JP2020202119A - Luminaire - Google Patents

Abstract

To provide a luminaire in which convenience of measurement is improved.SOLUTION: A luminaire L1 includes a casing 1, a plurality of plate materials 2, and a light source 3. An inner surface 12 of the casing 1 defines a semi-spherical internal space, and is constituted by a material for diffusing and reflecting light. An observation part 14 is arranged being separated in the circumferential direction along the inner surface from an apex 132. Each plate material 2 is arranged in the internal space and covers part of the inner surface when viewed from the center. The surface facing the center of each plate material 2 is constituted by a material for absorbing light. Each of the plurality of plate materials 2 includes a first plate material 201, a second plate material 202 arranged symmetrically with the first plate material 201 with respect to the center, and a third plate material which is not arranged symmetrically with any one of the other plate materials with respect to the center. Each of the second plate material 202 and the third plate material has a transmission port 2021 arranged at the position corresponding to the observation part 14.SELECTED DRAWING: Figure 3

Description

The present invention relates to a lighting device.

In order to measure the color or gloss of an object, it is desirable to satisfy the illumination and light receiving conditions defined by the industrial standard, and many contact-type colorimeters and gloss meters conforming to the industrial standard are commercially available. If the object can produce a flat and uniform sample surface, the color and gloss of the object can be measured by a commercially available contact type colorimeter and gloss meter. However, in order to measure a sample having a complicated shape as it is, a color luminance meter and a camera are used to observe the target object in a non-contact manner, and lighting is separately provided. Then, the illumination and light receiving conditions tend to vary, and it becomes difficult to ensure the measurement accuracy.

The inventors of the present invention have proposed in Non-Patent Documents 1 and 2 a dome-shaped lighting device capable of solving such a problem. Specifically, the proposed luminaire was equipped with a dome that imitated an integrating sphere, and the inner wall of the dome was white. Further, a blade-shaped plate material serving as an optical trap was arranged near the inner wall in the dome. The plate material is configured to be movable around an axis passing through the center of the internal space where the sample table is placed. In addition, a light receiving port was provided at the zenith of the dome, and color measurement was possible from this light receiving port with a camera. According to this lighting device, by arranging an object in a dome filled with illumination light under certain lighting conditions, it is possible to measure the color of the object with good reproducibility even if it is not in contact. Furthermore, by taking a picture while changing the position of the movable plate material, color measurement without the specular reflection component (Specular Component Exclude: SCE) and color measurement including the specular reflection component (Specular Component Include: SCI) are performed. be able to.

Hideki Sakai, Mai Isomi, Hiroshi Iyoda, "Development of a non-contact color measurement system using dome-shaped illumination Part 1: Color measurement of free-form surface samples", Journal of the Japan Color Society, 2017, Vol. 41, No. 3. No., supplement, p10-11 Mai Isomi, Hideki Sakai, Hiroshi Iyoda, "Development of a non-contact color measurement system using dome-shaped lighting Part 2: Gloss measurement of free-form surface samples", Journal of the Japan Color Society, 2017, Vol. 41, No. 3. No., supplement, p12-15

The inventors of the present invention have found that the lighting device proposed in Non-Patent Documents 1 and 2 has the following problems. That is, in the proposed lighting device, a light receiving port is provided at the zenith (vertical position). Therefore, it is difficult to measure the color of the object at an angle and to photograph the object in consideration of the retroreflective component. Further, for the SCE method and the SCI method of color measurement, the position of the plate material is frequently changed to photograph the object. Therefore, the number of times of shooting tends to increase, and it takes time and effort to measure. Due to these, the present inventors have found that the proposed lighting device has a problem that the measurement is not convenient.

The present invention, on the one hand, has been made in view of such circumstances, and an object of the present invention is to provide a lighting device with improved measurement convenience.

The present invention employs the following configuration in order to solve the above-mentioned problems.

That is, the lighting device according to one aspect of the present invention is a casing having an outer surface, an inner surface, a hemispherical internal space, and an observation portion, and the inner surface defines the hemispherical internal space and emits light. The hemispherical internal space, which is made of a material that diffusely reflects, has a center, an apex, a bottom surface, and an axis, the axis passes through the center and the apex, and the casing is the bottom surface side of the internal space. The observation unit is provided for observing an object arranged in the internal space, and is arranged apart from the apex along the inner surface in the circumferential direction. A casing and a plurality of plate materials each facing the inner surface and being divided and arranged around the axis in the internal space, and the plurality of plate materials are each a part of the inner surface when viewed from the center. Each of the plurality of plate materials includes a first surface facing the inner surface and a second surface facing the center, and the plurality of plate materials are configured to be adjustable in position around the axis. Each of the second surfaces is made of a material that absorbs light, and the plurality of plate materials are arranged symmetrically with respect to the first plate material and the center of the first plate material. A second plate material having a transmission port that is arranged at a position corresponding to the observation unit and is configured to transmit light, and a second plate material that is arranged at a position corresponding to the observation unit and emits light. A third plate material having a permeation port configured to transmit light, and none of the other plate materials among the plurality of plate materials is arranged symmetrically with respect to the center of the third plate material. It includes a plurality of plate materials including the plate material of 3, and a light source arranged so as to irradiate the internal space with light.

In the lighting device according to this configuration, by arranging the object near the center of the internal space of the casing, the observation unit can observe the object for color measurement. At the time of this observation, the light emitted from the light source is diffusely reflected on the inner surface of the casing, so that the illumination conditions in the internal space can be kept constant. Therefore, according to the lighting device according to the configuration, it is possible to measure the color of the object in a non-contact manner with good reproducibility. Further, since the observation unit is arranged apart from the apex along the inner surface in the circumferential direction, it is possible to measure the color of the object at an angle. Further, in the lighting device according to the configuration, each plate material plays a role of a light trap. By appropriately arranging each of these plate materials, it is possible to carry out color measurement by the SCE method and the SCI method in consideration of the retroreflection component.

Specifically, when the second plate material is arranged according to the position of the observation unit, the first plate material is arranged at a position symmetrical with respect to the center of the internal space and the second plate material and the observation unit. When observing an object by the observing unit, the first plate material arranged in this way can block the incident light that causes a specular reflection component measurable from the observing unit on the object. In addition, the second plate material arranged according to the position of the observation unit can block the incident of light that causes a retroreflective component measurable from the observation unit on the object. Therefore, by arranging the second plate material in accordance with the position of the observation unit, the diffuse reflection component of the object can be measured.

Further, when the third plate material is arranged according to the position of the observation unit, the third plate material arranged in this way causes the incident of light that causes a retroreflection component measurable from the observation unit to the object. It can be blocked. On the other hand, in this case, since no other plate material is arranged at a position symmetrical to the observation portion with respect to the center of the internal space, light that generates a specular reflection component that can be measured from the observation portion is incident on the object. be able to. Therefore, by arranging the third plate material in accordance with the position of the observation unit, the diffuse reflection component and the specular reflection component of the object can be measured.

Therefore, in the lighting device according to the configuration, the color measurement of the object can be performed at an angle by the observation units arranged apart from the apex along the inner surface in the circumferential direction. Further, by arranging each of the above plate materials, it is possible to carry out color measurement by the SCE method and the SCI method in consideration of the retroreflection component. Therefore, according to the configuration, it is possible to provide a lighting device with improved measurement convenience.

In addition, "arranged symmetrically with respect to the target plate material with respect to the center" means that it is arranged at a position 180 degrees around the axis with respect to the target plate material. Arranged asymmetrically with the target plate material with respect to the center (not arranged symmetrically) is not arranged at a position 180 degrees around the axis with respect to the target plate material, that is, is arranged around the axis with respect to the target plate material. It is to be arranged at an angle deviated from 180 degrees. The observation unit may be appropriately configured so that the object can be observed, and may be, for example, a light receiving port for observing the internal space with an optical sensor such as a camera, or an optical sensor. The "material that diffusely reflects light" is not particularly limited as long as it can diffusely reflect light, and may be, for example, a member painted in white, a member made of white material, or the like. As a specific example, the material that diffusely reflects light may be, for example, barium sulfate, a porous PTFE (polytetrafluoroethylene) resin, or the like. The "material that absorbs light" is not particularly limited as long as it can absorb light, and may be, for example, a member painted in black, a member made of black material, or the like. As a specific example, the material that absorbs light may be, for example, carbon black, a non-reflective brushed cloth, or the like. Each plate may be configured to be individually movable. When each plate material is individually movable, the second plate material and the third plate material may be composed of the same plate material. That is, one plate material having a transmission port may also serve as a second plate material and a third plate material.

In the lighting device according to the one side surface, the plurality of plate materials are the fourth plate materials, and any of the other plate materials among the plurality of plate materials is symmetrical with respect to the center of the fourth plate material. A fourth plate material that is not arranged may be further included. When the fourth plate material is arranged at a position symmetrical to the observation portion with respect to the center, no other plate material is arranged at the position corresponding to the observation portion. Therefore, light that produces a retroreflective component that can be measured from the observation unit can be incident on the object. In addition, the fourth plate material arranged at a position symmetrical to the observation unit can block the incident of light that causes a specular reflection component measurable from the observation unit to the object. Therefore, by arranging the fourth plate material at a position symmetrical to the observation portion with respect to the center, the diffuse reflection component and the retroreflection component of the object can be further measured. Therefore, according to the configuration, in addition to the SCE method and the SCI method of color measurement, it is possible to measure the retroreflective component of the object, so that it is possible to provide a lighting device with further improved measurement convenience. it can.

In the lighting device according to the one side surface, the transmission port of the third plate material may be configured to be in an open state for transmitting the light and a closed state for blocking the transmission of the light. In this configuration, the closed third plate material can be used in the same manner as the fourth plate material. That is, the diffuse reflection component and the retroreflection component of the object can be further measured by using the third plate material. Therefore, according to the configuration, in addition to the SCE method and the SCI method of color measurement, it is possible to measure the retroreflective component of the object, so that it is possible to provide a lighting device with further improved measurement convenience. it can. In this configuration, the fourth plate material may be omitted.

