JPH11230823A - Photometry device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photometry device which can measure the reflected light or transmitted light from an object, the intensity of the light emitted from a luminous body, and spatial distribution of spectrum components with accuracy at a high speed regardless of the shape of the object. SOLUTION: A photometry device which measures the spatial intensity distribution of the light radiated from an object is constituted of a light condensing dome 1 provided with a concave elliptic reflecting mirror having an ellipsoidal surface of revolution, a sample frame 3 which sets a sample 2 to the first elliptic focal point 1a of the dome 1, light receiving sections 5 and 6 which are set to the second elliptic focal point 1c of the dome 1 and receive the light radiated from the sample 2 and reflected by the surface of the reflecting mirror of the dome 1 by means of two-dimensional photodetector elements, and a data collecting section 7 which finds the spatial intensity distribution of the light from variable density pictures obtained by collecting the outputs of the sections 5 and 6.

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 diffused light such as reflected light and transmitted light from an object, luminous intensity of a self-luminous body, and spatial distribution of spectral components.

[0002]

2. Description of the Related Art Conventionally, as a photometric device for measuring diffused light such as reflected light or transmitted light emitted from an object irradiated with light, emission intensity distribution of a self-luminous body, and spectral components,
There is an apparatus as shown in FIG. In this photometric device, the light receiving system 131 is step-scanned using a goniometer, and the installation angles α and β of the measurement target 132 are respectively changed by the stage 133, and the illumination light incident on the measurement target 132 from the light source 134 is incident. By measuring the intensity of the diffused light with respect to the angle, the spatial intensity distribution of the diffused light has been obtained. 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, as shown in FIG. 14, there is also a photometric device using a microscope optical system having a large-diameter objective lens. In this photometric device, the spatial intensity distribution of light is obtained by projecting light emitted from the measurement object 131 onto the area sensor 144 by using the Fourier lenses 142 and 143 and measuring the light intensity distribution. In this optical system, the measurement limit of the light reflected at the angle at which the surface of the measuring object 131 is slightly confined is limited by the aperture of the lens and the distance between the lens and the measuring object. That is, the larger the diameter of the objective lens,
As the object to be measured approaches the objective lens, the measurable angle range becomes wider.

[0004]

However, in a conventional photometric device using a goniometer, in order to obtain light intensity data densely measured from a plurality of measurement angles over a wide area in a space, It took a lot of time to measure. For example, when measuring the reflection characteristics (diffusion characteristics) of an object, a light beam is irradiated on the measurement object from a certain incident angle, and the intensity of the diffused light from the measurement object due to the irradiation light is measured on the spherical surface around the measurement object surface. It measures from the position where the latitude and the longitude differ. 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 illumination, if all 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 the conventional photometric device shown in FIG. 14, when the object to be measured is a three-dimensional object, there is a case where the object to be measured and the objective lens are three-dimensionally interfered with each other and cannot be measured. For example, there is an example of a measurement target in which the measurement target is covered with a transparent body such as glass or plastic and the optical system cannot focus on the measurement surface. The present invention has been made in view of such conventional problems,
Provided is a photometric device that can quickly and accurately measure diffused light such as reflected light or transmitted light of an object, luminous intensity of a self-luminous body, and spatial distribution of spectral components regardless of the shape of the object. It is intended to be.

[0006]

In order to achieve the above object,
The present invention provides a photometric device that measures a spatial intensity distribution of light emitted from an object, a condensing dome including a concave elliptical reflecting mirror formed by using a spheroidal curved surface as a reflecting surface, A measuring object pedestal for setting the measuring object at the first elliptical focal position, and a measuring object pedestal arranged at the second elliptical focal position of the converging dome, radiated from the measuring object and reflected by the reflecting mirror surface of the converging dome A light receiving unit that receives light with a two-dimensional light detecting element and a data collecting unit that obtains a spatial light intensity distribution from a grayscale image obtained by collecting the output from the light receiving unit are configured. . As a result, light emitted from the object at the first elliptical focal position is reflected by the elliptical reflecting mirror surface of the converging dome and condensed at the second elliptical focal position, and the light intensity for each radiation angle is reduced. Detection can be performed collectively by a two-dimensional photodetector.

