JP2010249700A - Surface state detection method and device of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of detecting relatively shallow unevenness and change in color of a surface of a specimen in a simple constitution, and a device of the same. <P>SOLUTION: A first laser 11A for radiating red light and a second laser 11B for radiating blue light having normal intensity distribution centering the optical axis in the tire circumferential direction are arranged separately by a predetermined distance in the tire circumferential direction. Red light and blue light are simultaneously radiated to the surface of a sidewall part 51 of an unvulcanized tire 50, and the overlapping part of the red light and blue light is photographed by a color line camera 12. The intensities I<SB>r</SB>and I<SB>b</SB>of reflected lights of the red light and blue light are calculated, respectively, then intensity ratio R=(I<SB>r</SB>/I<SB>b</SB>) is calculated. The height h from a reference position z<SB>0</SB>is calculated using the intensity ratio R, and the R-z table 34T showing the relationship between a predetermined intensity ratio and the height from the reference position z<SB>0</SB>, and the unevenness state of the surface of the sidewall part 51 is detected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method and apparatus for detecting surface conditions such as surface irregularities and color changes of tires and tire components.

Conventionally, there are a surface shape measurement method using a light cutting method and an image determination method using a color camera as a method for detecting irregularities on the surface of an object by image processing (see, for example, Patent Documents 1 to 3).
In the light cutting method, for example, while rotating the tire, the slit light is irradiated by a light projecting means for irradiating the tire surface with monochromatic light such as a semiconductor laser, and the slit light irradiation portion is imaged with an area camera. After obtaining the two-dimensional coordinates of the slit image, the two-dimensional coordinates are converted into three-dimensional coordinates using the rotation angle of the tire to obtain the outer shape of the tire. Then, by comparing this outer shape with the determination target image stored in advance, it becomes possible to inspect the shape of the tire such as the beat portion, the tread portion, and the sidewall portion.

On the other hand, the image determination method using a color camera irradiates the subject surface with white slit light and images the reflected image using a line camera. It detects the color change. The line camera does not have to be a color camera, and it takes a grayscale image of the subject using slit light as monochromatic light, and detects the uneven state and color change of the subject surface from the density of the taken image. Is also possible.
In addition, an appearance shape inspection apparatus that simultaneously inspects the appearance and shape of a subject using an imaging mechanism in which a color line camera and a line projector and an area camera and an area projector are integrated in one frame is also proposed. (For example, see Patent Document 4).

Japanese Patent Laid-Open No. 11-138654 Japanese Patent Laid-Open No. 2003-240521 JP 2003-139714 A Japanese Patent Laid-Open No. 2001-249012

However, the conventional optical cutting method cannot be said to have sufficient detection accuracy for relatively shallow irregularities having a depth of about 0.5 mm or less. In particular, on the surface of a thin rubber with a remarkable change in shape, there is a problem that it is easy to erroneously detect because there are similar irregularities.
In addition, the optical cutting method processes the slit image photographed with the area camera to obtain the three-dimensional coordinates of the tire surface, and then detects the unevenness of the tire surface, so the data becomes enormous. However, since an ultra-high-speed camera (area camera) and an image processing apparatus are essential, there is a drawback that the system is expensive.

On the other hand, in the method for determining unevenness using a color image, it is possible to detect the unevenness state and color change of the subject surface, but it is difficult to detect even the three-dimensional shape of the unevenness.
In addition, in the method using a device equipped with a color line camera and an area camera, it is difficult not only to optically match the line portion photographed by the line camera and the line portion photographed by the area camera, but also the light cutting method. Similarly to the above, the detection accuracy of relatively shallow unevenness is not sufficient, and the system is expensive.

  The present invention has been made in view of the conventional problems, and an object of the present invention is to provide a method and apparatus for detecting relatively shallow unevenness and color change on the surface of a subject with a simple configuration.

