JPH09218910A - Method and device for reading marking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remotely and easily identify the component or the like of an object member with high accuracy without directly touching it with hands or approaching it by identifying the object member by irradiating that object member with light and detecting reflected light. SOLUTION: Radiation light is outputted from two light emitting diode flood instruments 4a and 4b and a marking area 3 on the surface of an object member 2 is irradiated with that light. The reflected light reflected by the marking area 3 is converged by a lens 5a and narrowed by a diaphragm member 5b and afterwards, the image of marking 3 is formed on a photoelectric transducing plane 6a of a CCD image sensor 6. The sampling of reflected light due to an optical system 5 for sampling is performed out of the direction of regular reflection (mirror reflection direction). Then, difference is generated between the quantity of detected light diffused and reflected from the smooth area of marking area 3 and the quantity of detected light diffused and reflected from the rough area. A data processor 7 can discriminate this difference and remotely read the marking 3 corresponding to the difference in roughness on the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a marking to an object which is difficult to approach by a person, such as a component of a nuclear reactor which has been activated, at a distance (distance). More particularly, the present invention relates to a method for reading a marking due to a difference in surface roughness applied to the surface of a metal member, and an apparatus directly used for the method.

[0002]

2. Description of the Related Art Light water reactors are roughly classified into pressurized water reactors and boiling water reactors. A large number of various components made of materials having sufficient corrosion resistance under a high temperature and high pressure environment, such as austenitic stainless steel, nickel base alloys, zirconium alloys, etc., are used in these nuclear reactors.

Building a nuclear reactor with these materials,
It is necessary to identify each component accurately when manufacturing the components of the reactor, or when inspecting the reactor or repairing or replacing the components of the reactor after starting the operation of the nuclear power plant. Sexuality occurs.

For example, the constituent members have radioactivity,
When it is necessary to perform identification while installed in a nuclear reactor, identification is required to be performed remotely (distance) in order to reduce exposure of workers.

However, in a method of remotely monitoring the external appearance of a target member using a camera or the like and identifying it only by shape recognition, a large number of structurally similar components are used in the reactor, or Accurate identification may be difficult when only part of the monitor can be monitored because it is installed. For this reason, a method has been adopted in which some of the components of the nuclear reactor are directly marked and the components are read remotely to identify the components.

[0006]

By the way, when marking a component, it is necessary not to impair the high corrosion resistance required for the component of the nuclear reactor. As such a marking construction technique, a method has been developed in which marking is performed on the surface of a target member by using a laser or the like due to a difference in surface roughness. However, no method or device for reading this marking remotely is known.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for remotely reading a marking made by irradiating a metal target member with a laser or the like due to a difference in surface roughness.

Another object of the present invention is to provide a marking reading method and apparatus capable of easily reading such marking with high accuracy and reliability.

[0009]

The present invention has been made paying attention to the fact that the light diffusivity of the surface of a metal or the like has a correlation with the roughness of the surface, and the marking reading method according to claim 1 Is irradiated with irradiation light to a target object made of metal, which is preformed on the surface of the marking, which is composed of a pattern having a smooth area and a surface having a surface rougher than this, and from the marking of the irradiation light Diffuse reflection of
Collected from a direction deviating from the direction of specular reflection determined by the marking of the target member and the traveling direction of the irradiation light, and the detected light amount of diffuse reflection light from the smooth area of the marking. The marking is read based on the difference from the detected light amount of diffusely reflected light from the rough area.

According to a second aspect of the present invention, there is provided a marking reading device which is a metallic target member having markings formed in advance on the surface, the markings having a pattern of a smooth surface area and a rougher surface area. And a diffuse reflection light of the irradiation light, which is caused by the marking of the irradiation light, deviates from the direction of regular reflection determined by the marked surface portion of the target member and the traveling direction of the irradiation light. Sampling optical system that collects from a different direction, a light receiving sensor that detects the diffused reflected light that is sampled, the detected light amount of the diffused reflected light from the smooth area of the marking that is detected by this light receiving sensor, and from the rough area Reading means for reading the marking on the basis of the difference from the detected light amount of the diffuse reflection light of.

In these claims 1 and 2, the marking is a pattern formed by irradiating a metal target member with, for example, a laser beam and having a difference in surface roughness. The pattern includes, for example, letters, numbers and symbols. , Barcodes, etc. are included. Diffuse reflected light refers to light reflected in a direction other than the specular reflection direction along the specular reflection direction of the marking surface.

The surface roughness is defined as the root mean square of the height of the surface irregularities. Therefore, when observing the marking surface from a direction deviating from the direction of regular reflection determined by the marking surface of the target member and the traveling direction of the irradiation light, if the surface is rougher than smooth In this case, since the amount of diffused reflection light is larger, high brightness can be obtained.

Therefore, according to the marking reading device of the first or second aspect, when the marking surface of the metallic target member is irradiated with light from the light projector, it is reflected here. The reflected light is collected by the collecting optical system and further detected by the light receiving sensor.

By the way, the reflected light is divided into specular reflection in the specular reflection direction and diffuse reflection light in the other directions.
The reflected light is collected by the sampling optical system from a direction deviating from the specular reflection direction (specular reflection direction) determined by the marking surface and the traveling direction of the irradiation light, so the light receiving sensor diffuses and reflects from the marking surface. Detect light. Then, in the rough surface area, the diffusivity is improved and the diffuse reflection light quantity increases, while in the smooth surface area, the diffuse reflection light quantity decreases conversely.

For this reason, the light receiving sensor for receiving the diffusely reflected light detects the difference in the detected light amount corresponding to the difference in the surface roughness. The reading unit can read the marking pattern by discriminating the difference in the detected light amount from the entire marking surface.

