JP2018186022A - Indoor illumination structure and indoor illumination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure high homogeneity of indoor illuminance, in a medical office comprising a rectangular frame-shaped air conditioning vertical wall on its ceiling.SOLUTION: An indoor illumination structure for illuminating a medical office includes: a light-transmissive plate vertical wall 4 arranged so as to vertically suspend from a ceiling surface 1, and where a light-transmissive plate 4a capable of transmitting light is arranged and formed into a rectangular-frame shape; a base illumination 6 installed on the ceiling surface 1 along sides of a square concentric to the rectangular frame of the light-transmissive plate vertical wall 4 so as to surround the entire periphery of the light-transmissive plate vertical wall 4; and vertical wall illumination 7 arranged linearly along an upper end surface of the light-transmissive plate vertical wall 4 between the ceiling surface 1 and the light-transmissive plate vertical wall 4, and configured to radiate light from the upper end surface of the light-transmissive plate vertical wall 4 toward the inside of the light-transmissive plate vertical wall 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an indoor lighting technique for illuminating a room in a medical room, and more particularly to an indoor lighting technique for improving the uniformity of the indoor lighting in a medical room.

  In a medical room such as an operating room or an anatomical room, room lighting is performed around a work table such as an operating table or an anatomical table installed on the floor in the room. As an indoor lighting technique in a medical room, for example, those described in Patent Documents 1 to 3 are known. The air conditioning / lighting system described in Patent Literature 1 includes a lighting fixture, a human sensor, and a light control device in each of the system ceiling modules that constitute each section of a system ceiling (grid ceiling) partitioned in a grid pattern. The lighting fixture is controlled by the light control device (see FIGS. 2, 4, and 8 of Patent Document 1). The lighting device for grid ceiling described in Patent Literature 2 has two lighting fixtures (fluorescent lamps) arranged in parallel in a grid of grids with a predetermined interval on the system ceiling (grid ceiling) (see FIG. 2 of Patent Literature 2). 1, see FIG. 7). The lighting device for a grid ceiling described in Patent Document 3 has a lighting fixture arranged so as to straddle two grids.

  On the other hand, in a medical room, in order to keep indoor air clean, a rectangular frame-shaped hanging wall is installed on the ceiling for the purpose of adjusting the airflow in the room (see, for example, Patent Documents 4 to 7). ). The hanging wall is usually installed on the ceiling surface above the working table such as an operating table so as to surround the working table (for example, see FIG. 1 of Patent Document 7), and is cleaned downward from the frame of the hanging wall. By blowing out air and sucking and discharging air from the vicinity of the floor or ceiling of the wall around the room (see, for example, FIGS. 1 and 4 of Patent Document 5), the indoor air is kept clean.

JP 2006-125727 A JP 2003-173715 A JP 2003-7119 A Japanese Utility Model Publication No. 62-6428 Japanese Utility Model Publication No. 63-32525 No. 3-2273 Japanese Utility Model Publication No. 62-14261 Japanese Utility Model Publication No. 56-124428

  In a medical room such as an operating room or a dissection room, the airflow in the room is adjusted by using the above-described hanging wall. Generally, in addition to air conditioning equipment, various medical equipment is installed on the ceiling in the frame of the hanging wall. In general, a monitor or the like is suspended and arranged (see, for example, FIG. 1 of Patent Document 7). In such a case, it is difficult to widely provide a lighting fixture in the vertical wall frame, and the awning and indoor lighting are arranged so as to surround the vertical wall on the ceiling around the vertical wall.

  However, when the room lighting is arranged so as to surround the hanging wall, the illuminance at the central portion of the hanging wall inevitably becomes lower than the surroundings. For this reason, there is a problem in that the degree of illuminance uniformity in the room is increased, and the visual appearance and the brightness of the room are felt greatly. In particular, in a medical room, it is required to maintain the uniformity of illuminance as much as possible, because it is an obstacle to perform detailed work if the operator senses the brightness of the room greatly.

  Accordingly, an object of the present invention is to provide an indoor lighting structure and an indoor lighting method capable of ensuring high uniformity of indoor illuminance in a medical room having a rectangular frame-shaped air-conditioning vertical wall on the ceiling. It is in.

