JP3424706B2 - Column shape abnormality detection method and detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting an abnormal surface shape of a columnar body such as an optical fiber.

[0002]

2. Description of the Related Art Conventionally, a method of measuring the outer diameter of a columnar body by irradiating the columnar body with light from the side and measuring the light and darkness of the light generated by the shielding of the columnar body with an image sensor or the like has been conventionally known. Are known. This method is described in, for example, Japanese Patent Laid-Open No.
7-127803.

Further, as a method for detecting an abnormality in the surface shape of the columnar body, a method as shown in FIG. 8 (a) is conventionally known. This is a method of irradiating a parallel light flux while moving the columnar body along the longitudinal direction, and detecting a component of the light flux not blocked by the columnar body with a photodetector. The parallel light flux is formed using a collimator lens or the like. The detected light intensity level is also constant as long as the columnar body has a constant outer diameter along the longitudinal direction,
If the surface of the columnar body has a shape abnormality such as a concave portion or a convex portion, the light shielding ratio changes, and thus the detected light intensity also changes. For example, as shown in FIG. 8A, when the convex portion formed on the surface of the columnar body crosses the parallel light flux,
In (b), a pulse-like level decrease as indicated by reference numeral 80 is detected. From the time when this change occurs and the moving speed of the columnar body, it is possible to determine at which position of the columnar body the shape abnormality has occurred.

However, according to this method, it is difficult to accurately detect the change in the light intensity due to the factors such as the vibration of the columnar body and the fluctuation in the power of the light source, and the change in the light intensity due to the abnormal shape to be detected. For example, as shown in FIG. 8B, when a noise pulse such as 90 is detected due to vibration of the columnar body or the like, the shape is based on the fact that the light intensity becomes equal to or lower than a predetermined threshold value. As long as the abnormality is detected, the pulse 80 and the pulse 90 are similarly processed as the pulses caused by the shape abnormality.

In order to solve this problem, a double beam method using two beams as shown in FIG. 9 (a) has been devised. This is based on the difference between the time waveform of the light intensity of the component of the first beam that was not blocked by the columnar body and the time waveform of the light intensity of the component of the second beam that was not blocked by the columnar body. Is a method of detecting. As shown in FIG. 9B, noise 9 due to vibration of the columnar body, etc.
Since 0 and 91 are detected by the first and second beams at the same time, the noises 90 and 91 are canceled by obtaining the difference between the two time waveforms, and the pulses 80 and 81 caused by the convex portion 2 of the columnar body 1 are canceled. Only can be detected.

[0006]

However, in the above-mentioned double beam method, when random noise which is detected by one beam but not the other beam occurs, the noise cannot be removed. For example, in FIG.
Since the random noise 92 as shown by 0 is detected only by the first beam, it remains as it is even if the difference of the time waveforms is obtained, and the pulse 80 based on the shape abnormality of the columnar body is obtained.
Like 81 and 81, it is determined that the shape is abnormal.

Airborne dust in the atmosphere is known as a cause of such random noise. When one suspended dust crosses one inspection beam, noise is generated, but unless another suspended dust crosses another inspection beam at the same time, noise is not detected by another inspection beam. Further, the vibration of the columnar body does not always show the same amplitude for each inspection beam depending on the vibration state, and therefore, it may not be completely removed by the double beam method.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method and an apparatus capable of highly accurately detecting a shape abnormality of a columnar body by eliminating random noise. And

[0009]

In order to solve the above-mentioned problems, the shape abnormality detecting method of the present invention uses first and second inspection light beams traveling in directions substantially parallel to each other on a predetermined measurement line. A first step of moving the columnar body to be measured relative to each inspection light from the first irradiation position toward the second irradiation position on the measurement line while irradiating the first and second irradiation positions in And a second step of detecting a component of the first inspection light that is not shielded by the columnar body and detecting a change in the light intensity of this component, and a second inspection light that is not shielded by the columnar body. Third step of detecting the component and attempting re-detection of the light intensity change measured in the second step after the elapse of the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position And the column based on the change in light intensity detected again in this third step. The determining abnormality of the surface shape of the body 4
And the process of.

The third step is performed at the time when the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position has elapsed from the time when the light intensity change was detected in the second step. The step of detecting the component of the second inspection light that is not blocked by the columnar body over a predetermined time may be used.

The first and second inspection lights are inspection lights formed by branching light from a single light source, and preferably have substantially the same light intensity.

The first and second inspection lights are preferably substantially parallel light beams.

Next, the shape abnormality detecting device of the present invention irradiates the first and second inspection lights, which travel in directions substantially parallel to each other, to the first and second irradiation positions on a predetermined measurement line, respectively. By this means, a device for detecting an abnormality in the surface shape of the columnar body that moves relative to each inspection light from the first irradiation position to the second irradiation position on the measurement line,
(A) light projecting means for irradiating the first and second irradiation positions with the first and second inspection lights, respectively, and (b) detecting components of the first inspection light that are not blocked by the columnar body, A first detection unit that detects a change in the light intensity of this component, and (c) a component that is not shielded by the columnar body in the second inspection light is detected,
A second detector that attempts to re-detect the change in the light intensity detected by the first detector after the elapse of the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position;
(D) An abnormality determination unit that determines the shape abnormality of the columnar body based on the light intensity change detected again by the second detector.

The first detection unit detects the component of the first inspection light that is not blocked by the columnar body, and the trigger pulse in response to the change in the output level of the first light receiving unit. A trigger generation unit that generates a signal and a delay unit that delays the trigger pulse signal by a time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position are provided. The detection unit outputs the output of the second light receiving unit in response to the input of the trigger light pulse signal output from the delay unit and the second light receiving unit that detects the component of the second inspection light that is not blocked by the columnar body. The abnormality determining means may determine the shape abnormality of the columnar body based on the output of the gate means.

Further, the shape abnormality measuring apparatus of the present invention calculates the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position according to the moving speed of the columnar body, A delay time calculating means for inputting the time information to the delay means may be further provided, and the delay means may delay the trigger pulse signal based on the time information.

The above-mentioned light projecting means splits a single light source and light emitted from this light source to form first and second inspection light beams having substantially the same light intensity, and these inspection light beams are formed. May be provided from each of the first and second emission ends.

The light projecting means may further include first and second collimator lenses arranged at positions where the first and second emission ends of the light branching means are the focal points.

The optical branching means comprises first and second optical fibers to which light from a single light source is incident from one end thereof, and the other ends of these optical fibers are respectively the first and second optical fibers. It may be an emission end.

