JP2000121567A - Device and method for inspecting surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for inspecting surfaces which can be applied to the inspections of the surfaces of products and is capable of quantifying the state of surfaces with high accuracy. SOLUTION: A surface to be measured 9 formed of a paint film or resin is vertically irradiated with light by a light irradiation means, and photometry is performed only on regularly reflected light by a photo-detecting means. By this, it is possible to quantify the state of a surface to be measured 9 with high accuracy, and furthermore, application not only to material tests but also to the inspections of the surfaces of products is possible. In addition, the measured quantity of light of a plurality of parts with satisfactory results of visual observation is averaged to be the reference value of the quantity of regularly reflected light, and the measured value of the surface to be measured, which is an object to be inspected, is compared with the reference value of the quantity of regularly reflected light to obtain difference in the quantity of light and the rate of change. By this, it is possible to obtain the state of the surface to be measured 9 as values corresponding to the results of visual observation with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface inspection apparatus and a surface inspection method for measuring the surface condition of a coating film or a resin.

[0002]

2. Description of the Related Art In the field of interior and exterior parts of automobiles, office automation, home appliances, etc., many products have surfaces made of coating films or resins, and their appearance, specifically, scratches, unevenness, uneven gloss, and the like. Demand levels for color unevenness and the like are becoming stricter year by year. In particular, in the case of a product made of a synthetic resin, in addition to the above-mentioned various properties, gloss, a weld line, a flow mark, a whitening flaw, etc. of the product surface are greatly involved in the commercial value. Conventionally, the surface condition of such products has been evaluated by visual ranking, but detailed information on the surface condition cannot be stored, which hinders quality control and material development. In order to solve such a problem, the surface state of the product is stored in a photograph or the like. However, objective data is not obtained because the contrast differs depending on photographing conditions, printing conditions, and the like. For this reason, there has been a long-felt need for a method and apparatus capable of accurately quantifying and quantifying the surface state of products and materials.

On the other hand, as a method of quantifying the surface state of a synthetic resin material, the present applicant has proposed a method of quantifying the degree of whitening due to the material (Japanese Patent Publication No. 7-52160). According to this method, a synthetic resin sample is scratched in a predetermined shape, and the scratched whitened portion is irradiated with light obliquely in a ring shape by dark field illumination, and the reflected light parallel to the optical axis of the objective lens. In this method, the light intensity of the component is measured to determine the degree of whitening due to scratching.

[0004]

Although this method is useful for material testing in material development and the like, it has a problem that it cannot be applied to surface inspection of products. In other words, the sample must be scratched in a predetermined shape for the measurement, and furthermore, the scratch is only digitized. Therefore, it is not suitable as a method for digitizing the surface state as it is. In addition, it was not possible to numerically express high-gloss portions and shining scratches formed by gathering relatively fine irregularities with high precision. In particular, when a pattern is provided on the measurement surface, there is a problem that a difference between the pattern and a flaw or the like is difficult to be detected as a difference in the amount of reflected light.

An object of the present invention is to provide a surface inspection apparatus and a surface inspection method which can be applied to the surface inspection of a product and can quantify the surface state with high accuracy.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a surface inspection apparatus for measuring the surface condition of a coating film or a resin, which irradiates a measuring surface made of the coating film or the resin with light perpendicularly from an emitting portion. A light irradiating means, and a light detecting means for receiving only a regular reflection light among the reflected lights of the light irradiated on the measurement surface by the light irradiating means at the light receiving unit and obtaining the light amount thereof, are provided.

[0007] In the present invention, the light vertically emitted from the emission part is reflected by the measurement surface, and only the specularly reflected light, that is, the light reflected perpendicularly to the measurement surface, is reflected out of the reflected light. The light enters the light receiving unit and is measured. In the present invention, since light is irradiated perpendicularly to the measurement surface by the light irradiation means,
Light is irregularly reflected according to the surface irregularities. For this reason, the amount of regular reflection light reflected in the same direction as the irradiation direction, that is, in the direction perpendicular to the measurement surface, changes according to the unevenness of the measurement surface. Since only the specularly reflected light is measured by the light detecting means, the measured light amount is obtained as a value corresponding to the surface state of the measurement surface. Therefore, the surface state can be quantified with high precision as it is, and it is not necessary to make a scratch as in the prior art, so that the present invention can be applied not only to material testing but also to surface inspection of products.

