JPH0771945A - Method and device for measuring surface shape - Google Patents

Abstract

PURPOSE:To precisely analyze the surface condition of an object as to gloss, etc., by applying light to the surface for analysis of an object with the varying angle of illumination of plural illuminating light paths, measuring the reflectivity of the light, and comparing the reflectivity with a reference reflectivity measured in advance. CONSTITUTION:To measure the surface reflectivity of the skin of a human body, a head 4 is made to abut on a predetermined portion to be measured, and inputs from an input portion 6, a control portion 7 and an output portion 8 are turned on to measure the surface reflectivity of the skin. Light is applied to the surface for analysis of an object from one of plural illuminating light paths 2a, 2b and a plurality of receiving light paths 3c-3d each receive the illuminating light reflected from the surface for analysis. While an angle of analysis, which is the sum of the angle at which the optical paths 3c-3e receive the light and the angle at which the optical paths 2a, 2b give off light, is varied by the selecting of the optical paths 2a, 2b in sequence, the reflectivity of the light on the surface for analysis is measured and compared with the premeasured reflectivity of light on a reference surface, so as to analyze the surface condition of the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface texture measuring method and apparatus for analyzing the surface condition of an object, particularly the condition such as "texture", "gloss" and "luster" on the skin surface of a human body.

[0002]

2. Description of the Related Art Generally, as a method of analyzing surface conditions such as unevenness, flatness, gloss, and gloss of an object surface, a method of measuring light reflectance on the object surface is known. For example, in Japanese Unexamined Patent Publication (Kokai) No. 52-62082, the surface of the mirror surface is irradiated with light, the reflected light of the irradiation light is detected by an analyzer, and the specular reflection intensity is measured to determine the flatness of the mirror. A method for analyzing the surface condition of the above is disclosed.

Further, Japanese Patent Laid-Open No. 2-57949 discloses that
A technique is disclosed in which the illuminator is fixed and the light-receiving angle of the light-receiving device is variously changed to measure the skin surface, that is, the incident angle is constant and the light-receiving angle is variously 20 °, 45 °, 60 °, and the like. The intensity of the reflected light from the reflecting surface at each angle is changed, and the specular glossiness and the like are analyzed.

[0004]

However, in the former prior art described above, the incident angle and the light receiving angle are fixed, and a constant angle is always formed for measurement. Therefore, when measuring the flatness of a target surface to be analyzed, such as a mirror, it is sufficient to receive only a certain amount of reflected light, but in a complicated direction such as the skin of the human body. It is not possible to analyze the condition such as the gloss of the surface to be analyzed having the unevenness.

On the other hand, in the latter prior art, since the light receiving angle is changed, it is possible to analyze the surface state having complicated irregularities such as skin, but the angle formed by the light receiving optical path is changed. It is not possible to measure the minute surface distribution on the surface to be analyzed only by performing the above. Here, the minute surface is a surface that faces various directions forming the wall surface of the uneven surface of the skin, and the minute surface distribution means a distribution state of the minute surface that faces a certain direction. That is, when measuring gloss or the like on a surface to be analyzed having complicated irregularities such as the skin, it is necessary to measure the fine surface distribution that forms the irregular surface, because the degree of flatness or reflection is not sufficient. .

Specifically, the reflected light on the surface of the object having a rough shape is distributed over a wide angle range. However, in order to efficiently measure the reflected light distribution, not only the light receiving angle but also the irradiation angle is set. It is necessary to make various changes and automatically perform the measurement in a short time. Also, in order to analyze the surface condition by associating the appearance of "luster", "glossy", etc. on the surface of an object with a rough shape with the shape of the surface of the object, the irradiation light path and the receiving light path must be combined. It is necessary to measure the reflection intensity by variously changing the angle formed by. Because
This is because the reflected light distribution measured by this method coincides with the distribution of the minute bare surface that bisects the irradiation direction and the light receiving direction. However, the conventional technology cannot measure such a minute surface distribution, and cannot accurately measure the “skin gloss” and “skin gloss” of the skin surface having complicated unevenness. was there.

Accordingly, an object of the present invention is to provide a surface texture measuring method and apparatus capable of accurately analyzing the states of "texture", "gloss", "luster", etc. on the surface of an object.