The lighting device according to the one side surface may further include a frame material that supports the open end of the casing. The frame member is a side wall formed in a cylindrical shape and is arranged apart from the inner surface of the casing toward the center, and may include a side wall having an outer peripheral surface facing the inner surface, and the light source may be provided. May be arranged on the outer peripheral surface of the side wall toward the inner surface of the casing. According to this configuration, by arranging the light source on the outer peripheral surface of the side wall arranged inside the casing, it is possible to reliably irradiate the light toward the inner surface of the casing made of the material that diffusely reflects. Therefore, it is possible to realize lighting conditions suitable for color measurement in the internal space.

The lighting device according to the one side surface is further provided with a reflector which is arranged so as to block the bottom surface of the internal space at least partially, and the surface facing the internal space mirror-reflects light. May be good. According to this configuration, a space similar to the internal space of the casing can be formed on the opposite side of the casing by a reflecting mirror. Therefore, the integrating sphere can be imitated with a simple and low-cost configuration in which a reflecting mirror is arranged on the bottom surface of the internal space. Furthermore, since the reflector does not have to completely block the bottom surface of the internal space, it is not necessary to completely confine the object in the internal space of the casing. Therefore, it is possible to measure the color of an object that is difficult to arrange in the conventional integrating sphere. Further, for example, the color measurement of a relatively large area object such as a road surface or a building wall surface can be performed on the spot without cutting out the object. Further, the color measurement of the product transported on the production line such as a belt conveyor can be performed on the spot. The configuration for imitating the integrating sphere does not have to be limited to such an example. The illuminating device according to the one side surface may further include another casing having the same hemispherical internal space as the casing, instead of the reflecting mirror. As a result, the illuminating device according to the one aspect may imitate an integrating sphere.

In the lighting device according to the one side surface, the plurality of plate members are connected to each other, and may be configured so that the position can be adjusted by moving in conjunction with the axis. According to this configuration, it is possible to improve the operability of moving each plate material when observing an object, and thereby it is possible to reduce the labor of measurement.

In the lighting device according to the one side surface, the inner surface may be evenly divided into a plurality of regions around the axis in a plane passing through the apex and the center, and each of the plurality of plate materials is one region of the inner surface. It may have a shape corresponding to. According to this configuration, since the shape of each plate material corresponds to the divided region of the inner surface, it becomes easy to grasp the region of the inner surface shielded by each plate material, and thereby when performing color measurement of the object. Lighting conditions can be set easily. Therefore, the convenience of measurement can be enhanced. The "shape corresponding to one region" may be a shape that shields the target region when viewed from the object, and may be, for example, a bilateral spherical trigonometric shape.

In the lighting device according to the one side surface, the observation unit may be configured by a light receiving port configured to transmit light from the inner surface to the outer surface. In this configuration, the color of the object is measured through the light receiving port by an optical sensor such as a camera arranged outside the casing. According to this configuration, since the optical sensor and the casing are prepared separately, the optical sensor can be easily replaced.

Alternatively, in the lighting device according to the one side surface, the observation unit may be composed of an optical sensor. According to this configuration, it is possible to provide a lighting device having a simple structure.

In the lighting device according to the one side surface, the inner surface of the casing is made of a material that diffusely reflects light, and the second surface of each plate material is made of a material that absorbs light. That is, in the lighting device according to the one side surface, the inner surface of the casing plays a role of diffusing and reflecting light, and the second surface of each plate material plays a role of an optical trap. However, the configuration of the lighting device does not have to be limited to such an example, and this role may be interchanged. That is, the inner surface of the casing may be made of a material that absorbs light, and the second surface of each plate material may be made of a material that diffusely reflects light.

For example, the lighting device according to one aspect of the present invention is a casing having an outer surface, an inner surface, a hemispherical internal space, and an observation portion, and the inner surface defines the hemispherical internal space and emits light. The hemispherical internal space, which is composed of a material to be absorbed, has a center, an apex, a bottom surface, and an axis, the axis passes through the center and the apex, and the casing is on the bottom surface side of the internal space. A casing that is open and the observation unit is provided for observing an object arranged in the internal space, and is arranged apart from the apex along the inner surface in the circumferential direction. And, in the internal space, there are a plurality of plate materials that face the inner surface and are divided and arranged around the axis, and the plurality of plate materials are the first surface facing the inner surface, respectively, and A second surface facing the center is provided, and the second surface of each of the plurality of plate materials is composed of a material that diffuses and reflects light, and the plurality of plate materials are the first plate materials and the plurality of plate materials. The plurality of plate materials include a first plate material that is not arranged symmetrically with respect to the center with any other plate material among the plate materials of the above, and the plurality of plate materials are two plate materials adjacent to the axis of the plurality of plate materials. It has a plurality of intervals arranged between the above, and the plurality of intervals include a first interval and a second interval arranged symmetrically with respect to the center. A plurality of plate materials and a light source arranged so as to irradiate the internal space with light are provided.

Further, in the lighting device according to the one side surface, the observation unit is arranged at a position separated from the apex in the circumferential direction along the inner surface, so that the color measurement of the object can be performed at an angle. ing. However, the configuration of the lighting device does not have to be limited to such an example. If the convenience of measurement is enhanced by reducing the labor of measurement, the observation unit may be arranged at the apex.

For example, the lighting device according to one aspect of the present invention is a casing having an outer surface, an inner surface, a hemispherical internal space, and an observation portion, and the inner surface defines the hemispherical internal space and emits light. The hemispherical internal space, which is composed of a material that diffusely reflects, has a center, an apex, a bottom surface, and an axis, the axis passes through the center and the apex, and the casing is the bottom surface side of the internal space. The observation unit is provided on the inner surface of the casing and the inner space, respectively, which are provided for observing an object arranged in the internal space and are arranged at the apex. A plurality of plate materials facing each other and arranged at equal intervals around the axis, each of which covers a part of the inner surface when viewed from the center and can adjust the position around the axis. Each of the plurality of plate materials includes a first surface facing the inner surface and a second surface facing the center, and the second surface of each of the plurality of plate materials absorbs light. It is provided with a plurality of plate materials made of the material to be used, and a light source arranged so as to irradiate the internal space with light.

If the plates that act as optical traps are not evenly spaced around the axis, before and after changing the arrangement of each plate around the axis in order to perform SCE and SCI colorimetry, Overlapping positions are likely to occur. If the positions of the plate materials are likely to overlap, the position of each plate material is changed many times in order to shield the entire circumference of the object with the plate materials, which leads to an increase in the number of measurements. On the other hand, in the lighting device according to the configuration, each plate material is arranged around the axis at equal intervals. As a result, when the arrangement of each plate material is changed around the axis and the object is measured, the overlap of the positions of the plate materials can be suppressed. For example, the position of each plate material may be changed by moving each plate material around the axis so as to fill the area between the adjacent plate materials. Therefore, it is possible to reduce the number of measurements when performing color measurement by the SCE method and the SCI method. Therefore, according to the configuration, it is possible to provide a lighting device with improved measurement convenience.

In the lighting device according to the one side surface, the inner surface may be evenly divided into a plurality of regions around the axis in a plane passing through the apex and the center, and each of the plurality of plate materials is one region of the inner surface. The number of the regions on the inner surface may be an integral multiple of 2 or more of the number of the plate members. In this configuration, since the shape of each plate material corresponds to the divided region on the inner surface, it is possible to suppress the occurrence of overlapping positions of each plate material, and assuming that the number of regions is n times the number of plate materials. The number of measurements when performing color measurement by the SCE method and the SCI method is only n times. Therefore, according to the configuration, it is possible to provide a lighting device with further improved measurement convenience.

According to the present invention, it is possible to provide a lighting device with improved measurement convenience.

FIG. 1 is a side view schematically illustrating the lighting device according to the embodiment. FIG. 2 is a plan view schematically illustrating the lighting device according to the embodiment. FIG. 3 is a cross-sectional view schematically illustrating the lighting device according to the embodiment. FIG. 4 schematically illustrates the arrangement of each plate material of the lighting device according to the embodiment. FIG. 5A schematically illustrates an example of using the lighting device according to the embodiment. FIG. 5B schematically illustrates an example of using the lighting device according to the embodiment. FIG. 5C schematically illustrates an example of using the lighting device according to the embodiment. FIG. 5D schematically illustrates an example of use of the lighting device according to the embodiment. FIG. 6 is a cross-sectional view schematically illustrating a lighting device according to another embodiment. FIG. 7 is a cross-sectional view schematically illustrating a lighting device according to another embodiment. FIG. 8 schematically illustrates the arrangement of each plate material of the lighting device according to another form. FIG. 9A schematically illustrates an example of using the lighting device according to another embodiment. FIG. 9B schematically illustrates an example of using the lighting device according to another embodiment. FIG. 9C schematically illustrates an example of using the lighting device according to another form. FIG. 9D schematically illustrates an example of using the lighting device according to another form. FIG. 10 is a cross-sectional view schematically illustrating a lighting device according to another form. FIG. 11 schematically illustrates the arrangement of each plate material of the lighting device according to another form.

Hereinafter, embodiments according to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to the drawings. However, the embodiments described below are merely examples of the present invention in all respects. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. That is, in carrying out the present invention, a specific configuration according to the embodiment may be appropriately adopted. In the following description, for convenience of explanation, the description will be made with reference to the orientation in the drawing.

