JPH11311570A - Photometry device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photometry device and a method that has a simple configuration and superior cost performance and portability and can be easily used. SOLUTION: A photometry device 1 measures the spatial intensity distribution of light being radiated from an object, arranges a light deflection dome 2 for receiving radiation light Lout from an object 3 to be measured with the object 3 to be measured on a placement member 5 as a center, and detects the radiation light being deflected by the light deflection dome 2 from the upper part of the light deflection dome 2 by radiation light detection parts 7 and 8. The sculptured surface shape of the light deflection dome 2 is set so that an angle θout being formed by the light path of the radiation light Lout before light path deflection and a normal line Z of the measurement surface of the object 3 to be measured is in proportion to horizontal distance (r) from a position where the radiation light Lout crosses the light deflection dome 2 to the normal line of the measurement surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric device for measuring reflected light and transmitted light from an object, the luminous intensity of a self-luminous body, and the spatial distribution of spectral components.

[0002]

2. Description of the Related Art Conventionally, a photometric device for performing spectral measurement of the intensity distribution of reflected light or transmitted light radiated from an object irradiated with light, the luminous intensity distribution of a self-luminous body, and spectral components, etc. There is a photometric device as shown in FIG. In this photometric device, a goniometer is used to
1 and the object 172 to be measured
Are respectively changed by the stage 173, and the intensity of the diffused light with respect to the incident angle of the illumination light emitted from the light source 174 to the measurement object 172 is measured to obtain the spatial intensity distribution of the diffused light. I have. In this case, the diffused light intensity distribution is obtained by measuring the light intensity of the illumination light incident from a plurality of different directions in the space at a plurality of different positions in the space.

On the other hand, there is also a photometric device using a microscope optical system having a large-diameter objective lens as shown in FIG. In this photometric device, the light emitted from the measuring object 181 is projected onto the area sensor 184 by the Fourier lenses 182 and 183 to measure the light intensity distribution, thereby obtaining the spatial intensity distribution of the light. is there. The measurable range of this optical system is such that the larger the aperture of the Fourier lens 182 is, the more the measurement object 181 is located on the Fourier lens 18.
The closer it is to 2, the larger it will be.

[0004]

However, in a conventional photometric device using a goniometer, in order to obtain light intensity data densely measured from a plurality of angles over a wide area in a space, it is necessary to perform measurement. It took a lot of time.

For example, when measuring the reflection characteristic (diffusion characteristic) of an object, a light beam is radiated to the measurement object from a certain incident angle, and the intensity of the diffused light from the measurement object by the irradiation light beam is calculated as
The measurement is performed by the light receiving system from different positions on the spherical surface around the object to be measured at different latitudes and longitudes. That is, measurement is performed from M × N grid points obtained by dividing latitude into M and longitude into N. Moreover, when measuring the diffused light intensity distribution at a plurality of incident angles by changing the incident angle of the illumination light, if all the combinations are simply performed, (M × N) ^two measurements will be performed. . For example, even if M and N are very coarse division numbers of about 10, the total number of photometry is 10,000 times, and a long time is required for measurement. In addition, there is a problem that the apparatus is expensive because high accuracy is required for the mechanism section.

Also, the photometric device shown in FIG. 19 has a problem that the whole device is expensive because the Fourier optical system is very expensive. Furthermore, there is a common problem that none of the above photometric devices can be easily carried, and the light intensity cannot be observed with the naked eye.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has as its object to provide an easy-to-use photometric device and a photometric method with a simple configuration, which are excellent in cost performance and portability. .

[0008]

In order to achieve the above object,
The present invention relates to a photometric device for measuring a spatial intensity distribution of light emitted from an object, comprising a mounting member for mounting an object to be measured, and a dome-shaped shell having a substantially circular bottom surface. A light deflecting dome in which the object to be measured is placed at the center of the bottom surface of the shell, and light emitted from the object to be measured is diffused on the shell; A radiated light detecting unit for detecting the radiated light from above the light deflecting dome. The angle formed by the line was set so as to be proportional to the horizontal distance from the position where the emitted light intersected the light deflection dome to the normal to the measurement surface.

Thus, the radiated light from the object to be measured is applied to the light deflecting dome and diffused on the surface of the light deflecting dome, and the diffused radiated light is detected by the radiated light detecting section. In the detection data at this time, the angle between the optical path of the emitted light before the optical path deflection and the normal to the measurement surface is proportional to the horizontal distance from the position where the optical path of the emitted light intersects the light deflection dome to the normal to the measurement surface. Therefore, the three-dimensional intensity distribution of the emitted light can be collectively and easily detected. Here, the light deflecting dome may be formed by laminating a light diffusion layer having light diffusion transmittance on the surface of the dome.

In a photometric device for measuring a spatial intensity distribution of light radiated from an object, a mounting member for mounting an object to be measured and a dome-shaped shell having a substantially circular bottom surface. An optical deflecting dome that is installed so that the object to be measured is arranged at the center of the bottom surface of the shell, and that aligns the optical path of the radiated light from the object upward through the shell; A radiated light detector that detects the radiated light whose optical path is aligned by the dome from above the light deflecting dome, wherein the curved surface shape of the light deflecting dome is the same as the radiated light path before the light path deflection and the measurement object The angle between the object and the measurement surface normal was set so as to be proportional to the horizontal distance from the position where the emitted light intersected the light deflection dome to the measurement surface normal.