[0008]

SUMMARY OF THE INVENTION The present invention irradiates a surface to be analyzed of an object surface with light from one of a plurality of irradiation light paths having different irradiation angles, and the reflected light of the irradiation light reflected by the surface to be analyzed. Are received by a plurality of light-receiving optical paths having different light-receiving angles, and the irradiation angle of the irradiation optical path is changed by variously selecting the plurality of irradiation optical paths to obtain various analysis angles that are the sum of the light-receiving angle and the irradiation angle. Alternately, the surface is characterized by measuring the light reflectance to the surface to be analyzed at a plurality of analysis angles and comparing the light reflectance of the reference surface measured in advance to analyze the state of the surface of the object. The above object is achieved by providing a property measuring method. Furthermore, the present invention irradiates light on the surface to be analyzed of the object surface, a plurality of irradiation optical paths having mutually different irradiation angles, and a plurality of light receiving optical paths for receiving reflected light of the irradiation light reflected on the surface to be analyzed, An input unit for selecting various ones of the plurality of irradiation light paths, a control unit for converting the reflectance of the light received from all the light receiving optical paths into an output signal, and comparison with the reflectance of the light on the reference surface measured in advance. The present invention has achieved the above object by providing a surface texture measuring device characterized by comprising an output unit for analyzing the condition of the skin surface.

[0009]

According to the surface texture measuring method of the present invention, first, one of a plurality of irradiation light paths set in advance at a predetermined angle is specified, the irradiation light is guided to the surface to be analyzed of the object surface, and the light receiving angles are mutually different. The reflected light intensities in the plurality of light receiving optical paths different from each other are measured. Subsequently, the other irradiation optical paths having different irradiation angles are similarly measured, and the reflected light intensities at various irradiation angles and various light receiving angles are measured. Next, the reflected light distribution is compared with a reference reflected light distribution in advance from the above-described reflectance measurement values, and the "texture", "gloss", and "luster" of the measured object surface are compared.
Analyze the surface condition of the etc.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. In the following examples, the case where human skin is used as the analyzed surface will be described.
First, the surface texture measuring device 1 used in the examples of the present invention will be described. The surface texture measuring device 1 is shown in FIG.
As shown in FIG. 4, the irradiation optical paths 2a to 2d and the receiving optical path 3 are shown.
a to 3e are arranged, the head 4 to be applied to the surface to be analyzed, the irradiation light paths 2a to 2d and the light reception light paths 3a to 3d in the head 4 are arranged.
It is composed of a main body 5 for controlling 3e.

The main body 5 includes an input section 6 for controlling the light sources of the irradiation optical paths 2a to 2d and the receiving optical paths 3a to 3e, a control section 7 for controlling the operation of the input section and the output signal of the reflectance, and the output signal. An output unit 8 for analyzing the skin surface condition by processing and displaying or comparing with the light reflectance of the reference surface measured in advance, and further, the surface texture measuring device 1
Is equipped with a video camera 9 for displaying the surface state of the surface to be analyzed.

The head 4 is formed in a compact size of the palm of the hand, and has a size such that it can be held on one hand and moved on the surface of the skin. As shown in FIGS. 2 to 4, the head 4 has four incident optical fibers 2 as incident optical paths.
a to 2d and five light receiving optical fibers 3a to 3e are arranged as a light receiving optical path, and these incident optical fibers 2a to 2d and light receiving optical fibers 3a to 3e are
The concave hemispherical surfaces 11 are arranged so as to form respective predetermined angles.

That is, in FIG. 2, incident optical fibers 2a, 2b and light receiving optical fibers 3c, 3d, 3e are shown.
, And the optical fibers 2c, 2d for incidence and the optical fibers 3c, 3b, 3a for light reception are arranged in a line on the concave spherical surface, and the lines are arranged so as to be orthogonal to each other in FIG. The optical fibers 2a to 2d and 3a to 3e have predetermined angles θ ₁ and θ, respectively.
₂ , θ ₃ , θ ₄ , θ ₅ , θ ₆ , θ ₇ , and θ ₈ are formed. Here, in FIG. 3 and FIG. 4, θ ₁ is the angle formed by the incident optical fiber 2a and the incident optical fiber 2b,
θ ₂ is an incident optical fiber 2b and a light receiving optical fiber 3
angle formed is c, the angle theta ₃ formed by the light-receiving optical fibers 3d and light receiving optical fiber 3c, the angle theta ₄ is formed between the light-receiving optical fiber 3e and the light receiving optical fiber 3d, theta
₅ is a light receiving optical fiber 3a and a light receiving optical fiber 3b
Angle between the bets, the angle theta ₆ formed between the light-receiving optical fiber 3c and the light receiving optical fiber 3b, the angle theta ₇ formed between the incident optical fiber 2c and the light receiving optical fiber 3c, theta ₈
Is an angle formed by the light receiving optical fiber 3c and the incident optical fiber 2c.