§1 Configuration example An example of the configuration of the lighting device L1 according to the present embodiment will be described with reference to FIGS. 1 to 3. 1 to 3 are a side view, a plan view, and a cross-sectional view schematically illustrating an example of the configuration of the lighting device L1 according to the present embodiment. As shown in each figure, the lighting device L1 according to the present embodiment includes a casing 1, a plurality of plate members 2, a light source 3, a frame member 4, and a reflecting mirror 5. The lighting device L1 according to the present embodiment is used for color measurement of the object S.

(casing)
The casing 1 according to the present embodiment includes an outer surface 11, an inner surface 12, a hemispherical internal space 13, and a light receiving port 14. The outer surface 11 faces the outside of the casing 1, and the inner surface 12 faces the inside of the casing 1. In this embodiment, the inner surface 12 is made of a material that diffusely reflects light. The material that diffusely reflects light may not be particularly limited as long as it can diffusely reflect light, and may be, for example, a member painted in white, a member made of white material, or the like. As a specific example, the material that diffusely reflects light may be, for example, barium sulfate, a porous PTFE resin, or the like. Further, the inner surface 12 is formed in a hemispherical shape, thereby defining the hemispherical internal space 13. The inner surface 12 is made of a material that diffusely reflects light.

The hemispherical interior space 13 has a center 131, an apex 132, a bottom surface 133, and a shaft 134. The center 131 is located in the middle of the sphere including the hemisphere of the internal space 13. When performing color measurement, the object S is arranged near the center 131 in the internal space 13. The apex 132 is located above the center 131 in the vertical direction. The shaft 134 passes through the center 131 and the apex 132. The bottom surface 133 includes the center 131 and is formed in a circular shape. The casing 1 is open to the bottom surface 133 side of the internal space 13, and has an open end 15 formed in an annular shape. The shape of the internal space 13 does not have to be a perfect hemisphere as long as it does not have a fatal effect on the color measurement of the object S.

The light receiving port 14 is provided for observing the object S arranged in the internal space 13. The light receiving port 14 is an example of the "observation unit" of the present invention. The light receiving port 14 is arranged apart from the apex 132 along the inner surface 12 in the circumferential direction. The position of the light receiving port 14 does not have to be particularly limited, and may be appropriately set according to the embodiment. For example, the light receiving port 14 is arranged so that the angle between the line connecting the light receiving port 14 and the center 131 and the shaft 134 is 20 degrees, 45 degrees, 60 degrees, or 85 degrees so as to be suitable for measuring specular reflection. You can. Further, for example, the light receiving port 14 may be arranged so that the angle between the line connecting the light receiving port 14 and the center 131 and the shaft 134 is 45 degrees so as to be suitable for the measurement of diffuse reflection. Further, for example, the light receiving port 14 is arranged so that the angle between the line connecting the light receiving port 14 and the center 131 and the axis 134 is 5 degrees, 30 degrees, or 40 degrees so as to be suitable for measuring retroreflection. May be good.

In the present embodiment, the light receiving port 14 is configured to transmit light from the inner surface 12 to the outer surface 11. The configuration of the light receiving port 14 does not have to be particularly limited as long as it can transmit light, and may be appropriately determined according to the embodiment. For example, the light receiving port 14 may be made of a transparent material such as a resin material. Further, for example, the light receiving port 14 may be configured by a through hole penetrating from the inner surface 12 to the outer surface 11. The through hole may be filled with a transparent material such as a resin material.

Further, the light receiving port 14 may be configured to have an open state in which light is transmitted and a closed state in which light transmission is blocked. The configuration for opening and closing the light receiving port 14 does not have to be particularly limited, and may be appropriately determined according to the embodiment. For example, a closing member (not shown) such as a cap configured to be attached to the light receiving port 14 may be prepared. By closing the light receiving port 14 with this closing member, the light receiving port 14 may be in a closed state. On the other hand, the light receiving port 14 may be opened by removing the closing member from the light receiving port 14.

The casing 1 may be integrally formed. Alternatively, the casing 1 may be divided into a plurality of portions around the axis. Further, the material of the casing 1 does not have to be particularly limited, and may be appropriately selected depending on the embodiment. For the casing 1, for example, an acrylic resin, a stainless steel material, or the like may be used. As the material of the casing 1, it is desirable that the material has excellent workability and can guarantee the strength. In addition, in FIGS. 1 and 2, the outer surface 11 of the casing 1 is formed in a hemispherical shape like the internal space 13. However, the shape of the outer surface 11 of the casing 1 does not have to be limited to such an example, and may be appropriately selected according to the embodiment.

(Plate)
Next, a plurality of plate materials 2 will be described with reference to FIG. FIG. 4 schematically illustrates the arrangement of each plate material 2 of the lighting device L1 according to the present embodiment. In detail, FIG. 4 schematically illustrates the relationship between each plate material 2 and the inner surface 12 as viewed from the center 131.

The plurality of plate members 2 are arranged in the internal space 13 so as to face the inner surface 12 and to be divided around the shaft 134. Each plate member 2 covers a part of the inner surface 12 when viewed from the center 131, and is configured so that the position around the shaft 134 can be adjusted. Each plate material 2 may be configured to be movable in conjunction with each other. Alternatively, each plate material 2 may be configured to be individually movable. In the present embodiment, the plurality of plate members 2 are connected to each other and are configured to be adjustable in position by moving in conjunction with each other around the shaft 134. The configuration for connecting the plate members 2 does not have to be particularly limited, and may be appropriately selected depending on the embodiment. For example, at least one of the lower end and the upper end of each plate member 2 may be connected by a connecting tool (not shown) such as a frame material.

Each plate member 2 includes a first surface 21 facing the inner surface 12 and a second surface 22 facing the center 131. The second surface 22 of each plate material 2 is made of a material that absorbs light. As a result, each plate material 2 functions as an optical trap. The material that absorbs light is not particularly limited as long as it can absorb light, and may be, for example, a member painted in black, a member made of black material, or the like. As a specific example, the material that absorbs light may be, for example, carbon black, a non-reflective brushed cloth, or the like. On the other hand, the configuration of the first surface 21 does not have to be particularly limited, and may be appropriately selected depending on the embodiment. Like the second surface 22, the first surface 21 may be made of a material that absorbs light. Alternatively, the first surface 21 may be made of other materials.

The number of each plate material 2 does not have to be particularly limited, and may be appropriately selected depending on the embodiment. In the present embodiment, the lighting device L1 includes four plate members 2. Specifically, the four plate materials 2 include a first plate material 201, a second plate material 202, a third plate material 203, and a fourth plate material 204. When each plate material 2 is distinguished, an individual name such as "first plate material" is used, and when each plate material 2 is generically referred to without distinction, the term "plate material" is simply used.

The first plate member 201 and the second plate member 202 are arranged symmetrically with respect to the center 131. On the other hand, the third plate member 203 is arranged at a position that is not symmetrical with respect to the center 131 with any of the other plate members (201, 202, 204) among the plurality of plate materials 2. Like the third plate material 203, the fourth plate material 204 is also arranged at a position that is not symmetrical with respect to the center 131 with any of the other plate materials (201, 202, 203) of the plurality of plate materials 2.

FIG. 4 shows an example of the arrangement of each plate material 2 according to the present embodiment. Specifically, the second plate member 202 is arranged at a position of 180 degrees around the axis 134 from the first plate member 201. Further, the third plate member 203 is arranged at a position of 90 degrees from the first plate member 201 around the axis 134 with the clockwise direction as positive. The fourth plate member 204 is arranged at a position of 300 degrees from the first plate member 201 around the axis 134 with the clockwise direction as positive. No plate material 2 is arranged at a position symmetrical to each of the third plate material 203 and the fourth plate material 204 with respect to the center 131, and the inner surface 12 is exposed.

The fact that the target plate material is arranged symmetrically with respect to the center 131 means that the target plate material is arranged at a position of 180 degrees around the axis 134. Being placed at a position of 180 degrees means that when observing the object S from one plate material, if the other plate material is arranged so as to block the incident of the specular reflection component, the center positions of each other are 180. It may include deviation from the degree position. On the other hand, not being arranged symmetrically with respect to the target plate material with respect to the center 131 (that is, being arranged asymmetrically) means that the material is not arranged at a position of 180 degrees around the axis 134 with respect to the target plate material, in other words, the target plate material. It is arranged at a position deviated from 180 degrees around the shaft 134 with respect to the plate material. Specifically, being placed at an angle deviated from 180 degrees means that when observing the object S from one plate material, the other plate material cannot block the incident of the specular reflection component by 180 degrees. It is to be placed at a position that deviates from the angle.

The second plate member 202 has a transmission port 2021 which is arranged at a position corresponding to the light receiving port 14 and is configured to transmit light. Similarly, the third plate member 203 also has a transmission port 2031 that is arranged at a position corresponding to the light receiving port 14 and is configured to transmit light. Arranged at a position corresponding to the light receiving port 14 means that when each plate material (202, 203) is arranged according to the position of the light receiving port 14, the light receiving port 14 passes through each transmission port (2021, 2031). The object S arranged near the center 131 is arranged so as to be observable.

The configuration of each transmission port (2021, 2031) is not particularly limited as long as it can transmit light, and may be appropriately determined according to the embodiment. For example, each transmission port (2021, 2031) may be made of a transparent material such as a resin material. Further, for example, each transmission port (2021, 2031) may be formed by a through hole penetrating from the first surface 21 to the second surface 22. The through hole may be filled with a transparent material such as a resin material.

Further, each transmission port (2021, 2031) may be configured to have an open state in which light is transmitted and a closed state in which light transmission is blocked. The configuration for opening and closing each transmission port (2021, 2031) does not have to be particularly limited, and may be appropriately determined according to the embodiment. For example, a closing member (not shown) such as a cap configured to be attached to each transmission port (2021, 2031) may be prepared. By closing each transmission port (2021, 2031) with this closing member, each transmission port (2021, 2031) may be in a closed state. On the other hand, the light receiving port 14 may be in an open state by removing the closing member from each of the transmission ports (2021, 2031).