As a result, the radiated light paths passing through the light deflecting dome are aligned upward, and are detected by the radiated light detector located above. Therefore, most components of the radiated light from the measurement target are introduced into the radiated light detection unit without being dispersed, so that the radiated light intensity distribution can be measured more accurately.

It is preferable that the light deflecting dome deflects the optical path of the light emitted from the object by refraction or diffraction. For example, a Fresnel lens, a prism, a diffraction lens, a volume hologram, or the like can be used.

When the height of the light deflecting dome is Z and the horizontal distance from the center of the dome bottom to the dome curved surface is Z, the curved shape of the light deflecting dome excluding the zenithal portion is Z
= Rtan (90 ° -R). Thereby, the angle between the emitted light path before deflection of the optical path and the normal to the measurement surface of the object to be measured is the horizontal distance from the position where the emitted light intersects the light deflection dome to the normal to the measurement surface. Can be set to be linearly proportional.

[0014] Further, it is preferable that the radiation light detecting section is an area sensor. This makes it possible to collectively measure the intensity distribution of the emitted light from the light deflection dome. still,
The radiation light detection unit may detect the radiation light using a plurality of optical sensors disposed along a projection surface of the light deflection dome.

Further, the photometric device preferably includes a light source for illuminating a measurement surface of the measurement object at a predetermined incident angle, wherein the light source emits monochromatic light;
The light source may be a light source whose emission wavelength is variable and emits monochromatic light of an arbitrary wavelength, or a multi-color light source having various wavelength components.

Further, the light source may be provided outside the light deflecting dome, and the light deflecting dome may be provided with a light transmitting portion for introducing light from the light source into the dome. It may be arranged inside. It is preferable that the photometric device includes an incident angle changing unit that changes an incident angle of the illumination light on the measurement object by moving the light source.

It is preferable that the photometric device includes an incident azimuth changing means for changing the incident azimuth of the illumination light by rotating the object to be measured in a horizontal plane. further,
It is preferable that the photometric device includes a light blocking unit configured to block light from the light source irradiated to a portion other than the measurement surface of the measurement target.

Further, it is preferable that the light deflecting dome changes the optical path without depolarizing the light, thereby measuring the two-dimensional polarization reflection distribution of the object to be measured. It is preferable that the photometric device includes an ND filter in the optical path from the light deflection dome to the radiation light detection unit. Thereby, the dynamic range of the detection data can be expanded. Further, the photometric device,
It is preferable that the detection signal is corrected by providing a detection signal correction unit that corrects a dark level, detection sensitivity, and uniformity with respect to the detection signal from the emission light detection unit.

It is preferable that the photometric device includes an integrating means for integrating the detection signal from the radiation detecting section.

Next, a photometric method according to the present invention is a photometric method for measuring a spatial intensity distribution of light radiated from an object, the method comprising a dome-shaped shell having a substantially circular bottom. The curved surface of the shell surface has an angle formed by an optical path of radiated light emitted from the measurement object and a measurement surface normal of the measurement object when the measurement object is installed at the center of the bottom surface. Using a light deflecting dome set so as to be proportional to the horizontal distance from the position where the light intersects the shell surface to the normal to the measurement surface, the measurement object placed at the bottom center position of the light deflecting dome And detecting the radiated light irradiated onto the light deflecting dome by a radiated light detector disposed above the light deflecting dome.

Here, the photometric method includes: (1) holding the light source at a position for illuminating the measurement object at a predetermined incident angle; and (2) rotating the measurement object in a horizontal plane. The incident azimuth is changed, and the radiation light intensity distribution from the surface of the light deflection dome is detected by the radiation light detection unit during one rotation of the measurement object. (3) After the detection is completed, the light source is turned off. (1) to (1) to change the incident angle of the illumination light to the measurement object by moving the step angle by a predetermined step.
By repeating each step of (3) for different incident angles, the spatial intensity distribution of the emitted light can be measured efficiently.

The detection signal obtained by the radiation detector is integrated for a predetermined period to change the intensity of the radiation emitted from the object irradiated onto the light deflection dome and the incident azimuth. By detecting the measurement object while rotating it continuously throughout the entire period, the emission light intensity distribution can be measured at a higher speed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of a photometric device according to the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram schematically showing the configuration of a photometer, FIG. 2 is a partially cutaway perspective view showing the configuration of a light deflection dome portion of the photometer, FIG. 3 is a plan view of the light deflection dome, and FIG. FIGS. 5 and 6 are a sectional view and an explanatory view showing an example of the shape and dimensions of a light deflecting dome.

The light measuring device 1 shown in FIG. 1 has a light deflecting dome 2 having a circular cross-section and a bowl-like shape as shown in FIG. A mask 4 which is provided and has an opening 4a which is opened at a central portion so as to expose the measurement object 3, a mounting member 5 on which the measurement object 3 is mounted and which can be rotated in a horizontal plane, and a measurement object A light source 6 that generates a laser beam Lin that illuminates the light 3, a condensing lens 7 that condenses the diffused light due to the reflected light Lout from the measuring object 3, and an optical element of the measuring object 3 via the condensing lens 7. An image sensor 8 is provided for imaging characteristics, that is, information on luminance distribution on the light deflection dome. The condenser lens 7 and the imaging device 8 correspond to a radiation light detection unit.