The light splitting means splits the incident side optical fiber on which the light from a single light source is incident and the light emitted from the incident side optical fiber to form first and second inspection light. And a first and second emission-side optical fibers on which these inspection lights are respectively incident, and the other ends of these emission-side optical fibers are the first and second, respectively.
May be the emission end of the.

[0020]

When the surface shape of the columnar body is substantially the same along the longitudinal direction, the light amount of the component of the inspection light that is blocked by the columnar body becomes substantially constant, and the measured light intensity also becomes substantially constant. .
However, if a shape abnormality such as a convex portion or a concave portion occurs on the surface of the columnar body, the amount of the component of the inspection light that is blocked by the columnar body changes over the time that the abnormal portion crosses the inspection light. This appears as a pulsed light intensity change in the time waveform of the light intensity of the component of the inspection light that is not blocked by the columnar body.

The change in the light intensity of the inspection light may include a noise pulse that is irrelevant to the shape abnormality of the columnar body, in addition to that corresponding to the shape abnormality of the columnar body. These noise pulses are not only normal noise pulses that are simultaneously detected by each inspection light due to vibration of the columnar body, but also random noise that is detected by one inspection light but not by another inspection light. There is a noise pulse.

In the shape abnormality detecting method of the present invention, the change in the light intensity detected by the first inspection light is after the elapse of the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position. It is confirmed whether or not it is detected again by the second inspection light. Since the abnormal shape portion of the columnar body is irradiated with the second inspection light after the lapse of the time from the irradiation of the first inspection light,
If the light intensity change corresponds to the shape abnormality of the columnar body, the second
Re-detected by inspection light. However, when the change in light intensity measured by the first inspection light is a random noise pulse, this change in light intensity is rarely detected again by the second inspection light after the above time has elapsed. Therefore, by determining the shape abnormality of the columnar body based on the re-detected change in light intensity, it is possible to detect the shape abnormality with high accuracy without random noise.

The re-detection described above is, for example, the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position from the time when the light intensity change is detected in the second step. At the time when has passed, a component of the second inspection light that is not blocked by the columnar body is detected for a predetermined time, and it is possible to check whether a light intensity change is detected by this. it can.

In the shape abnormality detecting method of the present invention, when the inspection light formed by branching the light from the single light source is used, the change in the intensity of the inspection light due to the change in the brightness of the light source is substantially the same among the inspection lights. Therefore, the intensities of the inspection lights are kept substantially the same, and the situation where the intensities of the inspection lights are extremely different is prevented.
As a result, the amplitude of the light intensity change corresponding to the shape abnormality of the columnar body detected by each inspection light is maintained substantially the same between the inspection lights, so that the light intensity change corresponding to the shape abnormality of the columnar body is reproduced again. The detection is preferably performed.

Further, when the inspection light of substantially parallel light flux is used, the light density of the inspection light tends to be constant at the irradiation position on the measurement line. Therefore, even if a minute vibration occurs in the columnar body in a direction intersecting with the inspection light, a large change in the amount of the inspection light shielded by the columnar body does not occur unless the inspection light is irradiated to the abnormal shape of the columnar body. Does not occur. As a result, noise is less likely to occur in the detected light intensity, so that suitable shape abnormality detection is performed.

Next, in the shape abnormality detecting device of the present invention, the abnormality determining means determines the shape abnormality based on the change in the light intensity detected by the first detecting section and further detected again by the second detecting section. It is possible to eliminate the random noise that is detected by the first detection unit but is not detected by the second detection unit and can perform highly accurate shape abnormality detection.

In the shape anomaly detecting device of the present invention, in which the light projecting means has a single light source and the light branching means, the intensity change of the inspection light due to the change of the brightness of the light source is substantially different between the inspection lights. Since they are the same, the intensities of the inspection lights are maintained substantially the same, and a situation in which the intensities of the inspection lights are extremely different is prevented.
Therefore, according to this apparatus, since the amplitude of the light intensity change corresponding to the shape abnormality of the columnar body detected by each detection unit is maintained substantially the same between the detection units, it is possible to cope with the shape abnormality of the columnar body. The re-detection of the change in the light intensity is suitably performed.

In the device in which the light projecting means is provided with the first and second collimator lenses, since the exit ends of the light splitting means are located at the focal points of the collimator lenses, the inspection light exits from the exit ends. Is made into a substantially parallel light flux by the collimator lens. As a result, the light projecting means emits the inspection light of the substantially parallel light flux. When using the inspection light of substantially parallel light flux,
The light density of the inspection light tends to be constant at the irradiation position on the measurement line. Therefore, according to this apparatus, even when a minute vibration in the direction intersecting the inspection light is generated in the columnar body,
As long as the inspection light is not radiated to the abnormal shape portion of the columnar body, a large change does not occur in the light amount of the inspection light shielded by the columnar body. As a result, noise is less likely to occur in the light intensities detected by the first and second detectors, so that suitable shape abnormality detection is performed.

In an apparatus in which the light splitting means includes first and second optical fibers from which light from a single light source is incident from one end, the light from the light source is incident on each optical fiber so that the light from the light source is emitted from the light source. Light is branched to form first and second inspection lights, and these inspection lights are emitted from the other end of each optical fiber. By appropriately disposing the light incident end of each optical fiber with respect to the light source, the light intensities of the first and second inspection lights become substantially the same. Since the optical fiber is used, the first and second
Each of the inspection lights has a substantially uniform light density. Therefore, according to this apparatus, even if a minute vibration occurs in the columnar body in a direction intersecting with the inspection light, the inspection light is shielded by the columnar body unless the abnormal shape of the columnar body is irradiated with the inspection light. No significant change in the light intensity of
Noise is less likely to occur in the light intensities detected by the first and second detectors, so that suitable shape abnormality detection is performed.

Similarly, the light branching means is an incident side optical fiber,
Also in the device including the light branching portion and the first and second emission side optical fibers, each inspection light has a substantially uniform light density because the optical fiber is used.
Therefore, also in the case of this device, even if a minute vibration of the columnar body occurs, a large change does not occur in the light amount of the inspection light shielded by the columnar body, and the light intensity detected by the first and second detection units is large. Since noise is less likely to occur in the shape, suitable shape abnormality detection is performed.

[0031]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.
Further, the dimensional ratios in the drawings do not always match those described.

In this embodiment, an abnormality in the surface shape of the optical fiber, which is one of the columnar bodies, is detected. The optical fiber to be measured is a bare fiber made of quartz glass having a circular cross section with a diameter of 125 μm, coated with an ultraviolet curable resin (UV resin), and further coated with a colored layer made of white UV ink. And is an optical fiber colored core wire having a circular cross section with a diameter of 250 μm.

