JPH08220020A - Woven-fabric inspecting apparatus - Google Patents

Abstract

PURPOSE: To perform a highly accurate cloth inspection even when the speed of a sensor head is changed. CONSTITUTION: An endless belt 4 is reciprocated and turned around by the reciprocating driving of a motor 5, and a sensor head 2 is reciprocated along a rail 1. The light projected from a light projecting element 14 is cast on the outer surface of a disk 13 on a supporting shaft 6-1 of a guide pulley 6 and reflected. When the disk 13 is rotating, the reflected light from the disk 13 turns pulsated and the light is acquired by a photodetector 15. A speed computing circuit 18 computes the speed of a sensor head 2 based on the electric signal obtained by the photodetector 15 and the measured time of a clock. A cloth- inspection control circuit C0 corrects the reference time width, which becomes the object of the comparison for the time width of the specified part of the electric signal, based on the electric signal obtained from the sensor head 2 and the detected speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a woven fabric inspecting device for detecting a defect of a woven fabric by using a photoelectric sensor which outputs an electric signal according to the amount of received light.

[0002]

2. Description of the Related Art A woven fabric inspection device of this type is disclosed in Japanese Patent Laid-Open No. 3-24.
It is disclosed in Japanese Patent No. 9243. In this device, a spatial filter is used in which one light receiving element group in which light receiving elements are arranged in parallel and the other light receiving element group in which light receiving elements are arranged in parallel are inserted between light receiving elements.
The reflected light of the light projected from the light source onto the woven fabric is received by the spatial filter. The electric signal converted by both light receiving element groups is sent to the differential operation circuit. When P is between elements of one light receiving element group, V is the speed of the sensor head, and m is the magnification of the optical lens, the frequency f output from the differential operation circuit is mV / P. When a so-called warp is generated, the amplitude of the output signal from the differential operation circuit corresponding to a portion without warp is larger than that in a normal case without a warp. The period 1 / f of the signal output from the differential operation circuit is P / (mV), and if the number of elements in one light receiving element group is N, the width of the output signal is NP / (mV). . This width NP /
Out of (mV), the output signal portion having a larger amplitude than in the normal case is taken out. The number of pulse signals from the clock included in the extracted signal portion is counted, and when the counted number exceeds the reference value, it is determined that there is a defect. In other words, the defect presence / absence determination is performed by comparing the time width of the signal portion with the reference time width.

[0003]

The number of pulse signals per unit time is constant, and the count value of the pulse signals represents the time width. The speed V of the sensor head is included in the width NP / (mV) of the output signal. If the speed V changes, the width N
P / (mV) changes. Therefore, if there is an output signal portion corresponding to the meridian portion, the pulse count number of this output signal portion also changes. Such a change in the pulse count number reduces the accuracy of defect detection. Therefore, the velocity V of the sensor head must be constant, but constant velocity control is a fairly difficult control technique.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a woven fabric inspection device capable of performing highly accurate inspection even when the speed of the sensor head changes.

[0005]

Therefore, according to the present invention,
The present invention according to claim 1 is directed to a woven fabric inspection device that uses a time width of an electric signal obtained from a photoelectric sensor that outputs an electric signal according to a received light amount to detect a defect of the woven fabric. A sensor head that travels in the width direction of the woven fabric while picking up light that reflects the state, speed detection means that detects the traveling speed of the sensor head, and a value of an electric signal obtained from the photoelectric sensor are compared with a reference value. Along with the comparison means for outputting the time width confirmation signal corresponding to the electric signal exceeding the reference value, and the reference time width based on the comparison between the detection speed detected by the speed detection means and the reference speed, the time in the detection speed state. A woven fabric inspection device is provided with correction means for correcting the width and determination means for determining the presence or absence of a defect based on the comparison between the corrected time width and the time width of the time width determination signal.

According to a second aspect of the invention, a sensor head that travels in the width direction of the woven fabric while picking up light that reflects the woven state of the woven fabric, a speed detection unit that detects the traveling speed of the sensor head, and Comparison means for comparing the value of the electric signal obtained from the photoelectric sensor with the reference value and outputting a time width determination signal corresponding to the electric signal exceeding the reference value, and the detected speed detected by the speed detecting means and the reference Correcting means for correcting the time width of the time width determination signal to the time width in the reference speed state based on the comparison with the speed, and determining the presence or absence of a defect based on the comparison between the corrected time width and the reference time width. A woven fabric inspection device provided with a determination means.