As shown in FIGS. 1 to 3, the light deflecting dome 2 has a slit 9 for introducing illumination light into the dome from the center toward the end. The slit 9 may be formed by opening the dome 2 or may be a window made of a transparent material. The light source 6 is disposed outside the light deflecting dome 2 so as to be movable in the directions of arrows A and B along the outer peripheral surface of the light deflecting dome 2, and the incident light Lin from the light source 6 passes through the slit 9. Measurement object 3 exposed in opening 4a
Is configured to be irradiated. The light source 6 is configured to be positioned and fixed at a desired position. The light deflecting dome 2 is made of a material capable of transmitting light,
The inner surface is formed as a smooth surface, while the outer surface is provided with, for example, randomly distributed fine irregularities on the surface to form a matte surface. Thus, the reflected light Lout transmitted from the inside of the dome to the outside is isotropically diffused on the outer surface of the dome.

The mask 4 is made of a material that absorbs and blocks the laser beam Lin incident from the slit 9 and prevents secondary reflection due to the reflected light Lout from the object 5 to be measured. Opening 4a is formed. The mounting member 5 is configured to mount the measuring object 3 and to be rotatable in a horizontal plane as indicated by an arrow. Therefore, by rotating the mounting member 5,
Until the position of the light source 6 is fixed, the incident azimuth φin of the laser beam Lin to the object 3 can be changed. On the other hand, the incident angle θin can be controlled by controlling the angle of the light source 6. In the present embodiment, a CCD (Charge Coupled Device) is used as the imaging element 8,
MOS (Metal Oxide Semiconductor) may be used.

Next, a photometric method will be described. At the time of photometry, the measuring object 3 is mounted on the mounting member 5, and the mounting member 5 is rotated in a horizontal plane to adjust the azimuth of the measuring object 3 to a desired incident azimuth angle φin. The measurement object 3 is, for example, an EL (Electro luminescenc) in addition to a painted piece of an automobile, a small piece of a plastic product serving as a cabinet of a home appliance, and the like.
e) or a self-luminous body such as an LED (Light Emitting Diode). In the case of a light-transmitting material such as glass or transparent plastic, illumination is performed from below the mounting member 5 to measure the intensity distribution of transmitted light transmitted through the material by the illumination. In this case, an illumination hole may be provided in the mounting member 5, and light from a light source may be introduced through the hole. Here, in the case of the self-luminous body and the light transmitting material,
The emitted light and the transmitted light will be measured, and these are hereinafter collectively referred to as reflected light. The alignment of the measurement direction of the measurement object 3, that is, the setting of the incident azimuth angle φin of the illumination light, is performed based on the position of the slit 9 at which the illumination light is incident from the light source 6 (0 °). Defined by the rotation angle from the position.

Next, by appropriately moving the light source 6 in the directions of arrows A and B, the incident angle θin of the illumination light to the object 3 is measured.
Set. In the present embodiment, the angle defined by the Z axis and the incident direction of the illumination light is defined with the Z axis, which is the center axis of the light deflection dome 2 and the normal of the measurement surface of the measurement target 3, as a reference (0 °). . That is, the angle between the normal to the measurement surface of the measurement target 3 shown in FIG. 1 and the incident direction of the light source 6 is the incident angle θin.

As described above, after the measurement object 3 and the light source 6 are aligned, the light source 6 emits a laser beam Lin.
(Incident light) is directed toward the measuring object 3 with an incident angle θin. Then, in FIG. 1, the reflected light Lout from the measuring object 3 hits the light deflecting dome 2 at the reflection angle θout, and the reflected light Lout is diffused on the surface of the light deflecting dome 2.
Note that the reflection angle θout is also based on the Z axis (0
Ii).

Since the outer surface of the light deflecting dome 2 is formed of a random fine uneven surface, when the reflected light Lout passes through the light deflecting dome 2, it is reflected as shown in FIG. The light Lout isotropically diffuses outside the dome.

Of the reflected light Lout diffused by the light deflecting dome 2, the upwardly reflected light component is condensed by the condenser lens 7, forms an image on the image sensor 8, and is imaged by the image sensor 8. . This imaging result is schematically shown in FIG. 4, for example. That is, while the point P becomes brighter due to the diffusion of the reflected light Lout, the other areas become darker captured images. In FIG. 4, P is shown at a position at a distance r from the center on the X axis, which is shown in correspondence with FIG. 1, for example, the surface of the measurement object 3 is defined as a mirror surface. This corresponds to a captured image in the case of performing. Actually, measurement object 3
The reflected light has a different three-dimensional distribution depending on the material and the surface state of the light source, and therefore, the reflected light intensity distribution according to the reflection angle θout and the reflection azimuth φout.

