JPH0352562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for measuring the apparent outer diameter of processed yarn such as crimped yarn.

That is, the outer diameter of the thread can be easily determined if it is uniform in the longitudinal direction. However, the outer diameter of the bulky processed yarn is not uniquely determined. Therefore, as shown in FIG. 1, the apparent outer diameter of such processed yarn is defined by the distance d between the outermost single yarns when an arbitrary constant tension is applied. The present invention relates to a method for measuring the apparent outer diameter of such processed yarn.

<Conventional technology> Conventionally, a general method for measuring the apparent outer diameter of yarn includes a light source and a plurality of light receiving cells arranged in a row, which are arranged to face each other, and which measures the amount of incident light. A thread path is formed between the scanning image sensor and the scanning image sensor whose operating point is set in a saturated region where the output does not change even when the A light image is formed on an image sensor, and the output obtained by scanning the image sensor once is compared with a threshold level set to approximately 50% of the saturation value of the image sensor. It is known that the apparent outer diameter is determined from the number of light-receiving cells that output an output lower than the level. However, such conventional methods have a problem in that the measured value appears lower than the actual apparent outer diameter.

In other words, in the conventional method described above in which the operating point of the image sensor is set in the saturation region, the output of the image sensor does not change even if the light intensity of the light source changes slightly, so the measurement is not affected by a decrease in light intensity due to light source deterioration or stray light. Although it has the advantage of being less susceptible to damage, the yarn to be measured has a core where the single yarns are relatively densely gathered, as shown in Figure 1, and a core where the single yarns are relatively loosely gathered. In the case of a processed yarn that has a peripheral edge, only the core where the output decreases greatly is measured as the apparent outer diameter, and it is difficult to interpret minute changes in the amount of light due to the single yarn in the peripheral edge as a decrease in the output of the image sensor. Can not.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the above-mentioned problems of the conventional method and to measure with high precision the apparent outer diameter of processed yarn in which single yarns are densely assembled. We are here to provide you with a method that allows you to do so.

<Means for Solving the Problems> To achieve the above object, the present invention includes a light source and a plurality of light receiving cells arranged in a row, which are arranged to face each other, and which are arranged in a manner that is proportional to the amount of incident light. A yarn path is formed between the yarn path and the scanning image sensor, whose operating point is set in the unsaturated region where the output changes. An optical image of the processed yarn is formed on the image sensor while scanning the processed yarn, and the output obtained by scanning the image sensor once is transmitted to each light receiving cell obtained when there is no processed yarn on the yarn path. The output is compared with a threshold level set to K times (0.8≦K<1.0) the lowest output among the outputs of To provide a method for measuring the apparent outer diameter of processed yarn, which is characterized in that the apparent outer diameter of processed yarn is determined from the number of light-receiving cells until the number of light-receiving cells exceeds a level.

In this invention, the scanning type image sensor is generally called an image sensor, and for example,
The light-receiving cells are photodiodes that convert light into electrical signals, and the light-receiving cells are arranged in rows to form an array, an address switch for selecting each light-receiving cell, a shift register, and the like. Such an image sensor is able to capture the output of each light-receiving cell in sequence by applying a scanning pulse from the outside.
It is possible to extract an output corresponding to the amount of incident light. For example, when uniform light is irradiated onto an image sensor composed of n light-receiving cells, an output as shown in FIG. 2 is obtained by one scan. In FIG. 2, t on the horizontal axis is time, and e on the vertical axis is output. As shown in FIG. 3, the output e of each light-receiving cell initially increases as the amount h of incident light increases, but it eventually becomes saturated. In other words, the image sensor has an unsaturated region and a saturated region.

In addition, in this invention, a threshold level (threshold level) is defined for processing the output of an image sensor, and is defined as the output of any light-receiving cell when uniform light is irradiated to the image sensor. is also low.

To explain this invention based on one embodiment thereof, in FIG.
consists of a drive roller 4 driven by a pulse motor 3 and a driven roller 5. on the other hand,
Similarly, the take-up roller 6 for the processed yarn 1 is made up of a drive roller 8 driven by a pulse motor 7 and a driven roller 9. The supply roller 2 and the take-up roller 6 are arranged horizontally so as to face each other, and a straight yarn path with no bends is formed between the rollers 2 and 6.