In addition, a beam splitter is provided in the optical path of the light receiving section, and a light beam from a light source is introduced through a mask having a two-dimensional light and dark pattern, and the light is reflected from the condensing dome from the second elliptical focal position. The measurement object may be illuminated via a mirror surface. In this case, the light source and the mask may be a surface light emitter and include a pattern control unit that controls a light emission pattern of the surface light emitter. This makes it possible to easily create a light-dark pattern and to easily switch between different light-dark patterns to illuminate without having to remove and replace the mask each time the pattern is switched.

The light source may irradiate an object to be measured from an opening provided with the converging dome.
Thereby, illumination light can be incident from multiple directions. Further, the rear surface of the object to be measured may be illuminated from below the pedestal of the object to be measured, and the illumination may be an illumination having a two-dimensional light and dark pattern. This makes it possible to measure the intensity distribution of the transmitted light with respect to the light-transmitting measurement object, and to perform surface illumination with a specific illumination pattern.

The light detecting element may be used as a color detecting element to spectrally measure light from the object to be measured. A color wheel may be provided in the optical path of the photometric device, or a monochromator may be provided as a light source. With the provision, the spectral characteristics may be measured. In addition, the photometric device is provided with a two-dimensional photodetector for measuring a light intensity distribution of illumination light to be introduced into the beam splitter, and an illumination obtained by measuring a light intensity distribution of illumination light obtained by the detection element. A double beam optical system using the light intensity distribution of light as a reference may be configured.

Further, the light-dark pattern of the mask may be formed as a light-dark pattern in which a light source position of an illumination environment to be measured is photographed, and an arbitrary illumination pattern may be formed by a combination based on a method such as Fourier transform. May be formed as a plurality of patterns based on the basis vectors of the orthogonal function. The elliptical reflecting mirror may be a concave elliptical reflecting mirror having a paraboloid of revolution as a reflecting surface instead of a spheroidal curved surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of a photometric device according to a first embodiment of the present invention. First, a first embodiment will be described with reference to FIG. The photometric device 100 shown in FIG. 1 has a converging dome 1 having a concave elliptical reflecting mirror surface formed by using a spheroidal curved surface as a reflecting surface, and one elliptical focal point 1a (first elliptical focal point) of the converging dome 1. The object base 3 on which the object 2 is to be installed, and the converging dome 1
A light source 4 for irradiating a parallel light beam to the measurement object 2 from the opening 1b of the light source 4 and a light source 4 including the optical system, and the other elliptical focal point 1
A wide-angle optical system 5 having a wide-angle light receiving optical system near c (second elliptical focal point), and a CCD (Charge Coupled Device) or MO for detecting the intensity distribution of the light beam projected on the element surface
An area sensor 6 such as S (Metal Oxide Semiconductor),
And a data collection unit 7 for collecting and analyzing output data from the area sensor 6. Here, the condensing dome 1 is illustrated as a shell, but is not limited to this, and may be configured, for example, to form a concave spheroidal surface by hollowing out the inside of a rectangular parallelepiped block, and in any case. It is preferable to use a structure and a material having good workability and little deformation after assembly.

Next, the principle of measuring the light intensity distribution by the elliptical reflecting mirror will be described. The light emitted at one focal position 1a of the elliptical reflecting mirror is reflected by the mirror surface of the reflecting mirror and then reflected at the other focal position.
1c has the property of condensing light. The photometric device 100 uses this property to place the measurement target 2 at one focal position 1a and to install photometric systems 5 and 6 at the other focal position 1c. Thereby, the spatial diffused light intensity distribution when the light source 4 irradiates a light beam to the measurement target 2, that is, in what direction and at what intensity the diffused light such as reflected light emitted from the measurement target surface The spatially diffused light intensity distribution indicating whether the light is radiated can be detected by the photometric systems 5 and 6. If the elliptical reflecting mirror of this condensing dome is, for example, a spherical reflecting mirror,
Since the center of the spherical surface, which is one point, corresponds to the above two focal points, the light emitting point and the photometric point coincide, so that photometry cannot be actually performed. On the other hand, in the case of an elliptical reflecting mirror, the light emitting point and the measuring point can be set at two different focal positions, so that the elliptical reflecting mirror can be said to be a very convenient shape for the above measurement.