The invention according to claim 1 is a method for detecting the surface state of a subject, wherein the subject surface is irradiated with light having different wavelengths from two different directions, and the two different wavelengths of light are both The reflected light of the irradiated part is received, and the uneven state or color change of the subject surface is detected from the intensity of the two different wavelengths of the received reflected light.
That is, as shown in FIG. 3, when light R and B having different wavelengths are partially overlapped and irradiated on the subject surface from different directions, the convex portion (z = z _r0 ) is closer to the light receiving means. Since the intensity of the reflected light of the light R is large and the intensity of the reflected light of the light B on the side far from the light receiving means becomes large in the concave portion (z = z _b0 ), the reflected light from the overlapping portion of the irradiation area is increased. By detecting and comparing the intensity for each wavelength, it is possible to detect the uneven state on the surface of the subject.
In addition, when the color of the subject surface changes from white to black or from black to white as on the side surface of the unvulcanized tire, the intensity for each wavelength is the same. The strength itself of the material changes. Therefore, it is possible to detect a change in the color of the subject surface from the intensity of the reflected light from the overlapping portion of the irradiation region.

  According to a second aspect of the present invention, the light projecting means for irradiating the subject with light, the light receiving means for receiving the reflected light from the surface of the subject, the light projecting means, the light receiving means, and the subject are relative to each other. A surface condition detecting device comprising: means for moving the light source; and unevenness detecting means for detecting unevenness on the surface of the subject based on information of the reflected light received by the light receiving means, wherein the light projecting means comprises: A first light source for irradiating light having an intensity distribution centered on the optical axis center in the relative movement direction of the light projecting and receiving means and the subject; and the optical axis center in the movement direction. The irradiation region on the moving direction side has an intensity distribution overlapping with a part of the irradiation region on the opposite side to the moving direction of the first light source, and has a wavelength different from that of the irradiation light of the first light source. A second light source for irradiating light, and the light receiving means comprises: The reflected light from the portion where the irradiation region of the first light source and the irradiation region of the second light source overlap is received, and the unevenness detecting means has a wavelength of the irradiation light of the first light source of the reflected light. The unevenness of the surface of the subject is detected based on the size of the component having a wavelength and the size of the component having the wavelength of the irradiation light of the second light source. Thereby, it is possible to detect relatively shallow unevenness on the surface of the subject with a simple configuration.

  Further, the invention according to claim 3 is the surface state detection device according to claim 2, wherein the color change of the surface of the subject is detected from the intensity change and the means for detecting the intensity change of the reflected light. And means for detecting. Thereby, it is possible to detect not only the uneven state of the subject surface but also the color change.

  According to a fourth aspect of the present invention, in the surface state detection apparatus according to the second or third aspect, the first and second light sources have a predetermined width in the direction perpendicular to the moving direction. It is a surface irradiation light laser having a constant distribution, and the light receiving means is a line camera having a plurality of light receiving elements arranged in a direction orthogonal to the moving direction. . Thereby, it is possible to efficiently and reliably detect the uneven state and the color change of the subject surface.

  The summary of the invention does not enumerate all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

It is a figure showing the outline of the tire inspection device concerning an embodiment of the invention. It is a figure which shows the outline | summary of a sensor part and a rotation mechanism part. It is a figure which shows arrangement | positioning of the 1st and 2nd laser and a color line camera. It is a figure which shows an example of the image for determination. It is a figure which shows the determination method of a boundary position. It is a flowchart which shows the method of test | inspecting the surface state of the side wall part of an unvulcanized tire. It is a figure for demonstrating the determination method of the surface state of a side wall part. It is a figure which shows the other example of arrangement | positioning of the 1st and 2nd laser and a color line camera.

  Hereinafter, the present invention will be described in detail through embodiments. However, the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

FIG. 1 is a diagram showing an overview of a tire inspection apparatus 1 according to the present embodiment, and FIG. 2 is a diagram showing an overview of a sensor unit 10 and a rotation mechanism unit 20.
The tire inspection apparatus 1 includes a sensor unit 10, a rotation mechanism unit 20, and an inspection unit 30.
The sensor unit 10 includes first and second lasers 11 </ b> A and 11 </ b> B as light projecting means for irradiating light on the surface of the sidewall portion 51 of the unvulcanized tire 50 that is the subject, and the surface of the sidewall portion 51. And a color line camera 12 as a light receiving means for receiving the reflected light.
In the unvulcanized tire 50 to be inspected in this example, the sidewall portion 51 is positioned on the bead portion 53 side and the white raw rubber portion 51a formed by winding the white rubber strip material positioned on the tread 52 side. The tire includes a black raw rubber portion 51b formed by winding a black rubber strip material. The tire inspection apparatus 1 determines the unevenness of the surface of the white raw rubber part 51a and the black raw rubber part 51b of the unvulcanized tire 50 and the boundary position between the white raw rubber part 51a and the black raw rubber part 51b (such as a protruding state or a step shift). inspect.
Hereinafter, the region where the white belt-like rubber is laminated is referred to as a white raw rubber portion 51a, and the region where the black belt-like rubber is laminated is referred to as a black raw rubber portion 51b.