As described above, when the reflected light is diffused on the light deflecting dome 2 and an image is taken from above the dome, 3
A two-dimensional plane can represent a two-dimensional reflection intensity distribution. Since the distance r from the center of the light deflection dome 2 is related to the reflection angle θout, the reflection angle θout can be obtained by measuring the distance r in a two-dimensional plane. The shape of the light deflecting dome 2 is a dome shape as shown in FIG. 2, but becomes a circular flat plate shape as shown in FIG. Therefore, in order to easily and accurately obtain the distance r from the center of the dome at the position P, it is preferable to form the light deflection dome 2 in a shape in which the reflection angle θout is linearly proportional to the distance r. This makes it possible to directly and accurately determine the reflection angle θout when viewed from above the dome.

As described above, the present invention is characterized in that the shape of the light deflection dome 2 is formed so that the reflection angle θout has a linear proportional relationship to the horizontal distance r from the center of the dome when an image is taken from above the dome. Features.

(Specific Example 1) A first specific example of the light deflection dome 2 will be described below with reference to FIGS. FIG. 5 shows the XZ plane (the same applies to the YZ plane) of the light deflection dome 2. The light deflection dome 2 has a shape in which the Z axis of the center of the dome is rotationally symmetric. In the example, 90mm, 94
mm. X1 and X2 are appropriately set according to the size of the measurement surface and the intensity of the illumination light. The distance Z from the dome center O to the inner surface of the dome at the top of the dome
1 and the distance Z2 to the outer surface of the dome are 57.3 mm and 57.3 mm, respectively.
It is set to 9.8mm. Here, as shown in FIG. 6A, X (Y), Z, and angle θ of the surface of the light deflecting dome 2
Is expressed by equation (1). Z = Xtan (90 ° −θ) (1)

In order for the distance X from the center of the dome in equation (1) to be linearly proportional to the reflection angle θout as shown in FIG. 6 (b), it is necessary to have the relationship in equation (2). X = aθ (2) where a is a proportional constant [mm / deg] with respect to a unit angle.
It is. By substituting equation (2) into equation (1), the relationship between X and Z shown in equation (3) is obtained. Z = X · tan (90 ° −X / a) (3)

Equation (3) is a basic equation in which the distance X from the center of the dome and the reflection angle θout have a linear proportional relationship. Equation (3) is an equation on the ZX plane, but since the light deflecting dome 2 has a symmetrical shape about the Z axis,
Hereinafter, the distance R from the center of the dome will be displayed. Therefore, equation (3) is represented by equation (4). Z = R · tan (90 ° −R) (4) where a is set to 1 for simplicity. According to equation (4), the curved shape of the inner surface of the dome is expressed by equation (5). z1 = r1 · tan (90 ° −r1) (5)

Here, r1 represents a horizontal distance from the center O of the inner surface of the dome with respect to an arbitrary reflection angle θ shown in FIG. 6A, and z1 represents a vertical distance. According to equation (5), z1 is infinite at the dome zenith, so that the vicinity of the zenith is smoothly connected to other areas by performing interpolation processing at a preset Z1 distance. It is set to be. On the other hand, the shape of the outer surface of the dome is set as follows. That is, the dimensional difference between the inner surface and the outer surface of the dome at the bottom of the dome is obtained by X2-X1, and in the present embodiment, 94-90 = 4 mm. Based on the dimensional difference X2-X1 at the bottom of the dome, the shape of the outer surface of the dome is set in proportion to the distance from the center O of the dome. Specifically, first, the relationship between X1 and X2 is set by equation (6).

B = X2 / X1 (6) In the present embodiment, b = 90/94. Equation (4) can be expressed by equation (7) based on the relationship of equation (6). z2 = r2 · tan (90 ° −br2) (7) Equation (7) is also the same as equation (5) at the dome apex.
Is set to be infinite, so that the vicinity of the zenith is set to be smoothly connected to other areas by performing interpolation processing on the distance of Z2 set in advance.

As described above, when the inner and outer surfaces of the dome are formed based on the equations (5) and (9), the present embodiment is performed when the light deflecting dome 2 is viewed from directly above, that is, from the imaging position of the imaging element 8. In the embodiment, a distance of 1 cm from the center of the dome corresponds to a reflection angle of 10 °, and the reflection angle θout is linearly proportional to the horizontal distance r.

Although the first embodiment of the present invention has been described above, the present invention is not limited to the above-described configuration.
The thickness of the light deflection dome 2 may be the same over the entire dome. The irregularities on the dome surface for diffusing the reflected light Lout may be formed not only on the outer surface of the light deflecting dome 2 but also on the inner surface or on both surfaces.

Next, various specific examples of the shape of the light deflection dome 2 according to the second embodiment of the present invention will be described. (Second Specific Example) In this specific example, the light deflecting dome 2 is formed by cutting a part of the spherical shell 21 shown in FIG. 7 (a part shown by a solid line). In this configuration, since a commercially available spherical shell can be used, the light deflection dome 2 can be manufactured inexpensively and easily.
Although the reflection angle θout and the distance from the center of the dome are not linearly proportional in this shape, the reflection angle θout can be obtained by performing appropriate correction processing in the same manner as in the first embodiment.

(Third Specific Example) In this specific example, the light deflecting dome 2 is constituted by a conical cover 22 as shown in FIG. In this configuration, since the shape of the cover 22 is simple, the production is easy, and it can be produced at low cost and simply. Of course, you may manufacture using a commercial item. In this case as well, the reflection angle θout and the distance from the center of the dome are not linearly proportional, but by performing the same correction as in the specific example 2, the reflection angle θout is obtained as in the first embodiment.
Can be requested. In any of the specific examples 1 and 2, the light diffusion structure is one of the outer surface and the inner surface,
Alternatively, it may be formed on both sides.