Next, a procedure for measuring the diffused light intensity by the photometric device according to the present embodiment will be described. Prior to the measurement of the diffused light intensity distribution, first, calibration of angle information in a photometric system of the photometric device is performed as necessary. As a specific method of this calibration, for example, the following method can be mentioned. First, a hemisphere 20 on which graticules are accurately cut at predetermined intervals shown in FIG. 2 is placed so that the bottom surface 21 of the hemisphere matches the surface of the object to be measured, and the reference meridian is set to the major axis of the ellipse. The whole hemisphere is illuminated with a light beam from a light source while being fixed to the measurement object gantry 3 so as to match the direction. Then, the graticule pattern shown in FIG. 3 is projected onto the area sensor of the photometric system. This graticule pattern is such that each latitudinal line is inclined at an angle θ
, And each meridian represents the rotation angle φ. Therefore, based on the obtained graticule pattern, the pixel position of the captured image
The relationship between (i, j) and the latitude and longitude position representing the reflection direction (θ, φ) is tabulated or expressed as a mathematical expression. By performing such calibration of the angle information, it is possible to accurately associate the pixel position on the captured image with the reflection angle.

Next, after performing this calibration, the intensity L of the diffused light from the object to be measured by illumination is measured. To measure the diffused light intensity, first,
The measurement object 2 is mounted on the installation plate 3a, and the installation plate 3a is set at a predetermined inclination angle α. This inclination angle α corresponds to the angle of incidence of the light beam from the light source 4 on the object 2 to be measured. Next, a parallel light beam from the light source 4 is
And irradiates the point to be measured of the measurement object 2 through. When the object 2 is irradiated with parallel rays, the diffused light from the surface of the object is reflected by the mirror surface of the converging dome and the wide-angle optical system
Focused on 5. Then, for example, FIG.
(2) A two-dimensional gray image of diffused light is formed. The obtained grayscale image of the diffused light is analyzed in the data collection unit 7, and the spatial intensity distribution of the diffused light with respect to the incident angle θ of the light beam is obtained. That is, the light intensity distribution on the image of FIG.
(i, j, L _ij ) is converted into a light intensity distribution (θ, φ, Lψ) on the reflection space by a conversion table obtained by calibration.
φ). Here, the spatial intensity distribution can be obtained at one time by one measurement in which the light beam is irradiated with the incident angle α fixed, so that the measurement time can be greatly reduced. In addition, since the angle θ from the surface normal of the object to be measured can be measured over a wide range from 0 to an angle close to 90 °, it can detect diffused light with an extremely low angle θ close to 90 °. can do.

In order to perform photometry by changing the incident angle α of the light beam, a method of inclining the object pedestal 3 as described above can be considered.
May be provided, and a light beam may be sequentially incident from the opening toward the object to be measured. In this case, openings may be provided in the light collection dome 1 by the number of incident angles at which measurement is performed.However, openings are provided at roughly typical incident angle positions, and the measuring object pedestal 3 is formed with a small incident angle. Used together for angle adjustment,
The light beam may be incident at a substantially continuous incident angle. This makes it possible to stably measure the diffused light intensity at each light incident angle by simple tilt angle control and light source switching control in a narrow range. Further, the opening of the light collection dome 1 may be formed as a continuous slit, and the light source 4 may be moved to an arbitrary incident angle position by, for example, an electric motor.