The first laser 11A emits laser light (red light) having a center wavelength of about 680 nm, and the second laser 11B sends laser light (blue light) having a center wavelength of about 450 nm to the sidewalls of the unvulcanized tire 50. Irradiate the surface of each part 51.
In this example, as shown in FIG. 3, the first and second lasers 11 </ b> A and 11 </ b> B have an optical axis in the tire circumferential direction (x-axis direction) that is the relative movement direction of the sensor unit 10 and the tire 50. 10 mm spot luminance uniform surface irradiation light having a normal distribution intensity distribution centering on the tire and a substantially flat distribution intensity distribution in the tire radial direction (y-axis direction) perpendicular to the moving direction A laser was used. In this example, a surface irradiation laser having a flat region size of about 100 mm was used. The z-axis direction is a direction parallel to the tire axial direction. Hereinafter, the z-axis direction is referred to as the vertical direction.
The first laser (red laser in FIG. 3) 11A and the second laser (blue laser in FIG. 3) 11B are arranged such that their optical axes are spaced apart from each other by a predetermined distance in the tire circumferential direction. It has a portion where regions overlap.
Further, the first laser 11A and the second laser 11B are installed with their respective focal points shifted in the depth direction. The irradiation angle of the first laser 11A to the surface of the sidewall portion 51 of the unvulcanized tire 50 is 75 °, and the irradiation angle of the second laser 11B to the surface of the sidewall portion 51 of the unvulcanized tire 50 is 65 °.

The color line camera 12 is a CCD color camera in which pixels are arranged in one row, and is installed above the center of the sidewall portion 51 of the unvulcanized tire 50 so that the direction of the pixel row is perpendicular to the tire circumferential direction. . In this example, the angle formed by the optical axis of the color line camera 12 and the surface of the sidewall portion 51 is 82.5 °.
As shown in FIG. 3, the color line camera 12 receives reflected light from a portion where the irradiation region of the first laser 11 </ b> A and the irradiation region of the second laser 11 </ b> B overlap (hereinafter referred to as a detection unit).
Specifically, the color line camera 12 detects the intensity of the irradiation light from the first laser 11A and the second laser 11B at the reference height position that is the initial position indicated by z = 0 in FIG. It is installed so as to receive reflected light from a place where the intensity of irradiation light is the same. That is, the color line camera 12, the tire in the circumferential direction, of the reflected light of the blue light which is light emitted and the intensity I _r of the reflected light of the red light is irradiated light of the first laser 11A the second laser 11B intensity ratio which is the ratio of the intensity _{I b R = (I r /} I b) is installed at a position of 1, the flat intensity distribution where the first and second laser 11A, 11B is irradiated in the tire radial direction The reflected light from the region having

  The rotation mechanism unit 20 includes a rotary table 21 on which an unvulcanized tire 50 that is a subject is mounted, a motor 22 that rotates the rotary table 21, motor control means 23 that drives and controls the motor 22, and a rotating tire 50. A rotation angle sensor 24 for measuring the rotation angle of the unvulcanized tire 50 measured by the rotation angle sensor 24 and rotating the unvulcanized tire 50 at a constant speed with respect to the sensor unit 10. Is output to the inspection unit 30.

The inspection unit 30 includes a received light intensity calculation unit 31, a surface unevenness state detection unit 32, a rubber color detection unit 33, a storage unit 34, a determination image creation unit 35, and a determination unit 36.
The received light intensity calculating means 31 uses the information of the reflected light in which red light and blue light are mixed and input to the CCD element of the color line camera 12, and the intensity I _r of the reflected light of the red light and the intensity I of the reflected light of the blue light. _b is calculated.
The storage means 34 measures the rotation angle θ of the unvulcanized tire 50 measured by the rotation angle sensor 24 and the intensity data [I _r (θ), I of the reflected light received by the color line camera 12 when the rotation angle is θ. _b (θ)] and the Rz table 34T indicating the relationship between the intensity ratio R and the degree of unevenness obtained in advance are stored.

