JP4000890B2 - Inner surface observation method and inner surface observation apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for observing the inner surface of a cylinder or the like.
[0002]
[Prior art]
An apparatus for observing the inner surface of a cylinder or the like is disclosed in Japanese Patent Laid-Open Nos. 9-89788 and 2001-281556. In these conventional apparatuses, a mirror image of the inner surface of the hole reflected on the cone mirror is taken with a camera. In these conventional devices, the cone mirror picks up irregularly reflected light from the inner surface of the hole. In the apparatus disclosed in Japanese Patent Laid-Open No. 9-89788, the amount of reflected light from the defect on the inner surface of the hole toward the cone mirror is larger than the amount of reflected light from the normal surface toward the cone mirror, and the photographed image that the normal surface is dark and the defective portion is bright. can get. In the apparatus disclosed in Japanese Patent Laid-Open No. 2001-281556, a captured image is obtained in which a normal surface is bright and a defective portion is dark.
[0003]
[Problems to be solved by the invention]
However, in a photographed image using diffusely reflected light, the contrast between the defective part and the normal part is low, and a good-quality photographed image cannot be obtained.
[0004]
An object of the present invention is to obtain a high-quality captured image in which the contrast between a defective portion and a normal portion is increased.
[0005]
[Means for Solving the Problems]
The first to fourth aspects of the invention are directed to the inner surface observation device. In the first and second aspects of the invention, a camera for photographing the inner surface of the hole to be observed and the projection to the inner surface of the hole to be observed. A surface light emitting means having a light emitting surface for generating diffuse light, and a regular reflected light guiding means for guiding the regular reflected light from the inner surface of the hole related to the diffused light projected from the surface light emitting means to the inner surface of the hole, to the camera. The inner surface observation apparatus provided with was comprised.
[0006]
Light projected from the light emitting surface that generates diffused light to the inner surface of the hole is reflected in the form of regular reflection or irregular reflection on the inner surface of the hole. The regular reflection light guiding means guides regular reflection light from the inner surface of the hole to the camera. The ratio of the specularly reflected light from the defective part on the inner surface of the hole toward the camera is small compared to the ratio of the specularly reflected light from the normal part on the inner surface of the hole toward the camera. High contrast. Therefore, a high quality image can be obtained.
[0007]
Further, in the invention of claim 1 and 2, prior SL-emitting surface has a circumferential surface shape.
The light emitting surface having a circumferential surface shape is optimal for observation of the inner surface of the cylinder.
Particularly, in the invention of claim 1, wherein the surface-emitting means, the cylindrical body is diffused from the previous SL-emitting surface light, the light emitting surface was the outer circumferential surface of the cylindrical body.
[0008]
Such a surface emitting means is simple.
Particularly, in the invention of claim 2, constitute the regular reflection light guiding means comprising a co Nmira, the said cone mirror and the camera is disposed on the light emitting surface of the axis of the circumferential surface shape, the cone The axis of the mirror coincides with the axis of the light emitting surface, and at least a part of the specularly reflected light related to the diffused light projected from the light emitting surface onto the inner surface of the hole to be observed is reflected and guided to the camera side by the cone mirror. I made it.
[0009]
The surface light emitting means projects diffused light to the entire circumference of the hole inner surface, and the cone mirror projects the entire circumference of the hole inner surface. The cone mirror is suitable as a constituent part of the regular reflection light guiding means.
According to a third aspect of the present invention, in the second aspect, the base angle of the conical surface of the cone mirror is an angle other than 45 °.
[0010]
A cone mirror having a base angle of 45 ° is not suitable as a component of the regular reflection light guiding means.
According to a fourth aspect of the present invention, the surface light emitting means is formed in a cylindrical body that transmits light.
Invention of Claim 5 is an inner surface observation method which observes a hole inner surface using the inner surface observation apparatus as described in any one of Claims 1-4, Comprising: The diffused light produced | generated by surface emission of observation object The reflected light of the diffused light projected on the inner surface of the hole and regularly reflected by the inner surface of the hole is captured by a camera and photographed.
[0011]
The method of capturing and photographing the specularly reflected diffused light that is specularly reflected from the inner surface of the hole increases the contrast between the normal part and the defective part.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0013]
As shown in FIG. 1A, a CCD camera 11 is installed on the table 10, and a support block 12 is installed in front of the CCD camera 11. The support block 12 supports a light source 13 and a surface light emitting device 14 in series.