That is, according to the present invention, the target member is identified by irradiating the target member with light and detecting the reflected light, so that the target member can be remotely accessed without directly touching or approaching it. Thus, the constituent materials of the target member can be identified easily and with high accuracy.

According to a third aspect of the present invention, there is provided the marking reading device according to the second aspect, wherein, when the surface of the target member is a mechanically polished surface, the light projector is orthogonal to the mechanical polishing streak direction. It is characterized in that the light is emitted from the direction.

Therefore, according to the marking reading apparatus of the third aspect, the mechanically polished surface is used as a region having a rough surface, and the mechanically polished surface is irradiated with a laser or the like to partially smooth the surface. By forming the area, the marking can be easily applied.

When light is irradiated from a direction orthogonal to the mechanical polishing streak direction on the surface of the object member, the root mean square of the heights of the irregularities on the mechanical polishing surface is large in the direction orthogonal to the streak, and Therefore, it is possible to obtain uniform diffuse reflected light having good diffusivity, that is, the directionality of the luminance is gentle and uniform from the region of the mechanical polishing surface. Therefore, the marking reading accuracy can be improved.

A marking reading device according to a fourth aspect is the marking reading device according to the second or third aspect, wherein the projector has a wide-angle radiation light source capable of irradiating the entire marking area at one time, and the light receiving sensor is one-dimensional. Alternatively, it is a two-dimensional imaging device.

Therefore, according to the marking reading device of the fourth aspect, the irradiation light output from the wide-angle type radiation light source irradiates the entire marking area at one time, and the diffuse reflection light from the marking area is one-dimensional or A two-dimensional image pickup device detects a one-dimensional or two-dimensional image.

For this reason, a mechanism for scanning the irradiation light over the entire marking area and a mechanism for maintaining the positional relationship between the irradiation spot and the light entering portion of the sampling optical system are not required, so that the apparatus structure is simple. And can be easily implemented.

Further, since the image pickup device converts a one-dimensional or two-dimensional input optical image into an electric signal and detects it, various data processing can be performed at the time of identifying the surface roughness or recognizing the pattern. , Can be easily read.

A marking reading device according to a fifth aspect of the present invention is the marking reading device according to any one of the second to fourth aspects, in which the projector has a direct-current light source.

A marking reading device according to a sixth aspect is the marking reading device according to any one of the second to fourth aspects, in which the projector has a light source which is turned on at a high frequency at a cycle less than a detection time of the light receiving sensor. .

Therefore, according to the marking reading device of the fifth and sixth aspects, if an AC lamp is used for the projector, the irradiation light amount per unit time fluctuates at a constant cycle (T). The amount of reflected light per unit time also fluctuates in the same period (T), and therefore the amount of detected light depends on the timing of detection, and in some cases a sufficient amount of detected light may not be obtained.

However, by setting the cycle (T) of the AC lamp to be equal to or less than the detection time (D) of the light receiving sensor (T≤D) as in the invention described in claim 6, the detection timing dependency of the detected light amount is reduced. Thus, it is possible to prevent the phenomenon of insufficient detection light amount. Therefore, both reliability and marking reading accuracy can be improved.

Further, by using a direct current lamp for the projector as in the fifth aspect of the invention, it is possible to further reduce the detection timing dependency of the detected light amount and the risk of insufficient detected light amount. And reliability can be improved together.

A marking reading device according to a seventh aspect is the marking reading device according to any one of the second to sixth aspects, wherein the light receiving sensor is a CCD (charge coupled device) image sensor. .

Therefore, according to the marking reading device of the seventh aspect, the wide-angle type radiation light source is used and the CCD (charge coupled device) image sensor is used as the light receiving sensor. Since it has high resolution and high resolution, it is possible to read markings made in a narrow area with high reliability.

Since it is desired that markings be made in as narrow a region as possible on the surface of the components of the nuclear reactor so as not to impair the high corrosion resistance, the present invention provides the components of the nuclear reactor. Suitable for identification. Also, CCD
Image sensors are cheap and easy to handle,
Easy to implement.

The marking reader according to claim 8 is the marking reader according to any one of claims 2 to 7, which is an incident angle of the irradiation light with respect to the marked surface portion of the target member, The angle formed by the traveling direction of the irradiation light with respect to the perpendicular to the marked surface is 45 ° to 70 °, and is the reflection angle of the diffuse reflection light from the marking area of the target member detected by the light receiving sensor. The angle formed by the traveling direction of the reflected light with respect to the perpendicular of the marked surface is 0 ° to 10 °.

Therefore, according to the marking reading device of the eighth aspect, in order to set the reflection angle of the diffusely reflected light to be detected to 0 ° to 10 °, the light entrance portion of the sampling optical system is set in the marking area. However, in this case, the projected area of the marking area viewed from the light entrance of the sampling optical system is more apparent than when it is installed diagonally to the marking area. Grows up.

Therefore, since the optical image of the marking formed on the photoelectric conversion portion of the image pickup device also becomes large, it is possible to detect a high-resolution image, and it is possible to improve both reading accuracy and reliability.

Further, since the incident angle of the irradiation light is 45 ° to 70 °, the diffuse reflection light not including the specular reflection can be obtained by avoiding overlapping with the angle range of the reflection angle (0 ° to 10 °). It can be detected by a light receiving sensor. As a result, both reading accuracy and reliability can be improved.

A marking reading device according to a ninth aspect of the present invention is the marking reading device according to any one of the second to eighth aspects, wherein a plurality of light projectors are provided.

Therefore, according to the marking reading device of the ninth aspect, if the light is irradiated onto the marking surface by one light projector, the irradiation light is incident at different positions in the marking area. Differences occur in angle and illuminance. Especially, when the length of the marking area cannot be regarded as sufficiently smaller than the distance from the projector to the marking area, the above difference becomes large. Therefore, the dependency of the amount of diffusely reflected light detected by the light receiving sensor on the position in the marking area becomes large, and the reliability of marking reading may be reduced.