The surface unevenness detecting means 32 calculates the intensity ratio at the rotation angle θ from the intensity I _r (θ) of the reflected light of red light calculated by the light intensity calculation means 31 and the intensity I _b (θ) of the reflected light of blue light. R (θ) = (I _r (θ) / I _b (θ)) is calculated, and the calculated intensity ratio R (θ) and the Rz table 34T stored in the storage unit 34 are used. Thus, the height h (θ) from the reference plane z = 0 on the surface of the sidewall portion 51 is calculated. And the uneven | corrugated state of the side wall part 51 surface is detected from the change of the tire circumferential direction of the said height h ((theta)).
The range in which the height h (θ) can be measured is measured by z = z _r0 where the distribution center of the first laser 11A is a measurement point and the distribution center of the second laser 11B shown in the region Z of FIG. This is a range corresponding to a region where the distribution curve of the first laser 11A decreases approximately linearly and the distribution curve of the second laser 11B increases approximately linearly between the point z = z _b0. .
The data of the reflected light intensity I _r (θ), I _b (θ), the intensity ratio R (θ), and the height h (θ) are the tires of the first and second lasers 11A and 11B. It is obtained over the entire area of a flat region (approximately 100 mm width) of radial distribution. In other words, the strength ratio R (θ) and the height h (θ) are the strength ratio R (θ, r) and height h (θ, r) where r is the distance from the tire center in the flat region. ).

The rubber color detection means 33 is an average value I (θ, r) of the intensity I _r (θ, r) of the reflected light of the first laser 11A and the intensity I _b (θ, r) of the reflected light of the second laser 11B. r) is calculated, and this I (θ, r) is compared with a preset reference intensity I ₀ to detect the intensity change of the reflected light, and the detection unit is white rubber or black rubber. To detect.
As shown in FIG. 3, the intensity distribution of the irradiation light of the first laser 11A and the intensity distribution of the irradiation light of the second laser 11B are approximately centered on the reference plane z = 0 of the surface of the sidewall 51. Since it increases or decreases linearly, the average value I (θ, r) of the intensity I _r (θ, r) of the reflected light of the first laser 11A and the intensity I _b (θ, r) of the reflected light of the second laser 11B. r) is large in the white raw rubber portion 51a and small in the black raw rubber portion 51b.
Therefore, the reference intensity I _0, the case of using the intensity of the reflected light from the white raw rubber portion 51a at the reference position z = 0, is I (θ, r) is a predetermined amount smaller threshold K or higher than the reference intensity I ₀ In this case, it is determined that the reflected light is reflected light from the white raw rubber portion 51a. On the other hand, when I (θ, r) is less than the threshold value K, it is determined that the reflected light is reflected light from the black raw rubber portion 51b. This makes it possible to determine whether the detection unit is the white raw rubber part 51a or the black raw rubber part 51b.

The determination image creating means 35 includes data on the size of the unevenness on the surface of the sidewall 51 detected by the surface unevenness detecting means 32 and the rubber type (white rubber or black rubber of the detection part detected by the rubber color detecting means 33. ) Is used to create a determination image.
FIG. 4 is a schematic diagram of the determination image G, in which the horizontal axis represents r, the vertical axis represents θ, and the contour lines represent the size of surface irregularities. In the figure, the white portion is the white raw rubber portion 51a, and the shaded portion is the black raw rubber portion 51b. Contour lines drawn with solid lines indicate convex portions, and contour lines drawn with broken lines indicate concave portions. By using such a determination image G, it is possible to easily detect an uneven state on the surface of the sidewall portion 51, a position shift (step shift) of the joint between white rubber and black rubber, protrusion of rubber, or rubber breakage. be able to.
The determination image may be a three-dimensional image in which the x-axis is θ, the y-axis is r, and the z-axis is the size of the surface unevenness. Also in this case, if the white portion is the white raw rubber portion 51a and the shaded portion is the black raw rubber portion 51b, the uneven state of the surface of the sidewall portion 51 and the boundary between the white rubber and the black rubber can be detected simultaneously.
Note that the schematic diagram of the determination image G shown in FIG. 4 is a collection of unevenness, step shift, rubber tear, and the like. In practice, an image without unevenness, step shift, rubber tear, etc. The majority.

