and then sets the horizontal address H (Oll...) to 0 (S51). The vertical direction of the image memory 55 corresponds to the longitudinal direction of the transparent film 20, and the horizontal direction corresponds to the width direction of the transparent film 200. Further, the entire memory area of the image memory 55 is the first and second TV cameras 41 and 42.
Compatible with the entire imaging field of view.

The reason for specifying the vertical address V here is that since the transparent film 20 is moving, the - point in the vertical direction (direction of film movement) is sufficient even if the width of the entire area is not detected. be.

Now, when the process of step S51 is completed, the pixel data in the area specified by the vertical address V and the horizontal address H is read out (552), and it is determined whether this pixel data is a black pixel (S53). If it is determined that the pixel is a black pixel, the horizontal direction address H is sequentially incremented by one address and the same process is performed (S54-355→S52
→553-354).

Then, it is determined whether the horizontal direction address H has reached the maximum address value, that is, the pixel data from the left end to the right end of the imaging field of view of the first TV camera 41 is read out, and all of the read pixel data remains black pixels. When this is confirmed (S55), the detection flag CTI is set to 0 at that point to be in a non-detectable state (556), and the process returns to the main flow.

On the other hand, in step S53, when it is confirmed that the pixel data read out from the image memory 53 is a white pixel,
The horizontal direction address H at this time is taken out as data for calculating the distance A (557), and the distance A between the point D and the front 3F in the width direction is calculated based on this data (35
8). Then, the detection flag C? Set I to CTI=1 indicating the detection execution state (359) and return to the main flow.

When the subroutine shown in step S5 is completed, as shown in FIG. 3, a switching command signal is issued to the input image switching circuit 53, and the image signal captured by the second TV camera 42 is then applied to the binarization circuit 54. The image data thus converted is written into the image memory 55 (S6). Then, the subroutine shown in step S7 is executed, and the process of calculating the distance @B shown in FIG. 7 is executed.

FIG. 5 shows the subroutine of step S7.
First, the vertical address V is specified (570), and then the horizontal address H at the vertical address (2) is set to the maximum value. In this case, the distance B is the transparent film 2
Since it corresponds to the distance between the rear end G in the width direction of 0 and point E, the distance 1
Contrary to the case of calculating iiA, the distance B is calculated by sequentially decrementing the horizontal address H of the image memory 55 from the maximum value HIRIIX.

Therefore, in step S72, the CPU 56 reads the pixel data at the last address of the horizontal address H in the vertical address V, and determines whether the read pixel data is a black pixel (573). The direction address H is sequentially decremented and similar processing is performed (S74-375-372-573→574).

Then, when it is confirmed whether the horizontal direction address H has become address O, that is, the pixel data from the right end to the left end of the imaging field of view of the second TV camera 42 is read out, and all the read pixel data are black pixels ( At that point, the detection flag CT□ is set to 0 and the detection is not possible (576), and the process returns to the main flow.

On the other hand, in step 373, when it is confirmed that the pixel data read out from the image memory 53 is a white pixel,
The horizontal direction address H at this time is taken out as data for calculating the distance, f, and IB (377), and based on this data, the distance B between the point E and the rear end G in the width direction is calculated (378). Thereafter, the detection flag CtZ is set to CT□=1 indicating the detection execution state (579), and the process returns to the main flow.

When the subroutine shown in step S7 is finished, as shown in FIG. It is determined whether CT2 is set to 1 (S9).

Then, when it is confirmed that the rain detection flags C7 and C7 are both set to 1, since the calculations of distance A and distance B have already been executed, the next step is the calculation process of width dimension measurement shown in step S10. , that is, the calculation [C-(A+B)) is executed to calculate the width dimension of the transparent film 200. Then, this calculation result is reported to be fed back to the recorder and the extrusion molding machine (Sll). In this way, the width dimension of the transparent film 20 is maintained at a desired value. When step Sll is completed, step Sll is shown as ■ in the figure.
4, and repeat the same width dimension measurement process again.

In this case, since the transparent film 20 is being conveyed in the longitudinal direction, the width dimension of the entire length of the transparent film 20 in the longitudinal direction is measured by repeatedly performing the width dimension measurement process.

On the other hand, if one or both of the detection flags CTl and CTl are set to 0, the width dimension cannot be measured, so in this case, an error message will be displayed on the display (not shown). and reports this to the operator (512). When step S12 is completed and the extrusion molding machine is adjusted by manual operation by the operator, the process proceeds to step S4 in the same manner as described above.

Note that the measurement object of the present invention is not limited to the transparent film 20 described above, and it is possible to measure the width dimension of various sheet materials having a thickness dimension that allows diffuse reflection on both end faces in the width direction.

Further, in the embodiment, two TV cameras are used as imagers, but a single TV camera having a wide detection field of view may be used. Furthermore, the detection field of view is not a 4° area, but may be a long line in the width direction of the sheet material, so a line type CC is used instead of a TV camera.
A D sensor can also be used.

In the case of the method of the present invention described above, an imaging device is used to image the scattered light from both edges in the width direction of the sheet material, and this image signal is used to measure the width dimension of the notebook material. Unlike conventional laser measuring methods that measure reflected light from the back surface of a sheet material, this method does not cause detection failures due to insufficient amount of detected light, and the width dimension of the sheet material can be measured with high accuracy.

Furthermore, as a matter of course, it is possible to measure the width more quickly and with higher precision than in the conventional visual measurement by a general operator.

[Brief explanation of drawings]

Figure 1 is a schematic perspective view showing the implementation state of the method of the present invention;
The figure is a block diagram showing the circuit configuration of the width measuring device, FIG. 3 is a flowchart showing the main flow of width measurement processing, and FIG.
5 and 5 are flowcharts showing subroutines for calculating width measurement takes, FIG. 6 is a drawing showing addresses of the image memory, and FIG. 7 is a drawing showing the measurement principle of the method of the present invention. 2...Transparent cylindrical film, 20...Transparent film,
3.3... Light source, 41... First TV camera, 42...
...Second TV camera, 5...Width dimension measuring device, 54.
...Binarization circuit, 55...Image memory, 56...C
PU, A...Distance between the imaging field of view of the first TV camera and the front end of the transparent film in the width direction, B...Distance between the imaging field of view of the second TV camera and the rear end of the transparent film in the width direction, C.
...Distance between the imaging field of view of the first TV camera and the imaging field of view of the second TV camera.

Claims (1)

[Claims] (1) Light is irradiated onto the sheet material from a light source, the scattered light from both ends of the sheet material in the width direction is detected by an imager disposed opposite to the sheet material in the width direction, and the detected image signal is Convert to digitized image data and temporarily store it in the storage unit, then read the stored image data, and calculate the distance between the two positions of the imaging field edge of the imager and both ends of the sheet material in the width direction from this image data. and measuring the width of the sheet material based on the calculation result.