However, by irradiating light from a plurality of projectors to the marking area from a plurality of end sides thereof, it is possible to reduce the difference in incident angle and illuminance. Therefore, the position dependency of the detected light amount is reduced, and therefore, both the marking reading accuracy and the reliability can be improved.

A marking reading device according to a tenth aspect of the present invention is the marking reading device according to any one of the second to ninth aspects, in which the projector is a laser device instead of a light source for direct current lighting or high frequency lighting. The light receiving sensor is a 0-dimensional photoelectric conversion element instead of the 1-dimensional or 2-dimensional imaging device, and means for scanning the irradiation spot of the laser beam from the laser device onto the marking area, and the marking. Incident angle of laser beam with respect to surface area, area of irradiation spot on marking, reflection angle with respect to marked surface area of diffuse reflected light detected by the light receiving sensor, and diffuse reflected light detected by the light receiving sensor And a means for fixing the solid angle of.

Therefore, according to the marking reading device of the tenth aspect, the laser beam from the laser device is applied to the marking area on the surface of the target member,
The diffuse reflected light is sampled by a sampling optical system from a direction deviating from the direction of specular reflection, and the collected diffuse reflected light is detected by a 0-dimensional photoelectric conversion element. At that time, the irradiation spot of the laser beam is scanned over the entire marking area by scanning the laser beam or the target member, and the diffuse reflection light from the marking area is detected as a one-dimensional or two-dimensional image.

When scanning the irradiation spot, the incident angle of the laser beam with respect to the marked surface area, the area of the irradiation spot on the marking, and the surface area marked with the diffuse reflection light detected by the light receiving sensor. The four physical quantities of the reflection angle with respect to and the solid angle of the diffuse reflection light detected by the photoelectric conversion element are fixed.

The detected light quantity of the diffuse reflected light strongly depends on these four physical quantities in addition to the surface roughness of the reflecting surface. By eliminating or suppressing the fluctuation of these physical quantities during scanning, the disturbance is disturbed. It is possible to suppress and clearly distinguish the difference in surface roughness.

Further, even if the marking surface is a curved surface or the marking area covers a wide area, the reading can be performed with high reliability.

Further, since the light receiving sensor converts the input light quantity into an electric signal and detects it, various data processing can be performed at the time of surface roughness identification, pattern recognition, etc.
It can be read easily.

The marking reader according to claim 11 is the marking reader according to any one of claims 2 to 10, wherein the projector is a CW (continuos wa).
ve) is a CW laser device that outputs a laser beam.

Therefore, according to the marking reading device of the eleventh aspect, since the intensity of the irradiation light is temporally stable by using the CW light source, the laser device, the light receiving sensor, and the mechanical scanning means are provided. Even in the case where it is provided, there is almost no possibility of the dependency of the detection light amount by the light receiving sensor on the detection timing and the accompanying shortage of the detection light amount. Therefore, both reading accuracy and reliability can be improved.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 5, the same or corresponding parts are designated by the same reference numerals.

FIG. 1 is an overall configuration diagram of a first embodiment of a marking reading apparatus directly used in the marking reading method according to the present invention. In this figure, a marking reading device 1 is preliminarily applied to a surface 2a of a metal object 2 which is difficult for humans to approach, such as a component of a nuclear reactor to identify the component. The marking 3 is read at a remote position without approaching, that is, at a remote position to identify the structure of the component. The light diffusivity of the metal surface is in relation to the roughness of the surface. It is constructed based on the principle.

That is, in general, when a certain surface is irradiated with a light beam, the light is reflected not only in the specular reflection direction but in all directions. Such reflection is called diffuse reflection, and the reflected light at this time is called diffuse reflected light.

FIG. 2 is a diagram showing a general directional characteristic of luminance when the light b is obliquely applied to a surface a such as a metal. In the figure, the vector direction indicates the observation direction and the vector magnitude. The height represents the high brightness.

Further, in FIG. 2, when a thin light beam b is obliquely applied to a certain surface a, the brightness c of the irradiation spot formed on the surface a is usually close to specular reflection which is the specular reflection direction. Although it has a maximum in any direction, it represents the property of reflecting a certain amount of light in all directions. Here, when the directionality of the luminance is small, it is said that this surface has good diffusivity.

That is, it is known that there is a correlation between the light diffusivity of the surface a and the roughness of the surface a, and the rougher the surface a, the better the light diffusivity of the surface a. Therefore, the wavelength λ of the irradiation light b is an index of the surface roughness σ.

That is, as shown in FIGS. 3A and 3B, if the roughness σ of the surface a is sufficiently smaller than the wavelength λ of the irradiation light b (σ << λ), the surface a is smooth. Therefore, the diffusivity is poor. On the other hand, if the roughness σ of the surface a is equal to or larger than the wavelength λ of the irradiation light b (σ = λ, or σ> λ), the roughness of the surface a is rough. Therefore, the diffusivity is good. Here, the surface roughness (σ) is defined by the root mean square of the heights of the surface irregularities.

Therefore, when observing from a direction deviating from specular reflection (specular reflection direction) as shown in FIGS. 3 (a) and 3 (b), as shown in FIG. As shown in FIG. 3B, the luminance e when the roughness of the surface a is rough, as compared with the luminance d when the height σ is smooth, is higher because of the diffuse reflection effect.

Therefore, on the surface 2a of the metallic object 2 shown in FIG. 1, in order to identify the structural member or the like, a marking composed of a pattern of a smooth surface area and a rough surface area is formed on the surface 2a. And apply the above principle,
The marking reading device 1 is a device for reading this marking remotely. The marking pattern includes characters, figures, symbols, numbers, bar codes and the like.