According to the third aspect of the invention, a sensor head that travels in the width direction of the woven fabric while picking up light that reflects the woven state of the woven fabric, a speed detection means that detects the traveling speed of the sensor head, and a warp yarn. A plurality of photoelectric sensors for separately receiving light picked up from a plurality of regions on the woven fabric arranged in the yarn direction, and at least one electric signal of the plurality of photoelectric sensors and an electric signal of another photoelectric sensor. Difference calculation means for calculating the difference, and a comparison means for comparing the value of the difference signal obtained by the calculation of the difference calculation means with a reference value and outputting a time width determination signal corresponding to the difference signal exceeding the reference value, Correction means for correcting the reference time width to the time width in the detected speed state based on the comparison between the detected speed detected by the speed detection means and the reference speed; and the corrected time width and the time width of the time width confirmation signal. To constitute a woven fabric inspection device provided with a determination unit configured to defect whether based on a comparison of.

According to a fourth aspect of the invention, instead of the correcting means and the determining means of the third aspect, the time width of the time width fixing signal is determined based on the comparison between the detected speed detected by the speed detecting means and the reference speed. The correction means for correcting the time width in the reference speed state and the judgment means for judging the presence or absence of a defect based on the comparison between the corrected time width and the reference time width are used.

[0009]

According to the invention of claim 1, the comparing means compares the value of the electric signal obtained from the photoelectric sensor with the reference value, and
A time width confirmation signal corresponding to an electric signal exceeding the reference value is output. The correction means corrects the reference time width to the time width in the detected speed state based on the comparison between the detected speed detected by the speed detection means and the reference speed. The time width of the electric signal is a measure of whether or not there is a defect, but when the speed of the sensor head changes, the time width of the electric signal also changes. By correcting the reference time width to the time width in the detected speed state, the influence of the speed change of the sensor head is excluded from the reference time width to be compared with the detection time width. The determination means determines the presence or absence of a defect based on the comparison between the corrected reference time width and the detected time width.

According to the second aspect of the invention, the correction means corrects the time width of the time width determination signal to the time width in the reference speed state based on the comparison between the detection speed of the sensor head and the reference speed. The determining means determines the presence / absence of a defect based on the corrected detection time width and the reference time width.

According to the third aspect of the invention, the difference between at least one electric signal of the plurality of photoelectric sensors arranged in the warp direction and the electric signal of the other photoelectric sensor is calculated by the difference calculating means. The value of the difference signal calculated by the difference calculation means is compared with the reference value by the comparison means. The comparison means outputs a time width determination signal corresponding to the difference signal exceeding the reference value. The correction means corrects the reference time width based on the detection speed of the sensor head. The determining means compares the corrected reference time width with the detection time width to determine the presence or absence of a defect.

According to the invention of claim 4, the correcting means corrects the time width of the time width determination signal to the time width in the reference speed state. The judging means judges the presence / absence of a defect based on the comparison between the corrected detection time width and the reference time width.

The detection of the time width of the time width determination signal in claims 3 and 4 is for eliminating the influence of the warp detection which is not a defect by the photoelectric sensor.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying the present invention will now be described with reference to FIG.
This will be described with reference to FIG. As shown in FIG. 1, a rail 1 is arranged above the woven fabric W in the weaving width direction of the woven fabric W. A sensor head 2 is suspended and supported on the rail 1 via a guide body 3. The guide body 3 can move along the rail 1. An endless belt 4 is connected to the sensor head 2, and the endless belt 4 drives the drive pulley 5-1 of the motor 5.
And the guide pulley 6. The endless belt 4 reciprocates around by the reciprocating drive of the motor 5, and the sensor head 2 reciprocates along the rail 1.

A light projector 7, a light receiver 8 and optical systems 9 and 10 are housed in the sensor head 2. Floodlight 7
The light projected from illuminates the woven cloth W via the optical system 9, and the light reflected from the woven cloth W is received by the light receiver 8 via the optical system 10. The reciprocating range of the sensor head 2 is a range in which the projection light of the projector 7 scans the entire cloth width of the cloth W.