In this case, a cylindrical measuring head is provided in which a light emitting part and a light receiving part are inserted into a base end and a front end is brought into contact with a measuring surface, and the inner diameter of the front end of the measuring head is made variable. Is desirable. When such a measurement head is brought into contact with the measurement surface, irradiation and reflection of light are performed within the measurement head, so that the measurement area can be adjusted by changing the inner diameter of the measurement head, More accurate measurement can be realized. For example, when performing measurement on a corner-shaped measurement surface, the measurement area is made smaller than when the measurement surface is flat, and when the measurement surface is a curved surface, the measurement area is made larger. Therefore, it is possible to suppress a decrease in measurement accuracy due to the shape of the object to be measured. Also,
Just by bringing the measurement head into contact with the measurement surface, the relative position between the measurement surface, the emission unit, and the light reception unit can be determined.
Measurement can be facilitated.

In this case, the inner diameter of the tip of the measuring head is
It is desirable to be variable in the range of 2 mm to 50 mm, and more preferably, it is in the range of 7 mm to 15 mm. That is, when a pattern is provided on the measurement surface, particularly when the object to be measured is a resin molded product and the surface is embossed, if the inner diameter of the measurement head is less than 2 mm, reproducibility may be reduced. There is. When the inner diameter exceeds 50 mm, operability may be deteriorated.

[0010] Preferably, the tip of the measuring head is formed by selectively attaching replacement heads having different inner diameters. By doing so, the inner diameter of the measurement head can be changed simply by replacing the replacement head, so that the measurement area can be easily adjusted and the structure can be simplified.

In the above, it is desirable that the light emitting portion and the light receiving portion are constituted by optical fibers. That is, since the optical fiber has flexibility and can be formed in a long length, the light emitting portion and the light receiving portion can be moved to desired positions, so that the measurement can be easily performed regardless of the direction and the position of the measurement surface.

Preferably, the light detecting means is configured to detect only the light amount. That is, in order to measure not only lightness but also chromaticity, etc., in an existing color difference meter or the like, a plurality of filters are mounted on a rotating plate and measurement is performed while rotating the rotating plate. This requires a space for accommodating the device, and there is a limit to miniaturization of the device. In the present invention, since only the photometry of the specular reflection light is performed, only one photometric filter (Y filter) may be provided as a filter.
Other filters for measuring chromaticity, such as filters and Z filters, are not required. Therefore, since it is not necessary to provide a plurality of filters, the rotating plate can be omitted, and the space required for the filter and the rotating plate can be reduced, so that the device can be downsized.

On the other hand, the present invention relates to a surface inspection method for measuring the surface condition of a coating film or a resin, and irradiates a plurality of portions of the coating film or the resin surface with good visual results with light vertically. Specular reflection light quantity measurement is performed to obtain the light quantity of only the regular reflection light out of the reflected light of the irradiated light, and these regular reflection light quantity measurement values are averaged to obtain a regular reflection light quantity reference value. The specular reflection light amount is measured for a desired part in the above, the difference between the specular reflection light amount measurement value and the specular reflection light amount reference value is obtained, and the change rate obtained by dividing the difference by the specular reflection light amount reference value is obtained. Features.

In the present invention, since the light is irradiated perpendicularly to the measurement surface, the light is irregularly reflected according to the unevenness of the surface, and the amount of the specularly reflected light depends on the surface condition of the measurement surface. It will change. Therefore, by measuring only the specularly reflected light, the measured light amount can be obtained as a value corresponding to the surface state of the measurement surface, so that the surface state of the measurement surface can be quantified with high accuracy, and it is not necessary to make a scratch. Therefore, it can be applied to surface inspection of products.