Next, a description will be given of a method of illuminating the object to be measured when measuring the light transmitting material. A light-transmitting measurement target is basically irradiated with a light beam from the back side of the measurement target, and the transmitted scattered light at that time is measured. In this case, the following two methods can be considered as an illumination method for the measurement target. First, as shown in FIG. 6, an opening 3b is formed in the installation plate 3a of the object stand, a light source 4a is installed below the opening 3b, and a light beam is measured through the opening 3b. There is a method of irradiating the back of an object. The irradiated light beam is transmitted and diffused in the object to be measured, and is converged on the photometric system. Then, by changing the incident angle of the light source 4a with respect to the measurement object, the light intensity distribution of the transmitted diffused light at a plurality of different incident angles can be measured. Secondly, there is a method of performing surface illumination instead of a method of entering from one point. In this method, similarly, an opening 3c is formed in the installation plate 3a of the object stand, and the light source 71 is provided below the opening 3c.
And a mask 72 having two-dimensional light / dark pattern information is provided in the middle of the optical path from the light source 71 to the opening 3c, and a lens 73 is provided downstream of the mask 72 on the optical path. It is provided to focus on With this method,
The object to be measured can be surface-illuminated based on the light and dark pattern of the mask 72, and the illumination pattern described in detail in the second embodiment can be changed.

As described above, according to the present embodiment, diffused light such as reflected light or transmitted light emitted from one focal position of the concave elliptical reflecting mirror is focused on the other focal position. The spatially diffused light can be concentrated at one point. By using the area sensor, which is a two-dimensional detection element, for the diffused light detection system, it is possible to collectively measure light intensity information having a spatial distribution radiated from an object to be measured. In addition, the measurement time can be greatly reduced. In addition, since the measurement points of the area sensor are densely arranged, measurement can be performed without missing a unique intensity change in a narrow angle range, and measurement can be performed with high resolution. This is particularly effective for a measurement object that may show a unique light intensity distribution, such as a hologram, and spatially continuous data can be easily obtained.

Even when an optical response to a high-speed electrical input such as an electronic device is measured, a transient optical response is measured independently for each of a plurality of spatial directions. Since measurement can be performed at one time, measurement can be performed with sufficient responsiveness and measurement accuracy even for photometric applications that require high-speed photometry. Further, for example, N
By interposing a D (Neutral Density) filter,
The dynamic range can be expanded.

Next, a description will be given of a second embodiment in which an object to be measured is installed at one elliptical focal position of the converging dome and both a photometric system and an illumination system are installed at the other elliptical focal position. FIG. 8 shows the configuration of photometric device 200 in the present embodiment.
The present photometric device has the first configuration except that the illumination system is provided on the photometric system side.
The configuration is the same as that of the photometric device 100 in the present embodiment. Here, the configuration and operation of the illumination system and the photometric system will be described. In the illumination system, the light beam emitted from the light source 8 is made substantially parallel by the lens 9 and guided to the mask 10 having two-dimensional light / dark pattern information. The light beam transmitted through the mask 10 is condensed by a lens 11, and is split into two light paths from a light source 8 by a beam splitter 13 arranged in the middle of the light path of the wide-angle optical system 12. One of the split light beams is guided to the converging dome 1,
The other light beam is introduced into an incident light measuring area sensor 14 for measuring the intensity distribution of the incident light.

One of the light beams guided to the converging dome is reflected by the elliptical reflecting mirror surface of the converging dome 1 from the wide-angle optical system 12 disposed at the elliptical focal position, and the measurement object 2 is illuminated by the mask 10. Illuminate according to the pattern. Here, the wide-angle optical system means an optical system that has the function of converting parallel light into wide-angle radiation light and converting wide-angle image light into parallel light when moving backward. In the above configuration, the object to be measured is illuminated by surface illumination according to the light / dark pattern of the mask 10. The diffused light from the measurement object returns along the path of the illumination light, and is condensed on the wide-angle optical system 12. In other words, in this optical system, the path followed by the illumination light and the path followed by the diffused light from the measurement object are the same for the same angle (incident angle, reflection angle) components in the converging dome. . The diffused light collected by the wide-angle optical system 12 is
The scattered light intensity distribution projected from the object to be measured is measured.