Next, various specific examples of the light diffusion structure will be described. (Fourth specific example) In this specific example, the light deflection dome 2 is
As shown in FIG. 9, a light transmitting layer 23a made of a transparent resin or the like
And a light diffusion member 23 in which a diffusion layer 23b having an uneven shape or the like is laminated in two layers. Note that the diffusion layer 23b may have a configuration in which fine particles having different refractive indexes are dispersed and mixed. According to this specific example, the reflected light Lout can be appropriately diffused even if the shape of the light deflection dome 2 is configured in any of the shapes exemplified in the first embodiment and each specific example. Further, by making the diffusion layer freely exchangeable, it is possible to easily switch different diffusion effects according to the purpose.

(Fifth Embodiment) In this embodiment, the light deflecting dome 2 is made of a single light diffusing material 24 shown in FIG. The light diffusing material 24 is formed by mixing light-permeable, for example, synthetic resin with fine particles having different refractive indices or a porous material, and integrally molding the resin. Light diffusion material 24
Can be easily formed into the shape shown in the first embodiment by an injection molding method or the like.
Can be obtained. In addition, it is easy to form the shape shown in FIGS.

Next, a third embodiment of the present invention will be described with reference to FIGS. (Sixth specific example) In this specific example, the Fresnel lens 25 shown in FIG. 11 is applied as the light deflecting dome 2, and the configuration other than the light deflecting dome 2 may be the same as that of the first embodiment. . The Fresnel lens 25 has the effect of changing the angle of refraction of light incident from one side surface (in the present example, the inner surface) in accordance with the incident position of the light, so that the light is emitted in one direction. . Therefore, the light deflection dome 2
When the Fresnel lens 25 is used, as shown in the center of FIG. 11, the reflected light Lou along the Z-axis at the center of the dome.
t goes straight through and passes through. On the other hand, the reflected light Lout having the reflection angle θout as shown in the left and right directions in two directions is:
When the light passes through the Fresnel lens 25, the light path is changed by refraction, and the light is emitted substantially right above.

According to this configuration, the reflected light Lout is directly emitted toward the image sensor 8 without being diffused.
The detected reflected light is brighter than when it is diffused, and a clearer captured image can be obtained. That is, data with little noise and a high S / N ratio can be obtained.
Further, since the state in which the reflected light Lout is refracted is always maintained, it is possible to measure the polarization characteristics by utilizing the fact that the polarization state is also constantly maintained. Further, the Fresnel lens 25 is preferably dome-shaped in order to detect a reflection component at a low angle, but may be a flat Fresnel lens.

(Seventh Specific Example) In this specific example, a diffraction type lens shown in FIG. A diffractive lens is a lens to which deflection by light diffraction is applied. For example, a thin film having stripes with minute intervals (about 1 μm to several μm) having different transmission amplitudes is formed on the dome surface, and diffraction can be performed by causing diffraction according to the interval and the wavelength of light. The stripes can be formed by photolithographic etching or laser.
A holographic method using light beam interference exposure or the like can be applied. In this case, the stripes are concentric, and their intervals and amplitudes are calculated and set in advance so that the emitted light is almost directly upward through the dome. Then, in order to further enhance the transmission efficiency, the transparent film on the dome or the surface of the dome itself may have a refractive index distribution having a diffraction effect. Further, the transparent film on the dome or the surface of the dome itself may be directly relieved to have a diffraction deflection effect. In this case, in addition to the same manufacturing method as described above, direct precision processing is also possible. For mass production, injection molding, photo printing, photopolymer method, etc. are also possible. The shape of the grating can be rectangular, sine, saw-toothed, or the like. Further, deflection by a volume hologram having a refractive index change in the thickness direction is also possible.

As shown in the center of FIG. 12, a laser beam Lout along the Z-axis at the center of the dome is formed by the diffractive lens.
Is transmitted straight through as it is, and the reflected light Lout having a reflection angle θout shown in two directions on the left and right thereof changes its optical path when transmitted through the dome 26 by the diffractive lens, and is emitted substantially right above. According to this configuration, since the reflected light Lout is emitted toward the image sensor 8 without being diffused, the detected reflected light is brighter than when diffused, and a clear image can be captured.

Next, a fourth embodiment of the present invention will be described in which the optical system of the photometric device 1 is modified. (Eighth Specific Example) First, the configuration of the photometric device shown in FIG. 13 will be described. A small light source 10 is disposed inside the light deflection dome 2 instead of the light source 6 described in the first embodiment. still,
The configuration and operation of each member other than the small light source 10 are the same as those of the photometric device 1 of the first embodiment. According to this configuration, the incident light Lin is irradiated on the measurement target 3, and the reflected light Lout from the measurement target 3 is diffused on the surface of the light deflection dome 2.
The state of the dome surface at this time is imaged by the image sensor 8. According to the present embodiment, the slit 9 provided in the light deflecting dome 2 for introducing the incident light Lin becomes unnecessary, and the measurement is performed over almost the entire dome except for a small narrow area such as the small light source 10. Therefore, the measurable area can be further expanded.