As shown in FIG. 2, the light receiver 8 is provided with a pair of light receiving elements 11 and 12, and the light receiving elements 11 and 12 are arranged in series in the warp T direction of the woven fabric W. Reference numeral 11-1 shown in FIGS. 3 and 4 represents a detection range on the woven fabric W by the light receiving element 11, and 12-1 represents a detection range on the woven fabric W by the light receiving element 12. The widths of the detection ranges 11-1 and 12-1 in the weft Y direction are set to about the pitch of the reed wing of the reed (not shown). The widths of the detection ranges 11-1 and 12-1 in the warp yarn T direction are several times larger than the width of the weft yarn Y direction. The area surrounded by the arrow Q _R pointing to the right in FIG. 4 is the detection range 11-1, 12-1 on the woven fabric W due to the movement of the sensor head 2 in the right direction.
Represents the sweep range of. Area surrounded by the arrow Q _L of left represents the sweep range of the detection area 11-1 and 12-1 on the fabric W by leftward movement of the sensor head 2.

A disc 13 is fixedly attached to a support shaft 6-1 of the guide pulley 6. A fine ridge 13-1 is formed on the circumferential surface of the disk 13.
Are arranged at equal pitches in the circumferential direction. A light projecting element 14 and a light receiving element 15 are installed near the peripheral surface of the disk 13. The light projected from the light projecting element 14 hits the peripheral surface of the disk 13 and is reflected, and if the disk 13 is rotating, the disk 13 is rotated.
The reflected light from is converted into a pulsed state and is captured by the light receiving element 15. The light receiving element 15 converts the received light into a current and outputs it to the current-voltage conversion circuit 16. The waveform D _{1 in} FIG. 5A represents the voltage signal converted by the current-voltage conversion circuit 16.

The current-voltage conversion circuit 16 has a voltage signal D₁To
It outputs to the binarization circuit 17. Binarization circuit 17 input
Voltage signal D₁Reference voltage D₀Pulse based on comparison with
Signal D₂Convert to. Straight line D in FIG. 5 (a)₀Is the reference voltage
Represents the waveform D of FIG. ₂By the binarization circuit 17
Represents a pulsed signal. Binarization circuit 17 is a pulse
Signal D₂Is output to the speed calculation circuit 18. Speed calculation circuit
A clock 19 is connected to 18. Speed calculation circuit
18 is a pulse signal D based on the measurement time of the clock 19.
₂Of the velocity V of the sensor head 2_YCalculate
It

The light receiving elements 11 and 12 in the sensor head 2 convert the received light into an electric current. This converted current signal becomes an electric signal according to the amount of received light. The light receiving elements 11 and 12 are connected to the detection control circuit C ₀ . The light receiving element 11 outputs the converted current signal to the current-voltage conversion circuit 21, and the light receiving element 12 outputs the converted current signal to the current-voltage conversion circuit 22. The current-voltage conversion circuit 21 converts the converted current signal into a voltage signal S ₁ and outputs it to the sum calculation circuit 23 and the difference calculation circuit 24. The current-voltage conversion circuit 22 converts the converted current signal into a voltage signal S ₂ and the sum calculation circuit 23 and the difference calculation circuit 24.
Output to. The sum calculation circuit 23 adds the voltage signals S ₁ and S ₂ , and the difference calculation circuit 24 subtracts the value of the voltage signal S ₂ from the value of the voltage signal S ₁ .

The sum calculation circuit 23 outputs the sum signal S ₁₂ obtained by the calculation to the comparison circuit 25. The comparison circuit 25 compares the input sum signal S ₁₂ with the reference value V ₃ preset by the reference value setting circuit 26. When the value of the sum signal S ₁₂ exceeds the reference value V ₃ , the comparison circuit 25 outputs the defect detection signal S _T to the output circuit 27. The value of the sum signal S ₁₂ is the reference value V
_In the case of ₃ or less, the comparison circuit 25 does not output the defect detection signal S _T to the output circuit 27. The output circuit 27 outputs a weaving stop signal, an abnormality display signal, etc. based on the input of the defect detection signal S _T. The difference calculation circuit 24 outputs the difference signal ΔS ₁₂ obtained by the calculation to the comparison circuit 28.