[0014]
As shown in FIG. 1B, the surface light emitting device 14 includes a transparent acrylic resin guide rod 15, a cylindrical body 16 made of white resin for light diffusion, and a cone built in the cylindrical body 16. The reflector 17 has a shape. The light projected from the light source 13 is totally reflected on the peripheral surface of the guide rod 15 or travels through the guide rod 15 toward the reflecting mirror 17 without being reflected. The light that has traveled through the guide rod 15 toward the reflecting mirror 17 enters the cylindrical body 16 from the end face of the guide rod 15. A part of the entering light into the cylindrical body 16 is reflected by the reflecting mirror 17 toward the inner peripheral surface side of the cylindrical body 16, and a part of the entering light is not reflected by the reflecting mirror 17 and the inner peripheral surface of the cylindrical body 16. Head to. The light traveling toward the inner peripheral surface of the cylindrical body 16 is transmitted while diffusing through the wall of the cylindrical body 16, and the light transmitted through the cylindrical body 16 is diffused from the outer peripheral surface 161 of the cylindrical body 16.
[0015]
A cone mirror 18 is fixed to the tip of the cylindrical body 16. The axis 181 of the conical surface 183 of the cone mirror 18 and the optical axis 111 of the CCD camera 11 are matched. An axis 162 of the outer peripheral surface 161 as a light emitting surface is made to coincide with the axis 181. A cylindrical observation object 19 is disposed between the CCD camera 11 and the cone mirror 18. The observation object 19 is reciprocated in the direction of the optical axis 111 by the reciprocating drive means 20.
[0016]
Projection lights S 1 and T 1 indicated by arrows in FIG. 2A represent light projected from the outer peripheral surface 161 of the cylindrical body 16 toward the hole inner surface 191 of the observation object 19. The specularly reflected light S <b> 2 and T <b> 2 indicated by arrows represent light that is specularly reflected from the hole inner surface 191 of the observation object 19 toward the conical surface 183 of the cone mirror 18. Reflected light S3 and T3 indicated by arrows represent light regularly reflected from the cone mirror 18 toward the CCD camera 11. Reflected light S3 and T3 indicated by arrows are parallel to the optical axis 111 of the CCD camera 11. The CCD camera 11 captures the reflected light from the cone mirror 18 and takes a mirror image of the cone mirror 18, that is, the hole inner surface 191 of the observation object 19.
[0017]
It is assumed that a part of the hole inner surface 191 of the observation object 19 is inclined with respect to the optical axis 111 of the CCD camera 11 (accordingly, the axis 181 of the cone mirror 18) as indicated by the inclined line L1 in FIG. The projected light U1 indicated by an arrow in FIG. 3 is light projected from the outer peripheral surface 161 of the cylindrical body 16 to the hole inner surface 191, and the specularly reflected light U2 indicated by the arrow is a conical surface of the cone mirror 18 at an inclination line L1. The light regularly reflected toward 183 is represented. The reflected light U3 indicated by the arrow represents the light that is regularly reflected from the cone mirror 18 toward the CCD camera 11. If the reflected light U3 is parallel to the optical axis 111 of the CCD camera 11, the reflected light U3 is reliably captured by the CCD camera 11. In order for the reflected light U3 parallel to the optical axis 111 to exist, the projection light U1 has only to be projected from the range [u1, u2] on the outer peripheral surface 161 shown in FIG.
[0018]
It is assumed that a part of the hole inner surface 191 of the observation object 19 is inclined with respect to the optical axis 111 of the CCD camera 11 (accordingly, the axis 181 of the cone mirror 18) as indicated by the inclined line L2 in FIG. The projected light Y1 indicated by an arrow in FIG. 4 is light projected from the outer peripheral surface 161 of the cylindrical body 16 to the hole inner surface 191, and the specularly reflected light Y2 indicated by the arrow is a conical surface of the cone mirror 18 at an inclination line L2. The light regularly reflected toward 183 is represented. The reflected light Y3 indicated by the arrow represents the light that is regularly reflected from the cone mirror 18 toward the CCD camera 11. If the reflected light Y3 is parallel to the optical axis 111 of the CCD camera 11, the reflected light Y3 is reliably captured by the CCD camera 11. In order for the reflected light Y3 parallel to the optical axis 111 to exist, the projection light Y1 has only to be projected from the range [y1, y2] on the outer peripheral surface 161 shown in FIG.