The marking reader 1 has wide-angle projectors 4a and 4b for irradiating the marking 3 of the target member 2 with light from, for example, two directions at a time, and for collecting diffused reflected light reflected by the marking 3. Optical system 5,
A CCD (charge-coupled device) image sensor 6 which is a light receiving sensor for receiving the diffuse reflected light collected by the collecting optical system 5 and converting it into an electric signal, and a data processing device electrically connected to the sensor 6. 7 and.

Although a light emitting diode is used as a light source of each of the projectors 4a and 4b, other DC lighting lamps or lamps which are lit at a high frequency having a period less than the detection time of the CCD image sensor 6 may be used.

The sampling optical system 5 has a lens 5a for condensing diffusely reflected light from the marking 3, a diaphragm member 5b for narrowing the condensing light, and light other than the condensing light for photoelectric conversion surface 6a of the CCD image sensor 6. It is composed of a light-shielding cover 5c that shields the light from entering the device, and forms a marking image on the photoelectric conversion surface 6a of the CCD image sensor 6.

The light-shielding cover 5c is made of a material that blocks light of a wavelength that can be detected by the CCD image sensor 6, and is made of CC.
Photoelectric conversion surface 6a of D image sensor 6 and diaphragm member 5b
It covers the circumference of the optical path between and.

The CCD image sensor 6 has a large number of photoelectric conversion elements arranged side by side on its photoelectric conversion surface 6a.
Although the case of constructing a two-dimensional CCD image sensor is illustrated, other two-dimensional image pickup devices may be used. Also, for example, the marking 3 is 1 like a bar code.
When only dimensional information is included, a one-dimensional imaging device such as a one-dimensional CCD image sensor may be used.

The data processing device 7 is connected to the CCD image sensor 6 via a signal cable 8 so as to exchange electric signals between them.

The data processing device 7 uses the marking signal 3 based on the electric signal detected by the CCD image sensor 6.
A series of operations for recognizing the pattern over the entire area of the image is performed by electrical processing, and the detection signal detected by the CCD image sensor 6 is the same as that of the marking 3 as already described with reference to FIGS. The difference is based on the difference in the diffuse reflection light amount corresponding to the difference in the surface roughness.

Therefore, the data processing device 7 discriminates the difference in the detected light amount, discriminates whether the surface is a smooth region or a rough region, and performs this discrimination over the entire marking region, Perform pattern recognition. Depending on the type of the marking 3, the data processing device 7 may be a ready-made product available on the market.

The incident angle of the irradiation light with respect to the surface of the target member 2 on which the marking 3 is applied, that is, the angle formed by the traveling direction of the irradiation light with respect to the perpendicular of the surface of the target 3 on which the marking 3 is applied is 45 °. The angle of reflection of the diffusely reflected light from the marking area of the target member 2 that is included in the range of up to 70 ° and is sampled by the sampling optical system 5, that is, the marking 3
The marking 3, the light-emitting diode projectors 4a and 4b, and the sampling optical system 5 are arranged so that the angle formed by the traveling direction of the diffusely reflected light with respect to the perpendicular of the surface-marked surface is within the range of 0 ° to 10 °. The positional relationship is set.

Next, the operation and effect of this embodiment will be described.

Irradiation light is output from the two light emitting diode projectors 4a and 4b, and the irradiation light is applied to the marking area 3 on the surface of the target member 2. These light emitting diode projectors 4a and 4b are so-called wide-angle type radiation light sources and illuminate the entire marking area 3 at once.

The emitted irradiation light is reflected by the marking area 3. The reflected light is condensed by the lens 5a,
CCD image sensor 6 after being squeezed by diaphragm member 5b
An image of the marking 3 is formed on the photoelectric conversion surface 6a of the.
The light shielding cover 5c prevents light other than the reflected light from a desired direction from being applied to the photoelectric conversion surface 6a and detected.

The image of the marking 3 formed on the photoelectric conversion surface 6a is converted into an electric signal by the photoelectric conversion element of the photoelectric conversion surface 6a, and the electric signal including the information of the image of the marking 3 is processed by the signal cable 8. It is transmitted to the device 7.

By the way, the reflected light from the marking area 3 on the surface 2a of the target member 2 is classified into specular reflection which is the specular reflection direction and diffuse reflection light in the other directions. The marking 3 and the light emitting diode projector As is clear from the positional relationship between 4a, 4b and the collection optical system 5, the collection of reflected light by the collection optical system 5 is determined by the surface 2a of the irradiated target member 2 and the traveling direction of the irradiation light. The CCD image sensor 6 detects the diffuse reflection light from the marking area 3 because the reflection is performed from a direction deviating from the direction of specular reflection (specular reflection direction). At this time, there is a difference in the detected light amount of the diffuse reflected light from the smooth region of the marking region 3 and the detected light amount of the diffuse reflected light from the rough region.

The data processing device 7 discriminates the difference in the detected light amount, discriminates whether it is a smooth region or a rough region, and this discrimination is performed over the entire marking region 3 to recognize a pattern. Work is performed by electrical processing. Thereby, the target member 2 made of metal
Marking directly on the surface due to the difference in surface roughness 3
Can be read remotely, and the target object 2 can be identified.

Further, in the present embodiment, a mechanism for scanning the marking area 3 with the irradiation light, a mechanism for maintaining the positional relationship between the irradiation spot and the light entering portion of the sampling optical system 5 are not required, and therefore the apparatus is not used. Simple to configure.

Further, since the image pickup device such as the CCD image sensor 6 converts the input optical image into an electric signal, it is possible to use a high-level electric data processing device such as a computer. Therefore, the marking 3 can be easily read.