Further, as shown in FIG. 4, in the present embodiment, the inner surface 12 is virtually evenly divided into a plurality of regions A1 around the axis 134 in a plane passing through the apex 132 and the center 131. Each plate member 2 has a shape corresponding to one region A1 of the inner surface 12. The shape corresponding to one region A1 may be a shape that shields the target region A1 when viewed from the object S, and may be, for example, a bilateral spherical trigonometric shape. In the example of FIG. 4, the inner surface 12 is divided into 12 equal parts. However, the number of divisions does not have to be limited to such an example, and may be appropriately determined according to the embodiment.

The material of each plate material 2 does not have to be particularly limited and may be appropriately selected according to the embodiment. For each plate material 2, for example, an acrylic resin, a stainless steel material, or the like may be used. As the material of each plate material 2, it is desirable that the material has excellent workability and can guarantee the strength.

(Light source and frame material)
Next, the light source 3 and the frame material 4 will be described. As shown in FIG. 3, the light source 3 is arranged so as to irradiate the internal space 13 with light. In this embodiment, the light source 3 is attached to the frame member 4. The frame member 4 is formed in an annular shape and is configured to support the open end 15 of the casing 1. In the present embodiment, the frame member 4 includes a main body portion 40, an outer peripheral wall 41, and an inner peripheral wall 42. The main body 40 is formed in an annular shape. The outer peripheral wall 41 is provided on the outer peripheral side of the main body 40, so that the outer peripheral wall 41 is arranged on the outer side (outer surface 11 side) of the casing 1. On the other hand, since the inner peripheral wall 42 is provided on the inner peripheral side of the main body 40, the inner peripheral wall 42 is arranged so as to be separated from the inner surface 12 of the casing 1 toward the center 131. The outer peripheral wall 41 and the inner peripheral wall 42 are each formed in a cylindrical shape. The inner peripheral wall 42 is an example of the "side wall" of the present invention. The inner peripheral wall 42 has an outer peripheral surface 421 facing the inner surface 12 of the casing 1. In the present embodiment, the light source 3 is arranged on the outer peripheral surface 421 of the inner peripheral wall 42 toward the inner surface 12 of the casing 1.

The material of the frame material 4 does not have to be particularly limited, and may be appropriately selected according to the embodiment. In the present embodiment, since the light source 3 is attached to the frame material 4, it is desirable to use a material having good thermal conductivity capable of effectively releasing the heat generated from the light source 3 for the frame material 4. From this point of view, it is desirable to use, for example, an aluminum material for the frame material 4. Further, the type and number of the light sources 3 are not particularly limited, and may be appropriately selected according to the embodiment. As the light source 3, for example, an LED (light emitting diode), a fluorescent tube, an organic EL (electro-luminescence), or the like may be used. Further, a plurality of light sources 3 may be arranged on the cylindrical outer peripheral surface 421 at intervals (for example, at equal intervals) around the shaft 134.

(Reflector)
Next, the reflector 5 will be described. The reflector 5 is arranged so as to at least partially block the bottom surface 133 of the internal space 13. In the example of FIGS. 1 to 3, the reflecting mirror 5 is formed in a rectangular shape larger than the open end 15 of the casing 1 and is configured to completely close the bottom surface 133 of the internal space 13. In this case, when the color measurement is performed, the object S is housed in the internal space 13 of the casing 1.

However, the shape and dimensions of the reflector 5 are not limited to such an example, and may be appropriately determined according to the embodiment. The reflecting mirror 5 may be configured not to completely block the bottom surface 133 of the internal space 13, but to partially block the bottom surface 133. For example, the reflecting mirror 5 may be formed so that the internal space 13 and the outside communicate with each other in the vicinity of the center 131 by removing the portion near the center 131. In this case, when performing color measurement, the object S may be arranged at least partially outside the internal space 13 and may access the internal space 13 from the communicating portion thereof.

The reflecting mirror 5 has a surface 51 facing the internal space 13, and the surface 51 is configured to mirror-reflect light. The material of the reflector 5 does not have to be particularly limited, and may be appropriately selected depending on the embodiment. For the reflector 5, a resin material or stainless steel material on which aluminum is vapor-deposited may be used. Correspondingly, the surface 51 may be composed of an aluminum-deposited surface, a stainless steel surface, or the like. The reflector 5 may be divided into a plurality of parts.

§2 Usage method Next, the usage method of the lighting device L1 according to the present embodiment will be described with reference to FIGS. 5A to 5D. 5A to 5D schematically illustrate an example of how to use the lighting device L1 according to the present embodiment.

First, in preparation for color measurement, the user arranges the object S to be color-measured near the center 131 of the internal space 13 of the casing 1. Next, the user turns on the light source 3 to cause the light source 3 to irradiate the internal space 13 with light. As a result, the internal space 13 is in a state where light is diffusely reflected by the inner surface 12 of the casing 1. Then, the user arranges the optical sensor on the outer surface 11 side of the casing 1 in accordance with the light receiving port 14, and starts the measurement of each reflection component of the object S arranged in the internal space 13 by the optical sensor.

The type of the object S does not have to be particularly limited, and may be appropriately selected according to the embodiment. In addition to a flat and uniform sample surface, the object S includes, for example, uneven building materials (for example, tiles, stones, etc.), foods or foodstuffs (for example, bread, chocolate, etc.), plants, and creatures (for example, insects). Etc.) etc. Further, the type of the optical sensor is not particularly limited as long as the color of the object S can be measured, and may be appropriately selected according to the embodiment. As the optical sensor, for example, a color luminance meter, a digital camera, a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide-Semiconductor), or the like may be used.

(First step)
As shown in FIG. 5A, in the first step, the user adjusts the position of each plate material 2 so that the transmission port 2021 of the second plate material 202 is aligned with the position of the light receiving port 14. Deploy. Then, the reflection component of the object S is measured by the optical sensor. In this state, the first plate member 201 is arranged at a position symmetrical with respect to the center 131 of the internal space 13 and the second plate member 202 and the light receiving port 14. Therefore, the first plate member 201 blocks the incident of light that causes a specular reflection component measurable from the light receiving port 14 to the object S. In addition, the second plate 202 blocks the incident of light that causes a retroreflective component measurable from the light receiving port 14 on the object S. On the other hand, the light that causes the object S to generate a diffuse reflection component that can be measured from the light receiving port 14 is incident on the object S from the region between the plate materials 2. Therefore, in the first step, measurement data regarding the diffuse reflection component of the object S can be obtained.

(Second step)
Next, as shown in FIG. 5B, in the second step, the user moves each plate material 2 by 30 degrees from the first step around the axis 134 with the clockwise direction as positive. Then, the reflection component of the object S is measured by the optical sensor. In this state, no plate material 2 (201 to 204) is arranged at a position corresponding to the light receiving port 14 and a position symmetrical to the light receiving port 14 with respect to the center 131. Therefore, unlike the first step, the light that causes the specular reflection component and the retroreflective component that can be measured from the light receiving port 14 on the object S is incident on the object S. Further, as in the first step, the light that causes the object S to have a diffuse reflection component that can be measured from the light receiving port 14 is incident from other regions. Therefore, in the second step, measurement data regarding all the reflection components of the object S can be obtained. The method for measuring all the reflection components does not have to be limited to such an example. When measuring all the reflective components, other regions having similar effects (for example, the region between the first plate member 201 and the third plate member 203) may be aligned with the light receiving port 14.

(Third step)
Next, as shown in FIG. 5C, in the third step, the user moves each plate material 2 by 30 degrees from the second step around the axis 134 with the clockwise direction as positive. Then, the reflection component of the object S is measured by the optical sensor. In this state, the fourth plate member 204 is arranged at a position symmetrical to the light receiving port 14 with respect to the center 131. Therefore, the fourth plate member 204 blocks the incident light that causes the specular reflection component measurable from the light receiving port 14 to the object S. On the other hand, no plate material 2 (201 to 204) is arranged at the position corresponding to the light receiving port 14. Therefore, the light that causes the object S to generate a retroreflective component that can be measured from the light receiving port 14 is incident on the object S. Further, similarly to each of the above steps, the light that causes the object S to have a diffuse reflection component that can be measured from the light receiving port 14 is incident from other regions. Therefore, in the third step, measurement data regarding the diffuse reflection component and the retroreflection component of the object S can be obtained.

The method for measuring the retroreflection component is not limited to such an example. For example, no plate material 2 (201, 202, 204) is arranged at a position symmetrical to the third plate material 203 with respect to the center 131. Therefore, the user moves each plate material 2 so as to arrange the third plate material 203 at a position symmetrical to the light receiving port 14 (the position of the fourth plate material 204 in FIG. 5C) with respect to the center 131. At this time, it is desirable to close the transmission port 2031 with a closing member so that the reflected light on the inner surface 12 does not enter from the transmission port 2031. Then, the reflection component of the object S is measured by the optical sensor. As a result, measurement data regarding the diffuse reflection component and the retroreflection component of the object S can be obtained in the same manner as described above.

(4th step)
Next, as shown in FIG. 5D, in the fourth step, the user moves each plate material 2 by 30 degrees from the third step around the axis 134 with the clockwise direction as positive. At this time, the transmission port 2031 of the third plate member 203 is opened and aligned with the light receiving port 14. Then, the reflection component of the object S is measured by the optical sensor. In this state, the third plate member 203 is arranged at a position corresponding to the light receiving port 14. Therefore, the third plate member 203 blocks the incident light that causes the retroreflection component measurable from the light receiving port 14 to the object S. On the other hand, no plate material 2 (201 to 204) is arranged at a position symmetrical to the light receiving port 14 with respect to the center 131. Therefore, the light that causes the object S to generate a specular reflection component that can be measured from the light receiving port 14 is incident on the object S. Further, similarly to each of the above steps, the light that causes the object S to have a diffuse reflection component that can be measured from the light receiving port 14 is incident from other regions. Therefore, in the fourth step, measurement data regarding the diffuse reflection component and the specular reflection component of the object S can be obtained.