[0019]
The incident angle θo shown in FIGS. 3 and 4 is an incident angle of the projection lights S1 and T1 with respect to the hole inner surface 191. In order for the reflected lights S3 and T3 related to the projected lights S1 and T1 to exist, the projected lights S1 and T1 may be projected from the range [z1, z2] on the outer peripheral surface 161 shown in FIGS.
[0020]
FIG. 5 collectively shows the ranges [u1, u2], [y1, y2], [z1, z2] shown in FIGS. 3 and 4.
When the reflected light U3 is parallel to the optical axis 111 of the CCD camera 11, the incident angle θ1 of the projection light U1 with respect to the hole inner surface 191 is as shown in FIG. The tilt angle α is the tilt angle of the tilt line L1 with respect to the hole inner surface 191.
[0021]
The incident angle θ1 is expressed by the following formula (1).
θ1 = θo + 2α (1)
When the reflected light Y3 is parallel to the optical axis 111 of the CCD camera 11, the incident angle θ2 of the projection light Y1 with respect to the hole inner surface 191 is as shown in FIG. The inclination angle β is an inclination angle of the inclination line L2 with respect to the hole inner surface 191. The incident angle θ2 is expressed by the following equation (2).
[0022]
θ2 = θo−2β (2)
In FIG. 5, the length H of the range [y1, u2] is expressed by the following equation (3).
H = I + d / tan θ 2 − (IM−d · tan γ) (3)
However, as shown in FIG. 5, d is the distance between the outer peripheral surface 161 and the hole inner surface 191, and M is the length of the range [z1, z2]. I represents a distance from a plane P (shown in FIG. 5) orthogonal to the hole inner surface 191 to the bottom 182 of the cone mirror 18. γ (shown in FIG. 5) is an angle of (90 ° −θ1). M is represented by the following formula (4).
[0023]
M = h−W / tan [2 (90 ° −δ)] (4)
h (shown in FIG. 5) represents the length of the cone mirror 18, and W (shown in FIG. 5) represents the width of the cone mirror 18. δ (shown in FIG. 5) represents the base angle of the cone mirror 18. In the present embodiment, the base angle δ is larger than 45 °.
[0024]
The length H expressed by the equation (3) is arranged as the following equation (5).
H = d / tan θ2 + M−d · tan γ (5)
A distance D (shown in FIG. 5) between the range [z1, z2] and the bottom 182 of the cone mirror 18 is expressed by the following equation (6).
[0025]
D = I + d / tan θo−M (6)
The following effects can be obtained in the first embodiment.
(1-1) Light projected from the outer peripheral surface 161 serving as a light emitting surface for generating diffused light to the hole inner surface 191 is reflected by the hole inner surface 191 in the form of regular reflection or irregular reflection. The cone mirror 18 as the regular reflection light guiding means guides the regular reflection light from the hole inner surface 191 to the CCD camera 11. As shown in FIG. 2B, the ratio of specularly reflected light from the defective portion K toward the camera on the hole inner surface 191 is the ratio of specularly reflected light S2 and T2 from the normal portion on the hole inner surface 191 to the camera. Is slight. As a result, the contrast between the normal portion and the defective portion K captured by the CCD camera 11 is increased, and a high-quality image can be obtained.
[0026]
(1-2) The observation of the hole inner surface 191 of the cylindrical observation object 19 is favorably performed by uniformly illuminating the entire circumference of the hole inner surface 191. The outer peripheral surface 161 of the cylindrical body 16 is a circumferential light emitting surface. The circumferential light emitting surface is optimal for illuminating the entire circumference of the hole inner surface 191 of the cylindrical observation object 19 almost uniformly. That is, the circumferential light emitting surface is optimal for observing the inner surface.
[0027]
(1-3) The cylindrical body 16 constitutes a surface light emitting means that transmits light and diffuses it from the outer peripheral surface 161 as a light emitting surface. A configuration in which the light emitting surface is formed using the cylindrical body 16 made of white resin is simple.
[0028]
(1-4) The cone mirror 18 reflects the entire circumference of the hole inner surface 191, and a mirror image of the entire circumference of the hole inner surface 191 in the cone mirror 18 is taken by the CCD camera 11. The cone mirror 18 that reflects the entire circumference of the hole inner surface 191 is suitable as a component of the regular reflection light guiding means.
[0029]
(1-5) The base angle δ of the conical surface 183 of the cone mirror 18 is an angle other than 45 °. The cone mirror having a base angle δ of 45 ° cannot reflect the regular reflected light from the hole-shaped inner surface 191 toward the CCD camera 11 in a state parallel to the optical axis 111 of the CCD camera 11. That is, a cone mirror having a base angle δ of 45 ° is inappropriate as a component of the regular reflection light guiding means for the inner surface 191 of the circumferential shape, and the cone mirror 18 having a base angle δ other than 45 ° is not suitable. The inner surface observation apparatus provided with is suitable for an observation object provided with a circumferentially shaped hole inner surface.