The determining unit 36 compares the size (height or depth) of the unevenness on the determination image G created by the determination image creating unit 35 with a preset threshold value H, and determines the size of the unevenness. It is determined whether or not there are abnormal irregularities exceeding the threshold value H, and whether the boundary position between the white raw rubber part 51a and the black raw rubber part 51b detected by the rubber color detection means 33 is deviated from a predetermined boundary position. If there is an abnormality such as abnormal unevenness, protrusion of rubber, or rubber breakage, it is determined that the inspected unvulcanized tire is defective.
As a method for determining the boundary position, for example, as shown in FIG. 5, a reference image with a white raw rubber portion 51 a and a black raw rubber portion 51 b of a good tire having a horizontal axis as a radial position and a vertical axis as a circumferential position. If S is created and stored in the storage means 34 in advance, and the reference image S and the judgment image G created by the judgment image creation means 35 are compared, such as rubber protrusion or rubber tearing. Abnormalities can be easily detected and determined. In the case of this example, a simple image with black rubber on the right (radially inner side) and white rubber on the left (radially outer side) with the boundary position r = r ₀ as a boundary.

Next, a method for inspecting the surface state of the sidewall portion 51 of the unvulcanized tire 50 using the tire inspection apparatus 1 of this example will be described with reference to the flowchart of FIG.
First, the unvulcanized tire 50 that is the subject is mounted on the turntable 21 so that the side wall 51 that is the detection surface is on the upper side, and the side wall 51 of the unvulcanized tire 50 is mounted. The first and second lasers 11A and 11B and the color line camera 12 are set immediately above (step S11).
Then, the motor 22 is driven / controlled to rotate the rotary table 21 to rotate the unvulcanized tire 50 at a predetermined rotational speed (step S12).
Then, the color line camera 12 images the detection unit while irradiating the surface of the sidewall 51 with red light and blue light from the first and second lasers 11A and 11B, respectively (step S13).

Next, the information of the reflected light received by the color line camera 12, the blue light is light emitted and the intensity I _r of the reflected light of the red light is irradiated light of the first laser 11A the second laser 11B The intensity I _{b of the} reflected light is calculated (step S14), and the position (from the intensity I _r (θ, r) of the reflected light of red light and the intensity I _b (θ, r) of the reflected light of blue light is determined. The intensity ratio R (θ, r) = I _r (θ, r) / I _b (θ, r) at θ, r) is calculated (step S15). Here, θ is the rotation angle, and r is the position of the detection portion in the tire radial direction.
Then, using the calculated intensity ratio R (θ, r), the previously calculated intensity ratio and the Rz table 34T representing the relationship from the reference position z ₀ , the reference position of the detection point is used. After calculating the height h (θ, r) from z ₀ (step S16), the intensity I _b (θ, r) of the reflected light of the first laser 11A and the intensity I of the reflected light of the second laser 11B are calculated. _b The average value I (θ, r) with (θ, r) is calculated, and the average value I (θ, r) is compared with the reference intensity I _0, and the detection unit is made of white rubber or black rubber. It is detected whether or not there is (step S17).
Steps S13 to S17 are repeated until the unvulcanized tire 50 makes one revolution, and h (θ, r) and rubber type data for one round of the tire are collected.

After the data is collected, the determination image G is created using the unevenness data h (θ, r) and the rubber type data (step S18). The unevenness on the determination image G and the reference image S Are compared to determine whether there are abnormalities such as abnormal irregularities, protrusion of rubber, and rubber breakage, and it is determined whether the inspected unvulcanized tire is a good product or a defective product (step S19).
FIG. 7 shows the reference image S and the determination image G superimposed on each other. A thick broken line in the figure is a boundary line between the white raw rubber portion 51a and the black raw rubber portion 51b of the reference image S. In addition, the boundary line between the white portion and the hatched portion in FIG. By comparing these two boundary lines, the misalignment of the seam between the white rubber and the black rubber indicated by the arrow A (step shift), the protrusion of the rubber indicated by the arrow B in FIG. Rubber breakage indicated by the arrow C can be easily detected.
Further, among the contour lines representing the size of the unevenness of the surface, the contour lines representing the height exceeding the threshold value H where the height is set, and the contour lines representing the depth deeper than the threshold value H where the depth is set, That is, if a contour line satisfying | h |> H is indicated by a thick contour line, it can be easily determined whether or not the irregularity exists in the sidewall portion 51. Specifically, the convex portion indicated by arrow P and the concave portion indicated by arrow Q in FIG. 7 are abnormal irregularities.
The above determination may be made by the measurer by determining an image obtained by superimposing the reference image S and the determination image G on the display, but the determination result and the image are programmed by programming the software of a computer. Are preferably displayed on the display.