Although each of the angles θ _{1 to} θ ₈ is set to an arbitrary angle, in the present embodiment, θ ₁ is 30 ° and θ ₂ is 4 °.
5 °, θ ₃ 15 °, θ ₄ 30 °, θ ₅ 30 °, θ
₆ is 30 °, θ ₇ is 30 °, and θ ₈ is 30 °. A total of nine incident optical fibers 2a to 2d and light receiving optical fibers 3a to 3e are connected to the input unit 6, respectively, and their incidence and light reception are controlled. The head 4 is further provided with a fiber 12 for capturing the image of the video camera.
Has been set up so that you can shoot with a video camera.

The input section 6 serves as a light source, and the four lamps 1 connected to the base ends of the respective incident optical fibers 2a to 2d.
3, lamp switch 14, lamp lighting control device 15
Are provided, and predetermined optical fibers for incidence 2a-2
Light is selectively and continuously emitted from d. Further, in the input section 6, five light receiving elements 16 are respectively provided at the base ends of the respective light receiving optical fibers 3a to 3e.
The analog signal amplifier 17 and the amplification control device 18 are connected to convert the intensity of the received light into an output signal.

Further, the input section 6 is provided with a video camera 19 for controlling the image of the image capturing fiber 12 and a camera controller 20 for controlling the image camera so as to control the image captured by the fiber 12. It has become.

The control unit 7 includes an analog circuit controller 21 connected to the lamp lighting controller 15 and an amplifier controller 18, an analog / digital signal processing converter 22 connected to an analog signal amplifier, and a video camera 19. A CRT control device 23 that is connected and controls the CRT (cathode ray chip) of the output device 8 is provided. These analog circuit control device 21, analog / digital signal processing converter 22, and CRT control device 23 are digital signals. It is connected to the processing unit 24 and digitally processes the measurement data and transmits a command from the microcomputer to each unit.

The output unit 8 has a microcomputer 25.
And a CRT 26 are provided so that the light reflectance of the surface of an object serving as a reference, which has been measured in advance, is compared, arithmetic processing is performed, graphing is performed as necessary, or evaluation by ranking is performed. ing. Specifically, when the surface to be analyzed is skin, calculation is performed based on the data in which the correlation between the “gloss of skin” or the so-called “skin gloss” and the reflectance is input in advance, and the “skin roughness” is calculated. Indicating "state". on the other hand,
At the same time, on the CRT 26, the state of the skin surface taken by the video camera is displayed as an enlarged image.

Next, the operation of this embodiment using the surface texture measuring device will be described. First, when measuring the surface reflectance of human skin, the head 4 is to be measured at a predetermined site,
For example, it is brought into contact with the forehead and the cheek, and the inputs of the input unit 6, the control unit 7, and the output unit 8 are turned on, and the surface reflectance of the skin is measured.

The surface texture measuring method according to this embodiment is shown in FIG.
And, as shown in FIG. 4, one of the plurality of irradiation optical paths 2a to 2d.
From one object to the surface to be analyzed,
Each of the paths 3a to 3e faces the analyzed surface of the irradiation light.
Received reflected light. Then, the plurality of irradiation optical paths 2a
~ 2d are sequentially selected so that the light receiving optical path 3a ~
3e acceptance angle θ₃, Θ_Four, Θ_Five, Θ₆And irradiation light path 2a-
2d irradiation angle θ₁, Θ ₂, Θ₇, Θ₈Analysis that is the sum of
By changing the angle variously, it can be applied to the surface to be analyzed at multiple analysis angles.
The surface that serves as a pre-measured reference surface by measuring the reflectance of light
The state of the surface of the object is analyzed by comparing with the reflectance of the light.
The irradiation and the light reception are first performed by the ramp point in the input unit 6.
Control by the lamp control device 15 and the amplifier control device 18
All the light receiving optical paths 3a to 3e and the predetermined irradiation optical path 2
One of a to 2d is selected.

Next, the microcomputer 25 and the analog circuit control device 21 perform control based on the combination of the irradiation angle and the light receiving angle at each analysis angle shown in Table 1 below, and the light receiving optical paths 3a to 3e and the irradiation optical path are sequentially performed. 2a-2d
Is to be selected.

[0022]

[Table 1]

For example, when the analysis angle is 90 °, the irradiation light path 2a having an irradiation angle of 75 ° (θ ₁ + θ ₂ ), the irradiation light path 3d having a light receiving angle of 15 ° (θ ₃ ) and then 60 °.
2d, which is (θ ₇ + θ ₈ ), and 3 which is 30 ° (θ ₆ ).
b, and 2b which becomes 45 ° (θ ₂ ) and 45 ° (θ ₃ +
θ ₄ ) is selected in the order of 3e. The light received by the light receiving optical path is amplified by the analog signal amplifier 17, converted into a predetermined output signal by the analog / digital signal converter 22, and then analyzed by the microcomputer 25.