(Derivation step)
Then, each reflection characteristic is derived by using the measurement data obtained in each step. For example, the retroreflection component can be derived from the difference between the measurement data of the diffuse reflection component and the retroreflection component obtained in the third step and the measurement data of the diffuse reflection component obtained in the first step. Similarly, the specular reflection component can be derived from the difference between the measurement data of the diffuse reflection component and the specular reflection component obtained in the fourth step and the measurement data of the diffuse reflection component obtained in the first step. Further, the difference between the data of the retroreflection component and the specular reflection component derived in this way, the measurement data of the diffuse reflection component obtained in the first step, and the measurement data of the total reflection component obtained in the second step is obtained. By taking it, the presence or absence of other reflection characteristics can be verified. A computer such as a general-purpose personal computer (Personal Computer) may be used for the derivation step.

The procedure for using the lighting device L1 is an example of a color measurement method for the object S. However, the above usage procedure is only an example, and each step may be changed as much as possible. Further, the order of each step may be changed as appropriate. In particular, the first to fourth steps do not have to be performed in the above order. Further, regarding the above-mentioned usage procedure, steps can be omitted, replaced, and added as appropriate according to the embodiment. In each of the above steps, when the transmission ports (2021, 2031) are not arranged in accordance with the light receiving port 14, they may be closed by a closing member to be closed.

§3 Features As described above, in the lighting device L1 according to the present embodiment, by arranging the object S near the center 131 of the internal space 13 of the casing 1, the reflection characteristics of the object S can be measured from the light receiving port 14. It can be carried out. At the time of this measurement, the light emitted from the light source 3 is diffusely reflected by the inner surface 12 of the casing 1, so that the illumination conditions in the internal space 13 can be kept constant. Therefore, according to the lighting device L1 according to the present embodiment, it is possible to measure the color of the object S in a non-contact manner with good reproducibility. Further, since the light receiving port 14 is arranged apart from the apex 132 along the inner surface 12 in the circumferential direction, the color measurement of the object S can be performed at an angle. Further, in the present embodiment, the SCE method and the SCE method and the SCE method and the retroreflection component are taken into consideration by the first step, the second step, and the fourth step using the first plate material 201 to the third plate material 203. SCI colorimetric measurement can be performed.

Further, the lighting device L1 according to the present embodiment includes a fourth plate member 204. Further, the transmission port 2031 of the third plate member 203 may be configured to be in an open state and a closed state. Therefore, the retroreflection component of the object S can be measured by the third step of using the fourth plate member 204 or the third plate member 203 in the closed state. As a result, in the derivation step, the retroreflection component is derived from the difference between the measurement data of the diffuse reflection component and the retroreflection component obtained in the third step and the measurement data of the diffuse reflection component obtained in the first step. be able to. Therefore, in the lighting device L1 according to the present embodiment, the convenience of measurement is improved as compared with the conventional lighting device.

Further, the lighting device L1 according to the present embodiment includes a frame member 4 that supports the open end 15 of the casing 1, and the frame member 4 includes an inner peripheral wall 42 arranged inside the casing 1. Then, the light source 3 is arranged on the outer peripheral surface 421 of the inner peripheral wall 42 of the frame member 4 toward the inner surface 12 of the casing 1. By arranging the light source 3, it is possible to reliably irradiate the light from the light source 3 toward the inner surface 12 of the casing 1 made of the material that diffusely reflects. Therefore, according to the present embodiment, lighting conditions suitable for color measurement can be realized in the internal space 13.

Further, the lighting device L1 according to the present embodiment includes a reflecting mirror 5 that at least partially closes the bottom surface 133 of the internal space 13. The reflecting mirror 5 is configured such that a surface facing the internal space 13 mirror-reflects light. Therefore, the reflector 5 can form a space imitating the internal space 13 of the casing 1 on the side opposite to the casing 1 (lower side of the casing 1). Therefore, according to the present embodiment, the integrating sphere can be imitated with a simple and low-cost configuration. Further, since the reflecting mirror 5 does not need to completely block the bottom surface 133 of the internal space 13, the object S does not have to be housed in the internal space 13 of the casing 1. Therefore, it is possible to measure the color of an object that is difficult to arrange in the conventional integrating sphere. Further, for example, the color measurement of a relatively large area object such as a road surface or a building wall surface can be performed on the spot without cutting out the object. Further, the color measurement of the product transported on the production line such as a belt conveyor can be performed on the spot.

Further, in the present embodiment, the plate members 2 may be configured so that their positions can be adjusted by being connected to each other and moving in conjunction with each other around the shaft 134. As a result, when carrying out the first to fourth steps, the operability of moving each plate material 2 can be improved, and thereby the labor of measurement can be reduced.

Further, in the present embodiment, the inner surface 12 is evenly divided into a plurality of regions A1 around the shaft 134, and each plate member 2 has a shape corresponding to one region A1 of the inner surface 12. As a result, as shown in FIGS. 5A to 5D, when the first to fourth steps are carried out, it becomes easier to grasp the region of the inner surface 12 shielded by each plate material 2, which makes it easier to grasp the region of the inner surface 12 of the object S. It becomes easy to set the lighting conditions (specifically, the settings of the first to fourth steps) when the color measurement is performed. Therefore, the convenience of measurement can be enhanced.

Further, the lighting device L1 according to the present embodiment includes a light receiving port 14 as an example of an observation unit for observing the object S. Therefore, in the first to fourth steps, the color measurement of the object S is performed through the light receiving port 14 by the optical sensor arranged outside the casing 1. According to the present embodiment, since the optical sensor and the casing 1 are prepared separately, the optical sensor can be easily replaced.

§4 Modified Examples Although one embodiment of the present invention has been described above, the above description is merely an example of the present invention in all respects. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. For example, the following changes can be made. In the following, the same reference numerals will be used for the same components as those in the above embodiment, and the same points as in the above embodiment will be omitted as appropriate. The following modifications can be combined as appropriate.

<4.1>
In the above embodiment, the casing 1 includes a light receiving port 14 as an example of the observation unit. However, the configuration of the observation unit does not have to be limited to such an example, and may be appropriately selected depending on the embodiment. For example, the observation unit may be composed of the optical sensor itself.

FIG. 6 is a cross-sectional view schematically illustrating an example of the lighting device L1A according to the present modification. The lighting device L1A is configured in the same manner as the lighting device L1 according to the above embodiment, except that the light receiving port 14 replaces the optical sensor 14A. That is, the casing 1 of the lighting device L1A includes an optical sensor 14A instead of the light receiving port 14. The optical sensor 14A is attached to the inner surface 12 of the casing 1 at a position separated from the apex 132 in the circumferential direction toward the center 131. The optical sensor 14A is an example of the "observation unit" of the present invention. The type of the optical sensor 14A does not have to be particularly limited, and may be appropriately selected depending on the embodiment. For the optical sensor 14A, for example, a color luminance meter, a digital camera, a CCD, a CMOS, or the like may be used. According to this modification, the observation unit can be provided by a simple process of attaching the optical sensor 14A to the inner wall 12 without providing the light receiving port 14. Therefore, it is possible to provide a lighting device having a simple structure. Further, according to the present modification, since the angle at which the optical sensor 14A is attached can be easily adjusted, the measurement angle of the object S can be easily adjusted.

In the above-described embodiment and modified example, the number of observation units (light receiving port 14, optical sensor 14A) is one. However, the number of observation units is not limited to one, and the casing 1 may be provided with a plurality of observation units. Correspondingly, the number of transmission ports (transmission port 2021 and transmission port 2031) of the plate material may not be limited to one. A plurality of transmission ports corresponding to each observation unit may be provided on the plate material.

<4.2>
In the above embodiment, the lighting device L1 includes four plate members 2. Further, each plate material 2 has a shape corresponding to one region A1 of the inner surface 12. The third plate member 203 is arranged at a position of 90 degrees from the first plate member 201 around the axis 134 with the clockwise direction as positive. The fourth plate member 204 is arranged at a position of 300 degrees from the first plate member 201 around the axis 134 with the clockwise direction as positive. However, the number, shape, dimensions, and arrangement of the plate members 2 need not be limited to such examples, and may be appropriately determined according to the embodiment. For example, the fourth plate member 204 may be omitted. The lighting device L1 may include plate materials other than the first plate material 2001 to the fourth plate material 204. The shape of each plate member 2 does not have to correspond to the region A1 of the inner surface 12. The dimensions and shapes of the plate materials 2 do not have to match.

Further, in the above embodiment, the plate members 2 are connected to each other and are configured to be adjustable in position by moving in conjunction with each other around the shaft 134. However, the configuration of each plate material 2 does not have to be limited to such an example. Each plate material 2 may be configured to be individually movable. In this case, the second plate material 202 and the third plate material 203 may be made of the same plate material. That is, one plate material having a transmission port may also serve as the second plate material 202 and the third plate material 203.

<4.3>
In the above embodiment, the lighting device L1 further includes a frame member 4. However, the configuration of the lighting device L1 does not have to be limited to such an example. The frame material 4 may be omitted. Further, the shape of the frame member 4 does not have to be limited to the above example as long as it can support the casing 1, and may be appropriately determined according to the embodiment.

Further, in the above embodiment, the light source 3 is arranged on the outer peripheral surface 421 of the inner peripheral wall 42 of the frame member 4 toward the inner surface 12 of the casing 1. However, the arrangement of the light source 3 does not have to be limited to such an example as long as the internal space 13 can be irradiated with light, and may be appropriately determined according to the embodiment.