The waveform E _{1 in} FIG. 6A represents the voltage signal S ₁ output from the current-voltage conversion circuit 21, and FIG.
The waveform E ₆ of represents the voltage signal S ₂ output from the current-voltage conversion circuit 22. The waveform E _{3 in} FIG. 6C represents the difference signal ΔS ₁₂ obtained by subtracting the value of the waveform E ₂ from the value of the waveform E ₁ . The square waves E ₄ and E _{5 in} FIG. 6D represent the confirmation request signal C _Y output from the comparison circuit 28. 6 (a) to 6
The horizontal axis in (d) represents time. 6 (a) to 6
The vertical axis in (c) represents voltage.

Waveform E₁Protrusion E_1-1Is the light receiving element 11
Therefore, it indicates the detected abnormality of the weft. Waveform E₂of
Projection E_2-1Is the weft detected by the light receiving element 12.
Represents a related abnormality. Projection E_1-1, E_2-1The time difference is
The light receiving elements 11 and 12 which move in the direction of the yarn Y are set to the warp Y direction.
It is caused by arranging in parallel. Waveform E₃Protrusion E
_3-1Is the protrusion E_1-1And this protrusion E_1-1In the time domain of
Corresponding waveform E₂It is the difference from the substantially flat part. Waveform E
₃Protrusion E_3-2Is the protrusion E_2-1And this protrusion E_2-1
Waveform E corresponding to the time domain of₁Due to the difference with the flat part of
is there. Square wave E_FourTime width t₁Is the reference value V₁Collision beyond
Departure E_3-1Square wave E corresponding to the time width of_FiveTime width t₂
Is the reference value V₂Projection E below_3-2It corresponds to the time width of
It

The waveform E _{6 in} FIG. 6E represents an example of the voltage signal S ₁ output from the current-voltage conversion circuit 21. Figure 6
The waveform E _{7 in} (f) represents an example of the voltage signal S ₂ output from the current-voltage conversion circuit 22. Waveform E ₈ of FIG. 6 (g)
Is a sum signal S ₆₇ obtained by adding the waveform E ₆ and the waveform E _7.
Represents

When the weft Y has an abnormality such as a loop state or a break in the middle, the amount of light received by the light receiving elements 11 and 12 is different between the abnormal portion of the weft on the woven fabric W and the normal portion, and the waveforms E ₆ and E ₇ protruding portion E _6-1 of the voltage signal S ₃ as shown in E _7-1, variations in S ₄ can be obtained. Square wave E ₄ ,
The signal represented by E ₅ is generated by the light receiving elements 11, 1
The determination is made based on the result of comparison between the difference signal ΔS _{12 of the} voltage signals S ₁ and S ₂ obtained from ₂ and the reference values V ₁ and V ₂ . The voltage signals S ₁ and S ₂ contain changes due to disturbance. However, a difference signal Δ obtained by taking the difference between the voltage signals S ₁ and S ₂
At S ₁₂ , the change due to the disturbance that has entered each voltage signal is almost canceled. Further, since the light receiving elements 11 and 12 are arranged in series in the warp direction, the change of the electric signal due to the reflected light from the warp is canceled. Therefore, the difference signal ΔS ₁₂
Highly accurately reflects the presence or absence of an abnormality regarding the weft Y,
The comparison between the difference signal ΔS ₁₂ and the reference values V ₁ and V ₂ enhances the accuracy of the detection of the presence or absence of abnormality regarding the weft.