Here, the spot diameter of the illumination light applied to the object to be measured is not strictly one point but has a predetermined spread. If this optical system is an optical system that simply converts wide-angle image light into parallel light, the larger the spot diameter on the object to be measured, the lower the angular resolution of diffused light measurement. To solve this problem, an optical system may be designed based on a Fourier transform method using a lens. As the objective lens, a fisheye lens shown in FIG. 9A can be used, and a lens having a concave front surface shown in FIG. 9B can be used. In the case of the fisheye lens shown in FIG. 9A, commercially available optical components can be used, and the objective lens can be easily and inexpensively formed. Further, in the case of the concave lens shown in FIG. 9B, it is possible to prevent the rays to be measured by the lens itself from being hidden. In any case, if the converging dome is used, even if the object to be measured is a three-dimensional object having a three-dimensional bulge, the measurement can be stably performed without interference of the objective lens.

On the other hand, the light beam branched by the beam splitter 13 and incident on the incident light measuring area sensor 14 is the same light beam as the illumination light illuminating the object to be measured, and this light beam is used for reference. . That is, by correcting the diffused light intensity distribution from the measurement target obtained from the area sensor 15 with reference to the reference light intensity distribution obtained from the area sensor 14, a double-beam optical system in which noise components such as shading are reduced. Make up the system.

The light / dark pattern of the mask 10 determines the angle of incidence on the object 2 to be measured. For example, in the case where the mask pattern transmits light only at the center, An illumination pattern that is illuminated from the surface normal direction of the measurement object is formed. Similarly, in order to reproduce the illumination state of a plurality of light sources as often seen in indoor lighting, a transmission part is provided at a mask position corresponding to the illumination position of each light source when the installation position of the measurement target is viewed from the viewpoint. ,
What is necessary is just to illuminate by interposing this mask in a predetermined position. Thereby, the above-mentioned illumination state can be reproduced, and an illumination pattern closer to actual illumination can be formed.
As a simple method, a positive film is obtained by photographing an actual illumination pattern to be reproduced (for example, photographing by looking up at a light source such as a fluorescent lamp or a spotlight from a position to be measured). The position of the light source is almost transparent on this positive film, so if this is used as it is as a mask, or if a mask in which the pattern of the positive film is transferred to another medium is used, the position of the light source captured Thus, the illumination light is applied to the object to be measured, and an illumination pattern substantially the same as the actual illumination pattern can be reproduced in a pseudo manner.

Further, there is a method of obtaining a target illumination pattern by a predetermined technique such as Fourier series expansion using a plurality of patterns based on orthogonal function basis vectors as a pattern of the mask 10. That is, by applying Fourier series expansion to a pattern of a specific illumination light intensity distribution, the pattern is decomposed into components of each series, which are base vectors of orthogonal functions.
Then, the target light pattern is reproduced by multiplying the diffused light intensity distribution at the time of lighting the light pattern by each base vector by a series component corresponding to the light pattern, and cumulatively adding this to all the base vectors. Is done. Specific examples of the basis vector include a basis vector such as Laplace's spherical function and DCT (Discrete Cosine Transform). In this case, by configuring the mask using an LCD (Liquid Crystal Display) capable of easily displaying a desired light-dark pattern, an illumination pattern suitable for the purpose, that is, a light-shielding pattern that is a display pattern of the LCD can be freely set. Since it can be created and can be easily switched and displayed, measurement can be performed continuously without removing and replacing the mask.

Next, a third embodiment for illuminating an object to be measured by using a surface emitting device such as a CRT (Cathode Ray Tube) will be described. FIG. 10 shows the configurations of the illumination system and the photometry system in the present embodiment. The configuration of this illumination system is similar to that of the second embodiment except that
, And the light diffusely radiated from the surface light emitting device 101 is condensed and parallelized by a diffusion preventing means such as a lens 102. The light / dark pattern displayed by the surface light emitting device 101 is displayed by driving the driver 104 based on the pattern information stored in the pattern control unit 103 in advance. The configuration of the photometric system is the same as that of the photometric system according to the second embodiment. In addition to the CRT, the above-mentioned surface light emitting device includes a TFT (Thin Film Transistor).
r), LCD, PDP (Plasma Display Panel), LED (Light Emitting Diode) and EL (Electro L
uminescence) or the like.