<4.4>
In the above embodiment, the lighting device L1 further includes a reflecting mirror 5. However, the configuration of the lighting device L1 does not have to be limited to such an example. The reflector 5 may be omitted. In this case, the configuration of the bottom surface 133 side of the internal space 13 may be appropriately determined according to the embodiment. For example, the object S may be placed on the stage. In this case, the casing 1 may be arranged so as to include or on the stage. Further, for example, the object S may be arranged on the floor. In this case, the casing 1 may be arranged on the floor. Alternatively, another casing having the same configuration as the casing 1 may be prepared. In this case, the integrating sphere can be imitated by arranging the other prepared casing and the casing 1 with the open ends aligned with each other.

<4.5>
In the lighting device L1 according to the above embodiment, the inner surface 12 of the casing 1 is made of a material that diffusely reflects light, and the second surface 22 of each plate material 2 is made of a material that absorbs light. That is, in the above embodiment, the inner surface 12 of the casing 1 plays a role of diffusely reflecting light, and the second surface 22 of each plate member 2 plays a role of an optical trap. However, the configuration of the lighting device L1 does not have to be limited to such an example. These roles may be interchanged. That is, the inner surface of the casing may be made of a material that absorbs light, and the second surface of each plate material may be made of a material that diffusely reflects light.

FIG. 7 is a cross-sectional view schematically illustrating an example of the lighting device L2 according to the present modification. The lighting device L2 according to this modification includes a casing 1B, a plurality of plate members 2B, and a light source 3B. The lighting device L2 according to the present modification may basically have the same configuration as the lighting device L1 according to the above embodiment, except that the above roles are exchanged between the inner surface of the casing and each plate material.

(casing)
First, the casing 1B will be described. Similar to the casing 1 of the above embodiment, the casing 1B has an outer surface 11B, an inner surface 12B, a hemispherical internal space 13B, and a light receiving port 14B. The inner surface 12B defines a hemispherical interior space 13B. In this modification, it is composed of a material that absorbs light.

The interior space 13B has a center 131B, an apex 132B, a bottom surface 133B, and a shaft 134B, similarly to the interior space 13 of the above embodiment. The shaft 134B passes through the center 131B and the apex 132B. The casing 1B is open to the bottom surface 133B side of the internal space 13B. The light receiving port 14B is provided for observing the object SB arranged in the internal space 13B as in the light receiving port 14 of the above embodiment, and is separated from the apex 132B along the inner surface 12B in the circumferential direction. Be placed. The light receiving port 14B is an example of the "observation unit" of the present invention. The light receiving port 14B may be replaced with the optical sensor 14A.

In the example of FIG. 7, the outer surface 11B of the casing 1B is formed in a hemispherical shape. However, the shape of the outer surface 11B does not have to be limited to such an example, and may be appropriately selected depending on the embodiment. Similarly, in this modification, the internal space 13B (inner surface 12B) is formed in a hemispherical shape. However, the shape of the internal space 13B (inner surface 12B) does not have to be limited to such an example, and may be appropriately selected according to the embodiment.

(Plate)
Next, each plate material 2B will be described with reference to FIG. FIG. 8 schematically illustrates the arrangement of each plate material 2B of the lighting device L2 according to this modification. In detail, FIG. 8 schematically illustrates the relationship between each plate material 2B and the inner surface 12B as seen from the center 131B.

Similar to each plate material 2 according to the above embodiment, the plurality of plate materials 2B are arranged in the internal space 13B so as to face the inner surface 12B and to be divided around the shaft 134B. Each plate member 2B includes a first surface 21B facing the inner surface 12B and a second surface 22B facing the center 131B. In this modification, the second surface 22B of each plate member 2B is made of a material that diffusely reflects light. That is, the inner surface 12B of the casing 1B plays the role of a light trap, while the second surface 22B of each plate member 2B plays the role of diffusely reflecting light.

Similar to the above embodiment, the number, shape, size, and arrangement of the plate members 2B may be appropriately determined according to the embodiment. In this modification, the lighting device L2 includes four plate members 2B. The four plate materials 2B include a first plate material 231 and a second plate material 232, a third plate material 233, and a fourth plate material 234. Of these, at least one of the second plate material 232, the third plate material 233, and the fourth plate material 234 may be omitted or replaced.

The first plate member 231 is arranged at a position that is not symmetrical with respect to the center 131B with any other plate member (232, 233, 234) of the plurality of plate members 2B. Similarly, the fourth plate material 234 is also arranged at a position that is not symmetrical with respect to the center 131B with any other plate material (231, 232, 233) of the plurality of plate materials 2B. On the other hand, the second plate member 232 and the third plate member 233 are arranged symmetrically with respect to the center 131B.

FIG. 8 shows an example of the arrangement of each plate material 2B according to this modified example. Specifically, the second plate member 232 is arranged at a position of 240 degrees from the first plate member 231 around the shaft 134B with the clockwise direction as positive. The third plate member 233 is arranged at a position of 60 degrees from the first plate member 231 around the shaft 134B with the clockwise direction as positive. The fourth plate member 234 is arranged at a position of 150 degrees from the first plate member 231 around the shaft 134B with the clockwise direction as positive. Similar to the above embodiment, the plate members 2B may be configured to be adjustable in position by being connected to each other and moving in conjunction with the shaft 134B.

The second plate member 232 has a transmission port 2321 arranged at a position corresponding to the light receiving port 14B and configured to transmit light. Similarly, the fourth plate member 234 also has a transmission port 2341 arranged at a position corresponding to the light receiving port 14B and configured to transmit light. Each transmission port (2321, 2341) may be configured in the same manner as each transmission port (2021, 2031) of the above embodiment. Further, each transmission port (2321, 2341) may be configured to have an open state in which light is transmitted and a closed state in which light transmission is blocked. A closing member such as a cap may be used to close the mouth. In this case, the surface of the closing member facing the second surface 22B is preferably made of a material that diffusely reflects light, as in the case of the second surface 22B.

Further, as in the above embodiment, in this modification as well, the inner surface 12B is evenly divided into a plurality of regions A2 around the shaft 134B in a plane passing through the apex 132B and the center 131B. Each plate member 2B has a shape corresponding to one region A2 of the inner surface 12B. The shape of each plate member 2B may be, for example, a bilateral spherical trigonometry. In the example of FIG. 8, the inner surface 12B is divided into 12 equal parts. However, the number of divisions does not have to be limited to such an example, and may be appropriately determined according to the embodiment. Further, the shape of each plate material 2B does not have to be particularly limited as long as the hemisphere can be partially constructed, and may be appropriately determined according to the embodiment.

The plurality of plate members 2B have a plurality of intervals arranged between two adjacent plate members 2B around the shaft 134B. The number of intervals may be determined according to the number of plate members 2B to be arranged. In this modification, four intervals 241 to 244 are provided. An interval 241 is provided between the second plate member 232 and the fourth plate member 234. An interval 242 is provided between the first plate member 231 and the second plate member 232. An interval 243 is provided between the first plate member 231 and the third plate member 233. An interval 244 is provided between the third plate material 233 and the fourth plate material 234.

The spacing 243 is symmetrical with respect to the center 131B with portion 2411 at spacing 241. The spacing 244 is symmetrical with respect to the center 131B and portion 2421 at spacing 242. The combination of the portions 2411 of the interval 243 and the interval 241 and the combination of the portions 2421 of the interval 244 and the interval 242 are examples of the "first interval" and the "second interval" of the present invention, respectively. Any of the combinations may be regarded as the "first interval". The same applies to the "second interval".

(light source)
Next, the light source 3B will be described. The light source 3B is arranged so as to irradiate the internal space 13B with light. In this modification, the light source 3B is arranged so as to irradiate the second surface 22B of each plate member 2B with light. The arrangement of the light source 3B does not have to be particularly limited, and may be appropriately determined according to the embodiment.

(Other)
The material of each component may be the same as in the above embodiment. Further, regarding other configurations, the same configurations as those in the above-described embodiment may be appropriately adopted in this modification. For example, the lighting device L2 may include a frame material that supports the open end of the casing 1B. In this case, the frame material is a side wall formed in a cylindrical shape and arranged apart from the second surface 22B of each plate member 2B toward the center 131B, and has an outer peripheral surface facing the second surface 22B. May be equipped. The light source 3B may be arranged on the outer peripheral surface of the side wall toward the second surface 22B. Further, for example, the lighting device L2 includes a reflecting mirror which is arranged so as to at least partially block the bottom surface 133B of the internal space 13B, and the surface facing the internal space 13B mirror-reflects light. Good.

(how to use)
Next, a method of using the lighting device L2 according to the present modification will be described with reference to FIGS. 9A to 9D. 9A to 9D schematically illustrate an example of how to use the lighting device L2 according to this modification. In this modified example as well, the user prepares for color measurement in the same manner as in the above embodiment, and then starts measuring each reflected component of the object SB arranged in the internal space 13B by the optical sensor.

As shown in FIG. 9A, in the first step, the user adjusts the position of each plate material 2B so that the transmission port 2321 of the second plate material 232 aligns with the position of the light receiving port 14B. Deploy. Then, the reflection component of the object SB is measured by the optical sensor. In this state, the third plate member 233 is arranged at a position symmetrical with respect to the center 131B and the second plate member 232 and the light receiving port 14B. Therefore, the light that causes the specular reflection component that can be measured from the light receiving port 14B to be generated on the object SB is diffusely reflected by the third plate material 233 and is incident on the object SB. Further, the light that causes a retroreflective component that can be measured from the light receiving port 14B to be generated on the object SB is diffusely reflected by the second plate material 232 and is incident on the object SB. Further, the light that causes a diffuse reflection component that can be measured from the light receiving port 14B to be generated on the object SB is diffusely reflected by another plate material (231, 234) and incident on the object SB. Therefore, in the first step, measurement data regarding all the reflection components of the object SB can be obtained.