Difference signal ΔS₁₂Value of range [V₁, V₂] Or
When it is out of the range, the comparison circuit 28 causes the counter 31 to generate a square wave.
E_Four, E_FiveConfirmation request signal C in the form of_YIs output. Difference signal
ΔS ₁₂Value of range [V₁, V₂] In case of
The circuit 28 sends the confirmation request signal C to the counter 31._YDo not output
Yes. The counter 31 includes a latch circuit 32 and a clock 19.
Is signal connected. The latch circuit 32 includes a correction circuit 2
0 is connected. The correction circuit 20 includes a speed calculation circuit 1
8 are connected. The correction circuit 20 is the speed calculation circuit 1
V obtained by 8_YBased on the reference time width t₀
Is corrected. This correction is based on the calculation of the following equation (1).
Done. t (V_Y) = V₀・ T₀/ V_Y (1) However, V₀Is the reference speed of the sensor head 2. Sensor
Head 2 detection speed V _YIs the reference speed V₀Bigger than
For example, the corrected time width t (V_Y) Is the reference time width t₀Than
Is also smaller. Detection speed V of the sensor head 2_YIs the reference speed
Degree V₀Smaller than the corrected time width t (V_Y)
Is the reference time width t₀Will be larger than. The correction circuit 20 detects
Start speed V_YThe time width is corrected based on
Time duration t (V_Y) Is stored in the latch circuit 32. this
The correction is performed sequentially, and the previous correction time width becomes the next correction time width.
It will be replaced.

The counter 31 measures the time of the clock 19.
Square wave E based on_Four, E_FiveTime width t₁, T₂Measure
I do. And the counter 31 has a square wave E_Four, E_Fivetime of
Width t ₁, T₂And the correction time width t (V_YBased on comparison with
Defect detection signal S_YWhether to output to the output circuit 27
judge.

The reference time width t ₀ is determined as follows. The time width t _Y for detecting a defect regarding the weft and the width t _T for detecting a defect regarding the warp are expressed by the following equations (2) and (3). t _Y = (L _T + D _Y ) / V _T (2) t _T = (L _Y + D _T ) / V ₀ (3) However, L _T is the detection range 11-1, 12-2 Represents the width in the yarn direction of the warp yarn T, and L _Y represents the width in the yarn direction of the weft yarns Y in the detection ranges 11-1 and 12-2. D _Y represents the width of the defect regarding the weft, and D _T represents the width of the defect regarding the warp. V _T is woven fabric W
Represents the relative movement speed of the warp yarns T in the detection directions 11-1 and 12-1 in the yarn direction, and V ₀ is the detection range 11 for the woven cloth W
-1, 12-1 represents the relative moving speed of the weft Y in the yarn direction, that is, the reference speed of the head sensor 2. The relative moving speed V _T is the moving speed of the woven cloth W.

Although a so-called warp is a defect relating to the warp yarn, a minute gap which is not a defect may intermittently occur on the woven fabric. Such a gap (hereinafter referred to as a false defect) is likely to occur when the warp density is high. The width of the weft Y in the yarn direction relating to the false defect is about one pitch of the warp T even at the largest, and is smaller than the width L _Y set to about the interval between the reeds. Therefore, if the width D _T in equation (3) is a false defect, the following equation (4) can be obtained by replacing the width D _T in equation (3) with L _Y. t _T <2L _Y / V ₀ (4) Further, the following formula (5) is obtained by setting the width D _Y in the formula (2) to zero.

T_Y> L_T/ V_T (5) The following expression (6) is obtained from the expressions (4) and (5). 2L_Y/ V_X≤L_T/ V_T(6) The following equation (7) is obtained by modifying the equation (6). V₀≧ (2L_Y/ L_T) ・ V_T(7) Therefore, the moving speed V that satisfies the condition of the expression (7)₀At Sen
If the head 2 is moved, the following equation (8) is established. t_Y<T_T (8) Time width t in equation (8)_TIs about false defects
, Time width t_YIs a drawback with respect to wefts. Follow
And the moving speed V that satisfies the condition of Expression (7)₀To the sensor
By moving the pad 2, it is possible to distinguish between the weft defect and the false defect.
You can For such discrimination, equations (6) and (7) are used.
L in_T/ V_TIs the reference time width t₀To decide.
Therefore, the speed of the sensor head 2 is the reference speed V₀Is
Mackerel, time width t_YIs the reference time width t₀If it is more than the time width
t_YSquare wave E_FourOr E _FiveThe actual weft defect
Represent Time width t₁, T₂Square wave E_Four, E_FiveIs time
It becomes a width confirmation signal.