A first configuration of an indoor lighting structure according to the present invention is an indoor lighting structure that performs indoor lighting in a medical room,
A light-transmitting plate hanging wall that is vertically suspended from the ceiling surface and has a light-transmitting light-transmitting plate arranged in a rectangular frame shape;
A base illumination that surrounds the entire periphery of the translucent plate hanging wall on the ceiling surface, and is installed along a rectangular side concentric with the rectangular frame of the translucent plate hanging wall,
Between the ceiling surface and the translucent plate hanging wall, it is arranged linearly along the upper end surface of the translucent plate hanging wall, and from the upper end surface of the translucent plate hanging wall, the translucent plate hanging wall And vertical wall illumination that illuminates inward.

  According to this configuration, light emitted from the hanging wall illumination is mainly emitted from the lower end of the light transmitting plate hanging wall through the inside of the light transmitting plate hanging wall, and serves as auxiliary lighting in the rectangular frame of the light transmitting plate hanging wall. It functions, and can reduce the illuminance uniformity within the rectangular frame of the translucent plate hanging wall. Thereby, it becomes possible to ensure the high uniformity of the illuminance in the room.

  According to a second configuration of the indoor lighting structure of the present invention, in the first configuration, the upper end portion of the translucent plate hanging wall covers a side surface of the upper end portion of the translucent plate hanging wall, and the translucent light is transmitted. A socket for fixing the plate wall to the ceiling surface is provided, and the inner surface of the socket is a mirror surface.

  According to this configuration, even if a gap is provided between the upper end surface of the translucent plate hanging wall and the illumination surface of the hanging wall illumination by using the inner surface of the socket as a mirror surface, optically This is almost equivalent to the case where the upper end surface of the translucent plate hanging wall and the illumination surface of the hanging wall illumination are arranged in close contact with each other. Thereby, even if there is the gap, the apparent directivity of the hanging wall illumination is lowered, and the optimization uniformity and the optimization variation coefficient can be kept low. In addition, by providing a gap between the upper end surface of the translucent plate hanging wall and the illumination surface of the hanging wall illumination, it is possible to cool the hanging wall illumination using this gap space, ensuring heat dissipation. It is also possible to prevent deterioration of the hanging wall illumination due to heat.

In a third configuration of the indoor lighting structure according to the present invention, in the first or second configuration, the translucent plate hanging wall is formed by arranging a plurality of flat translucent plates in a rectangular frame shape. And
The left and right end surfaces of each light transmissive plate constituting the light transmissive plate hanging wall are formed as inclined surfaces, and the inclined surface is formed so as to face the outside of the frame of the light transmissive plate hanging wall. Features.

  With this configuration, the illuminance uniformity within the rectangular frame of the translucent plate hanging wall can be further reduced, and the uniformity of the illuminance in the room can be further improved.

  According to a fourth configuration of the indoor lighting structure of the present invention, in any one of the first to third configurations, the translucent plate hanging wall has an inclined flat surface, a curved surface, or a folded folded surface. It is characterized by being formed.

  With this configuration, the illuminance uniformity within the rectangular frame of the translucent plate hanging wall can be further reduced, and the uniformity of the illuminance in the room can be further improved.

An interior illumination method according to the present invention is an interior illumination method for performing interior illumination of a medical room,
A translucent plate hanging wall in which a translucent plate that transmits light is arranged in a rectangular frame shape is vertically suspended from the ceiling surface,
On the ceiling surface, a base illumination is installed along a rectangular side concentric with the rectangular frame of the translucent plate hanging wall surrounding the entire periphery of the translucent plate hanging wall,
A hanging wall illumination that illuminates from the upper end surface of the light transmitting plate hanging wall toward the inside of the light transmitting plate hanging wall is provided between the ceiling surface and the light transmitting plate hanging wall. Arrange along the top edge,
The uniformity of the illuminance in the horizontal plane at a predetermined height between 0 m and 1.5 m from the floor surface of the space directly under the convex hull that includes the base illumination on the ceiling surface is minimized. An illuminance ratio between the illuminance of the base illumination and the illuminance of the hanging wall illumination is adjusted.