A normal optical fiber is required to have a substantially uniform outer diameter along the longitudinal direction. However, if the coating conditions change during the coating of the colored layer, abnormal shapes such as convex portions and concave portions occur on the surface of the colored layer. In this embodiment, such an abnormal surface shape of the optical fiber is detected.

FIG. 1 is an overall configuration diagram showing a shape abnormality detecting apparatus of this embodiment. The shape abnormality detection device of this embodiment is
The light projecting device 58, the light projecting side slit plate 50, the light receiving side slit plate 52, the first detection unit 120, the second detection unit 121, the abnormality determination circuit 100, and the delay time calculation circuit 110 are included.

The light projecting device 58 includes a light source 10 and an optical fiber 1.
2 and 15, and collimator lenses 22 and 23. As the light source 10, in addition to a tungsten lamp or a halogen lamp, a semiconductor laser light source such as an LD (laser diode) having high output light power and a long life, or an LED (light emitting diode) can be used. The optical fibers 12 and 15 guide the inspection light from the single light source 10. The incident end 13 of the optical fiber 12 and the incident end 16 of the optical fiber 15 are both arranged in the vicinity of the light source 10, and the light emitted from the light source 10 is incident on the incident end 13.
The light is incident on the optical fibers 12 and 15 via 16, respectively. If the incident ends 13 and 16 are sufficiently close to each other and the positional relationship between the light source 10 and the incident ends 13 and 16 is appropriately set, the amount of incident light on the optical fiber 12 and the amount of incident light on the optical fiber 15 are substantially the same. become.

The collimator lens 22 includes the optical fiber 12
Is disposed at a position with its emission end 14 as the focal point.
Similarly, the collimator lens 23 is also arranged at a position where the emitting end 17 of the optical fiber 15 is its focal point. Therefore, when the light beams emitted from the optical fibers 12 and 15 enter the collimator lenses 22 and 23, parallel light fluxes are emitted from the respective collimator lenses. The light projecting device 58 is
These parallel light beams are output as inspection lights 54 and 55.

When the portion of the light projecting device 58 from which the inspection light is emitted is a light emitting portion, the light emitting side slit plate 50 is arranged so as to face the light emitting portion. Emitter side slit plate 50
Has elongated slits 28 and 29 in a direction perpendicular to the paper surface. The slits 28 and 29 are provided to face the collimator lenses 22 and 23 of the light projecting device 58, respectively. These slits 28 and 29 are for preventing light other than the inspection light from entering the optical path of the inspection light.

The light receiving side slit plate 52 is arranged so as to face the light projecting side slit plate 50. Light receiving side slit plate 5
2 has elongated slits 32 and 33 in a direction perpendicular to the plane of the drawing, the slit 32 being the slit 28 of the light projecting side slit plate 50, and the slit 33 being the light projecting side slit plate 5.
It is provided at a position facing the 0 slit 29, respectively. These slits 32 and 33 prevent the photodetector 36 of the detector 120 and the photodetector 37 of the detector 121 from receiving light other than the inspection light, respectively.

It should be noted that the light-projecting side slit plate 50 and the light-receiving side slit plate 52 are preferably provided for stabilizing the luminous flux, but they are not necessary.

The two inspection lights 54 and 55 having passed through the slits 28 and 29, respectively, travel in directions substantially parallel to each other. In the shape abnormality detecting method of the present embodiment, the detection is performed while moving the optical fiber 1 to be measured along a longitudinal direction on a predetermined measurement line. In the present embodiment, as shown in FIG. 1, a line 62 which is a straight line perpendicular to the inspection lights 54 and 55 and which is positioned substantially in the middle of the light projecting side slit plate 50 and the light receiving side slit plate 52 is used as the measurement line. . Inspection light 5
4 and 55 are respectively irradiated to predetermined positions on the measurement line 62.

The detector 120 includes the photodetector 36 and the amplifier 4.
0, a trigger generation circuit 44, and a delay circuit 46. The photodetector 36 is arranged at a position facing the light emitting portion of the light projecting device 58 with the slits 28 and 32 interposed therebetween, and detects the inspection light 54 that has passed through the slits 28 and 32. The amplifier 40 is connected to the photodetector 36,
The output signal of the photodetector 36 is amplified. Trigger generation circuit 4
Reference numeral 4 is connected to the output terminal of the amplifier 40, compares the level of the output signal of the amplifier 40 with a predetermined trigger level, and outputs a predetermined trigger pulse signal according to the result. The delay circuit 46 is connected to the output terminal of the trigger generation circuit 44, and the same portion of the optical fiber 1 is connected to the inspection light 54.
The trigger pulse signal is delayed by the time required to reach the irradiation position of the inspection light 55 from the irradiation position of.

The delay circuit 46 includes a delay time calculation circuit 11
0 is connected. This delay time calculation circuit 110
Moving speed information 11 of the optical fiber 1 inputted from the outside
1, and the same position of the optical fiber 1 moving on the measurement line 62 based on the distance between the irradiation position of the inspection light 54 and the irradiation position of the inspection light 55 is the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54. Calculate the time required to reach. This time information 112 is input to the delay circuit 46.

The detector 121 includes the photodetector 37 and the amplifier 4.
1 and a gate circuit 48. Photo detector 3
7 is disposed at a position facing the light emitting portion of the light projecting device 58 with the slits 29 and 33 interposed therebetween.
And the inspection light 55 that has passed through 33 is detected. Amplifier 41
Is connected to the photodetector 37 and amplifies its output signal. The input terminal of the gate circuit 48 is connected to the output terminal of the amplifier 41, and the control terminal of the gate circuit 48 is
The output terminal of the delay circuit 46 is connected.

The abnormality judging circuit 100 is connected to the output terminal of the gate circuit 48. The abnormality determination circuit 100 determines the shape abnormality of the optical fiber 1 based on the output signal of the gate circuit 48.

In the shape abnormality detecting apparatus of the present embodiment, the change in the light intensity corresponding to the shape abnormality of the optical fiber 1 is detected by the first detecting section
After being detected by 20, the second detection unit 121 re-detects after a lapse of time until one position of the optical fiber 1 reaches the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54. ing. The light intensity change detected by the first detection unit 120 may include noise, but the noise is rarely detected again by the second detection unit 121. According to this, it is possible to detect the shape abnormality without noise.

Hereinafter, a method for detecting a shape abnormality of the optical fiber 1 by the apparatus of this embodiment will be described. First, while moving the optical fiber 1 on the measurement line 62 in the longitudinal direction from the irradiation position of the inspection light 54 toward the irradiation position of the inspection light 55, the light source 10 is caused to emit light and the inspection light 54, 55 is transmitted to the light projecting device 58. Is output.