10 is a package of processed yarn 1. Between this package 10 and the supply roller 2, there is a magnetic brake capable of imparting a pretension of 20 to 100 mg/denier to the processed yarn 1;
Tension adjuster 1 for dancer rollers, friction brakes, etc.
1 is provided. Further, in front of the take-up roller 6, an ejector 12 such as an air ejector is provided.

A tension gauge 13 is provided on the yarn path between the supply roller 2 and the take-up roller 6. This tension meter 1
3 is as shown in FIG.

In FIG. 5, the tension meter 13 has two yarn guides 14 and 15 provided on the yarn path, and an eccentric rotor 16 and a gauge 17 provided between these yarn guides 14 and 15.

The eccentric rotor 16 is rotated by a motor 18 in the same direction as the traveling direction of the processed yarn 1, and moves the processed yarn 1 traveling in the direction of the arrow to the yarn guides 14, 15.
θ (however, θ = θ ₁ ~ θ ₂ , θ ₁ =
0.5 to 2°, θ ₂ = 1 to 10°, θ ₁ < θ ₂ ), periodically oscillating,
deviate.

The gauge 17 has two gauges having exactly the same configuration, that is, a detection gauge 19 and a dummy gauge 20 for vibration compensation, and each gauge has a lever 21 (23) made of an elastic plate and a 21
(23) Semiconductor strain gauge 22 attached to
It consists of (24). The tip of the lever 21 of the detection gauge 19 is constantly in contact with the running thread 1 and receives a pressing force F as the thread 1 swings and shifts. This pressing force F is proportional to the tension of the running processed yarn 1, and is taken out by the semiconductor strain gauge 22, and only its alternating current component is sent to the differential amplifier 27 via a lead wire 26 having a capacitor 25. is input. On the other hand, dummy gauge 20
is not in contact with the running thread 1, so
Vibrations of the lever 23 due to vibrations of the device are picked up by the semiconductor strain gauge 24, and the vibrations of the lever 23 are extracted by the semiconductor strain gauge 24 and
Similarly, only the alternating current component is input to the differential amplifier 27 via a lead wire 29 having a diameter of 8. Therefore,
The output of the differential amplifier 27 is the signal from which noise contained in the signal obtained from the detection gauge 19 has been removed.

The output of the differential amplifier 27 is sent to the signal processing circuit 41. In this signal processing circuit 41, processing is performed based on the pressing force F 1 when the yarn 1 is displaced by θ ₁ by the eccentric rotor 16 _and the pressing force F ₂ when the yarn ₁ is displaced by θ 2. Assuming the tension of thread 1 as T,
The calculation ΔF=F ₂ −F ₁ =T(sin θ ₂ −sin θ ₁ ) is performed. Then, the output represents the tension T mentioned above. Note that the swinging and deflection of the processed yarn 1 caused by the eccentric rotor 16 described above is extremely small, at most 10 degrees, and is not large enough to substantially bend the yarn path.

An optical outer diameter measuring section is provided on the yarn path between the tension meter 13 and the take-up roller 6.

In FIG. 6, the outer diameter measuring section 30
A light source 31 provided on one side of the thread path;
a light scattering plate 32 provided between the thread path and the thread path, an image sensor 36 provided on the other side of the thread path, and a light scattering plate 32 provided between the thread path and the image sensor 3;
6, a front aperture 33, an optical lens 34, and a rear aperture 35 are provided. All the elements are arranged in a straight line on the optical path and housed in a dark box to prevent the influence of external light. Note that 37 and 39 are yarn guides for regulating the yarn path of the processed yarn 1. Further, the image sensor 36 is connected to an arithmetic processing section 38, which will be described later.