Further, since the measured light amounts of a plurality of parts having good visual results are averaged to obtain a regular reflected light amount reference value, the regular reflected light amount reference value can be obtained as a highly reliable value in consideration of variation, and high accuracy. Measurement can be realized. Furthermore, since the measured value of the desired part is compared with the specular reflection light amount reference value, and the light amount difference and the change rate are obtained, the difference between the visual result and the good part can be quantified. It can be obtained as the corresponding value.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a surface inspection apparatus 1 of the present embodiment. Surface inspection device 1
Is a device for measuring the surface condition of the coating film or resin,
A light irradiating means 2 for irradiating light perpendicularly to a measurement surface made of a coating film or a resin; The apparatus includes a detecting unit 3, a display unit 4 for outputting a measurement result obtained by the light detecting unit 3, and a printer 5 (see FIG. 3). In FIG. 1, reference numeral 51 denotes a recording roll paper of the printer 5, and reference numeral 52 denotes a paper cover.

As shown in FIG. 2, the light irradiating means 2 includes a light source 21, a collimator lens 22 for converting the light from the light source 21 into parallel light, and a parallel light emitted from the collimator lens 22 for measuring the light. And an optical fiber cable 23 for projecting light. A semi-transmissive mirror 24 is disposed between the collimating lens 22 and the light projecting optical fiber cable 23, and transmits light from the light source 21 to be incident on the light projecting optical fiber cable 23.
A part of the light is reflected. A light compensating photometric element 25 is provided in the reflected light path of the semi-transmissive mirror 24, and the light quantity of the light source 21 can be monitored by constantly measuring the reflected light of the semi-transmissive mirror 24 with the photometric element 25. I have.

The light detecting means 3 receives an optical fiber cable 31 for extracting light reflected in a direction perpendicular to the measuring surface, and receives the light emitted from the optical fiber cable 31 and converts it into a photocurrent. Light receiving element 32
And a processing unit 33 for processing a current value or the like from the light receiving element 32. The light receiving element 32 passes the received light through a filter, and photoelectrically converts the energy of the transmitted light by a photoelectric element such as a photoelectric tube. In the light receiving element 32 of the present embodiment, since it is not necessary to separate light as in the existing color difference meter, only a Y filter is used as a filter, and the light receiving element 32 is configured to detect only the amount of light (brightness) of specularly reflected light. .

As shown in FIG. 3, the processing means 33 includes an operation panel 331 for performing operations such as measurement, numerical input, function setting, and output, a stick switch 332 for performing measurement operations, and a measurement area. A sensitivity changeover switch 333 for switching the sensitivity in response to the signal, and an A / D converter 33 for digitizing an electric signal (current) from the light receiving element 32.
4, arithmetic processing means 335 for calculating a digitized signal based on instructions from the operation panel 331, stick switch 332, and sensitivity switch 333, and storage means 336 for storing a setting program and data for each function. It has. The stick switch 332 is
This is for performing at hand a measurement start / end instruction among the input operations performed on the operation panel 331. As shown in FIG. 1, by pressing the key 332A at the tip once, the measurement is started and the key 332A is started. The measurement is terminated by pressing twice continuously. Note that the stick switch 332 may be omitted.

The arithmetic processing means 335 is configured to perform an arithmetic operation using a setting program or data of each function stored in the storage means 336, and outputs an arithmetic result to the display unit 4 or the printer 5. ing. Specifically, the arithmetic processing means 335 averages a plurality of light quantity measurement values (specular reflection light quantity) input from the A / D converter 334 to obtain a regular reflection light quantity reference value, and stores this reference value in the storage means 336. And the regular reflection light amount reference value stored in the storage unit 336 when the regular reflection light amount input from the A / D converter 334 when the measurement is performed on the measurement surface to be inspected. And a process of obtaining the difference and the rate of change and outputting the difference and the change rate to the display unit 4 and the printer 5.
The light measuring element 25 and the light source 21 described above are connected to the processing unit 33, and are configured to control the light amount of the light source 21 to be constant based on the light amount detected by the light measuring element 25.