More specifically, the light emitted from the light source 10 propagates through the optical fibers 12 and 15 and becomes a parallel light flux by the collimator lenses 22 and 23. In this embodiment, the parallel light flux emitted from the collimator lens 22 and the parallel light flux emitted from the collimator lens 23 have substantially equal light intensities. In the present embodiment, the abnormal shape of the optical fiber 1 is detected by using this parallel light flux as the inspection light.

Inspection lights 54 and 5 emitted from the light projecting device 58.
The light-projecting side slit plate 50 is irradiated with each of the light beams 5. The inspection light 54 that has passed through the slit 28 and the inspection light 55 that has passed through the slit 29 are applied to the optical fiber 1 moving on the measurement line 62.

FIG. 2 is a diagram showing irradiation positions 64 and 65 of the inspection lights 54 and 55 on the measurement line 62. Since the optical fiber 1 moves on the measurement line 62, each part of the optical fiber 1 sequentially passes through the irradiation positions 64 and 65 and is irradiated with the inspection lights 54 and 55. In FIG. 2, d indicates the distance between the slits 32 and 33 (which is almost equal to the distance between the inspection lights 54 and 55), and v indicates the moving speed of the optical fiber 1. During the operation of the device, the moving speed information of the optical fiber 1 is input to the delay time calculation circuit 110.

The components of the inspection lights 54 and 55 that are not shielded by the optical fiber 1 are the slit plates 5 on the light receiving side.
2 is irradiated. The inspection light 54 that has not been blocked by the optical fiber 1 and has passed through the slit 32 is received by the photodetector 36. Similarly, the inspection light 55 that is not blocked by the optical fiber 1 and passes through the slit 33 is received by the photodetector 37.

The photodetectors 36 and 37 receive the inspection light 5 received.
The electric signals of the levels corresponding to the light intensities of 4 and 55 are output. The output signal of the photodetector 36 is amplified by the amplifier 40 and then input to the trigger generation circuit 44. On the other hand, the output signal of the photodetector 37 is amplified by the amplifier 41 and then input to the gate circuit 48.

FIG. 3 shows the output signal of the amplifier 40 input to the trigger generation circuit 44, the output signal of the trigger generation circuit 44, the output signal of the amplifier 41 input to the gate circuit 48, the output signal of the delay circuit 46, and the output signal of the delay circuit 46. Gate circuit 48
It is a figure which shows the output signal of. The levels of the output signals of the amplifiers 40 and 41 correspond to the light intensities detected by the photodetectors 36 and 37, respectively.

As shown in FIG. 1, when the convex portion 2 is present at one place of the optical fiber 1, the convex portion 2 moves along with the movement of the optical fiber 1 and the irradiation position of the inspection lights 54 and 55 (see FIG. 2). 64, 65), the amount of inspection light blocked by the optical fiber 1 increases. Therefore, at the time when the convex portion 2 passes through the irradiation positions of the inspection lights 54 and 55, the output signals of the amplifiers 40 and 41 undergo pulse-like level reductions. Reference numerals 80 and 81 in the output signal of the amplifier 40 and the output signal of the amplifier 41, respectively.
The pulse indicated by is the decrease in light intensity due to the convex portion 2. Since there is a difference in time when the convex portion 2 passes through the irradiation positions of the inspection lights 54 and 55, there is a difference between the time when the pulse 80 is generated and the time when the pulse 81 is generated even though both are pulses caused by the convex portion 2. Has occurred.

In the signal, pulses 90 to 92 appear in addition to the pulses 80 and 81, but these are noises unrelated to the convex portion 2. Such noise occurs when the optical fiber 1 vibrates, or when suspended dust in the atmosphere crosses the inspection light and shields or reflects the inspection light.

The noise caused by the vibration of the optical fiber 1 is indicated by reference numeral 90 in the signal and reference numeral 92 in the signal. Since the vibration is generated in the entire optical fiber 1, these noises are simultaneously detected by the inspection lights 54 and 56. On the other hand, the noise caused by airborne dust is
Even if it is detected by one inspection light, it is usually not detected by the other detection light. This is because the suspended dust moves in a random manner, and crossing one inspection light beam does not necessarily cross the other inspection light beam. Such noise is called random noise. In this embodiment, the signal indicated by reference numeral 91 is random noise and does not appear in the signal.

The trigger generation circuit 44 outputs a trigger pulse signal according to the output signal of the amplifier 40. Specifically, when the signal level falls below a predetermined threshold value, a trigger pulse having a predetermined pulse width is output. Therefore, the output signal of the trigger generation circuit 44 is a pulse train-shaped signal composed of the trigger pulses 130 to 132.
This output signal is input to the delay circuit 46.

The delay circuit 46 delays the output signal of the trigger generation circuit 44 by the time required for one portion of the optical fiber 1 to reach the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54. This delay time information is input from the delay time calculation circuit 110. The moving speed information 111 of the optical fiber 1 is input to the delay time calculation circuit 110,
The delay time calculation circuit 110 calculates the moving speed v of the optical fiber 1.
Also, the time t required for one position of the optical fiber 1 to reach the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54 is calculated based on the distance d between the light-receiving side slits 32 and 33. This time t is obtained as t = d / v. The delay time calculation circuit 110 outputs this time information 112 to the delay circuit 4
Then, the delay circuit 46 delays the output signal of the trigger generation circuit 44 by the time t and outputs the delayed signal.

The output signal of the delay circuit 46 is detected by the detection unit 12
1 is input to the control terminal of the gate circuit 48. This signal becomes a control signal for the gate circuit 48. In particular,
While the signal is high, the gate is controlled to be open, and when the signal is low, the gate is controlled to be closed. In other words, the gate is opened while the trigger pulses 130 to 132 are input to the gate circuit 48.

Under the gate control by the trigger pulse 130, the gate circuit 48 opens the gate for a time of the trigger pulse width from the time when the pulse 81 corresponding to the convex portion 2 crosses the inspection light 55. As a result, the pulse 81 corresponding to the convex portion 2 passes through the gate circuit 48. On the other hand, since the gate is not opened at the time when the noise pulse 92 appears, the noise pulse 92 cannot pass through the gate circuit 48.

Since the gate circuit 48 outputs the pulse base level signal of the output signal of the amplifier 41 during the closed state, the output signal of the gate circuit 48 is obtained by removing the noise pulse 92 from the output signal of the amplifier 41. Become.
This output signal is essentially a photodetector 36 and 37.
It is equivalent to taking the AND of each output signal. This signal is input to the abnormality determination circuit 100.