In the outer diameter measuring section 30 described above, the light from the light source 31 is turned into scattered light with a uniform light intensity distribution by the light scattering plate 32, and is irradiated onto the processed yarn 1 from a direction perpendicular to its yarn axis. The shadow of the processed yarn 1, that is, the optical image, is formed on the image sensor 36. At this time, the front diaphragm 33 and the rear diaphragm 35 limit the optical path and the optical lens 34
so that only the central part of the image sensor 3 is used.
This prevents blurring due to aberrations of the optical image lens 34 above 6. The output of the image sensor 36 is as shown in FIG. 7 (in FIG. 7, for convenience of explanation, the envelope of the output of each light receiving cell is drawn),
By comparing this output with a predetermined threshold level L, the apparent outer diameter d of the processed yarn 1 can be determined. This process is carried out by the arithmetic processing unit 38
Do it with

In FIG. 8, the arithmetic processing section 38 includes a control circuit 43, a comparator 44, a threshold level setting circuit 45, a bright/dark detection circuit 46, and a dark/bright detection circuit 4.
7, flip-flop 48, and gate 49,
Counter 50, primary memory 51, secondary memory 5
2, a digital/analog converter 53, a display circuit 54, etc.

The control circuit 43 applies a scanning pulse to the image sensor 36 and performs various controls necessary for one scan of the image sensor. The output of the image sensor 36 is then sent to a comparator 44 and compared with a predetermined threshold level set by a threshold level setting circuit 45. The output of the comparator 44 is
The light is input to the bright/dark detection circuit 46 and the dark/bright detection circuit 47, and it is detected that the output of the image sensor changes from bright to dark or from dark to bright. The flip-flop 48 is set by the output of the bright/dark detection circuit 46, and the AND gate 49 logically ANDs the set signal and the scanning pulse, and outputs the result from the counter 5.
Send to 0. The parallel output of the counter 50 is input to the primary memory 51, and the dark/light detection circuit 4
7 is stored by the output. The parallel output of the primary memory 51 is input to the secondary memory 52 and is stored in accordance with a signal from the control circuit 43. The output of the secondary memory 52 is input to the display circuit 54 via the digital/analog converter 53.

Referring again to FIG. 4, a speed controller 40 is connected to the pulse motor 3. This speed controller 40 is comprised of an oscillation circuit, a frequency dividing circuit, etc. for driving the pulse motor 3, and thus the supply roller 2, at a desired constant circumferential speed of 0.5 to 60 m/min.

In addition, the pulse motor 7 also has a speed controller 4.
2 are connected. This speed controller 42
is connected to the signal processing circuit 41 of the tension meter 13 described above. And the speed controller 42
is a circuit for setting the desired tension T ₀ of processed yarn 1,
It is comprised of a circuit that calculates the difference (T ₀ -T) between the set tension T ₀ and the above-mentioned detected tension T, a circuit that proportionally integrates the difference, a voltage/frequency conversion circuit, a drive circuit, and the like.

Now, in FIG. 4, the processed yarn 1 of the package 10 is passed through a so-called measurement system consisting of a tension adjuster 11, a supply roller 2, a tension meter 13, an outer diameter measuring section 30, a take-up roller 6, and an ejector 12. . Then, the pulse motor 3 and therefore the supply roller 2 are driven by the speed controller 40 at a desired constant circumferential speed. Then, the processed yarn 1 is unwound from the package 10 and given a desired constant tension.
It is fed into the outer diameter measuring section 30 via the tension meter 13. The tension T of the processed yarn 1 at this time is detected by the tension meter 13 and sent to the speed controller 42. The speed controller 42 has a set tension set therein.
Compare T ₀ and the above-mentioned detected tension T, and control the rotation speed of the pulse motor 7 so that T ₀ = T, that is, the tension of the processed yarn 1 is a constant value, and change the circumferential speed of the take-up roller 6. . For example, when T>T ₀ , the rotation speed of the pulse motor 7 is lowered and the peripheral speed of the take-up roller 6 is lowered. If the tension at this time is too large, the structure of the textured yarn 1 will change and the apparent outer diameter cannot be measured, so the tension should be set as low as possible without causing the textured yarn 1 to loosen. Specifically, it is in the range of 1 to 100 mg/denier. Preferred is a range of 1 to 10 mg/denier.

In FIG. 6, in the outer diameter measuring section 30, an optical image of the processed yarn 1 is captured by an image sensor 36 by an optical lens 34.
imaged on top. At this time, when the image sensor 36 is scanned once by the scanning pulse of the control circuit 43 of the arithmetic processing section 38, an output as shown in FIG. 7 is obtained.