Returning to FIG. 1 and FIG. 2, the optical fiber cables 23 and 3 of the light irradiating means 2 and the light detecting means 3 will be described.
Most of the components except 1 are incorporated in a box-shaped case 11. That is, two connection holes 11A and 11B are formed on one side surface of the case 11, and these connection holes 1A and 11B are formed.
One ends of the optical fiber cables 23 and 31 are inserted into 1A and 11B, respectively. Thereby, each end face of the optical fiber cables 23 and 31 is connected to each of the connection holes 11A and 11A.
B is exposed in the case 11. A light source 21 is disposed in the case 11, and a collimator lens 22 and a semi-transmissive mirror 24 are provided on an optical path connecting the light source 21 and an end face of the optical fiber cable 23 for light projection connected to the case 11.
Is disposed on the reflected light path of the semi-transmissive mirror 24.
Is arranged. Further, a light receiving element 32 is disposed on the optical path of light emitted from the end face of the light receiving optical fiber cable 31 on the side connected to the case 11, and a processing means 33 is provided adjacent to the light receiving element 32. . The operation panel 331 of the processing means 33 is assembled with the display unit 4 so as to be exposed on the side surface (front surface) of the case 11, and the sensitivity change switch 333 is provided on the upper surface of the case 11.

A substantially L-shaped arm 1 is provided on the side of the case 11 to which the optical fiber cables 23 and 31 are connected.
2 are installed. This arm 12 is used for the case 1
The device 1 is rotatably mounted in a plane along the side surface of the device 1 and can be used as a leg when the device 1 is placed by turning it under the case 11 and also as a handle when carrying the device 1. I can do it.

The optical fiber cable 23 for light projection and the optical fiber cable 31 for light reception connected to the case 11
Is a bundle of a plurality of light emitting optical fibers 61A and a plurality of light receiving optical fibers 61B, respectively. As shown in FIGS.
An end face on the other end side is an emission section 23A for light from the light source 21, and an end face on the other end side of the light receiving optical fiber 61B is a light receiving section 31A for receiving specularly reflected light. That is, the end of the light emitting optical fiber cable 23 on the side of the light emitting section 23A and the end of the light receiving optical fiber cable 31 on the side of the light receiving section 31A are bundled together by the binding member 62 (see FIG. 1) to form an optical fiber bundle. 63. The optical fiber bundle 63 is composed of optical fiber cables 23 and 31 for projecting and receiving light.
These optical fibers 61A, 61B are randomly bundled and covered with a tube-shaped covering portion 63A.

At the tip of the optical fiber bundle 63, the covering portion 63A is omitted and the exposed optical fiber 61 is omitted.
A cylindrical connection member 64 is fitted into A and 61B, and the distal ends of the optical fibers 61A and 61B protruding from the connection member 64 are covered with a protective layer 65. The distal end of such an optical fiber bundle 63 is inserted into the base end of a substantially cylindrical measuring head 70.

The measuring head 70 has a substantially cylindrical head main body 71, and substantially cylindrical exchange heads 72A and 72B mounted on the distal end of the head main body 71.
The measurement is performed by directly pressing the tip surfaces of the exchange heads 72A and 72B against the object to be measured. Hollow portions 711, 712, 713 penetrating in the axial direction are formed in the head main body 71, and the hollow portions 711, 712, 713 are closer to the exchange heads 72A, 72B (tip end side) in the axial direction.
The first hollow portion 711, the second hollow portion 712, and the third hollow portion 713 having different diameters are partitioned in this order. The replacement head 7 is provided on the peripheral surface of the first hollow portion 711.
2 is provided with a screw groove 71A for screwing.
An intermediate second hollow portion 712 includes first and third hollow portions 711,
713 is formed at a boundary portion between the second and third hollow portions 712 and 713.