Next, as shown in FIG. 9B, in the second step, the user moves each plate member 2B from the first step around the shaft 134B by 30 degrees with the clockwise direction as positive. Then, the reflection component of the object SB is measured by the optical sensor. In this state, the portion 2411 of the plate member 2B with the interval 241 is arranged in accordance with the light receiving port 14B. Therefore, the inner surface 12B exposed by the interval 241 (part 2411) blocks the incident of light that causes a retroreflective component measurable from the light receiving port 14B to the object SB. Further, the interval 243 arranged symmetrically with respect to the portion 2411 with respect to the center 131B blocks the incident of light that causes a specular reflection component measurable from the light receiving port 14B to the object SB. On the other hand, the light that generates a diffuse reflection component that can be measured from the light receiving port 14B on the object SB is diffusely reflected by each plate material (231, 232, 233, 234) and incident on the object SB. Therefore, in the second step, measurement data regarding the diffuse reflection component of the object SB can be obtained. The method for measuring the diffuse reflection component does not have to be limited to such an example. When measuring the diffuse reflection component, other regions having similar effects (for example, interval 243, interval 244 or interval 242 portion 2421) may be aligned with the light receiving port 14B.

Next, as shown in FIG. 9C, in the third step, the user moves each plate member 2B from the second step around the shaft 134B by 30 degrees with the clockwise direction as positive. Then, the reflection component of the object SB is measured by the optical sensor. In this state, the first plate member 231 is arranged at a position symmetrical to the light receiving port 14B with respect to the center 131B. Therefore, the light that causes the specular reflection component that can be measured from the light receiving port 14B to be generated on the object SB is diffusely reflected by the first plate member 231 and is incident on the object SB. Further, the light that generates a diffuse reflection component that can be measured from the light receiving port 14B on the object SB is diffusely reflected by another plate material (232, 233, 234) and incident on the object SB. On the other hand, no plate material 2B (231 to 234) is arranged at the position corresponding to the light receiving port 14B, and a part of the interval 241 is arranged. Therefore, the inner surface 12B exposed by the interval 241 blocks the incident light that causes the retroreflection component measurable from the light receiving port 14B to the object SB. Therefore, in the third step, measurement data regarding the diffuse reflection component and the specular reflection component of the object SB can be obtained.

The method for measuring the specular reflection component does not have to be limited to such an example. For example, no plate material 2B (231, 232, 233) is arranged at a position symmetrical to the fourth plate material 234 with respect to the center 131B. Therefore, the user moves each plate material 2B so as to arrange the fourth plate material 234 at a position symmetrical to the light receiving port 14B (the position of the first plate material 231 in FIG. 9C) with respect to the center 131B. At this time, it is desirable to close the transmission port 2341 with a closing member to close the opening. Then, the light sensor is used to remove the reflective component of the object SB. As a result, measurement data regarding the diffuse reflection component and the retroreflection component of the object SB can be obtained in the same manner as described above. Therefore, the first plate material 231 may be omitted, and the fourth plate material 234 may be used as the first plate material.

Next, as shown in FIG. 9D, in the fourth step, the user moves each plate member 2B from the third step around the shaft 134B by 30 degrees with the clockwise direction as positive. At this time, the transmission port 2341 of the fourth plate material 234 is opened and aligned with the light receiving port 14B. Then, the reflection component of the object SB is measured by the optical sensor. In this state, the fourth plate member 234 is arranged at a position corresponding to the light receiving port 14B. Therefore, the light that generates a retroreflective component that can be measured from the light receiving port 14B on the object SB is diffusely reflected by the fourth plate member 234 and is incident on the object SB. Further, the light that causes a diffuse reflection component that can be measured from the light receiving port 14B to be generated on the object SB is diffusely reflected by another plate material (231, 232, 233) and incident on the object SB. On the other hand, no plate material 2B (231 to 234) is arranged at a position symmetrical to the light receiving port 14B with respect to the center 131B, and a part of the interval 242 is arranged. Therefore, the inner surface 12B exposed by the interval 242 blocks the incident light that causes the specular reflection component measurable from the light receiving port 14B to the object SB. Therefore, in the fourth step, it is possible to obtain measurement data regarding the diffuse reflection component and the retroreflection component of the object SB.

Then, each reflection characteristic is derived by using the measurement data obtained in each step. The method for deriving each reflection identification may be the same as in the above embodiment. The procedure for using the lighting device L2 is an example of a color measurement method for the object SB. However, the above usage procedure is only an example, and each step may be changed as much as possible. Further, the order of each step may be changed as appropriate. In particular, the first to fourth steps do not have to be performed in the above order. Further, regarding the above-mentioned usage procedure, steps can be omitted, replaced, and added as appropriate according to the embodiment. In each of the above steps, when the transmission ports (2321, 2341) are not arranged in accordance with the light receiving port 14B, they may be closed by a closing member to be closed. According to the modification, it is possible to provide a lighting device (lighting device L2) with improved measurement convenience, as in the above embodiment.

<4.6>
In the lighting device L1 according to the above embodiment, the light receiving port 14 which is an example of the observation unit is arranged at a position separated from the apex 132 along the inner surface 12 in the circumferential direction. As a result, the lighting device L1 is configured to be able to measure the color of the object S at an angle. However, the configuration of the lighting device does not have to be limited to such an example. If the convenience of measurement is enhanced by reducing the labor of measurement, the observation unit may be arranged at the apex.

FIG. 10 is a cross-sectional view schematically illustrating an example of the lighting device L3 according to the present modification. The lighting device L3 according to this modification includes a casing 1C, a plurality of plate materials 2C, a light source 3, a frame material 4, and a reflecting mirror 5. Except for the position of the light receiving port and the arrangement of the plate members, the lighting device L3 according to the present modification may basically have the same configuration as the lighting device L1 according to the above embodiment.

(casing)
First, the casing 1C will be described. The casing 1C has an outer surface 11C, an inner surface 12C, a hemispherical internal space 13C, and a light receiving port 14C, similarly to the casing 1 according to the above embodiment. The inner surface 12C defines a hemispherical internal space 13C. The inner surface 12C is made of a material that diffusely reflects light.

The interior space 13C has a center 131C, an apex 132C, a bottom surface 133C, and a shaft 134C, similarly to the interior space 13 according to the above embodiment. The shaft 134C passes through the center 131C and the apex 132C. The casing 1C is open to the bottom surface 133C side of the internal space 13C, and has an open end 15C formed in an annular shape. The light receiving port 14C is provided for observing the object SC arranged in the internal space 13C, similarly to the light receiving port 14 of the above embodiment. In this modification, the light receiving port 14C is arranged at the apex 132C. The light receiving port 14C is an example of the "observation unit" of the present invention. The light receiving port 14C may be replaced with the optical sensor 14A.

(Plate)
Next, each plate material 2C will be described with reference to FIG. FIG. 11 schematically illustrates the arrangement of each plate material 2C of the lighting device L3 according to this modification. In detail, FIG. 11 schematically illustrates the relationship between each plate material 2C and the inner surface 12C as seen from the center 131C.

Similar to the plate material 2 according to the above embodiment, the plurality of plate materials 2C are arranged in the internal space 13C so as to face the inner surface 12C and at equal intervals around the shaft 134C. Each plate member 2C covers a part of the inner surface 12C when viewed from the center 131C, and is configured so that the position around the shaft 134C can be adjusted. Similar to the above embodiment, the plate members 2C may be configured to be adjustable in position by being connected to each other and moving in conjunction with the shaft 134C. Each plate member 2C includes a first surface 21C facing the inner surface 12C and a second surface 22C facing the center 131C. In this modification, the second surface 22C of each plate member 2C is made of a material that absorbs light.

The number, shape, and dimensions of the plate material 2C may be appropriately determined according to the embodiment. In this modification, the lighting device L3 includes four plate members 2C. Further, as in the above embodiment, in this modification as well, the inner surface 12C is evenly divided into a plurality of regions A3 around the axis 134C in a plane passing through the apex 132C and the center 131C. Each plate member 2C has a shape corresponding to one region A3 of the inner surface 12C. The shape of each plate member 2C may be, for example, a bilateral spherical trigonometry. However, the shape of each plate material 2C does not have to be limited to such an example. The shape of each plate material 2C does not have to correspond to the region A3. Further, the shapes of the plate materials 2C do not have to match each other.

In the example of FIG. 11, the inner surface 12C is divided into 12 equal parts. As a result, the number of regions A3 on the inner surface 12C is an integral multiple (specifically, 3 times) of 2 or more of the number of plate members 2C. The number of regions A3 and the number of plate materials 2C may be appropriately changed as long as the relationship is satisfied in which the number of regions A3 is an integral multiple of 2 or more of the number of plate materials 2C. However, this relationship does not necessarily have to be satisfied. The number of regions A3 on the inner surface 12C and the number of plate members 2C may be appropriately determined according to the embodiment within a range not satisfying this relationship.

(Other)
The light source 3, the frame material 4, and the reflecting mirror 5 are the same as those in the above embodiment. The frame member 4 supports the open end 15C of the casing 1C. The frame member 4 is an inner peripheral wall 42 formed in a cylindrical shape and is arranged apart from the inner surface 12C of the casing 1C toward the center 131C, and includes an inner peripheral wall 42 having an outer peripheral surface 421 facing the inner surface 12C. .. The light source 3 is arranged on the outer peripheral surface 421 of the inner peripheral wall 42 toward the inner surface 12C of the casing 1C. As a result, the light source 3 is arranged so as to irradiate the internal space 13C with light. The reflecting mirror 5 is arranged so as to at least partially block the bottom surface 133C of the internal space 13C, and the surface 51 facing the internal space 13C is configured to mirror-reflect light. In addition, the lighting device L3 may be configured in the same manner as the lighting device L1 according to the above embodiment.