In FIG. 7, the horizontal axis represents the image sensor 36 at time t.
The vertical axis is the output e.
The large concave area in the center is due to the shadow of the core of processed yarn 1 in Figure 1, that is, the area where single yarns are densely present, and the small unevenness on the left and right sides are due to the shadow of the core area of processed yarn 1 in Figure 1, and the small unevenness on the left and right sides are due to the shadow of the core area of processed yarn 1 in Figure 1. This is due to the shadow of These small irregularities on the left and right sides can be detected because the image sensor 36 is used in an unsaturated region, and the image sensor 36 responds to minute fluctuations in the amount of light due to the single fibers at the periphery. It is. and,
Compare the output e with the threshold level L, count the number of light receiving cells that output an output lower than the threshold level L, and convert the value to the apparent outer diameter of the processed yarn 1. Compatible. At this time, if the threshold level L is set too deep, the output will not fall below the threshold level L due to minute fluctuations in light intensity due to single fibers at the periphery, and the core diameter will be measured as the apparent outer diameter. Sometimes it happens. In order to reliably avoid this, the threshold level L must be
It is set to K times (0.8≦K<1.0) the lowest value of the output of each light-receiving cell (see FIG. 2) obtained when processed yarn 1 is not present.

By the way, when measuring the apparent outer diameter of processed yarn as shown in Figure 1, the output of the image sensor is temporarily shifted to the thread due to the single yarn on the peripheral edge, as shown in the unevenness seen on the left side of Figure 7. It can drop below the Jord level and then rise above it again. At this time, simply counting the number of light-receiving cells that output an output below the threshold level will not measure the true apparent outer diameter. The number of light-receiving cells in the area is counted. This is performed by the arithmetic processing section 38.

That is, in FIG. 8, the output of each light receiving cell of the image sensor 36 is successively compared with a predetermined threshold level set by a threshold level setting circuit 45 by a comparator 44. The bright/dark detection circuit 46 and the dark/bright detection circuit 47 each detect from the output of the comparator 44 that the output of each light receiving cell has crossed a threshold level. That is, in FIG. 7, the bright/dark detection circuit 46 detects both points A and C, and the dark/bright detection circuit 4
7 detects both points B and D, respectively.

On the other hand, flip-flop 48 is set by the output of bright/dark detection circuit 46. That is, it is set at point A shown in FIG. 7, but since it is already set at point C, the state remains unchanged. When flip-flop 48 is set, scanning pulses from control circuit 43 are input to counter 50 via AND gate 49 and counted.
That is, the counter 50 counts the number of light receiving cells after point A in FIG.

Since the primary memory 51 is connected in parallel to the counter 50, it stores the contents of the counter 50 every time the output of the dark/bright detection circuit 74 is input.
That is, in FIG. 7, the contents of the counter 50 at that time, that is, the number of light-receiving cells between A and B, are stored at point B. Next, at point D, the stored contents are updated to the number of light receiving cells between A and D.

When one scan is completed, the control circuit 43 outputs an end signal and a reset signal, and in response to the end signal, the contents of the primary memory 51 are transferred to the secondary memory 52, and then the flip-flop 48, the counter 50, and the primary memory 51 are transferred. Reset.

The output of the secondary memory 52 is converted into an analog quantity by the digital/analog converter 53, and then a value multiplied by a certain coefficient is displayed on the display circuit 54. The displayed value represents the apparent outer diameter of the processed yarn 1. The above coefficient is determined by the outer diameter measuring section 30
In place of the processed yarn 1, for example, a wire whose outer diameter is known is placed, and the value is determined so that the output of the display circuit 54 at that time will be the outer diameter of the wire.

In the above embodiment, in order to maintain the tension of the processed yarn at a constant value, the supply roller was driven at a constant circumferential speed and the circumferential speed of the take-off roller was controlled. Alternatively, the peripheral speed of the supply roller may be controlled by driving the supply roller at a constant peripheral speed.

In addition, as a tension meter, as shown in Figure 5,
Although a so-called rotary tension meter was used, any other known type of tension meter may be used.

Furthermore, the threshold level will change relatively when the output of the image sensor changes due to fluctuations in the amount of light from the light source, deterioration of the image sensor, etc., so it must be adjusted periodically or It is preferable to prevent the shadow of the processed yarn being measured from falling on the several light receiving cells, to make the output of this part blank, and to adjust the threshold level using the blank value.