Since the light emitting diode projectors 4a and 4b are direct current lamps, the irradiation light quantity per unit time is stable in time, so that it is possible to prevent the detection timing dependency of the detected light quantity and the risk of insufficient detected light quantity. . Therefore, both the reading accuracy and the reliability of the marking 3 can be improved.

The functions and effects of the light projectors 4a and 4b can be similarly obtained when a DC lamp other than the light emitting diode light projectors 4a and 4b is used. Further, even when an AC lamp is used, the high frequency lighting cycle (T) is C
Below the detection time (D) of the CD image sensor 6 (T ≦
By setting D), it is possible to reduce the detection timing dependency of the detected light amount and prevent the insufficient phenomenon of the detected light amount. Therefore, both reading accuracy and reliability of the marking 3 can be improved.

The irradiation of the irradiation light to the marking area 3 is 2
Since the light emitting diode projectors 4a and 4b perform the light emission from different directions, it is possible to suppress the difference in the incident angle and the illuminance of the irradiation light at positions distant from each other in the marking area 3, and to detect the diffuse reflection. It is possible to suppress the dependency of the amount of light depending on the position in the marking area 3 to be small. Therefore, the reading accuracy and reliability of the marking 3 can be improved. In addition,
Irradiation may be performed using three or more projectors, and the same action and effect are obtained.

Since the CCD image sensor 6 has a high degree of integration and a high resolution, the marking 3 may be applied to a region as narrow as possible on the surface 2a so as not to impair the high corrosion resistance, such as a component of a nuclear reactor. It is suitable for highly accurate and reliable reading of the marking 3 applied to a narrow area on a desired member. Further, the CCD image sensor 6 is inexpensive and easy to handle.

Since the reflection angle of the diffusely reflected light detected by the CCD image sensor 6 is limited within the range of 0 ° to 10 °, the light entering portion of the sampling optical system 5 is directed to the marking area 3. Are placed almost facing each other. in this case,
The projected area of the marking area 3 as seen from the light entering portion of the sampling optical system 5 is larger than that in the case where the marking area 3 is installed obliquely to the marking area 3. Therefore, the optical image of the marking 3 formed on the photoelectric conversion surface 6a of the CCD image sensor 6 becomes large, so that a high-resolution image can be detected, and the reading accuracy and reliability can be improved.

Since the incident angle of the irradiation light is limited to the range of 45 ° to 70 °, the diffuse reflected light not including the specular reflection is detected, and the diffuse reflected light from the smooth area of the marking area 3 is detected. Since there is a difference between the detected light amount of No. 1 and the detected light amount of diffusely reflected light from the target area in the marking area 3,
The marking 3 can be read.

FIG. 4 is an overall configuration diagram of a marking reading device 1A according to the second embodiment of the present invention. This is a machine of the target member 2 when the surface 2a of the target member 2 is a mechanical polishing surface 2b. The feature is that the irradiation light is emitted from a direction orthogonal to the striation direction 2c of the polishing surface 2b.

That is, this marking reading device 1A
Uses the mechanically polished surface 2b as a rough surface area and irradiates a laser or the like on the surface to form a partially smooth area, thereby forming the pattern of the marking 3. The direction 2 of the mechanical polishing streaks with respect to this marking 3
From the direction orthogonal to c, the light emitting diode projectors 4a, 4
Irradiation is performed by b. For others, first
The configuration is almost the same as that of the embodiment.

Therefore, according to the marking reading device 1A, the following actions and effects are obtained in addition to the actions and effects of the first embodiment.

That is, since the root mean square of the heights of the irregularities of the mechanically polished surface 2b is large and uniform in the direction orthogonal to the striations, the direction 2c orthogonal to the striation direction 2c of the surface 2a of the target member 2 is obtained. By irradiating from, the diffused light having a good diffusibility, that is, the directional directivity of the brightness is smooth and the diffused reflected light is uniform can be obtained from the region subjected to the mechanical polishing. If the diffusivity is good, the amount of diffusely reflected light will be large, and it will be easy to distinguish between a mechanically polished region, that is, a rough surface region and a smooth surface region. Therefore, both reading accuracy and reliability of the marking 3 can be improved.

FIG. 5 is an overall configuration diagram of a marking reading device 1B according to the third embodiment of the present invention, in which an XY driving device 11 for driving the target member 2 in the XY direction is newly provided. On the other hand, as a light source for irradiating the marking 3 with light, a CW (continuous
wave) The laser device 12 is used, and the photoelectric conversion element 1 is used as a light receiving sensor instead of the CCD image sensor 6.
The feature is that 3 is used.

The XY driving device 11 mounts and fixes the target member 2 and drives it in the XY directions, and the CW laser device 1
Mark the irradiation spot of the laser beam from 2 3
XY drive stage 11a that scans in the XY direction above
And a controller 11b which is connected to the data processing device 7 via a signal cable 14 and controls the XY drive of the XY drive stage 11a corresponding to the detection operation of the photoelectric conversion element 13. However, if the marking 3 has only one-dimensional information such as a bar code, 1
Dimensional X or Y drive stages may be used.

The irradiation optical system 15 of the CW laser device 12 is constituted by combining a lens 15a and a mirror 15b,
Laser beam 1 output from CW laser device 12
The marking 3 is irradiated with 5c.

The sampling optical system 15 includes at least the lens 15
a and the diaphragm member 15b are combined to collect the diffuse reflection light from the marking area 3 and collect the photoelectric conversion element 13
Is transmitted to the photoelectric conversion surface of. The light-shielding cover 5c is installed so as to cover the photoelectric conversion surface of the photoelectric conversion element 13,
The photoelectric conversion element 13 is made of a material that does not transmit light of a wavelength that can be detected.

The photoelectric conversion element 13 and the data processing device 7 are connected to each other by a signal cable 1 for exchanging electrical signals between them.
4 are connected.