The material of each component may be the same as in the above embodiment. Further, in this modification, the above modifications <4.1> to <4.5> may be appropriately adopted. For example, the inner surface 12C of the casing 1C may be made of a material that absorbs light. Correspondingly, the second surface 22C of each plate member 2C may be made of a material that diffusely reflects light.

(how to use)
Next, a method of using the lighting device L3 according to this modification will be described. In this modified example as well, the user prepares for color measurement in the same manner as in the above embodiment, and then uses an optical sensor to measure the color of the object SC arranged in the internal space 13C by the SCE method and the SCI method. To do.

In this modification, the user changes the position of each plate material 2C so that each part of the inner surface 12C is covered at least once by any of the plurality of plate materials 2C, and uses an optical sensor to detect the reflection component of the object SC. Measure. In this modification, the lighting device L3 includes four plate members 2C. The inner surface 12C is divided into 12 equal parts, and each plate material 2C has a shape corresponding to one region A3. Therefore, the observation for color measurement can be completed by three measurements.

One of the measurement data obtained by the three measurements includes the specular reflection component and the diffuse reflection component of the object SC, and the other measurement data does not include the specular reflection component of the object SC and diffuse reflection. Contains ingredients. Therefore, among the measurement data obtained by the three measurements, the brightness of the target position is compared with respect to the object SC, the brightness with the largest value is regarded as the SCI value, and the brightness with the smallest value is regarded as the SCE value. Can be regarded.

For example, when a digital camera is used as an optical sensor, a photographed image of the object SC can be obtained as measurement data. In this case, first, the pixel value of each pixel of each captured image obtained by the three measurements is converted into brightness. Next, the brightness obtained by the conversion is compared pixel by pixel between the captured images. Then, the SCI image can be generated by adopting the brightness having the largest value as the value of each pixel. Further, the SCE image can be generated by adopting the lightness having the smallest value as the value of each pixel. Thereby, in this modification, the SCE method and the SCI method of the object SC can be measured.

(Feature)
In this modification, when performing color measurement by the SCE method and the SCI method, the position of each plate material 2C is changed so that each portion of the inner surface 12C is covered at least once by any of the plurality of plate materials 2C. According to this modification, since the plate materials 2C are arranged around the shaft 134C at equal intervals, each plate material 2C is measured when the object SC in which the arrangement of the plate material 2C is changed around the shaft 134C is measured. It is possible to suppress duplication of positions. In particular, in this modification, the inner surface 12C is evenly divided into a plurality of regions A3 around the shaft 134C. Each plate material 2C has a shape corresponding to one region A3. The number of regions A3 on the inner surface 12C is n times greater than or equal to the number of plate members 2C. Therefore, it is possible to suppress the occurrence of overlapping positions of the plate materials 2C, and the number of measurements when performing color measurement by the SCE method and the SCI method is only n times (3 times in this modification). Therefore, according to this modification, the convenience of measurement can be improved as compared with the conventional lighting device.

L1 ... Lighting device,
1 ... Casing,
11 ... outer surface, 12 ... inner surface, A1 ... area,
13 ... Internal space,
131 ... center, 132 ... apex, 133 ... bottom, 134 ... axis,
14 ... Light receiving port (observation unit),
15 ... Open end,
2 ... Plate material, 21 ... 1st surface, 22 ... 2nd surface,
201 ... First plate material,
202 ... Second plate material, 2021 ... Transmission port,
203 ... Third plate material, 2031 ... Transmission port,
204 ... Fourth plate material,
3 ... Light source,
4 ... Frame material, 40 ... Main body,
41 ... Outer wall,
42 ... Inner peripheral wall (side wall), 421 ... Outer surface,
5 ... reflector, 51 ... surface,
L1A ... Lighting device, 14A ... Optical sensor,
L2 ... Lighting device,
1B ... Casing,
11B ... outer surface, 12B ... inner surface, A2 ... area,
13B ... Internal space,
131B ... center, 132B ... apex, 133B ... bottom,
134B ... Axis,
14B ... Light receiving port (observation unit),
2B ... Plate material, 21B ... 1st surface, 22B ... 2nd surface,
231 ... First plate material,
232 ... Second plate material, 2321 ... Transmission port,
233 ... Third plate material,
234 ... 4th plate, 2341 ... Transmission port,
241 to 244 ... Interval,
2411 ... part, 2421 ... part,
L3 ... Lighting device,
1C ... Casing,
11C ... outer surface, 12C ... inner surface, A3 ... area,
13C ... Internal space,
131C ... center, 132C ... apex, 133C ... bottom,
134C ... axis,
14C ... Light receiving port (observation unit),
2C ... Plate material, 21C ... 1st surface, 22C ... 2nd surface

Claims (12)

A casing having an outer surface, an inner surface, a hemispherical internal space, and an observation part.
The inner surface is made of a material that defines the hemispherical interior space and diffuses and reflects light.
The hemispherical interior space has a center, apex, bottom surface, and an axis.
The axis passes through the center and apex.
The casing is open to the bottom surface side of the internal space, and
The observation unit is provided for observing an object arranged in the internal space, and is arranged apart from the apex along the inner surface in the circumferential direction.
Casing and
A plurality of plate materials that face the inner surface and are divided and arranged around the axis in the internal space.
Each of the plurality of plate members covers a part of the inner surface when viewed from the center, and is configured so that the position around the axis can be adjusted.
Each of the plurality of plate materials includes a first surface facing the inner surface and a second surface facing the center.
The second surface of each of the plurality of plate materials is composed of a material that absorbs light, and
The plurality of plate materials are
First board,
A second plate material that is arranged symmetrically with respect to the center of the first plate material and has a transmission port that is arranged at a position corresponding to the observation unit and is configured to transmit light. 2 plate materials and
A third plate material having a transmission port arranged at a position corresponding to the observation unit and configured to transmit light, and any other plate material among the plurality of plate materials is relative to the center. The third plate material, which is not arranged symmetrically with the third plate material,
including,
With multiple boards
A light source arranged to irradiate the internal space with light,
To prepare
Lighting device. The plurality of plate materials are a fourth plate material, and none of the other plate materials among the plurality of plate materials is arranged symmetrically with respect to the center of the fourth plate material. Including,
The lighting device according to claim 1. The transmission port of the third plate material is configured to be in an open state for transmitting the light and a closed state for blocking the transmission of the light.
The lighting device according to claim 1 or 2. Further provided with a frame material for supporting the open end of the casing,
The frame member is a side wall formed in a cylindrical shape and is arranged apart from the inner surface of the casing toward the center, and includes a side wall having an outer peripheral surface facing the inner surface.
The light source is arranged on the outer peripheral surface of the side wall toward the inner surface of the casing.
The lighting device according to any one of claims 1 to 3. Further comprising a reflector which is arranged so as to at least partially block the bottom surface of the interior space and is configured such that a surface facing the interior space mirror-reflects light.
The lighting device according to any one of claims 1 to 4. The plurality of plate materials are connected to each other and are configured to be adjustable in position by moving in conjunction with the axis.
The lighting device according to any one of claims 1 to 5. The inner surface is evenly divided into a plurality of regions around the axis in a plane passing through the apex and the center.
Each of the plurality of plate materials has a shape corresponding to one region of the inner surface.
The lighting device according to any one of claims 1 to 6. The observation unit is composed of a light receiving port configured to transmit light from the inner surface to the outer surface.
The lighting device according to any one of claims 1 to 7. The observation unit is composed of an optical sensor.
The lighting device according to any one of claims 1 to 7. A casing having an outer surface, an inner surface, a hemispherical internal space, and an observation part.
The inner surface is made of a material that defines the hemispherical interior space and diffuses and reflects light.
The hemispherical interior space has a center, apex, bottom surface, and an axis.
The axis passes through the center and apex.
The casing is open to the bottom surface side of the internal space, and
The observation unit is provided for observing an object arranged in the internal space, and is arranged at the apex.
Casing and
A plurality of plate materials facing the inner surface and arranged at equal intervals around the axis in the internal space.
Each of the plurality of plate members covers a part of the inner surface when viewed from the center, and is configured so that the position around the axis can be adjusted.
Each of the plurality of plate materials includes a first surface facing toward the inner surface and a second surface facing toward the center, and the second surface of each of the plurality of plate materials is composed of a material that absorbs light. Be done,
With multiple boards
A light source arranged to irradiate the internal space with light,
To prepare
Lighting device. The inner surface is evenly divided into a plurality of regions around the axis in a plane passing through the apex and the center.
Each of the plurality of plate materials has a shape corresponding to one region of the inner surface.
The number of the regions on the inner surface is an integral multiple of two or more of the number of the plates.
The lighting device according to claim 10. A casing having an outer surface, an inner surface, a hemispherical internal space, and an observation part.
The inner surface is made of a material that defines the hemispherical interior space and absorbs light.
The hemispherical interior space has a center, apex, bottom surface, and an axis.
The axis passes through the center and apex.
The casing is open to the bottom surface side of the internal space, and
The observation unit is provided for observing an object arranged in the internal space, and is arranged apart from the apex along the inner surface in the circumferential direction.
Casing and
A plurality of plate materials that face the inner surface and are divided and arranged around the axis in the internal space.
Each of the plurality of plate materials includes a first surface facing the inner surface and a second surface facing the center.
The second surface of each of the plurality of plate materials is composed of a material that diffusely reflects light.
The plurality of plate materials include a first plate material, which is not arranged symmetrically with respect to the center of any of the other plate materials among the plurality of plate materials.
The plurality of plate materials have a plurality of intervals arranged between two plate materials adjacent to each other around the axis of the plurality of plate materials, and
The plurality of intervals include a first interval and a second interval arranged symmetrically with respect to the center.
With multiple boards
A light source arranged to irradiate the internal space with light,
To prepare
Lighting device.