In the shape abnormality detecting apparatus of this embodiment, the light intensity change detected by the first detecting section 120 is the pulses 80, 90 and 91 appearing in the output signal of the amplifier 40, and the second detecting section 121 detects the change. The detected light intensity change is the pulse 81 appearing in the output signal of the gate circuit 48. The pulse 81 is detected after a lapse of time from the time when the pulse 80 is detected until one position of the optical fiber 1 reaches the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54. This means that the change in light intensity detected by the detection unit 120 is re-detected by the second detection unit 121 after the above time has elapsed.

On the other hand, the noise pulse 90 detected by the first detector 120 is detected by the inspection light 54 and the inspection light 55 at the same time, so that it will not be detected again by the second detector 121 after the lapse of the above time. . In addition, the random noise pulse 91 detected by the first detection unit is
Since it is hardly detected by the inspection light of 1) after the elapse of the above time, it is not detected again. Thus, the first
The noise detected by the detection unit 120 is removed.

The abnormality judging circuit 100 detects the change in the light intensity detected again as described above, that is, the pulse 81 of the signal.
The shape abnormality is determined based on Specifically, the abnormality determination circuit 100 outputs a determination pulse signal 101 when the signal level falls below a preset threshold value. The threshold value is set to a value between the pulse top level and the pulse base level of the pulse 81. As a result, the convex portion 2 having the abnormal shape of the optical fiber 1 is detected.

The threshold value can be determined by performing a trial waveform measurement in advance and measuring the amplitude of the pulse corresponding to the shape abnormality.

By separately measuring which part of the optical fiber 1 passes the irradiation position of the inspection light 55, the optical fiber passing the irradiation position of the inspection light 55 at the time when the judgment pulse signal 101 is output. It is possible to find one point. This is where the shape abnormality occurs. Further, if the reference time and the location of the optical fiber 1 passing through the irradiation position of the inspection light 55 at this reference time are obtained in advance, the time when the determination pulse signal 101 is output and the moving speed of the optical fiber 1 are obtained. The location where the shape abnormality occurs can be obtained based on

In this embodiment, the convex shape abnormality is generated on the optical fiber 1, but the concave shape abnormality may occur on the surface of the optical fiber 1. In this case, since the amount of inspection light blocked by the optical fiber 1 is reduced,
In the output signals of the amplifiers 40 and 41, a pulse-like level increase corresponding to the recess appears.

Even in such a case, the shape abnormality judging circuit 1
The threshold value is set to a value between the pulse top level and the pulse base level of the pulse corresponding to the concave portion input to 00, and when the level of the input signal exceeds this threshold value, the abnormality determination circuit 100 determines. By setting the pulse signal to be output, it is possible to detect the abnormal shape of the recess.

Usually, in order to detect both a convex shape abnormality and a concave shape abnormality, two threshold values having different levels are set to detect the shape abnormality.
The high level threshold is for detecting a concave shape abnormality, and the low level threshold is for determining a convex shape abnormality. The shape abnormality determination circuit outputs the first determination pulse signal when the level of the input signal is below the low level threshold value and the second determination pulse signal when the level of the input signal exceeds the high level threshold value. Output each. If the first determination pulse signal and the second determination pulse signal can be distinguished from each other by making the pulse amplitudes different, it is possible to predict what kind of shape abnormality.

As described above, according to the shape abnormality detecting method of the present embodiment, it is possible to eliminate noise and detect the shape abnormality of the optical fiber with high accuracy.

According to the shape abnormality detecting method of this embodiment, after the secondary coating is applied in the manufacturing process of the optical fiber, the optical fibers moving so as to be wound around the bobbin are irradiated with the inspection lights 54 and 55. Can be done by doing. In this case, by using the winding meter attached to the bobbin, the location of the optical fiber that passes the irradiation position of the inspection light 55 at the time when the determination pulse signal 101 is output can be obtained.

Next, in this embodiment, the single light source 10 is used.
The reason why the optical fibers 12 and 15 are adopted as means for branching the light from the light source 10 will be explained.

First, for comparison with this embodiment, consider a case where a light source is prepared for each inspection light instead of using a single light source. Even with such a method, the shape abnormality detection of the present invention can be sufficiently performed, but in this case, the stability of each light source becomes important. That is, since the sensitivity of the photodetector changes according to the light intensity of the inspection light, when the relative brightness of each light source changes due to the instability of each light source and the difference in the light intensity of each inspection light increases, light detection is performed. The amplitude of the pulse corresponding to the shape anomaly appearing in the output signal of the detector also greatly differs for each photodetector. In such a case, it is necessary to make the trigger level of the trigger generation circuit 44 and the threshold value of the abnormality determination circuit 100 significantly different, which increases the possibility that the re-detection of the light intensity change is erroneously performed.

Since the situation is the same in the conventional double beam method, as a remedy, the light is split from a single light source to form two split lights, and the split light is used as the test light. A method for suppressing the difference in light intensity has been devised. For example, “Spectral Measurement and Spectrophotometer” (Kazuo Shibata, Kodansha Scientific, 2nd printing, August 1, 1979), pages 96 to 99, describes a single light source in a double-beam type self-recording spectrophotometer. Means for splitting the light are disclosed.

It is fully possible to apply such a method to the present invention. However, in such a method, an optical system is assembled with a prism or the like, so that there are drawbacks such as complicated design of the optical system and large size of the device, and it is difficult to realize a compact shape abnormality detection device. is there. There is also a limitation that it is not possible to form three or more branched lights.

In this embodiment, as a more preferable mode of the method of branching the light from a single light source, as shown in FIG.
In the vicinity of the light source 10, the incident ends 13 of the optical fibers 12 and 15,
16 is arranged and the light is branched to form two inspection lights 54 and 55. This method is suitable when the light source 10 has a large light emitting surface such as a tungsten lamp or a halogen lamp. According to this method, it is easy to design the optical system and also to make the optical system compact. Furthermore, according to this method, it is easy to convert the light from the light source 10 into three or more branched lights.

Embodiment 2 The shape abnormality detecting apparatus of Embodiment 1 has two detecting units 120,
Although the apparatus configuration includes 121, the shape abnormality can be detected with higher accuracy by increasing the number of detecting units and increasing the number of times of re-detection. From this point of view, in the present embodiment, the shape abnormality detection is performed using the shape abnormality detection device including the three detection units 120 to 122.

FIG. 4 is an overall configuration diagram showing the shape abnormality detecting apparatus of this embodiment. This apparatus includes a light projecting unit 58 that outputs inspection lights 54 to 56, a slit plate 50 having slits 28 to 30, and a slit plate 5 having slits 32 to 34.
2, the detection units 120 to 122, the abnormality determination circuit 100, and the delay time calculation circuit 110.