The collection of the reflected light by the collection optical system 5 is always performed from the direction of specular reflection (specular reflection direction) determined by the surface 2a of the irradiated target member 2 and the traveling direction of the irradiation light. The mutual positional relationship between the irradiation optical system 15, the target member 2, and the sampling optical system 5 is set so that the irradiation optical system 15, the target member 2, and the sampling optical system 5 are arranged so as to be performed from the different directions.

Therefore, by scanning the XY drive stage 11a, the target member 2 fixed to the XY drive stage 11a is driven in the XY direction, and the irradiation spot of the laser beam 15c is on the marking 3. To be scanned. The scanning of the irradiation spot is carried out over the entire area of the marking 3 where the necessary information is marked.

At the time of this scanning, the angle of incidence of the laser beam 15c on the surface of the marking 3, the area of the irradiation spot on the marking 3, and the marking 3 of the diffuse reflection light collected by the irradiation optical system 15 are applied. The angle of reflection with respect to the surface area and the solid angle of the diffuse reflection light sampled by the irradiation optical system 15 are fixed. However, as the method of scanning the irradiation spot in the marking area 3, the method of driving the target member 2 has been illustrated, but the method of scanning the laser beam 15c on the marking 3 by the mechanical operation of the irradiation optical system 15 is used. May be.

Next, the operation and effect of this embodiment will be described.

A CW (continuous wave) laser device outputs a CW (Continuous Wave) laser beam, which passes through the lens 15a and is reflected by the mirror 15b to mark 3 on the surface 2a of the target member 2. The area is illuminated.

The lens 15a functions to focus the laser beam 15c so that the irradiation spot on the marking area 3 has a desired diameter. Mirror 15b
The laser beam 15c serves to irradiate the marking 3 from a desired direction. Irradiated laser beam 15
c is reflected by the marking area 3. The reflected light is condensed by the lens 15a of the sampling optical system 15, passes through the diaphragm member 5b, and is applied to the photoelectric conversion surface of the photoelectric conversion element 13. The light shielding cover prevents light other than reflected light from a desired direction from being irradiated on the photoelectric conversion surface and detected.

The reflected light incident on the photoelectric conversion surface is converted into an electric signal, and this electric signal is further converted into the signal cable 14.
To the data processing device 7.

By the way, the reflected light from the marking area 3 on the surface 2a of the target member 2 is classified into specular reflection, which is a specular reflection direction, and diffuse reflection light in other directions. As is clear from the positional relationship between the optical system 15 and the sampling optical system, sampling of the reflected light by the sampling optical system 15 is determined by the surface 2a of the irradiated target member 2 and the traveling direction of the irradiation light. The photoelectric conversion element 13 detects diffused reflected light from the marking area 3 because it is performed from a direction deviating from the direction of specular reflection (specular reflection direction).

At this time, there is a difference in the detected light amount of the diffuse reflected light from the smooth region of the marking region 3 and the detected light amount of the diffuse reflected light from the rough region.

The data processing device 7 discriminates the difference in the detected light amount and discriminates whether it is a smooth region or a rough region.

On the other hand, the XY drive stage 11a is moved to XY.
By driving in the XY direction, the irradiation spot of the laser beam 15c is scanned on the marking 3 in the XY directions. Controller 11b of XY drive stage 11a
Controls the XY drive stage 11a so that the scanning is performed over the entire area of the marking 3, and transmits the information on the position of the irradiation spot to the data processing device 7.

Then, the data processing device 7 uses the target member 2
Is performed over the entire marking area 3 to recognize the pattern. Therefore, the marking 3 directly applied to the metallic target member 2 due to the difference in surface roughness can be read remotely.

The amount of diffused reflected light detected strongly depends on four physical quantities in addition to the surface roughness of the reflecting surface. 4 here
The two physical quantities are the incident angle of the laser beam 15c with respect to the surface of the marking 3, the area of the irradiation spot on the marking 3, and the surface of the diffuse reflection light detected by the photoelectric conversion element 13. And the solid angle of diffusely reflected light detected by the photoelectric conversion element 13.

Therefore, in the present embodiment, since these physical quantities are fixed during scanning of the irradiation spot, disturbance can be suppressed and the difference in surface roughness can be discriminated with high precision and high accuracy. According to this method, marking 3
Even if the marked surface is a curved surface or the marking area 3 covers a wide area, the reading can be performed with high accuracy and reliability.

Further, since the photoelectric conversion element 13 converts the amount of input light into an electric signal, it is possible to use a high-level electric data processing device such as a computer. Therefore, the reading can be easily performed.

Further, the CW laser device 12 has a CW (Co
Since the amount of irradiation light per unit time is temporally stable due to the output of the ntinuous wave), it is possible to prevent the dependency of the detection light amount by the photoelectric conversion element 13 on the detection timing and the risk of insufficient detection light amount due to it. . Therefore, both reading accuracy and reliability of the marking can be improved.

[0104]

As described above in detail, the claims 1 and 2 of the present application are described.
In the described invention, when the marking surface of the metallic target member is irradiated with light from the light projector, it is reflected here. The reflected light is collected by the collecting optical system and further detected by the light receiving sensor. By the way, the reflected light is divided into specular reflection in the specular reflection direction and diffuse reflection light in other directions, but the collection of the reflected light by the sampling optical system is determined by the marking surface and the traveling direction of the irradiation light. Since it is performed from the direction of specular reflection (specular reflection direction), the light receiving sensor detects diffuse reflection light from the marking surface.
Then, in the rough surface area, the diffusivity is improved and the diffuse reflection light quantity increases, while in the smooth surface area, the diffuse reflection light quantity decreases conversely.