As described above, according to the present embodiment, the two uniform intensity surface irradiation light lasers (red) having a normal intensity distribution centered on the optical axis in the tire circumferential direction and a flat intensity distribution in the tire radial direction. The first laser 11 </ b> A for irradiating light and the second laser 11 </ b> B for irradiating blue light are disposed with their optical axes separated from each other by a predetermined distance in the tire circumferential direction. simultaneously with irradiating the red light and blue light 51 surface, the overlapping portion and the red light and blue light captured by the color line camera 12, the intensity of the reflected light of the red light I _r and blue light reflected light After calculating the intensity I _b of each, the intensity ratio R = (I _r / I _b ) is calculated, and the relationship between the intensity ratio R, the previously determined intensity ratio, and the height from the reference position z ₀ is calculated. Using the Rz table 34T to represent the reference position z _Since the height h from ₀ is calculated and the uneven state on the surface of the sidewall 51 is detected, relatively shallow unevenness on the surface of the sidewall 51 can be detected with a simple configuration.

Also, the average value I of the intensity I _r of the reflected light of the red light and the intensity I _b of the reflected light of the blue light is calculated, and the average value I is compared with the reference intensity I ₀ so that the detection unit is made of white rubber. It is detected whether it is black rubber or not, and a determination image G is created using the unevenness data h and the rubber type data, and the determination image G and the reference image S are compared to determine whether there is an abnormality. Since it is determined whether or not there is an abnormality such as unevenness, protrusion of rubber, rubber breakage, etc., it is possible to reliably determine whether the unvulcanized tire 50 is defective.

  In the above-described embodiment, the tire inspection apparatus 1 that inspects the unevenness state and boundary position of the white and black belt-like rubber surfaces of the unvulcanized tire 50 has been described. However, as illustrated in FIG. If the surface unevenness detecting device 2 that detects the unevenness state of the subject surface is configured by the sensor unit 10, the rotation mechanism unit 20, the received light intensity calculating unit 31, the surface unevenness state detecting unit 32, and the storage unit 34, it is not added. It is possible to efficiently detect the uneven state of the surface of a sulfur tire or ply.

In the above example, the height from the reference position z ₀ is calculated using the intensity ratio R = (I _r / I _b ) between the intensity I _r of the reflected light of red light and the intensity I _b of the reflected light of blue light. Although h is calculated, the height h from the reference position z ₀ is calculated using the intensity difference D = I _r −I _b between the reflected light intensity I _r of red light and the reflected light intensity I _b of blue light. May be. In this case, it goes without saying that a table representing the relationship between the intensity difference D and the height from the reference position z ₀ is prepared instead of the Rz table 34T.
When the detection unit is white rubber or black rubber, the intensity ratio R at the reference point is 1, but generally the intensity ratio R changes when the color of the detection unit changes.
However, when the color change of the detection unit is known in advance, the intensity ratio R1 of the first color and the intensity ratio R2 of the second color are obtained in advance, and the intensity ratio R is detected by the surface irregularity state detection means 32. (Θ, r) is obtained, and the region where the intensity ratio R (θ, r) is R1 and the region where the intensity ratio R (θ, r) is R2 are obtained first, and the boundary line between regions of different colors is obtained. After that, the intensity ratio R1 ′ (θ, r) is calculated based on the intensity ratio R1 in the first color area, and the intensity ratio R2 based on the intensity ratio R2 in the second color area. It is only necessary to calculate '(θ, r) and detect the uneven state of the surface.
Since the ratio of the uneven portion data to the entire data is small, the boundary line between the different color areas is R (θ, r) in the intensity ratio R (θ, r) calculated by the surface uneven state detecting means 32. ) Is sufficiently detectable using data excluding data that is neither R1 nor R2.

In the above example, the first laser 11A is a red laser and the second laser 11B is a blue laser. However, the present invention is not limited to this, and the wavelengths of irradiation light may be different from each other. However, if the difference between the wavelengths of the two irradiation lights is small, wavelength separation becomes difficult and the intensity error after separation becomes large. Therefore, it is preferable to use a red laser and a blue laser as in this example.
Further, the intensity distribution of the first and second lasers 11A and 11B is not necessarily limited to the normal distribution, and similarly to the normal distribution, the monotonously decreasing portion where the red light and the blue light overlap is 1 It is sufficient if the intensity distribution is about ˜3 mm or more.