The light projecting section 58 includes three optical fibers 12, 1
5 and 18 are provided. Incident end 19 of optical fiber 18
Is arranged in the vicinity of the light source 10 similarly to the incident ends 13 and 16 of the optical fibers 12 and 15, and the emitting end 20 of the optical fiber 18 is arranged at the focal point of the collimator lens 24.

FIG. 5 is a diagram showing irradiation positions 64 to 66 of the inspection lights 54 to 56 on the measurement line 62. Each part of the optical fiber 1 moving on the measurement line 62 sequentially passes through the irradiation positions 64 to 66 and is sequentially irradiated with the inspection lights 54 to 56. In FIG. 5, d ₁ is the distance between the slits 32 and 33 (this is the inspection light 54 and 55).
Is almost equal to the interval. ), D ₂ is slits 33 and 34
(Which is approximately equal to the spacing between the inspection lights 55 and 56), and v indicates the moving speed of the optical fiber 1.

The detecting section 120 is composed of the photodetector 36, the amplifier 40, the trigger generating circuit 44 and the delay circuit 46 as in the first embodiment. Like the first embodiment, the detection unit 121 also includes the photodetector 37, the amplifier 41, and the gate circuit 48, but further includes the trigger generation circuit 45 and the delay circuit 47. The trigger generation circuit 45 is connected to the output terminal of the gate circuit 48, compares the level of the output signal of the gate circuit 48 with a predetermined trigger level, and outputs a predetermined trigger pulse signal according to the result. . The delay circuit 47 is connected to the output terminal of the trigger generation circuit 45, and is the trigger generation circuit for the time required for the same portion of the optical fiber 1 to reach the irradiation position of the inspection light 55 from the irradiation position of the inspection light 55. The trigger pulse signal output from 45 is delayed.

The detecting section 122 includes the photodetector 38 and the amplifier 4.
2 and a gate circuit 49. Photo detector 3
The slit 8 is arranged at a position facing the light emitting portion of the light projecting device 58 with the slits 30 and 34 interposed therebetween.
And the inspection light 56 which has passed through 34 is detected. Amplifier 42
Is connected to the photodetector 38 and amplifies the output signal of the photodetector 38. The input terminal of the gate circuit 49 is connected to the output terminal of the amplifier 42. The control terminal of the gate circuit 49 is connected to the output terminal of the delay circuit 47 of the detection unit 121, and the output terminal of the gate circuit 49 is connected to the input terminal of the abnormality determination circuit 100.

The delay circuits 46 and 47 are connected to the delay time calculation circuit 110, respectively, and the delay time information is inputted.

FIG. 6 shows the output signals of the amplifiers 40, 41 and 42, the output signals of the trigger generation circuits 44 and 45, the output signals of the delay circuits 46 and 47, and the output signals of the gate circuits 48 and 49. FIG.

In the signals and, reference numeral 8 respectively
The pulses indicated by 0, 81, and 82 are reductions in light intensity due to the convex portions 2 of the optical fiber 1. Pulse 90 of signal
-92, signal pulses 93-95, and signal pulses 96-98 are all noise pulses. Among these, the pulses 92, 95 and 98 are due to the vibration of the optical fiber 1 and are generated at the same time. All other noise pulses are random noise pulses.

The trigger generation circuit 44 outputs a trigger pulse signal according to the output signal of the amplifier 40, as in the first embodiment. The output signal of the trigger generation circuit 44 is a pulse train-shaped signal composed of the trigger pulses 130 to 133 corresponding to the signal pulses 80 and 90 to 92.

This signal is input to the delay circuit 46,
The output is delayed by a predetermined time. The delay time calculation circuit 110, based on the moving speed v of the optical fiber 1 and the distance d1 between the light-receiving-side slits 32 and 33, causes one portion of the optical fiber 1 to reach the irradiation position of the inspection light 55 from the irradiation position of the inspection light 54. The time t1 required to do so is calculated. This time t
1 is obtained as t1 = d1 / v. The delay time calculation circuit 110 sends this time information 112 to the delay circuit 46. The delay circuit 46 delays the output signal of the trigger generation circuit 44 by the time t1 based on the time information 112.

The output signal of the delay circuit 46 is detected by the detector 12
1 is input to the control terminal of the gate circuit 48 and controls the gate circuit 48 as in the first embodiment. Thereby, the convex portion 2
The pulse 81 corresponding to passes through the gate circuit 48,
The noise pulse 95 cannot pass through the gate circuit 48.

However, in this embodiment, since the random noise pulses 93 and 94 happen to occur when the gates are opened by the trigger pulses 131 and 132 corresponding to the noise pulses 90 and 91 of the signal, the random noise pulses 93 and 94 are generated. 94 passes through the gate circuit 48. This is effectively equivalent to the change in the light intensity of the noise detected by the first detector being re-detected by the second detector.

As described above, when a random noise pulse is accidentally detected by the photodetector 37 when the gate is opened, the change in the light intensity of the noise will be detected by the second detector. In the shape abnormality detection device of the embodiment, the third detector 122 attempts to re-detect the change in the light intensity detected by the detector 121, so that it is possible to eliminate these noises.

That is, the trigger generation circuit 45 responds to the output signal of the gate circuit 48 to generate trigger pulses 134-1.
A pulse train signal composed of 36 is generated and output to the delay circuit 47. The delay circuit 47 delays the signal for a predetermined time. This delay time information is input from the delay time calculation circuit 110. Delay time calculation circuit 110
The delay time information is input to the delay circuit 47 from the delay time calculation circuit 110, and one position of the optical fiber 1 is determined based on the moving speed v of the optical fiber 1 and the distance d2 between the light-receiving side slits 33 and 34. Calculates the time t2 required to reach the irradiation position of the inspection light 56 from the irradiation position of the inspection light 55. This time t2 is obtained as t2 = d2 / v. The delay time calculation circuit 110 uses the time information 113.
To the delay circuit 47, and the delay circuit 47 delays the output signal of the trigger generation circuit 45 by this time and outputs it.

The output signal of the delay circuit 47 is detected by the detection unit 12
It is input to the control terminal of the second gate circuit 49 and controls the gate circuit 49. Of the pulse 82 and the noise pulses 96 to 98 appearing in the output signal of the amplifier 42, the pulse 82 corresponding to the convex portion 2 passes through the gate circuit 49, but the noise pulses 96 to 98 may pass through the gate circuit 49. Can not. This is because among the light intensity changes detected by the detection unit 121, only the pulse 82 corresponding to the convex portion 2 is detected by the detection unit 1.
22 means that it has been rediscovered.