The distal end of the optical fiber bundle 63 is inserted from the third hollow portion 713 into the hollow portions 711 to 713 of the head body 71 thus configured. That is, the connection member 64 is housed in the third hollow portion 713 and abuts on the stepped portion 73 of the head main body 71, and the optical fibers 61A and 61B protruding from the connection member 64 are connected to the second hollow portion 7.
12 and is inserted into the first hollow portion 711. The above-mentioned emitting part 23A and light receiving part 31A are constituted by end faces of the optical fibers 61A and 61B,
It is flush with the tip surface of the head body 71.

A plurality of types of exchange heads 72A and 72B having different inner diameters at the tips are prepared.
It is selectively attached to. In the present embodiment, two types of exchange heads 72A having an inner diameter of 10 mm and an exchange head 72B having an inner diameter of 4 mm are prepared, and are selectively used according to the measurement surface. These exchange heads 72A, 72
The length of each B in the axial direction is a length corresponding to its inner diameter. That is, the length of the exchange heads 72A and 72B in the axial direction is determined by the distance between the emission unit 23A and the light receiving unit 31A and the measurement surface 9 (see FIG. 6) abutting on the exchange heads 72A and 72B. The distance is set so that only the specularly reflected light reflected in a direction perpendicular to the direction can be picked up by the light receiving unit 31A. And the apparatus 1 of this embodiment is provided with the standard calibration cylinder 13 for calibration, and the zero calibration cylinder 14, as shown in FIG. These standard calibration cylinder 13 and zero calibration cylinder 1
The inner diameter of 4 is substantially the same as the outer diameter of the measuring head 70, so that the measuring head 70 can be inserted.

In this embodiment configured as described above, the surface inspection of the object to be measured is performed in the following procedure. Here, a case will be described in which a planar part having a poor visual result on the surface of one measured object is to be inspected. As the order of measurement, the specular reflection light amount reference value is set using the measurement result of the planar portion having a good visual result, and thereafter, the measurement of the poor planar portion having the visual result to be inspected is performed. The measured value is compared with a specular reflection light amount reference value.

More specifically, in this measurement, since the measurement surface is flat, the exchange head 7 having an inner diameter of 10 mm is used.
2A is mounted on the head main body 71 in advance, and the sensitivity switch 333 is switched to a sensitivity corresponding to the inner diameter of the replacement head 72A. Then, first, the calibration is performed after the power switch 337 of the apparatus 1 is turned on. That is, the standard calibration cylinder 13 and the zero calibration cylinder 14 are prepared, the measurement head 70 is inserted into the zero calibration cylinder 14 to perform zero calibration, and then the measurement head 70 is inserted into the standard calibration cylinder 13 to perform the standard calibration. Do.

Next, measurement is performed on each of a plurality of planar portions having good visual results to obtain a regular reflection light amount reference value. That is, the measuring head 70 is brought into contact with a planar portion having a good visual result on the surface of the object to be measured. At this time, FIG.
As shown in (5), the measuring head 70 is perpendicular to the measuring surface 9 and the tip of the replacement head 72A is brought into close contact with the measuring surface 9. Thereby, the emission unit 23A and the light receiving unit 3
1A and the measuring surface 9 face each other, and in the meantime, the exchange head 7
A measurement space surrounded by 2A is formed.