If the sensor head 2 moves at a constant speed of the reference speed V ₀ , the presence or absence of a high-precision weft defect can be determined by comparing the detected time width t _Y with the reference time width t ₀ . However, it is quite difficult to move the sensor head 2 at a constant speed, and the moving speed V _{Y of the} sensor head 2 is large.
If the fluctuation occurs, it is impossible to highly accurately determine the presence or absence of the weft defect by comparing the time width t _Y with the reference time width t ₀ . Therefore, the reference time width t ₀ is corrected by the equation (1), and the corrected time width t (V _Y ) becomes the correct reference time at the detection speed V _Y. Therefore, the moving speed V _Y of the sensor head 2
Even if fluctuates, the comparison between the detected time width t _Y and the corrected time t (V _Y ) guarantees highly accurate determination of the presence or absence of a weft defect.

In the counter 31 which constitutes the false defect judging means together with the latch circuit 32 and the clock 19, the time width t ₁ of the square wave E ₄ or the time width t ₂ of the square wave E ₅ is the correction time t.
If (V _Y ) or more, the defect detection signal S _Y is output. By such a discrimination judgment, the false defect and the weft defect can be discriminated, and the accuracy of the detection of the presence or absence of abnormality regarding the weft can be improved.

Next, a second embodiment shown in FIG. 7 will be described. First
The same members as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, a reflection plate 33 is fixed to the side surface of the sensor head 2, and a projector 34 is arranged on an extension of the movement path of the reflection plate 33 that moves integrally with the sensor head 2. The light projector 34 projects light toward the reflection plate 33 along the movement path of the reflection plate 33 as indicated by an arrow R ₁ . The reflection plate 33 detects the projection light from the projector 34 as indicated by an arrow R ₂ and detects the detection surface 35-1 of the position detector 35.
Reflect toward. The path R ₂ of this reflected light and the detection surface 35
The intersection with -1 moves on the detection surface 35-1. Position detector 3
5 is a differentiation circuit 3 for calculating the position information of the intersection on the detection surface 35-1.
6 is output. The differentiating circuit 36 calculates the moving speed of the reflecting plate 33, that is, the moving speed V _Y of the sensor head 2 based on this position information, and stores this detected speed V _Y in the latch circuit 32. The detected speed V _Y stored in the latch circuit 32 is used to determine the presence or absence of a weft defect as in the first embodiment.

In this embodiment, since the moving speed V _Y of the sensor head 2 is directly detected, the expansion and contraction of the endless belt 4 or the slip between the drive pulley 5-1 and the endless belt 4 causes the detection speed of the sensor head 2. Does not affect.

Next, a third embodiment of FIG. 8 will be described. First
The same members as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the electric resistance wire 3 is provided on the rail 1.
7, 38 are arranged in parallel. An electric short-circuit body 39 is fixed to the guide body 3. The electric short-circuit body 39 makes sliding contact with both electric resistance wires 37 as the sensor head 2 moves. The resistance value detection circuit 40 detects the resistance value of the electric short circuit 39 and the electric conduction path formed of the electric resistance lines 37 and 38 on the right side of the electric short circuit 39 in FIG.
The resistance value detection circuit 40 outputs resistance value information to the differentiating circuit 41, and the differentiating circuit 41 calculates the change in the resistance value. A speed calculating circuit 42 is connected to the differentiating circuit 41. The speed calculation circuit 42 calculates the moving speed of the electrical short-circuit body 39, that is, the moving speed V _Y of the sensor head 2 based on the resistance change obtained from the differentiating circuit 41, and the detected speed V _Y is used as the latch circuit 3.
2 is stored. Detection speed V stored in the latch circuit 32
_Y is used to determine the presence / absence of a weft defect as in the first embodiment.

Also in this embodiment, the expansion and contraction of the endless belt 4 or the slip between the drive pulley 5-1 and the endless belt 4 does not affect the detection speed of the sensor head 2. Moreover, the resolution of the change in the electric resistance value is high, and the detection accuracy of the moving speed of the sensor head 2 based on the change in the electric resistance value is high.