As a result, the noise pulses 96 to 98 are removed, and only the pulse 82 corresponding to the convex portion 2 appears in the output signal of the gate circuit 49. This output signal is substantially equivalent to the AND of the output signals of the photodetectors 36 to 38. This signal is the abnormality determination circuit 1
00 is input. The abnormality determination circuit 100 determines the shape abnormality by comparing the pulse peak level of the pulse 82 with a predetermined threshold value as in the first embodiment, and outputs the determination pulse signal 1
01 is output. As described above, highly accurate shape abnormality detection without noise is performed.

In the light projecting device 58 of this embodiment,
In addition to the above method, the optical branching can be performed by the method shown in FIG. In this method, the incident end 75 of the optical fiber 70 is arranged in the vicinity of the single light source 10, and the light is guided from the light source 10 through the single optical fiber 70. A plurality of optical fibers 71 to 7 are connected to the optical fiber 70 via a branching unit 74.
3 is connected. The branching unit 74 splits the incident light into three lights with almost equal light intensities. As the branch portion 74, a thin film optical waveguide or the like can be used. The branched light propagates through the optical fibers 71 to 73, respectively, and reaches each emission end (not shown). These exit ends are
It is arranged at the focal point of each collimator lens as in the device of FIG.

By this method, the light from the light source 10 can be branched to form three inspection lights. Also with this method, it is easy to design the optical system and make the optical system compact. Since this method guides light from the light source 10 with a single optical fiber, it is particularly suitable when a semiconductor laser light source such as an LD or a light source having a small light emitting surface such as an LED is used.

The method of branching the light from the light source with the optical fiber described above is extremely uniform as compared with the case where one light source is arranged at the focal point of each collimator lens without using the optical fiber. There is an advantage that a parallel light flux having a density can be obtained. From the viewpoint of achieving uniform light density, it is desirable that the total length of the optical fiber is long, but if it is too long, the optical fiber itself will cause a loss of light intensity due to transmission loss. It is desirable that the distance is about 5 to 50 cm.
In addition, a bundle fiber having a plurality of cores may be used as the optical fiber in order to increase the amount of light guided from the light source.

The reason why the collimator lens is used to form the inspection light of the substantially parallel light flux in the present embodiment is that each of the inspection lights has a uniform light density. When such inspection light is used, even when a slight vibration occurs in the optical fiber to be measured in a direction intersecting with the inspection light, the light amount of the inspection light shielded by the optical fiber does not significantly change. As a result, noise is less likely to occur in the output signal of the photodetector, and it is possible to perform suitable shape abnormality detection.

In order to confirm the effect of the present embodiment, the present inventors intentionally change the coating conditions when coating the colored layer of the optical fiber to form a plurality of wavy unevenness on the surface of the colored layer, and While winding the fiber at a linear velocity of 10 m / min, the shape abnormality was detected by moving 50 km on the measurement line 62 of the apparatus of FIG. The unevenness is formed at 10 points on the optical fiber, and its amplitude is 15 μm. When the detection was performed as described above, the detection was performed at an S / N ratio of about 5 times at all 10 locations, and there was no other detection (erroneous detection), and the error detection rate was 0%.

For comparison, a conventional double-beam type shape measuring apparatus was used to perform measurement under the same conditions as in the example, and detection was performed at an S / N ratio of about 5 times at 10 locations. In addition to this, there are 8 false detections, and the false detection rate is 44.
%Met. The causes of erroneous detection were 4 times the airborne dust in the atmosphere and 4 times the vibration of the optical fiber.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments and various modifications can be made. For example, it suffices that the columnar body to be measured moves relative to the inspection light, and it is also possible to move the shape abnormality detection device to perform detection, contrary to the embodiment. The columnar body to be measured is not limited to the optical fiber.

[0100]

As described above in detail, according to the shape abnormality detecting method of the present invention, the shape is detected based on the light intensity detected by the first inspection light and re-detected by the second inspection light. Since the abnormality is determined, it is possible to eliminate random noise and perform highly accurate shape abnormality detection.

In the shape abnormality detecting method of the present invention, when the inspection light formed by branching the light from the single light source is used, the amplitude of the light intensity change corresponding to the shape abnormality of the columnar body detected by each inspection light is used. Can be maintained substantially the same among the inspection lights, and the re-detection of the light intensity change corresponding to the shape abnormality of the columnar body can be suitably performed.

When the inspection light of the substantially parallel light flux is used in the shape abnormality detecting method of the present invention, noise is less likely to occur in the detected light intensity, so that suitable shape abnormality detection can be performed.

Next, according to the shape abnormality detecting apparatus of the present invention, the abnormality determining means determines the shape abnormality on the basis of the light intensity change detected by the first detecting section and re-detected by the second detecting section. Therefore, random noise can be eliminated and highly accurate shape abnormality detection can be performed.

According to the shape abnormality detecting device of the present invention, the light projecting means includes a single light source and a light branching means.
Since the amplitude of the light intensity change corresponding to the shape abnormality of the columnar body detected by each detection unit is kept substantially the same between the detection units, it is preferable to re-detect the light intensity change corresponding to the shape abnormality of the columnar body. Can be done.

According to the apparatus in which the light projecting means is provided with the first and second collimator lenses, the inspection light of the substantially parallel light flux is applied to the columnar body, so that it is detected by the first and second detectors. Noise is less likely to occur in the light intensity that is generated, and suitable shape abnormality detection can be performed.

According to the apparatus in which the light splitting means is provided with the first and second optical fibers from which light from a single light source is incident from one end, the first and second inspection lights are substantially uniform. Since it has a light density, noise is unlikely to occur in the light intensities detected by the first and second detectors, and suitable shape abnormality detection can be performed.

Similarly, the optical branching means is an incident side optical fiber,
According to the device including the light branching portion and the first and second emission-side optical fibers, the first and second inspection lights have substantially uniform light densities, so that the first and second detection portions detect the light. Noise is less likely to occur in the generated light intensity, and suitable shape abnormality detection can be performed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a shape abnormality detection device according to a first embodiment.

FIG. 2 is a diagram showing irradiation positions 64 and 65 of inspection lights 54 and 55 on a measurement line 62.

FIG. 3 shows an output signal of an amplifier 40 and a trigger generation circuit 44.
Output signal of the amplifier 41, the output signal of the amplifier 41, the delay circuit 46
6 is a diagram showing an output signal of the gate signal and an output signal of the gate circuit 48. FIG.

FIG. 4 is an overall configuration diagram showing a shape abnormality detection device according to a second embodiment.

5 is a diagram showing irradiation positions 64-66 of the inspection lights 54-56 on the measurement line 62. FIG.