Further, the light source of the outer diameter measuring section may be a white lamp, or may be a light source with a small intensity distribution such as a laser. When a laser is used as a light source, a light scattering plate, a diaphragm, etc. can be omitted.

Furthermore, a twisting mechanism is installed between the outer diameter measurement unit and the take-up roller, and by adding twist to the processed yarn being measured, it can be used to determine the average apparent outer diameter of flat yarns, or to emphasize the unevenness of specially processed yarns. You can also do things like measure.

<Effects of the Invention> The present invention provides a scanning image sensor that is equipped with a light source and a plurality of light receiving cells arranged in a row, and whose operating point is set in an unsaturated region where the output changes in proportion to the amount of incident light. A yarn path is formed between the two, and while the processed yarn is run on the yarn path while maintaining a constant tension in the range of 1 to 100 mg/denier, an optical image of the processed yarn is formed on the image pickup device. The output obtained by scanning the image sensor once is set to K times (0.8≦K<1.0) the lowest output among the outputs of each light receiving cell obtained when there is no processed yarn on the yarn path. The apparent value of the processed yarn is calculated from the number of light-receiving cells until the output first becomes lower than the threshold level and finally rises above the threshold level. Since the outer diameter is determined, even slight light intensity fluctuations due to the single yarns at the peripheral edge of the processed yarn, which has a core where the single yarns are densely gathered and a peripheral area where the single yarns are relatively loosely gathered, can be detected. The output of the image sensor follows extremely well, and the apparent outer diameter can be measured with high precision.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the apparent outer diameter of processed yarn;
3 and 3 are graphs showing the output of the image sensor when there is no processed yarn in the outer diameter measuring section, FIG. 4 is a schematic block diagram showing one embodiment of the present invention, and FIG.
The figure is a schematic perspective view of the tension meter shown in FIG. 4 above,
FIG. 6 is a schematic perspective view of the outer diameter measuring section shown in FIG. 4, FIG. 7 is a graph showing the output of the image sensor when there is processed yarn in the outer diameter measuring section, and FIG. FIG. 7 is a block diagram of the arithmetic processing section shown in FIG. 6 above. 1: Yarn, 2... Supply roller, 3: Pulse motor,
4: Drive roller, 5: Driven roller, 6: Take-up roller, 7: Pulse motor, 8: Drive roller, 9: Driven roller, 10: Package, 11: Tension adjuster, 12: Ejector, 13: Tension meter, 14 : Thread guide, 15: Thread guide, 16: Eccentric rotor, 1
7: Gauge, 18: Motor, 19: Detection gauge, 20: Dummy gauge, 21: Lever, 22:
Semiconductor strain gauge, 23: Lever, 24: Semiconductor strain gauge, 25: Capacitor, 26: Lead wire, 2
7: Differential amplifier, 28: Capacitor, 29: Lead wire, 30: Outer diameter measuring section, 31: Light source, 32: Light scattering plate, 33: Front diaphragm, 34: Optical lens, 3
5: Rear aperture, 36: Image sensor, 37: Thread guide,
38: Arithmetic processing unit, 39: Thread guide, 40: Speed controller, 41: Signal processing circuit, 42: Speed controller, 43: Control circuit, 44: Comparator,
45: Threshold level setting circuit, 46:
Bright/dark detection circuit, 47: Dark/bright detection circuit, 48:
flipflop, 49: and gate, 50:
Counter, 51: Primary memory, 52: Secondary memory, 53: Digital/analog converter, 5
4: Display circuit.

Claims (1)

[Claims] 1. A scanning image sensor, which is equipped with a light source and a plurality of light receiving cells arranged in a row, arranged to face each other, and whose operating point is set in an unsaturated region where the output changes in proportion to the amount of incident light. A yarn path is formed between the two, and while the processed yarn is run on the yarn path while maintaining a constant tension in the range of 1 to 100 mg/denier, an optical image of the processed yarn is formed on the image pickup device. The output obtained by scanning the image sensor once is multiplied by K times (0.8
≦K<1.0), the output of the light-receiving cell is compared with the threshold level set to ≦K<1.0), and the output of the light-receiving cell is measured until the output first becomes lower than the threshold level and finally becomes higher than the threshold level. A method for measuring the apparent outer diameter of processed yarn, which is characterized by determining the apparent outer diameter of processed yarn from the number of pieces.