Next, a fourth embodiment of FIG. 9 will be described. Second
The same members as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The sensor head 43 in this embodiment includes a pair of reflecting mirrors 43-1 and 43-2 and a half mirror 44. A light projector 45 is arranged on one side of the reciprocating region of the sensor head 43, and a light receiver 48 is arranged on the other side. A light projecting element 45-1, a slit plate 46 and a convex lens 47 are housed in the light projector 45, and a slit 46-1 is formed in the slit plate 46. The light projecting element 45-1 is on the focal point of the convex lens 47, and the convex lens 47 collimates the light projected from the light projecting element 45-1. The slit 46-1 extracts the parallel light emitted from the convex lens 47. The width of the slit 46-1 is about the same as the width of the detection ranges 11-1 and 12-1 of the light receiving elements 11 and 12 of the first embodiment in the warp yarn arranging direction.

A condenser lens 49 and a light receiving element 48-1 are housed in the light receiver 48. The light receiving element 48-1 is on the focal point of the condenser lens 49. The light receiving element 48-1 has the same structure as the light receiving elements 11 and 12 of the first embodiment.

The chain line arrow in FIG. 9 indicates the path of the parallel light emitted from the convex lens 47. A part of the parallel light passes through the half mirror 44 and hits the reflecting mirror 43-1 and the rest of the parallel light is detected by the position detector 35.
Reflect toward. The reflecting mirror 43-1 reflects the parallel light toward the woven cloth W, and a part of the reflected light from the woven cloth W is reflected by the reflecting mirror 43-1.
-Go to 2. The reflecting mirror 43-2 reflects the reflected light from the woven cloth W toward the condenser lens 49. The condenser lens 49 condenses the reflected light from the reflecting mirror 43-2 on the light receiving element 48-1.

The detection control circuit C ₀ makes the same detection determination as in the second embodiment based on the detection signals from the light receiving element 48-1 and the position detector 35. In this embodiment, the same effect as in the second embodiment can be obtained, and a single projector can be used as both the projector for projecting light onto the woven cloth W and the projector for detecting the moving speed of the sensor head 43. it can.

In each of the above embodiments, the reference time width in the reference speed state is corrected according to the detected speed.
The detected time width determination signal time width may be corrected in accordance with the detection speed. The correction in this case is expressed by the following equation (9). t _k (V _Y ) = V _Y · t _K / V ₀ (9) where t _k is t ₁ or t ₂ in FIG. The corrected time width t _k (V _Y ) is compared with the reference time width t ₀ .

Further, the present invention is disclosed in JP-A-3-249243.
The present invention can be applied to other inspection devices that detect the presence or absence of a defect based on the comparison between the time width of the detection signal and the reference time width, such as the device disclosed in the publication.

Inventions other than those described in the claims that can be understood from the above-described embodiments will be described below along with their effects. (1) The speed detecting means in the inventions of claims 1 to 4 comprises a means for detecting the displacement of the path of the reflected light of the light applied to the sensor head, and a means for calculating the speed from the detected displacement. Cloth inspection device.

High detection accuracy can be obtained by directly detecting the moving speed of the sensor head. (2) The speed detecting means in the inventions of claims 1 to 4 includes a pair of electric resistance wires arranged in parallel in the movement path of the sensor head, and the electric resistance wire which moves integrally with the sensor head and is connected to both electric resistance wires. A woven fabric inspection device comprising: an electric short-circuit body that is in sliding contact with the electric resistance path and a unit that detects the resistance value of an electric conduction path that is composed of the electric resistance line and the electric short-circuit body;

The detection accuracy of the moving speed of the sensor head based on the change of the electric resistance value is high, and high detection accuracy can be obtained.

[0045]

As described above in detail, in the present invention, either the detection time width or the reference time width is corrected in accordance with the detection speed of the sensor head, and after correction, the detection time width and the reference time width are compared. Since the presence / absence of a defect is determined by the above method, high inspection accuracy can be obtained even if the moving speed of the sensor head changes.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a combination diagram of an inspection control circuit and a sensor head.

FIG. 3 is a combination diagram of a detection range on a woven fabric and a control circuit.

FIG. 4 is a plan view showing a scanning area of a detection range.

5A and 5B are graphs illustrating signal processing for speed detection.

6A to 6G are graphs illustrating signal processing in a control circuit.

FIG. 7 is a combination diagram of a main part and a control circuit showing a second embodiment.

FIG. 8 is a combination diagram of a main part and a control circuit showing a third embodiment.

FIG. 9 is a front sectional view showing a fourth embodiment.