In the above example, the irradiation angle of the first laser 11A is 75 ° and the irradiation angle of the second laser 11B is 65 °. However, the irradiation angle of the first laser 11A is 90 °, The irradiation angle of the laser 11B can be 82.5 °. That is, if the irradiation angles of the first and second lasers 11A and 11B are set in the range of 65 ° to 90 °, the intensity ratio R of the reflected light can be sufficiently obtained.
On the other hand, the angle formed by the optical axis of the color line camera 12 and the surface of the sidewall portion 51 is preferably in the range of 65 ° to 85 ° in terms of light receiving sensitivity.

Moreover, in the said example, although the focus of the 1st laser 11A and the focus of the 2nd laser 11B were shifted and installed in the depth direction, as shown in FIG. 8, the same depth may be sufficient. However, in this case, since the upper limit of the size of the detected unevenness is smaller than in the case where the focal points are shifted in the depth direction, the focal point of the first laser 11A is different from the focal point of the first laser 11A. It is preferable to install the second laser 11B while shifting the depth of focus.
Moreover, in the said example, although the uneven | corrugated state and boundary position of the white and black belt-shaped rubber surface of the side wall part 51 of the unvulcanized tire 50 were inspected, it is not restricted to this, Rubber parts, such as tread rubber, and resin The present invention can also be applied to inspection of parts and products such as molded products that may have relatively shallow irregularities on the surface during the manufacturing process.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the embodiment. It is apparent from the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  According to the present invention, it is possible to detect not only a relatively shallow unevenness on the surface of the subject but also a color change with a simple configuration, so that the inspection accuracy of the surface state of the subject can be improved. it can.

1 tire inspection device, 2 surface irregularity detection device, 10 sensor unit,
11A 1st laser, 11B 2nd laser, 12 color line camera,
20 rotation mechanism, 21 rotation table, 22 motor, 23 motor control means,
24 rotation angle sensor, 30 inspection unit, 31 received light intensity calculation means,
32 surface unevenness detection means, 33 rubber color detection means, 34 storage means,
35 determination image creation means, 36 determination means,
50 unvulcanized tire, 51 sidewall portion, 51a white rubber portion,
51b Black raw rubber part, 52 tread, 53 bead part.

Claims (4)

  The surface of the subject is irradiated with light having different wavelengths from two different directions, the reflected light of the portion irradiated with the two different wavelengths of light is received, and the two different reflected lights are received. A surface state detection method comprising detecting an uneven state or a color change on the surface of the subject from the intensity of light of a wavelength. A light projecting means for irradiating the subject with light; a light receiving means for receiving reflected light from the surface of the subject; a means for relatively moving the light projecting means, the light receiving means and the subject; and the light receiving means. A surface state detection device comprising a concavo-convex detection means for detecting the concavo-convex state of the subject based on information of reflected light received at
The light projecting means is
A first light source that irradiates light having an intensity distribution centered on the center of the optical axis in a relative movement direction of the light projecting unit, the light receiving unit, and the subject;
The first light source has an intensity distribution in which a part of the irradiation area on the movement direction side is overlapped with a part of the irradiation area on the opposite side to the movement direction of the first light source. A second light source that emits light having a wavelength different from that of the light source of
The light receiving means receives reflected light from a portion of the subject surface where the irradiation region of the first light source and the irradiation region of the second light source overlap;
The unevenness detecting means is configured to detect the subject based on the magnitude of the component having the wavelength of the irradiation light of the first light source of the reflected light and the size of the component having the wavelength of the irradiation light of the second light source. A surface state detecting device for detecting the size of a surface irregularity.   3. The surface state detection apparatus according to claim 2, further comprising: means for detecting an intensity change of the reflected light; and means for detecting a color change of the surface of the subject from the intensity change.   The first and second light sources are surface irradiation light lasers having a distribution in which intensity in a direction orthogonal to the moving direction is constant at a predetermined width, and the light receiving means is the moving direction. The surface state detection device according to claim 2 or 3, wherein the surface state detection device is a line camera including a plurality of light receiving elements arranged in an orthogonal direction.

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