As shown in FIG. 7, in the most ideal state, the irradiation light is reflected with a spatial spread around a reflection angle equal to the irradiation angle of the light irradiation with respect to the skin surface. Therefore, if the light receiver 6 is held at an angle of reflection equal to the angle of incidence of the irradiation light on the skin surface, almost all light except the light absorbed on the skin surface will be received as reflected light. However, since the skin surface is formed in a concavo-convex shape by the minute surface, the reflected light from the minute surface A is reflected in various directions. Therefore, if the light receiving angle with respect to the incident angle of the surface is determined, the skin is inclined in the predetermined direction. The amount of light received changes according to the amount of the minute surface A. That is, for the distribution of the minute surface tilted in one direction, the reflectance R at that angle is measured by changing the light receiving angle while keeping the analysis angle x. The reflectance R can be expressed by the following formula.

[0025]

## EQU1 ## R (r) = f [(i + r) / 2] * g (θ)

Here, f [(i + r) / 2] is a function based on the Fresnel reflectance and is constant regardless of the light receiving angle r. g (θ) is the number of minute bare surfaces A facing in the θ direction. That is, the reflectance R (r) is the distribution g of the minute surface A.
(Θ) itself. Therefore, by measuring the reflectance R (r), the distribution state of the minute surface A can be analyzed.

On the other hand, in the microcomputer 25, the reflectance of the skin in a predetermined state is measured in advance, and this is used as reference data to compare it with
The "skin gloss" or "skin gloss" etc. can be measured. As the reference data, various data can be used as long as it can analyze a desired skin condition. Then, various reference data and measured values are compared to determine the degree of "skin gloss", "skin gloss", "skin aging", etc., on the surface to be analyzed. Such a determination may be made by an analyst by comparing the graphs, or
Required data that serves as a reference as described above is input to the computer 25 in advance, the measured value is compared and calculated with these data, and the degree thereof is evaluated value at a predetermined stage, for example, "A", "B", etc. It may be displayed by.

Based on such an analysis state, the subject can properly care for the skin based on "skin gloss" and "skin gloss" or apply the foundation appropriately. At the same time, on the CRT 26, an enlarged screen of the skin surface is displayed, and the surface texture is accurately grasped by visual observation without depending only on the reflectance of light.

Next, an experimental example of this embodiment will be described with reference to FIGS. FIG. 8 is a graph showing the relationship between the light receiving angle and the reflection intensity by the light receiving angle changing method, FIG. 9 is a graph showing the relationship between the light receiving angle and the reflection intensity by the sample angle changing method, and FIG. FIG. 12 is a graph showing the relationship of the incident angle dependence of the index, and FIG. 11 is a graph showing the distribution of reflected light by the light-receiving angle-change method. In order to investigate the basic relationship between the shape of the object surface, that is, the size of the unevenness and the distribution of the surface reflection, a replica of sandpaper with different roughness was taken with a dental impression material, and the surface reflection light distribution was measured.
The samples were of 80, 400, 1500 mesh.

[Measurement Conditions] In the light receiving deflection method shown in FIG. 8, irradiation angle i = 45 °, light receiving angle r = (0 to 80 °) diaphragm = (incident / light receiving) 3.0 / 1.0 sensitivity = 950/950, square slit is used. In the sample bending method shown in FIG. 9, irradiation angle i + r = 90 °, light receiving angle r = (15 to 75 °) diaphragm = (incident / light receiving) 3.0 / 1.0 sensitivity = 950/731, square slit used .

Although not shown in FIGS. 8 and 9, 2
The reflection intensity distributions of the 40 and 800 mesh (#) replicas are 80 and 400 mesh and 400 and 15 respectively.
An intermediate value of 00 mesh was output, but the graphs of 240 and 800 mesh are omitted here for simplification of description.

The following results are derived from the measurement results. From these FIGS. 8 and 9, the surface reflection light distribution has a relatively large reflection intensity on the side where the light receiving angle is large in the light receiving angle changing method, and in the sample angle changing method, the mirror surface direction (r = 45
It can be seen that the target distribution is shown around (). The surface-reflected light on the rough surface does not reach uniform diffusion, but its distribution is in a wide range from 0 to 80 °. The surface roughness changes the reflection intensity and distribution of the surface,
The surface roughness of the medium roughness (400 mesh) is the highest.