(Ninth Embodiment) In this embodiment, as shown in FIG. 14, a plurality of optical sensors 11 are arranged over the entire outer surface of the light deflecting dome 2. According to this configuration,
A condenser lens and an image sensor are not required. In addition, as for the light deflection dome 2, the reflected light Lout is
1, the reflected light Lout does not need to be diffused. Therefore, in this specific example, a transparent dome 12 is applied instead of the light deflection dome. However,
When the interval between the adjacent optical sensors 11 is large, it is preferable to prevent the leakage of detection by diffusing the reflected light Lout. It is preferable that the shape of the dome 12 is formed as a curved surface in which the reflection angle θout is linearly proportional to the distance from the center of the dome as in the first embodiment. According to this configuration, since the reflected light Lout is directly detected by the optical sensor 11 without being diffused, the position of the reflected light Lout can be detected more accurately, and thus the Z at the center of the dome can be detected.
The distance r from the axis will be determined more accurately.

Next, processing of captured image data will be described as a fifth embodiment of the present invention. (Tenth specific example) In this specific example, as shown in FIG. 15, an ND filter 13 is interposed between the condenser lens 7 and the image pickup device 8 so that the aperture and the time at the time of image pickup can be adjusted appropriately. ing. Except for the point that the ND filter 13 is interposed, the configuration may be the same as that described in the first embodiment. According to this configuration, the dynamic range of the image data captured by the image sensor 8, that is, the dynamic range of the amount of reflected light from the measurement target 3 can be further increased.

(Eleventh Specific Example) In this specific example, a control system shown in FIG. 16 is added to the configuration of the photometric device 1 in the first embodiment. That is, a motor M and a motor drive unit 21 for controlling the rotation of the mounting member 5, and a light source drive unit 22 for setting the incident angle θin by moving the light source 6 in the directions of the arrows A and B and then holding the light source 6 at a desired position. And the imaging device 8
An arithmetic unit 23 that takes in two-dimensional data obtained from the image processing unit and performs integration processing and the like; the motor driving unit 21 and the light source driving unit 2
And a control unit 24 that comprehensively controls the arithmetic unit 23. The motor driving unit 21 corresponds to an incident azimuth angle changing unit, and the light source driving unit 22 corresponds to an incident angle changing unit.

Next, a photometric procedure by the photometric device of this embodiment will be described. The intensity distribution of the reflected light Lout from the measuring object 3 is measured as follows. First, the light source 6 is moved by the light source driving unit 22 so that the incident angle θ in
Moves to the position of 0 ° and holds it. Next, the measuring object 3 is irradiated with the incident light Lin from the light source 6 and the reflected light L
out is diffused on the light deflecting dome 2 by the image sensor 8
To capture an image. The image data obtained at this time is sent to the control unit 24 via the arithmetic unit 23. The control unit 24 stores the obtained image data. Next, the motor driving unit 21
Drives the motor M to rotate the object 3 to be measured.
This rotation corresponds to changing the incident azimuth angle φin of the illumination light. The image sensor 8 continuously captures an image in synchronization with the rotation of the measurement target 3, and performs an integration process in the calculation unit 23. This integration processing method is a method of adjusting the optical shutter speed of the image pickup device 8 (setting so that light is received during one rotation of the measurement target 3), in addition to the signal integration method by the arithmetic unit 23. There may be. By the integration process, noise of the obtained data is reduced, and a more stable reflected light intensity distribution can be obtained.

Then, after the measurement object 3 makes one rotation,
The light source 6 is moved by the light source driving unit 22 in the direction of arrow B by a predetermined step angle △ θin to change the incident angle θin.
Then, the measuring object 3 is rotated once by the newly set incident angle θin + △ θin as described above, and the obtained image data is integrated. This integration process averages the reflected light intensity in the range of 0 ° to 360 ° of the incident azimuth angle φin if it is performed in one rotation cycle of the measurement object 3, and divides the incident azimuth angle into a plurality of parts. By performing the division at a cycle of the predetermined step azimuth angle △ φin, the reflected light intensity for each step azimuth angle can be obtained. By repeating the above processing over the range of the incident angle θin of 0 ° to 90 ° (an angle close to 90 °), the spatial reflection light intensity distribution from the measurement target 3 can be measured. Thus, in addition to being able to measure the reflected light distribution for each of the incident azimuth angle △ φin and the incident angle △ θin, it is also possible to measure the reflected light intensity distribution by diffuse illumination by integrating all of φin and θin.

The light intensity distribution (shade distribution) of the obtained image data is such that the distance r from the center of the dome is directly reflected by the reflection angle θou.
Since this corresponds to t, the reflection intensity distribution with respect to the reflection angle is directly expressed. The above-described series of operations can be programmed by the control unit 24, and a variety of photometric procedures can be easily and simply realized by appropriately changing the program according to the purpose of photometry and the object to be measured.

When the light source 6 reaches the position of 90 ° at the incident angle θin and completes imaging, the control unit 24 controls the light source 6 to return to the original position, and enters a standby state in preparation for the next photometry. .

In the present embodiment, the motor M, the motor drive unit 21, and the light source drive unit 22 are provided. However, the rotation of the mounting member 5 and the movement of the light source 6 may be performed manually. Further, both manual operation and automatic operation may be used.