  As described above, according to the present invention, the vertical wall illumination that illuminates from the upper end surface of the transparent plate vertical wall toward the inside of the transparent plate vertical wall is provided between the ceiling surface and the transparent plate vertical wall. Thus, the light emitted from the hanging wall illumination is mainly emitted from the lower end of the light transmitting plate hanging wall through the inside of the light transmitting plate hanging wall, and functions as auxiliary lighting in the rectangular frame of the light transmitting plate hanging wall, It is possible to reduce the illuminance uniformity within the rectangular frame of the translucent plate hanging wall. Thereby, it becomes possible to ensure the high uniformity of the illuminance in the room.

  Moreover, even if a gap is provided between the upper end surface of the translucent plate vertical wall and the illumination surface of the vertical wall illumination by making the inner surface of the socket at the upper end of the translucent plate vertical wall as a mirror surface Specifically, this is almost equivalent to the case where the upper end surface of the translucent plate hanging wall and the illumination surface of the hanging wall illumination are arranged in close contact with each other. Thereby, even if there is the gap, the apparent directivity of the hanging wall illumination is lowered, and the optimization uniformity and the optimization variation coefficient can be kept low. In addition, by providing a gap between the upper end surface of the translucent plate hanging wall and the illumination surface of the hanging wall illumination, it is possible to cool the hanging wall illumination using this gap space, ensuring heat dissipation. It is also possible to prevent deterioration of the hanging wall illumination due to heat.