FIG. 11 is a graph in which the incident angle dependence of the reflectance of the replica of the smooth surface is measured and the one corresponding to the Fresnel coefficient is derived. The measured values obtained by the gonio-variation method shown in FIG. Value obtained by multiplying the reflectance of
It can be seen that the value normalized by the reflection intensity of ° and shown by the solid line) is in good agreement with the measurement value (shown by the alternate long and short dash line in the figure) by the light receiving deflection method shown in FIG. From such experimental results, it is understood that the measurement by the sample bending method in which the irradiation angle and the light receiving angle are variously changed is more appropriate. This can usually be thought of as the glossiness of the sample as we rotate it into the plane of incidence when observing the surface.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention. For example, irradiation light is not limited to using natural light,
As shown in FIG. 6, polarized light using a polarizing filter 28 may be used. For example, it is assumed that the irradiation light is polarized light S (S-polarized light) having a vibrating surface perpendicular to the incident surface, and the light receiver measures the reflectance of the S-polarized light. At this time, the measured reflection intensity is the sum (Rss) of all the light (Ss) reflected on the surface and the internal diffused light (Ds). Therefore, next, the incident light is light having a vibrating surface parallel to the incident surface (P polarized light).
When the S-polarized light on the light receiving side is measured, surface reflected light is not observed, and only internal diffused light (Ds) is reflected in intensity (Rps).
Therefore, the value obtained by subtracting (Rps) from (Rss) can be reliably measured as the surface reflection intensity.
Therefore, if measurement is performed using such polarized light, more accurate skin surface analysis can be performed. In particular, by measuring only the internal diffused light (Ds) in the same manner, the light reflected on the surface of the skin can be cut and the internal condition of the skin, which is unrelated to the surface condition of the skin and the roughness and roughness of the skin, can be measured. Becomes Further, the irradiation light path and the light reception light path may be any medium that allows light to pass through, and is not limited to an optical fiber and may be another medium such as a lens. Needless to say, not only the skin but also other surface states such as metal may be used.

[0035]

According to the surface texture measuring method and the apparatus therefor of the present invention, the light irradiation angle and the light receiving angle are variously set, and the various angles are changed to measure the reflected light intensity on the surface of the object. With this, it is possible to accurately analyze the states such as “texture”, “gloss”, and “luster” on the surface of the object.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a surface texture measuring device used in an embodiment of the present invention.

FIG. 2 is a plan view of a head of the surface texture measuring device shown in FIG.

3 is a schematic sectional view of the head shown in FIG. 1 taken along line III-III.

FIG. 4 is a schematic sectional view of the head shown in FIG. 1 taken along line IV-IV.

5 is a block diagram showing a control mechanism of the surface texture measuring device shown in FIG.

FIG. 6 is a plan view of a head of a surface texture measuring device according to another embodiment of the present invention.

FIG. 7 is a diagram illustrating a measurement principle according to the present invention.

FIG. 8 is a graph showing a relationship between a light receiving angle and a reflection intensity by a light receiving bending method.

FIG. 9 is a graph showing the relationship between the light receiving angle and the reflection intensity by the sample bending method.

FIG. 10 is a graph showing the relationship between the reflectance and the incident angle dependency.

FIG. 11 is a graph showing a distribution of reflected light according to the light receiving deflection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface texture measuring device 2a-2d Irradiation optical path (incident optical fiber) 3a-3e Receiving optical path (optical receiving fiber) 4 Head 5 Main body 6 Input section 7 Control section 8 Output section

Claims (2)

[Claims] 1. A surface of an object to be analyzed is irradiated with light from one of a plurality of irradiation optical paths having different irradiation angles, and the reflected light of the irradiation light reflected by the surface to be analyzed is reflected at a plurality of different receiving angles. The light is received by the light-receiving optical path, and the irradiation angle of the irradiation optical path is changed by variously selecting the plurality of irradiation optical paths to change the analysis angle that is the sum of the light-receiving angle and the irradiation angle. A surface property measuring method characterized by measuring the reflectance of light with respect to an analysis surface and comparing it with the reflectance of light on a reference surface which has been measured in advance to analyze the state of the surface of an object. 2. A plurality of irradiation light paths that irradiate light on a surface to be analyzed of an object surface and have different irradiation angles, and a plurality of light reception optical paths that receive reflected light of the irradiation light reflected on the surface to be analyzed. An input unit for selecting various ones of the plurality of irradiation light paths, a control unit for converting the reflectance of the light received from all the light receiving optical paths into an output signal, and comparison with the reflectance of the light on the reference surface measured in advance. And an output unit that analyzes the state of the skin surface.