According to the illumination system of this embodiment, various illumination patterns can be freely formed, and a plurality of patterns can be easily and quickly switched for illumination. In addition, by preparing a number of patterns for measurement in advance and programming the pattern control unit 103 so that the measurement can be performed by sequentially switching the patterns, the photometric processing can be automated.

Next, a fourth embodiment for measuring color information of diffused light will be described. In the present embodiment, the diffusion characteristic of each spectrum component is measured by spectrally decomposing the diffused light from the measurement object or by illuminating a specific spectrum component. As a method of measuring the color information, a general color filter C
A method of measuring using a CD, as shown in FIG. 11, a color wheel provided with a filter that transmits only specific spectral components (for example, R, G, B) in the optical path of either the illumination system or the light receiving system. And a method of irradiating the object to be measured with a light beam split by a monochromator using a diffraction grating or the like.

According to the method using a CCD with a color filter, colorimetric data such as chromaticity and saturation can be collectively captured by one image pickup, and the measurement time can be greatly reduced. Further, according to the method using a color wheel, it is possible to divide the wavelength component of the light beam into the illustrated three primary colors (RBG) or more, and illuminate the light beam. Can be obtained. In particular, by using a color filter based on thin-film interference, light with an arbitrary wavelength can be extracted in the wavelength range of visible light. Furthermore, according to the method using a monochromator, light having a specific wavelength component can be extracted simply and accurately, and the response characteristic to the wavelength of illumination light can be measured with high accuracy. However,
Since the intensity of the light beam split by the monochromator generally decreases, the noise level of the obtained intensity distribution data may increase. In such a case, in order to improve the S / N ratio of the data, an integrating device or a cooling CC
It is desirable to use D.

The integrating device may be a system for adjusting an optical shutter speed (setting a long light receiving time) or a system for adjusting an electric signal integrating time. It is generally known that a cooled CCD can further reduce noise at the time of imaging. By using a cooled CCD, noise is reduced even if the light intensity of illumination light is weak, and S / N is reduced. Good light intensity distribution data with a high ratio can be obtained. In any case, the use of the reflecting mirror makes it possible to measure the spectral characteristics in a good state without chromatic aberration. It should be noted that the elliptical reflecting mirror of the condensing dome can form a substantially equivalent condensing optical system even if it is a parabolic mirror having two different focal points as shown in FIG.

The photometric device according to the present invention can exhibit functions with sufficient accuracy for the following photometric purposes. First, in the case of a measurement object having light diffusivity, measurement of the glossiness of a coated product having a different glossiness of the painted surface, measurement of the degree of scattering of frosted glass or milky white plastic, surface treatment of paper such as photographs and printing paper. And the degree of anti-glare treatment (anti-glare treatment) on the display surface of the electronic display element. In the case of a specular measurement object, the measurement of the amount of light and the spectrum of surface reflection with respect to a glass material processed into an optical thin film,
Measurement of the visual dependence of electro-optical characteristics on a CD, and the like. Furthermore, in the self-luminous measurement object, LED
Measurement of light emission directivity and glossiness of a light-emitting element such as an LCD and an EL, measurement of emission intensity distribution of a backlight such as an LCD module, and the like.

[0031]

According to the present invention, the spatial intensity of diffused light, such as reflected light or transmitted light, radiated from one of the elliptical focal points is formed by a converging dome having a concave elliptical reflecting mirror surface having a spheroidal curved surface. By measuring the distribution with the area sensor at the other elliptical focal point, it is possible to measure the diffusion characteristics and spectral characteristics of the object at high speed and with high accuracy. Also, by installing both the illumination system and the light receiving system at the elliptical focal position on one side and illuminating with the illumination pattern according to the mask pattern,
Lighting environment with light sources having various different incident angles
It can be reproduced by two illumination patterns. Furthermore, an arbitrary illumination pattern can be reproduced by using the light-dark pattern of the mask as the pattern of the basis vector of the orthogonal function.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a hemisphere for angle calibration.

FIG. 3 is a diagram showing a detection image at the time of angle calibration.

FIG. 4 is a diagram showing an example of a measurement result of a diffused light intensity distribution.