In this state, an instruction to start measurement is given by the operation panel 331 or the stick switch 332. Then, light is emitted from the light source 21 and the collimator lens 22
Is incident on the transflective mirror 24 as parallel rays. The light transmitted through the semi-transmissive mirror 24 is emitted perpendicularly to the measurement surface 9 from the emission part 23A through each light emission optical fiber 61A of the light emission optical fiber cable 23, and is reflected by the measurement surface 9. At this time, the light emitted from the emission unit 23A is irregularly reflected according to the surface state of the measurement surface 9, for example, irregularities. Then, of the light reflected on the measurement surface 9, only the regular reflection light, that is, only the reflection light perpendicular to the measurement surface 9 is incident on the light receiving unit 31 </ b> A, and each of the light receiving optical fibers 61.
B enters the light receiving element 32 in the case 11. The light receiving element 32 photoelectrically converts the energy of the received light and outputs it to the A / D converter 334 of the processing unit 33. The A / D converter 334 converts the energy into a digital signal and outputs the digital signal.
35. The arithmetic processing unit 335 outputs the input digital signal to the display unit 4 and the printer 5 as a measured value of the amount of specular reflection light, and causes the storage unit 336 to store the digital signal.

When light is emitted from the light source 21, a part of the light incident on the semi-transmissive mirror 24 is reflected and enters the light compensating photometric element 25. The photometric element 25 measures the incident light, and constantly outputs the measured light amount to the processing unit 33. The processing unit 33 controls the light amount of the light source 21 so that the measured light amount is constant. As a result, the light amount of the light source 21 is stabilized, and the light irradiated on the measurement surface can be kept constant, so that the measurement can be performed with high accuracy.

In this way, the measurement is performed for each of a plurality of planar portions having good visual results. At this time, the data for which measurement has failed or inappropriate data is
Input a deletion instruction from 1 and delete. When the required number of measurement values for obtaining the reference light amount reference value are obtained, the operation panel 331 or the stick switch 332 instructs to end the measurement for obtaining the reference value. Then, the arithmetic processing unit 335 averages the measured values stored in the storage unit 336, stores the average value in the storage unit 336 as a regular reflection light reference value, and displays the average value on the display unit 4 or the like.

Next, on the surface of the object to be measured, a planar portion having a poor visual result to be inspected is measured. Here, the part having a poor visual result is a part in which, when the object to be measured is a resin molded product, shining scratches and uneven gloss due to excessive gloss, weld lines, flow marks, whitening scratches, and the like are formed. is there. That is, the measurement head 70 is brought into contact with the measurement surface 9 and the measurement is started by the operation panel 331 or the stick switch 332 in the same manner as in the measurement for obtaining the regular reflection light reference value described above. This allows
As described above, light is emitted perpendicularly to the measurement surface 9 from the emission unit 23A, and only light reflected in the same direction enters the light receiving unit 31A and enters the light receiving element 32, where it is photoelectrically converted and subjected to arithmetic processing. It is input to the means 335. Arithmetic processing means 33
5 calculates the difference by comparing the input measurement value with the specular reflection light reference value stored in the storage means 336, and obtains a change rate which is a value obtained by dividing the difference by the specular reflection light amount reference value. , These differences and the rate of change together with the measured values
And so on. As a result, the measurement result of the defective portion of the visual result is displayed not only as the measured value but also as a difference from the regular reflection light reference value and the degree of the difference (change rate) in an easy-to-understand manner.

On the other hand, when the shape of the object to be measured is complicated, for example, when the measurement surface is in a corner as shown in FIG. 7, an exchange head is used to reduce the measurement area. The exchange head 72B having an inner diameter of 4 mm shown in FIG. 5 is attached to the head main body 71, and the sensitivity changeover switch 333 is switched to a sensitivity corresponding to the inner diameter of the exchange head 72B. Do.

According to the present embodiment, the following effects can be obtained. That is, since the light irradiating means 2 irradiates light perpendicular to the measurement surface 9, the amount of specularly reflected light reflected in the direction perpendicular to the measurement surface 9 changes according to the surface condition of the measurement surface 9. In the present embodiment, only the specularly reflected light is measured by the light detection means 3, so that the measured light amount is
Is obtained as a value corresponding to the surface state. Therefore, the surface state of the measurement surface 9 can be quantified with high accuracy as it is, and
Since there is no need for scratching as in the conventional case, the present invention can be applied not only to material testing but also to surface inspection of products.