[Explanation of symbols]

2, 43 ... Sensor head, 11, 12, 48-1 ... Light receiving element serving as photoelectric sensor, 13 ... Disk constituting speed detecting means, 14 ... Light projecting element constituting speed detecting means, 15 ... Speed detecting means , A light receiving element constituting the ... 18, a speed calculation circuit,
19 ... Clocks constituting speed detecting means and judging means,
20 ... Correction circuit, 24 ... Difference calculation circuit, 28 ... Comparison circuit,
31 ... Counter constituting the judging means, 32 ... Latch circuit constituting the judging means.

Claims (4)

[Claims] 1. A woven fabric inspection device that uses the time width of an electric signal obtained from a photoelectric sensor that outputs an electric signal according to the amount of received light to detect a defect of the woven fabric, and emits light that reflects the woven state of the woven fabric. A sensor head that travels in the width direction of the woven fabric while picking it up, a speed detection unit that detects the traveling speed of the sensor head, and the value of the electric signal obtained from the photoelectric sensor are compared with a reference value and exceed the reference value. Comparing means for outputting a time width confirmation signal corresponding to the electric signal, and correction means for correcting the reference time width to the time width in the detected speed state based on the comparison between the detected speed detected by the speed detecting means and the reference speed. And a determination unit that determines the presence or absence of a defect based on a comparison between the corrected time width and the time width of the time width determination signal. 2. A woven fabric inspection device that uses the time width of an electric signal obtained from a photoelectric sensor that outputs an electric signal according to the amount of received light to detect a defect of the woven fabric. A sensor head that travels in the width direction of the woven fabric while picking it up, a speed detection unit that detects the traveling speed of the sensor head, and the value of the electric signal obtained from the photoelectric sensor are compared with a reference value and exceed the reference value. Comparing means for outputting a time width confirmation signal corresponding to the electric signal, and comparing the detected speed detected by the speed detecting means with a reference speed, the time width of the time width confirmation signal is the time width in the reference speed state. 2. A woven fabric inspection device comprising: a correction unit that corrects the correction time and a determination unit that determines the presence or absence of a defect based on a comparison between the corrected time width and a reference time width. 3. A woven fabric inspection device which uses the time width of an electric signal obtained from a photoelectric sensor which outputs an electric signal according to the amount of received light to detect a defect of the woven fabric. A sensor head that travels in the width direction of the woven fabric while picking it up, a speed detection unit that detects the traveling speed of the sensor head, and a plurality of separately receiving lights that are picked up from multiple regions on the woven fabric that are arranged in the warp yarn direction. And a difference calculation means for calculating a difference between at least one electric signal of the plurality of photoelectric sensors and an electric signal of another photoelectric sensor, and a value of the difference signal obtained by the calculation of the difference calculation means. A comparison means for comparing with a reference value and outputting a time width confirmation signal corresponding to a difference signal exceeding the reference value, and a reference time width based on a comparison between the detected speed detected by the speed detection means and the reference speed. And correcting means for correcting the time width in the detection speed state, the corrected woven fabric inspection device provided with a determination unit configured to defect whether based on a comparison of the time width of the time width and time width determination signal. 4. A woven fabric inspection device, which uses a time width of an electric signal obtained from a photoelectric sensor that outputs an electric signal according to a received light amount to detect a defect of the woven fabric, wherein light reflecting a woven state of the woven fabric is detected. A sensor head that travels in the width direction of the woven fabric while picking it up, a speed detection unit that detects the traveling speed of the sensor head, and a plurality of separately receiving lights that are picked up from multiple regions on the woven fabric that are arranged in the warp yarn direction. And a difference calculation means for calculating a difference between at least one electric signal of the plurality of photoelectric sensors and an electric signal of another photoelectric sensor, and a value of the difference signal obtained by the calculation of the difference calculation means. A comparison unit that compares a reference value and outputs a time width determination signal corresponding to a difference signal that exceeds the reference value, and the time width based on a comparison between the detected speed detected by the speed detection unit and the reference speed. Woven cloth inspection provided with a correction means for correcting the time width of the constant signal to the time width in the reference speed state, and a judgment means for judging the presence / absence of a defect based on the comparison between the corrected time width and the reference time width. apparatus.