FIG. 6 shows output signals of amplifiers 40, 41 and 42,
, Output signals of the trigger generation circuits 44 and 45, output signals of the delay circuits 46 and 47, and the gate circuit 4
It is a figure which shows the output signal of 8 and 49.

FIG. 7 is a diagram showing a method of branching the light from the light source 10.

FIG. 8A is a diagram showing a conventional method for detecting an abnormality in the surface shape of a columnar body, and FIG. 8B is a diagram showing the time of the light intensity of the component of the parallel light flux that is not blocked by the columnar body. It is a figure which shows a waveform.

FIG. 9A is a diagram showing a double beam method,
(B) is a diagram showing cancellation of noises 90 and 91 by the double beam method.

FIG. 10 is a diagram illustrating a double beam method when random noise 92 occurs.

[Explanation of symbols]

1 ... Optical fiber to be measured, 2 ... Convex portion, 10 ... Light source, 1
2 and 15 ... Optical fiber, 22 and 23 ... Collimator lens, 36 and 37 ... Photodetector, 40 and 41 ... Amplifier, 44 ... Trigger generation circuit, 46 ... Delay circuit, 48 ... Gate circuit, 100 ... Abnormality determination circuit, 110 ... Delay time calculation circuit, 120 and 121 ... Detection section.

Continuation of the front page (56) References JP-A-3-87652 (JP, A) JP-A-57-127803 (JP, A) JP-A-52-4866 (JP, A) Jitsukaihei 3-44606 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G01N 21/84-21/958

Claims (11)

(57) [Claims] 1. A columnar body to be measured is applied while irradiating first and second inspection lights, which travel in directions substantially parallel to each other, to first and second irradiation positions on a predetermined measurement line, respectively. A first step in which the inspection light is moved relative to the second irradiation position from the first irradiation position on a line, and the first inspection light is not shielded by the columnar body. Second component for detecting the time-dependent change in the light intensity of the component, and detecting a component of the second inspection light that is not shielded by the columnar body, and detecting the component The third step of attempting re-detection of the temporal change in the light intensity measured in the second step after the time required for the object to reach the second irradiation position from the first irradiation position has elapsed; Based on the time change of the light intensity re-detected in the process of A fourth step of determining an abnormality in the surface shape of the columnar body , wherein the first step branches the light from the light source with an optical fiber,
Light emitted from the optical fiber enters the collimator lens
A method for detecting a shape abnormality of a columnar body for forming the first and second inspection lights . Wherein said third step, the light in the second step
Of the second inspection light, at the time when the time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position has elapsed from the time when the time change of the intensity was detected, The shape abnormality detection method according to claim 1, wherein the step is a step of detecting a component not shielded by the columnar body for a predetermined time. 3. The first and second inspection lights are substantially equal to each other.
The shape abnormality detection method according to claim 1, wherein the shape abnormality detection means has the same light intensity . 4. The first and second inspection lights traveling in directions substantially parallel to each other are respectively applied to first and second irradiation positions on a predetermined measurement line, so that the first and second inspection lights are moved on the measurement line. An apparatus for detecting an abnormality in the surface shape of a columnar body that moves relative to each of the inspection lights from one irradiation position toward the second irradiation position, wherein the first and second inspection lights are detected. A light projecting unit that irradiates the first and second irradiation positions, a component that is not shielded by the columnar body in the first inspection light, and detects a temporal change in light intensity of the component. No. 1 detection unit detects a component of the second inspection light that is not shielded by the columnar body, and one portion of the columnar body reaches the second irradiation position from the first irradiation position. It is detected by the first detection unit after the required time elapses. A second detection unit to try to time change <br/> redetection of the light intensity, the abnormality determining abnormal shape of the columnar body on the basis of the time variation of the re-detected light intensity by the second detector comprising a determining unit, wherein the light projecting means, light source, optical fiber, and a collimator
A lens , the light projecting means branches the light from the light source with an optical fiber,
Output light from the optical fiber to the collimator lens
Columnar bodies that are incident to form the first and second inspection lights
Abnormal shape detection device. 5. The length of the optical fiber is from the light source.
5 to 50 cm before reaching the collimator lens
The shape abnormality detecting device for a columnar body according to claim 4. 6. The optical fiber is a bundle fiber.
An apparatus for detecting a shape abnormality of a column according to claim 4. 7. The first detection unit detects a component of the first inspection light that is not shielded by the columnar body, and a change in output level of the first light reception unit. Trigger generating means for generating a trigger pulse signal in response to the trigger pulse signal, and delay means for delaying the trigger pulse signal by a time required for one portion of the columnar body to reach the second irradiation position from the first irradiation position. Is equipped with
The second detection unit receives a second light receiving unit that detects a component of the second inspection light that is not shielded by the columnar body, and an input of the trigger pulse signal that is output from the delay unit. And a gate unit that allows the output of the second light receiving unit to pass therethrough, and the abnormality determining unit includes:
The shape abnormality detecting apparatus according to claim 4, wherein the shape abnormality of the columnar body is determined based on the output of the gate means. 8. The time required for one position of the columnar body to reach the second irradiation position from the first irradiation position is calculated according to the moving speed of the columnar body, and the time information is used as the delay means. 8. The shape abnormality detecting apparatus according to claim 7 , further comprising a delay time calculating means for inputting to said, said delay means delaying said trigger pulse signal based on this time information. 9. The light projecting means branches a single light source and light emitted from the light source into substantially the same light intensity.
Forming first and second inspection lights having a degree of
Light is emitted from each of the first and second emission ends.
The light splitting means and the first and second exit ends are located at the focal point thereof.
A first collimator lens and a second collimator lens arranged respectively
The light splitting means is such that the light from the single light source is at one end thereof.
Comprising first and second optical fibers incident from
The other end of each of the optical fibers
The shape abnormality detection of the columnar body according to claim 4, which is at the shooting end.
apparatus. 10. The light projecting means splits a single light source and light emitted from the light source into substantially the same light intensity.
Forming first and second inspection lights having a degree of
Light is emitted from each of the first and second emission ends.
The light splitting means and the first and second exit ends are located at the focal point thereof.
A first collimator lens and a second collimator lens arranged respectively
The optical branching means is an incident side optical fiber on which the light from the single light source is incident.
And split the light emitted from this incident side optical fiber into the first
A light branching portion that forms the first and second inspection lights, and first and second outputs to which these inspection lights are respectively incident.
And an emitting side optical fiber, and the other ends of these emitting side optical fibers are respectively the first and the second side.
And the second emission end, the shape of the columnar body according to claim 4.
Abnormality detection device. 11. The first and second inspection lights are respectively provided.
5. The columnar structure according to claim 4, which is a substantially parallel light beam having a uniform light density.
Body shape abnormality detection device.