Further, the emitting section 23A and the light receiving section 3 are provided at the base end.
A cylindrical measuring head 70 into which 1A is inserted and whose tip abuts on the measuring surface 9 is provided. Since the inner diameter of the tip of the measuring head 70 is variable, the measuring area can be adjusted. Therefore, more accurate measurement can be realized. In particular, the measuring surface 9 having a corner shape (see FIG. 7)
Since the measurement area can be reduced when performing measurement on, the decrease in accuracy due to the shape of the measured object can be reduced. Then, the relative positions of the measurement surface 9 and the emission unit 23A and the light reception unit 31A can be determined only by bringing the measurement head 70 into contact with the measurement surface 9, thereby facilitating the measurement.

Further, the inner diameter of the tip of the measuring head 70 is in the range of 2 mm to 50 mm, particularly, 7 mm to 15 m.
m, the measurement range includes the pattern (texture) even if a pattern is formed on the measurement surface 9, especially if the measurement object is made of resin, even if it is textured. Is relatively wide, and the difference in the amount of specular reflection between the pattern and the flaw can be detected, so that the surface state of the measurement surface 9 can be accurately quantified. Further, by setting the inner diameter of the distal end portion of the measuring head 70 in the above-described range, excellent reproducibility and good operability can be obtained.

Since the tip of the measuring head is constituted by selectively attaching exchange heads 72A and 72B having different inner diameters, the exchange heads 72A and 72B are provided.
Since the inside diameter of the measuring head 70 can be changed only by replacing the measuring head, the measuring area can be easily adjusted and the device structure can be simplified.

Then, the emitting section 23A and the light receiving section 31A
Is composed of the optical fibers 61A and 61B, the optical fiber is flexible and can be formed long, so that the emission part 23A and the light reception part 31A can be moved to desired positions. It can be easily measured regardless of the direction and position of

The light detecting means 3 is configured to detect only the amount of specularly reflected light, and only a photometric filter (Y filter) is provided as a filter.
Since another filter for measuring chromaticity or the like such as a filter or a Z filter is not required, the size of the device 1 can be reduced.

Then, since the measured light amounts of a plurality of sites having good visual results are averaged to obtain a regular reflected light amount reference value, the regular reflected light amount reference value can be obtained as a highly reliable value in consideration of variation. Accurate measurement can be realized. Furthermore, since the measured value of the desired part is compared with the specular reflection light amount reference value, and the light amount difference and the change rate are obtained, the difference between the visual result and the good part can be quantified. It can be obtained as the corresponding value.

It should be noted that the present invention is not limited to the above-described embodiment, but includes other configurations capable of achieving the object of the present invention, and also includes the following modifications.
That is, in the above-described embodiment, the measured values of a plurality of sites having good visual results are averaged to obtain a regular reflection light amount reference value, and the measurement value of the portion to be inspected is compared with the regular reflection light amount reference value. Is not limited to this. For example, the ratio between the measured value of the inspection target and the reflected light amount reference value may be obtained. Alternatively, the average value of the measurement results of a plurality of sites having poor visual results may be used as a reference value and compared with the measurement value of the site to be inspected. Furthermore, the specular reflection light amount reference value need not be an average of a plurality of measurement values, and one measurement value may be set as the specular reflection light amount reference value.

In the above embodiment, the inner diameter of the measuring head is changed by replacing the replacement head.
A plurality of exchange heads may be made nestable and removable.
The exchange head is not limited to those having an inner diameter of 4 mm or 10 mm, and is not particularly limited as long as it has an inner diameter of 7 mm to 15 mm. Further, the exchange head may be omitted, and the inner diameter of the measurement head may be fixed.

In the above embodiment, the case where the surface inspection is performed on a flat or corner-shaped measurement surface has been described. However, the surface shape of the measurement surface is not limited thereto.
The measurement surface may be a curved surface, or may be a corner. Further, the present invention can be applied to both a measurement surface having a pattern (texture) and a measurement surface having no pattern (texture). As a result, remarkably high precision measurement can be realized.