[0030]
(1-6) In order to efficiently guide the regular reflection light from the hole inner surface 191 toward the CCD camera 11 by the cone mirror 18, it is necessary to send the regular reflection light from the hole inner surface 191 to the entire width W of the cone mirror 18. There is. The length M of the range [z1, z2] shown in FIG. 5 is the length of the light emitting surface necessary for efficiently guiding the specularly reflected light from the hole inner surface 191 toward the CCD camera 11 by the cone mirror 18. . Further, the configuration in which the range [z1, z2] is separated from the bottom 182 of the cone mirror 18 by the distance D is necessary to send the specularly reflected light from the hole inner surface 191 to the entire width W of the cone mirror 18. That is, the configuration having the surface emission region of the range [z1, z2] of the length M at a position away from the bottom 182 of the cone mirror 18 by the distance D is important for obtaining a good image by the CCD camera 11. .
[0031]
(1-7) As shown in FIG. 5, when the hole inner surface 191 is cut, a tool mark J may be generated. The tool mark J composed of the surfaces of the inclination angles α and β indicated by the inclination lines L1 and L2 is a slight dent generated when the processing tool is cut, but the tool mark J may be observed as a defective portion. is there. In order to distinguish the tool mark J from the original defective part, it is necessary to obtain an image in which the contrast between the tool mark J and the normal part is weakened. When the surface of the inclination angle α indicated by the inclination line L1 exists in the hole inner surface 191, the range [z2, u2] contributes to the reduction of the contrast between the surface of the inclination angle α indicated by the inclination line L1 and the normal portion. . When the surface of the inclination angle β indicated by the inclination line L2 exists in the hole inner surface 191, the range [y1, z1] contributes to the reduction of the contrast between the surface of the inclination angle β indicated by the inclination line L2 and the normal portion. . That is, the configuration in which the ranges [z2, u2] and [y1, z1] are added to the range [z1, z2] of the length M that is separated from the bottom 182 of the cone mirror 18 by the distance D is as follows. This is effective in obtaining an image with a low contrast.
[0032]
(1-8) As shown in FIG. 6, even when the observation object 19 </ b> A is changed and the diameter of the hole inner surface 192 is changed, the inner surface observation apparatus of the present embodiment including the cylindrical body 16 and the cone mirror 18. The hole inner surface 192 can be observed.
[0033]
(1-9) The inner surface observation apparatus of the present embodiment including the cylindrical body 16 and the cone mirror 18 enables observation of the hole inner surface 194 of the observation object 19B having the taper 193 as shown in FIG.
[0034]
Next, a second embodiment shown in FIGS. 8A and 8B will be described. The same reference numerals are used for the same components as those in the first embodiment.
As shown in FIG. 8A, a CCD camera 11 is installed on the table 10, and a support cylinder 21 is installed in front of the CCD camera 11. The light source 13 is supported on the support cylinder 21. A pair of transparent glass disks 22 and 23 are fitted in the cylinder of the support cylinder 21, and a transparent acrylic resin guide rod 24 is supported on the glass disks 22 and 23. One end of the guide rod 24 is formed on a 45 ° total reflection surface 241. As shown in FIG. 8B, a cone mirror 25 and a cylindrical body 26 made of white resin for light diffusion are fixed to the other end portion of the guide rod 24, and reflected on the end face of the cylindrical body 26. The mirror 27 is fixed. The axis 251 of the conical surface 252 of the cone mirror 25 and the optical axis 111 of the CCD camera 11 are matched.
[0035]
Light projected from the light source 13 (indicated by an arrow F1 in FIG. 8A) is reflected toward the reflecting mirror 27 by the total reflection surface 241 of the guide rod 24. The light reflected by the total reflection surface 241 (indicated by an arrow F2 in FIG. 8A) is totally reflected by the peripheral surface of the guide rod 24, or is not reflected inside the guide rod 24 toward the reflecting mirror 27. move on. The light traveling in the guide rod 24 toward the reflecting mirror 27 enters the cylindrical body 26 from the end face of the guide rod 24. A part of the entering light into the cylindrical body 26 is reflected by the reflecting mirror 27 toward the inner peripheral surface side of the cylindrical body 26, and a part of the entering light is not reflected by the reflecting mirror 27 and the inner peripheral surface of the cylindrical body 26. Head to. The light traveling toward the inner peripheral surface of the cylindrical body 26 is transmitted while diffusing through the wall of the cylindrical body 26, and the light transmitted through the cylindrical body 26 is diffused from the outer peripheral surface 261 of the cylindrical body 26.