Therefore, in the light receiving sensor which receives the diffusely reflected light, the difference in the detected light amount is detected corresponding to the difference in the surface roughness. The reading unit can read the marking pattern by discriminating the difference in the detected light amount from the entire marking surface.

That is, according to the present invention, the target member is identified by irradiating the target member with light and detecting the reflected light, so that the target member can be remotely accessed without directly touching or approaching it. Thus, the constituent materials of the target member can be identified easily and with high accuracy.

In the marking reader according to the third aspect, the mechanically polished surface is used as an area having a rough surface, and the mechanically polished surface is irradiated with a laser or the like to partially form an area having a smooth surface. By this, marking can be easily applied.

Therefore, when the irradiation light is irradiated from the direction orthogonal to the scratching direction of the mechanical polishing on the surface of the target member, the root mean square of the heights of the irregularities on the mechanical polishing surface is large in the direction orthogonal to the scratching, and Since it is uniform, it is possible to obtain uniform diffuse reflection light with good diffusivity, that is, the directionality of the luminance is gentle and uniform from the region of the mechanically polished surface. Therefore, the marking reading accuracy can be improved.

According to a fourth aspect of the present invention, in the marking reader, the irradiation light output from the wide-angle radiation source irradiates the entire marking area at once, and the diffuse reflection light from the marking area is imaged in one or two dimensions. The device detects it as a one-dimensional or two-dimensional image.

Therefore, a mechanism for scanning the irradiation light over the entire marking area, a mechanism for maintaining the positional relationship between the irradiation spot and the light entering portion of the sampling optical system, etc. are not required, and the device configuration is simplified. , Can be easily implemented.

Further, since the image pickup device converts a one-dimensional or two-dimensional input optical image into an electric signal and detects the electric signal, various data processing can be performed at the time of surface roughness identification or pattern recognition. , Can be easily read.

In the marking reader according to the present invention, if an alternating current lamp is used for the projector, the amount of irradiation light per unit time fluctuates at a constant cycle (T), and therefore the amount of reflected light per unit time. Also fluctuates in the same cycle (T), and therefore the amount of detected light depends on the timing of detection, and in some cases a sufficient amount of detected light may not be obtained.

However, by setting the cycle (T) of the AC lamp to be equal to or less than the detection time (D) of the light receiving sensor (T≤D) as in the invention described in claim 6, the detection timing dependency of the detected light amount is reduced. Thus, it is possible to prevent the phenomenon of insufficient detection light amount. Therefore, both reliability and marking reading accuracy can be improved.

Further, by using a direct current lamp for the projector as in the fifth aspect of the invention, it is possible to further reduce the detection timing dependency of the detected light amount and the risk of insufficient detected light amount, so that the reading accuracy is further improved. And reliability can be improved together.

According to a seventh aspect of the present invention, the marking reader uses a wide-angle radiation light source and a CCD (charge coupled device) image sensor as a light receiving sensor. The CCD image sensor has a high degree of integration and a high resolution. Therefore, the marking provided on the narrow area can be read with high reliability.

Since it is desired that markings are made on a region as narrow as possible on the surface of a structural member of a nuclear reactor so as not to impair high corrosion resistance, the present invention provides a structural member of the nuclear reactor. Suitable for identification. Also, CCD
Image sensors are cheap and easy to handle,
Easy to implement.

In the marking reading device according to the present invention, in order to set the reflection angle of the diffuse reflected light to be detected to 0 ° to 10 °, the light entering portion of the sampling optical system is substantially positive with respect to the marking area. However, in this case, the projected area of the marking area as seen from the light entering portion of the sampling optical system is apparently larger than that when it is installed diagonally to the marking area.

Therefore, the optical image of the marking formed on the photoelectric conversion portion of the image pickup device also becomes large, so that it is possible to detect a high-resolution image, and it is possible to improve both reading accuracy and reliability.

Further, since the incident angle of the irradiation light is set to 45 ° to 70 °, the diffuse reflection light not including the specular reflection can be obtained by avoiding overlapping with the angle range of the reflection angle (0 ° to 10 °). It can be detected by a light receiving sensor. As a result, both reading accuracy and reliability can be improved.

In the marking reader according to the present invention, if the marking surface is irradiated with light by a single projector, the incident angle and the illuminance of the irradiation light may be different depending on the positions separated from each other in the marking area. Differences occur. Especially, when the length of the marking area cannot be regarded as sufficiently smaller than the distance from the projector to the marking area, the above difference becomes large. Therefore, the dependency of the amount of diffusely reflected light detected by the light receiving sensor on the position in the marking area becomes large, and the reliability of marking reading may be reduced.

However, by irradiating the marking area with light from a plurality of projectors from a plurality of end sides, it is possible to reduce the difference in the incident angle and the illuminance. Therefore, the position dependency of the detected light amount is reduced, and therefore, both the marking reading accuracy and the reliability can be improved.

In the marking reading device according to the tenth aspect, the laser beam from the laser device is applied to the marking area on the surface of the target member, and the diffuse reflection light is extracted from the direction deviating from the direction of specular reflection. The collected diffuse reflection light is detected by the 0-dimensional photoelectric conversion element. At that time, the irradiation spot of the laser beam is scanned over the entire marking area by scanning the laser beam or the target member, and the diffuse reflection light from the marking area is detected as a one-dimensional or two-dimensional image.

When scanning the irradiation spot, the incident angle of the laser beam with respect to the marked surface area, the area of the irradiation spot on the marking, and the surface area of the diffuse reflection light detected by the light receiving sensor are marked. The four physical quantities of the reflection angle with respect to and the solid angle of the diffuse reflection light detected by the photoelectric conversion element are fixed.

The detected light quantity of the diffuse reflected light strongly depends on these four physical quantities in addition to the surface roughness of the reflecting surface. By eliminating or suppressing the fluctuation of these physical quantities during scanning, the disturbance can be prevented. It is possible to suppress and clearly distinguish the difference in surface roughness.