Further, in order to improve the measurement accuracy by the image pickup device 8, a uniform correction process of the measurement system such as dark correction for optimizing the black level, sensitivity correction using a standard white plate, and shading correction is performed. Is preferred. As a result, the measurement accuracy of the reflected light intensity distribution can be further improved, and the reliability of data can be improved.
Further, by making the imaging device 8 a cooled CCD,
Noise of measurement data can be further reduced. This is particularly effective in the case of weak reflected light.

As described above, the photometric device according to the present invention is excellent in portability because of its small size as described in the specific actual dimensions, and can be used to determine the density pattern of the reflected light projected on the light deflection dome. Since it is possible to confirm with the naked eye, the reflection characteristics can be immediately confirmed at the measurement site, and the usability is excellent. Further, the type of the incident light Lin is not limited to a laser beam, but may be broad wavelength light such as white light or monochromatic light obtained by spectroscopy. Furthermore, a light meter that measures a spectral reflection distribution may be configured by incorporating a light source capable of continuously changing the wavelength of light, for example, a light source using spectral distribution by a diffraction grating. In addition to the above light sources, various lamps and L
A general light source such as an ED may be used. In this case, the light from the light source is made to be incident on the object to be measured as a beam by a collimator or the like.

According to these configurations, it is possible to measure not only the intensity of the reflected light but also the spectral characteristics of the reflected light, and further, a subjective evaluation of glossiness, scattering, shine, surface texture and the like. Is performed, measurement can be performed with high accuracy, so that effective photometric data can be provided.

[0061]

According to the present invention, the object to be measured is covered with the light deflecting dome, and the light emitted from the object to be measured is diffused on the light deflecting dome or the optical path is aligned in a predetermined direction. Since the light deflection dome is formed in a shape whose distance from the center of the dome is linearly proportional to the reflection angle, the radiation angle can be obtained directly from the captured image data, and the radiation light intensity distribution can be increased with a simple configuration. It can be measured with accuracy.

The photometry of the object to be measured can be performed all at once by illuminating the object to be measured and imaging the entire surface of the light deflecting dome, so that photometry can be performed at high speed. Further, the incident azimuth angle can be changed by rotating the object to be measured in a horizontal plane, and the incident angle can be changed by changing the position of the light source, so that photometric data under various conditions can be easily obtained. it can.

Further, the photometric device is small and excellent in portability, and the radiation light intensity distribution can be confirmed by simply observing the optical deflection dome with the naked eye. In addition, since a configuration in which the radiant light intensity distribution is measured by a dome having a simple shape without a complicated mechanism or a special and expensive optical system is required, a photometric device excellent in cost performance can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a photometric device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a shape of a light deflecting dome of the photometric device.

FIG. 3 is a plan view of a light deflection dome of the photometric device.

FIG. 4 is a diagram illustrating an example of reflected light projected on a light deflection dome.

FIG. 5 is a sectional view showing a specific example of dimensions of the light deflection dome.

FIG. 6 is a diagram illustrating the shape of a light deflection dome.

FIG. 7 is a cross-sectional view showing the shape of a light deflecting dome formed by using a part of a spherical shell.

FIG. 8 is a sectional view showing the shape of a conical light deflection dome.

FIG. 9 is a diagram illustrating a light deflection dome including a light transmission layer and a diffusion layer.

FIG. 10 is a sectional view showing a light deflection dome formed of a light diffusing material.

FIG. 11 is a diagram illustrating a light deflection dome configured using a Fresnel lens according to a third embodiment of the present invention.

FIG. 12 is a diagram showing a light deflecting dome configured using a diffraction lens.

FIG. 13 is a diagram illustrating a configuration of a photometric device in which a light source is provided in a dome according to a fourth embodiment of the present invention.

FIG. 14 is a diagram showing a main configuration of a photometric device in which an optical sensor is provided over an outer surface of a light deflection dome.

FIG. 15 is a configuration diagram of a photometric device provided with an ND filter according to a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating a configuration example of a photometric device including a driving mechanism.

FIG. 17 is a perspective view showing an example of a conventional photometric device.

FIG. 18 is an explanatory diagram showing another configuration example of a conventional photometric device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photometry device 2 light deflection dome 3 object to be measured 4 mask 4 a opening 5 mounting member 6 light source 7 condenser lens 8 image sensor 9 slit 10 small light source 11 optical sensor 13 ND filter 21 motor drive unit 22 light source drive unit 23 calculation Unit 24 control unit M motor Lin incident light Lout reflected light θin incident angle θout reflection angle φin incident azimuth φout reflection azimuth Z light deflection dome height R distance from light deflection dome center

Claims (24)