[0036]
The outer peripheral surface 261 of the cylindrical body 26 is a light emitting surface that generates diffused light for projection onto the inner surface of the hole to be observed. The guide rod 24, the cylindrical body 26, and the reflecting mirror 27 constitute surface emitting means having a light emitting surface.
[0037]
The observation object 28 is reciprocated in the direction of the optical axis 111 by the reciprocating drive means 20.
The projected light G1 indicated by an arrow in FIG. 8A represents light projected from the outer peripheral surface 261 of the cylindrical body 26 toward the hole inner surface 281 of the observation target 28, and the regular reflection light G2 indicated by the arrow is the observation target. The light regularly reflected from the inner surface 281 of the hole 28 toward the conical surface 252 of the cone mirror 25 is represented. The reflected light G <b> 3 indicated by the arrow represents the light that is regularly reflected from the cone mirror 25 toward the CCD camera 11. The reflected light G <b> 3 is parallel to the optical axis 111 of the CCD camera 11. The CCD camera 11 captures the reflected light from the cone mirror 25 and takes a mirror image of the cone mirror 25, that is, the hole inner surface 281 of the observation object 28.
[0038]
A glass disk 29 is fitted into the inner end of the support cylinder 21 on the CCD camera 11 side, and a disk-shaped shield 30 is supported on the glass disk 29. The diameter of the shield 30 is slightly larger than the diameter of the guide rod 24. The peripheral edge of the total reflection surface 241 may cause halation at the peripheral edge of the total reflection surface 241 due to the light projected from the light source 13 onto the total reflection surface 241. When such halation is photographed, a good photographed image cannot be obtained. The shield 30 prevents the photographing of halation occurring at the periphery of the total reflection surface 241.
[0039]
In the second embodiment, the same effects as in the first embodiment can be obtained. Moreover, in the second embodiment, it is possible to photograph the inner surface 281 of the dead end hole. In addition, since the position of the observation object 28 is not between the CCD camera 11 and the support tube 21, it is not necessary to limit the size of the observation object 28.
[0040]
Next, a third embodiment of FIG. 9 will be described. The same reference numerals are used for the same components as those in the first embodiment.
The cylindrical support cylinder 31 is made of a transparent material (resin or glass), and the axis 311 of the support cylinder 31 is aligned with the optical axis 111 of the CCD camera 11. A light emitting tube 32 is fitted on the outer peripheral surface of the support tube 31. The outer peripheral surface of the light emitting cylinder 32 is a light emitting surface 321 that generates diffused light. The light emitting cylinder 32 serves as a surface light emitting means having a light emitting surface.
[0041]
A cone mirror 33 is attached in the cylinder of the support cylinder 31. The axis 331 of the conical surface 332 of the cone mirror 33 is made to coincide with the axis 311 of the support cylinder 31. The base angle δ of the cone mirror 33 is smaller than 45 °.
[0042]
Light projected from the light emitting tube 32 as a light source (indicated by an arrow N1 in FIG. 9) travels toward the hole inner surface 191 of the observation object 19. The specularly reflected light N <b> 2 indicated by an arrow represents light that is specularly reflected from the hole inner surface 191 of the observation object 19 toward the conical surface 332 of the cone mirror 33. The reflected light N3 indicated by the arrow represents the light that is regularly reflected from the cone mirror 33 toward the CCD camera 11. The reflected light N3 is parallel to the optical axis 111 of the CCD camera 11. The CCD camera 11 captures the reflected light from the cone mirror 33 and takes a mirror image of the cone mirror 33, that is, the hole inner surface 191 of the observation object 19.
[0043]
In the third embodiment, the same effects as the items (1-1), (1-2), and (1-4) to (1-9) in the first embodiment can be obtained.
In the present invention, the following embodiments are also possible.
[0044]
(1) In the first embodiment, a surface light emitting means having only a light emitting surface in a range [z1, z2] of a length M separated from the bottom 182 of the cone mirror 18 by a distance D is used.
[0045]
(2) In the first embodiment, the range [z2, u2], [y1, z1] is added to the range [z1, z2] of the length M separated from the bottom 182 of the cone mirror 18 by the distance D. Use surface emitting means having only the light emitting surface.