Further, even if the marking surface is a curved surface or the marking area covers a wide range, the reading can be performed with high reliability.

Further, since the light receiving sensor converts the amount of input light into an electric signal and detects it, various data processing can be performed at the time of identifying the surface roughness and the pattern.
It can be read easily.

In the marking reading device according to the eleventh aspect, since the intensity of the irradiation light is temporally stable by using the CW light source, even in the case where the laser device, the light receiving sensor and the mechanical scanning means are provided. The dependency of the detection light amount by the light receiving sensor on the detection timing and the risk of insufficient detection light amount due to it are almost eliminated. Therefore, both reading accuracy and reliability can be improved.

[Brief description of drawings]

FIG. 1 shows a first marking reading device according to the present invention.
1 is an overall configuration diagram of an embodiment.

FIG. 2 is a diagram generally showing the light diffusivity of the surface and the directional characteristics of luminance.

FIG. 3 is a diagram illustrating a general relationship between surface light diffusivity and surface roughness.

FIG. 4 is an overall configuration diagram of a second embodiment of the present invention.

FIG. 5 is an overall configuration diagram of a third embodiment of the present invention.

[Explanation of symbols]

 1, 1A, 1B Marking / reading device 2 Target member 2a Surface of target member 2b Mechanical polishing surface 3 Marking 4a, 4b Pair of light emitting diode projector 5 Collecting optical system 5a Lens 5b Aperture member 5c Shading cover 6 CCD image sensor 7 Data processing Device 8 Signal cable 9 Photoelectric conversion surface 11a XY drive stage 11b XY drive stage controller 12 CW laser device 13 Photoelectric conversion element 15 Irradiation optical system 15b Mirror

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobutada Aoki, No. 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa, Ltd. Inside the Toshiba Yokohama Works (72) Inventor, Yuji Sano, No. 8, Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Ceremony Company Toshiba Yokohama Works (72) Inventor Akitaka Yamada 1-1 1-1 Shibaura, Minato-ku, Tokyo Inside Toshiba Headquarters Co., Ltd. (72) Inventor Toshio Hagihara 26-23 Sakamachi, Shinjuku-ku, Tokyo 23 (72) Inventor Osamu Kodaira 1-34-2 Tamagawa, Chofu-shi, Tokyo Token Techno Co., Ltd.

Claims (11)

[Claims] 1. A target object made of metal, which is preliminarily provided with markings having a pattern composed of a region having a smooth surface and a region having a rougher surface, is irradiated with irradiation light, and Diffuse reflected light from the marking of irradiation light is collected from a direction deviating from the direction of specular reflection determined by the marking surface of the target member and the traveling direction of the irradiation light, A marking reading method for reading the above-mentioned marking based on a difference between a detected light amount of diffuse reflected light from a smooth region and a detected light amount of diffuse reflected light from a rough region. 2. A light projector for irradiating a target object made of metal, which has a marking having a pattern composed of an area having a smooth surface and an area having a surface rougher than the surface, with irradiation light. A sampling optics for sampling the diffuse reflection light of the irradiation light by the marking from a direction deviating from the direction of regular reflection determined by the marked surface portion of the target member and the traveling direction of the irradiation light. A system, a light receiving sensor that detects the diffused reflected light sampled, a detected light amount of the diffuse reflected light from the smooth area of the marking detected by the light receiving sensor, and a detected light amount of the diffuse reflected light from the rough area. A reading device for reading the above-mentioned marking based on the difference between the marking reading device and the marking reading device. 3. The marking reading device according to claim 2, wherein the light projector includes a mechanical polishing surface when the surface of the target member is a mechanical polishing surface.
A marking reading device characterized in that it is configured to irradiate light in a direction orthogonal to the striation direction of the mechanical polishing. 4. The marking reading device according to claim 2, wherein the projector has a wide-angle radiation light source capable of irradiating the entire marking area at one time, and the light receiving sensor is a one-dimensional or two-dimensional imaging device. A marking reading device characterized in that 5. The marking reading device according to claim 2, wherein the projector has a direct-current light source. 6. The marking reading device according to claim 2, wherein the projector has a light source that is turned on at a high frequency at a cycle that is equal to or less than a detection time of the light receiving sensor. . 7. The marking reading device according to claim 2, wherein the light receiving sensor is a CCD (charge coupled device) image sensor. 8. The marking reading device according to any one of claims 2 to 7, which is an incident angle of irradiation light with respect to a marked surface area of a target member, and the surface area marked with the irradiation light. The angle formed by the traveling direction of the irradiation light with respect to the perpendicular is 45 ° to 70 °,
Moreover, it is the reflection angle of the diffuse reflection light from the marking area of the target member detected by the light receiving sensor, and the angle formed by the traveling direction of the reflection light with respect to the perpendicular of the marked surface is 0 ° to 10 °. A marking reading device characterized by: 9. The marking reading device according to claim 2, wherein the marking reading device has a plurality of projectors. 10. The marking reading device according to claim 2, wherein the projector is a laser device instead of a light source for direct current lighting or high frequency lighting, and the light receiving sensor is one-dimensional or two-dimensional. A three-dimensional photoelectric conversion element instead of a three-dimensional image pickup device, means for scanning an irradiation spot of a laser beam from the laser device above a marking area, and an incident angle of the laser beam with respect to the marked surface area. A means for fixing the area of the irradiation spot on the marking, the reflection angle of the diffuse reflected light detected by the light receiving sensor with respect to the marked surface, and the solid angle of the diffuse reflected light detected by the light receiving sensor. A marking reading device comprising: 11. The marking reading device according to claim 10, wherein the projector is a CW laser device that outputs a CW laser beam.