[Claims] 1. A photometric device for measuring a spatial intensity distribution of light emitted from an object, comprising: a mounting member for mounting an object to be measured; and a dome-shaped shell having a substantially circular bottom surface. A light-deflecting dome in which the object to be measured is installed at the center of the bottom surface of the shell, and light emitted from the object to be measured is diffused on the shell; A radiation light detection unit that detects the emitted radiation light from above the light deflection dome, and the curved surface shape of the light deflection dome, the optical path of the radiation light before the light path deflection, and the measurement surface of the measurement object. The angle between the normal and
The photometric device is set so as to be proportional to a horizontal distance from a position where the emitted light intersects the light deflection dome to a normal to the measurement surface. 2. The photometric device according to claim 1, wherein the light deflecting dome is formed by laminating a light diffusion layer having a light diffusion transmittance on a surface of the dome. 3. A photometric device for measuring a spatial intensity distribution of light emitted from an object, comprising: a mounting member for mounting an object to be measured; and a dome-shaped shell having a substantially circular bottom surface. An optical deflecting dome which is installed so that the object to be measured is arranged at the center of the bottom surface of the shell, and aligns an optical path of the emitted light from the object upward through the shell; A radiation light detection unit that detects the radiation light whose optical path is aligned by the dome from above the light deflection dome; and the curved surface shape of the light deflection dome, the radiation light optical path before light path deflection and the measurement object A photometric device, wherein an angle between an object and a measurement surface normal is set so as to be proportional to a horizontal distance from a position where the emitted light intersects the light deflection dome to the measurement surface normal. 4. The photometric device according to claim 2, wherein said light deflecting dome deflects the optical path of the radiated light from the object to be measured by refraction or diffraction. 5. A curved surface shape of the light deflecting dome excluding a zenith portion, where Z is the height of the light deflecting dome and R is the horizontal distance from the center of the dome bottom surface to the dome curved surface, Z = R ·
The photometric device according to any one of claims 1 to 4, wherein the photometric device is set based on a relationship of tan (90 ° -R). 6. The photometric device according to claim 1, wherein the radiation light detection unit is an area sensor. 7. The radiation light detection unit according to claim 1, wherein the radiation light is detected by a plurality of optical sensors arranged along a projection surface of the light deflection dome. The photometric device as described. 8. The photometry device according to claim 1, wherein the photometry device includes a light source that illuminates a measurement surface of the measurement object at a predetermined incident angle. apparatus. 9. The photometric device according to claim 8, wherein the light source is a light source that emits monochromatic light. 10. The photometric device according to claim 8, wherein the light source is a light source whose emission wavelength can be changed and emits monochromatic light having an arbitrary wavelength. 11. The photometric device according to claim 8, wherein the light source is a multi-color light source having various wavelength components. 12. The light source according to claim 8, wherein the light source is disposed outside the light deflecting dome, and the light deflecting dome is provided with a light transmitting portion for introducing light from the light source into the dome. The photometric device according to claim 11. 13. The light source according to claim 8, wherein the light source is disposed inside the deflection dome.
The photometric device according to claim 1. 14. The photometric device according to claim 8, further comprising an incident angle changing unit configured to change an incident angle of the illumination light on the measurement object by moving the light source. The photometric device according to claim 1. 15. The photometric device according to claim 1, further comprising an incident direction changing unit configured to change the incident direction of the illumination light by rotating the measurement object in a horizontal plane.
The photometric device according to claim 14. 16. The photometric device according to claim 1, further comprising a light blocking unit configured to block light from the light source applied to a portion other than the measurement surface of the measurement target. 2. The photometric device according to claim 1. 17. The light deflecting dome changes an optical path without depolarizing the light.
The photometric device according to claim 1. 18. The photometric device according to claim 17, wherein the photometric device measures a two-dimensional polarized reflection distribution of a measurement object. 19. The photometric device according to claim 1, wherein an ND filter is provided in an optical path from the light deflection dome to the radiation light detection unit. Photometric device. 20. The photometric device according to claim 1, further comprising detection signal correction means for correcting a dark level, detection sensitivity, and uniformity of a detection signal from the radiation light detection unit. 20. The photometric device according to claim 19. 21. The photometric device according to claim 1, wherein the photometric device includes an integration processing unit that integrates a detection signal from the radiation light detection unit. . 22. A photometric method for measuring a spatial intensity distribution of light radiated from an object, comprising: a dome-shaped shell having a bottom surface formed in a substantially circular shape; When the measurement target is installed at the center position, the angle between the optical path of the radiation emitted from the measurement target and the normal of the measurement surface of the measurement target intersects with the surface of the shell. Using a light deflecting dome set in proportion to the horizontal distance from the position to the measurement surface normal, the light deflecting dome is radiated onto the light deflecting dome from a measurement object installed at the center of the bottom surface of the light deflecting dome. Wherein the emitted light is detected by an emitted light detector disposed above the light deflection dome. 23. (1) The light source is held at a position to illuminate the measurement target at a predetermined incident angle, and (2) the incident azimuth is changed by rotating the measurement target in a horizontal plane. , While the object to be measured makes one rotation,
The radiation light intensity distribution from the surface of the light deflection dome is detected by the radiation light detection unit. (3) After the detection is completed, the light source is moved by a predetermined step angle so that the incident angle of the illumination light to the measurement object is changed. 23. The photometric method according to claim 22, wherein the steps (1) to (3) of changing are repeated for different incident angles. 24. A detection signal obtained by the radiation light detection unit is integrated for a predetermined period to change the intensity of radiation light from the measurement object irradiated onto the light deflection dome and change the incident azimuth angle. 24. The photometric method according to claim 23, wherein the measurement object is detected while being continuously rotated throughout the entire period.