[0046]
(3) In the first embodiment, surface light emitting means in which a light source is accommodated in the cylindrical body 16 is used.
(4) As shown in FIG. 5, only reflected light in a partial range [ω1, ω2] (range between the position ω1 and the position ω2) of the conical surface 183 of the cone mirror 18 is used for photographing. . Alternatively, use a cone mirror in which only the range [ω1, ω2] is a mirror.
[0047]
(5) In the first embodiment, the observation object 19 and the CCD camera 11 are fixed, and the light source 13, the cylindrical body 16 and the cone mirror 18 are moved integrally while the focus and magnification are adjusted in the CCD camera 11. To do.
[0048]
(6) In the first embodiment, the observation object 19 is fixed, and the CCD camera 11, the light source 13, the cylindrical body 16, and the cone mirror 18 are integrated together while maintaining the distance between the CCD camera 11 and the cone mirror 18. Move and shoot.
[0049]
In this case, since the distance between the CCD camera 11 and the cone mirror 18 is constant, focus adjustment of the CCD camera 11 is unnecessary.
[0050]
【The invention's effect】
In the present invention, the diffused light generated by the surface light emission is projected onto the inner surface of the observation target, and the specularly reflected light of the diffused light that is specularly reflected by the inner surface is captured and photographed. There is an excellent effect that it is possible to obtain a high-quality photographed image with a high contrast with the portion.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a first embodiment. (B) is a principal part expanded side sectional view.
FIGS. 2A and 2B are enlarged side sectional views of main parts.
FIG. 3 is an enlarged side view of a main part for explaining light reflection.
FIG. 4 is an enlarged side view of a main part for explaining light reflection.
FIG. 5 is an enlarged side view of a main part for explaining light reflection.
FIG. 6 is an enlarged side sectional view of a main part.
FIG. 7 is an enlarged side sectional view of a main part.
FIG. 8 shows a second embodiment, and (a) is a side sectional view. (B) is a principal part expanded side sectional view.
FIG. 9 is an enlarged side cross-sectional view of a main part showing a third embodiment.
[Explanation of symbols]
11 ... CCD camera as a camera. 16, 26... Cylindrical body constituting the surface light emitting means. 161, 261 ... An outer peripheral surface as a surface emitting surface. 162: Axis of surface emitting surface. 18, 25, 33... Cone mirror constituting regular reflection light guiding means. 181 251 331... Axis of the cone mirror. 183, 252, 332 ... Conical surface. 19, 19A, 19B, 28 ... observation object. 191, 192, 194, 281... 32: A light emitting tube as a surface light emitting means. 321 ... Light emitting surface.

Claims (5)

A camera for photographing the inner surface of the hole to be observed;
A surface light emitting means having a light emitting surface for generating diffused light to be projected onto the inner surface of the hole to be observed;
Specular reflection light guiding means for guiding specular reflection light from the inner surface of the hole related to the diffused light projected from the surface light emitting means to the inner surface of the hole ;
The surface illuminating means is a cylindrical body that diffuses light from the light emitting surface, and the light emitting surface is an outer surface of the cylindrical body having a circumferential shape . A camera for photographing the inner surface of the hole to be observed;
A surface light emitting means having a light emitting surface for generating diffused light to be projected onto the inner surface of the hole to be observed;
Specular reflection light guiding means for guiding specular reflection light from the inner surface of the hole related to the diffused light projected from the surface light emitting means to the inner surface of the hole;
The light emitting surface, Ri circumferential surface shape der,
The regular reflection light guiding means includes a cone mirror, the cone mirror and the camera are arranged on an axis of the light emitting surface of the circumferential surface, and the axis of the cone mirror and the axis of the light emitting surface , And at least a part of specularly reflected light related to diffused light projected from the light emitting surface onto the inner surface of the hole to be observed is reflected and guided to the camera side by the cone mirror . The inner surface observation apparatus according to claim 2, wherein a base angle of the conical surface of the cone mirror is an angle other than 45 ° . The inner surface observation apparatus according to claim 1 , wherein the surface light emitting unit is formed in a cylindrical body that transmits light . An inner surface observation method for observing an inner surface of a hole using the inner surface observation apparatus according to any one of claims 1 to 4, wherein the diffused light generated by surface light emission is projected onto the inner surface of the hole to be observed, An inner surface observation method for capturing and photographing the specularly reflected light of the diffused light specularly reflected on the inner surface of a hole .

Images