FIG. 5 is a configuration diagram illustrating an illumination method at a plurality of incident angles.

FIG. 6 is a diagram showing a method of illuminating from the back surface of a measurement object.

FIG. 7 is a diagram showing a method of performing surface illumination from the back surface of a measurement object.

FIG. 8 is a configuration diagram of a photometric device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a fisheye lens as an objective lens and a lens having a concave surface.

FIG. 10 is a diagram showing another embodiment of the surface illumination method.

FIG. 11 is a diagram showing a state in which a color wheel is provided in the middle of the optical path.

FIG. 12 is a diagram showing a converging dome configured using a parabolic mirror.

FIG. 13 is a conceptual configuration diagram of a photometric device using a conventional goniometer.

FIG. 14 is a diagram showing a conventional microscope optical system with a large-diameter objective lens.

[Explanation of symbols]

 1 Condensing dome 1a, 1c Elliptical focal point 1b Opening 2 Measurement object 3 Measurement object mount 3a Installation plate 3b, 3c Opening hole 4,4a Illumination system 5,12 Wide-angle optical system 6,15 Area sensor 7 Data collection unit 8 , 71 light source 9,11,73 lens 10 mask 13 beam splitter 14 area sensor 51 ~ 55 aperture 101 surface light emitter 102 lens 103 pattern controller 100,200 photometric device

Claims (13)

[Claims] 1. A photometric device for measuring a spatial intensity distribution of light radiated from an object, comprising: a converging dome 1 having a concave elliptical reflecting mirror formed with a spheroidal curved surface as a reflecting surface; A measuring object gantry 3 for setting the measuring object 2 at a first elliptical focal position 1a of the dome 1, and a measuring object pedestal 3 disposed at a second elliptical focal position 1c of the condensing dome 1;
Light receiving units 5 and 6 for receiving light emitted from the object 2 and reflected by the reflecting mirror surface of the converging dome 1 with a two-dimensional photodetector
And a data collection unit 7 for obtaining a spatial light intensity distribution from a grayscale image obtained by collecting outputs from the light receiving units 5 and 6. 2. A beam splitter 13 is provided in the middle of the optical path of the light receiving sections 5 and 6, and a light beam from a light source 8 is introduced through a mask 10 having a two-dimensional light and dark pattern. 2. The photometric device according to claim 1, wherein the object to be measured 2 is illuminated from 1c via the reflecting mirror surface of the converging dome 1. 3. The light source 8 and the mask 10 are provided with a surface light emitter 91.
The photometric device according to claim 2, further comprising a pattern control unit (93) for controlling a light emission pattern of the surface light emitter (91). 4. The photometric device according to claim 1, wherein the light source irradiates the object to be measured 2 from an opening 1b provided with the converging dome 1. 5. The photometric device according to claim 1, wherein the light source irradiates the back surface of the measurement object from below the measurement object pedestal 3. 6. The photometric device according to claim 5, wherein the photometric device emits light having two-dimensional light / dark pattern information. 7. The photometry device according to claim 1, wherein the photodetection device is a color detection device, and measures the light from the object to be measured 2 by spectroscopy. apparatus. 8. The photometric device according to claim 1, wherein a color wheel is provided in the optical path of the photometric device to measure spectral characteristics. 9. The photometric device according to claim 1, wherein the light source includes a monochromator, and irradiates the split light. 10. A two-dimensional light detection element for measuring a light intensity distribution of illumination light introduced into the beam splitter, wherein the light intensity distribution of illumination light obtained by the detection element is measured. The photometric device according to claim 2, wherein: 11. The photometric device according to claim 2, wherein the light-dark pattern of the mask is a light-dark pattern representing a light source position of an illumination environment to be measured. 12. The mask according to claim 2, wherein the light and dark patterns of the mask are a plurality of patterns based on orthogonal function basis vectors that can create an arbitrary illumination pattern by combination. The photometric device as described. 13. The elliptical reflecting mirror according to claim 1, wherein the elliptical reflecting mirror is a concave elliptical reflecting mirror having a paraboloid of revolution as a reflecting surface instead of a spheroidal curved surface. The photometric device as described.