[0046]

As described above, according to the present invention,
Light is illuminated vertically by the light irradiating means on the measuring surface consisting of the coating film or resin, and only the specular reflection light is measured by the light detecting means. Therefore, the surface condition of the measurement surface can be quantified with high precision as it is, and since there is no need to make a scratch as in the prior art, it can be applied not only to material testing but also to surface inspection of products. In addition, by averaging the measured light amounts of a plurality of sites with good visual results and obtaining a regular reflection light amount reference value, the regular reflection light amount reference value can be obtained as a highly reliable value, so that highly accurate measurement can be realized. Furthermore, since the measured value of the desired part is compared with the specular reflection light amount reference value, and the light amount difference and the change rate are obtained, the difference between the visual result and the good part can be quantified. It can be obtained as the corresponding value.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the surface inspection apparatus of the embodiment.

FIG. 3 is a block diagram showing processing means of the embodiment.

FIG. 4 is a sectional view showing the measuring head of the embodiment.

FIG. 5 is a sectional view showing another state of the measuring head of the embodiment.

FIG. 6 is an enlarged view showing a measurement state in the embodiment.

FIG. 7 is a diagram showing another measurement state of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface inspection apparatus 2 Light irradiation means 3 Light detection means 9 Measurement surface 23 Light emitting optical fiber cable 23A Emission part 31 Light receiving optical fiber cable 31A Light receiving part 61A, 61B Optical fiber 63 Optical fiber bundle 70 Measurement head 71 Head main body 72A, 72B Exchange head

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Umetani 4-45-17 Sengoku, Bunkyo-ku, Tokyo (72) Inventor Satoshi Yamada 1-4-1, Chuo, Wako-shi, Saitama F Terms (reference) 2F065 AA49 DD03 EE03 FF44 GG02 HH03 HH13 JJ01 JJ19 JJ23 LL02 LL10 LL21 LL37 QQ03 QQ23 RR09 SS06 2G051 AA32 AB02 AB12 BB01 BB09 BB19 CA02 CA06 CB01 CC09 CB01 EB01 EC02 CC17 EB01 EC02

Claims (7)

[Claims] 1. A surface inspection apparatus for measuring a surface state of a coating film or a resin, wherein a light irradiating means for irradiating a measuring surface made of the coating film or the resin with light perpendicularly from an emission part; A surface inspection apparatus comprising: light detection means for receiving only regular reflection light among light reflected on a measurement surface by an irradiation means at a light receiving portion and obtaining the light amount. 2. The surface inspection apparatus according to claim 1, further comprising: a cylindrical measuring head into which the light emitting unit and the light receiving unit are inserted at a base end, and a tip of which is in contact with a measuring surface. A surface inspection apparatus characterized in that the inner diameter of the tip of the head is variable. 3. The surface inspection apparatus according to claim 2, wherein an inner diameter of a tip portion of the measurement head is variable in a range of 2 mm to 50 mm. 4. The surface inspection apparatus according to claim 2, wherein the tip of the measuring head is formed by selectively attaching an exchange head having a different inner diameter. Inspection equipment. 5. The surface inspection apparatus according to claim 1, wherein the emission unit and the light reception unit are configured by an optical fiber. 6. The surface inspection apparatus according to claim 1, wherein the light detection unit is configured to detect only a light amount. 7. A surface inspection method for measuring a surface state of a coating film or a resin, wherein a plurality of portions of the surface of the coating film or the resin having good visual results are irradiated with light vertically. The specular reflection light amount measurement for obtaining only the light amount of the specular reflection light among the reflected light of the light is performed, and these specular reflection light amount measurement values are averaged to obtain a specular reflection light amount reference value. Measuring the specular reflection light amount with respect to the portion, obtaining a difference between the specular reflection light amount measurement value and the specular reflection light amount reference value, and obtaining a change rate obtained by dividing the difference by the specular reflection light amount reference value. A surface inspection method characterized by the following.