It is a figure showing the whole indoor lighting structure concerning Example 1 of the present invention. It is a figure showing the structure of each translucent board 4a which comprises the translucent board hanging wall 4 of Example 1. FIG. It is a figure which shows the calculation result of the illumination distribution by only the base illumination. It is a figure showing the evaluation model of the translucent board 4a single-piece | unit. It is a figure showing the calculation result of the illumination distribution on the measurement line with respect to each lower end surface inclination | tilt angle (theta) _b when the space | interval _ds of the translucent plate 4a and a surface light source is 0.1t, t, 2t, 5t. It is a figure which shows the optical path entered into a translucent board from the upper end surface of a translucent board. Refractive index n ₁ of 1.5 transparent plate 4a, 1.6, 1.7, in the case of 1.8, a diagram representing the calculation result of the illuminance distribution measuring line for each lower end face inclination angle theta _b. It is a figure showing the change of illumination distribution when changing the upper end surface inclination | tilt angle (theta) _t and the lower end surface inclination | tilt angle (theta) _b in the translucent plate vertical wall 4 of FIG.1 and FIG.2. It is a figure showing the change of the optimization uniformity degree and the optimization variation coefficient with respect to the change of inclination-angle (theta) _t , (theta) _b of the upper end surface of a translucent board, and a lower end surface. It is a graph showing a change in illuminance distribution by distance d _s of the upper end surface and the surface light source of the transparent plate. It is a graph showing a change in the optimization uniformity and optimization variation coefficient by the distance d _s of the upper end surface and the surface light source of the transparent plate. It is a figure showing the structure which made the inner surface of the socket 7 the mirror surface. In the case of the case and the mirror surface of the inner surface of the socket 7 and the non-reflecting surface is a graph showing a change in the illuminance distribution when changing the distance d _s of the transparent plate 4a upper surface and the surface light source. Refractive index n ₁ = 1.5 of the transparent plate, 1.6, 1.7, for 1.8 is a graph showing a change in the illuminance distribution when changing the lower end face inclination angle theta _b. Refractive index n ₁ = 1.5 of the transparent plate, 1.6, 1.7, which is a diagram showing for 1.8, a change in the optimization uniformity and optimization variation coefficient with respect to a change in the lower end face inclination angle theta _b. It is a figure showing each translucent board which comprises the translucent board vertical wall and translucent board vertical wall in the indoor lighting structure which concerns on Example 2 of this invention. FIG. 17 is a diagram illustrating a change in illuminance distribution with respect to a change in the inclination angle θ _s of the side edge inclined surface when θ _t = θ _b = 0 ° and n ₁ = 1.5 in the light transmitting plate hanging wall 4 in FIG. 16. . _{θ t = θ b = 0 °} , graph showing a change in the side edge of the inclined surface with respect to the change of the inclination angle θ _s (a) optimizing uniformity and (b) optimizing the variation coefficient in the case of n 1 ₌ 1.5 It is. It is a figure showing each translucent board which comprises the translucent board vertical wall and translucent board vertical wall in the indoor lighting structure which concerns on Example 3 of this invention. In the translucent plate vertical wall 4 of FIG. 19, θ _{t =} 0 °, is a graph showing a change in the illuminance distribution with respect to the change of the inclination angle theta _b of the inclined arcuate surface when the n 1 ₌ 1.5. θ _{t =} 0 °, is a diagram showing changes in (a) optimizing uniformity and (b) optimizing the variation coefficient with respect to a change in the inclination angle theta _b inclined arcuate bottom surface when the n 1 ₌ 1.5 . It is sectional drawing of the lower end part of each translucent board 4a which comprises the translucent board vertical wall 4 in the indoor lighting structure which concerns on Example 4 of this invention. θ _{t =} 0 °, it is a diagram showing changes in (a) optimizing uniformity and (b) optimizing the variation coefficient with respect to a change in the relative curvature kappa _b in the horizontal arc-shaped lower end face of the case of n 1 ₌ 1.5 . It is sectional drawing of the lower end part of each translucent board 4a which comprises the translucent board vertical wall 4 in the indoor lighting structure which concerns on Example 5 of this invention. It is a figure showing the change of (a) optimization uniformity degree and (b) optimization variation coefficient with respect to the change of the outer side inclination | tilt angle (theta) ₂ of the folding surface lower end surface of the translucent plate 4a of FIG. It is a figure showing the change of (a) optimization uniformity and (b) optimization variation coefficient in the range of 55 ° ≦ θ _b2 ≦ 77.5 °. The transparent plate 4a of Figure 24, a diagram for each horizontal width x _1, represents the change in (a) optimizing uniformity and (b) optimizing the variation coefficient with respect to a change in outer inclined angle theta ₂ of the folding planar bottom surface It is. (A) Optimized uniformity and (b) Optimized variation coefficient with respect to the change of the outer inclination angle θ ₂ of the folded lower end surface when the refractive index n _{1 of the} light transmitting plate is 1.4 to 1.8 FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an overall configuration of an indoor lighting structure according to Embodiment 1 of the present invention. 1A is a perspective view looking up from the indoor side, FIG. 1B is a perspective view of a translucent plate hanging wall removed from the ceiling surface, FIG. 1C is a side view, and FIG. ) Represents a plan view. In FIG. 1, a room to be illuminated is a medical room such as an operating room or a dissection room, and includes a ceiling surface 1, a room wall surface 2, and a floor surface 3. In FIG. 1A, for convenience of illustration, a part of the room wall surface 2 is omitted, and a part of the floor surface 3 is shown broken away. The indoor lighting structure according to the present invention includes a translucent plate hanging wall 4, a socket 5, a base lighting 6, and a hanging wall lighting 7. The translucent plate hanging wall 4 is a hanging wall that is vertically hung from the ceiling surface 1 and has a translucent plate 4a through which a plurality of lights are transmitted arranged in a rectangular frame shape. The transparent plate 4a is made of a transparent material having a high light transmittance such as glass or an acrylic plate. The socket 5 is a fixing bracket provided over the entire upper end of the translucent plate hanging wall 4, and fixes the translucent plate hanging wall 4 to the ceiling surface 1. Both side surfaces of the socket 7 are formed in parallel with both side surfaces of the translucent plate 4a. The inner surface of the socket 5 is mirror-finished to reflect light, or a mirror seal is attached. The base illumination 6 is illumination installed on the ceiling surface 1 so as to surround the entire periphery of the translucent plate hanging wall 4 and along a rectangular side concentric with the rectangular frame of the translucent plate hanging wall 4. As the base illumination 6, illumination such as a fluorescent lamp or LED illumination, which is normally used as ceiling illumination, is used in which the light distribution characteristic distribution is spread almost uniformly in all directions. As shown in FIG. 1B, the hanging wall illumination 7 is arranged linearly along the upper end surface of the translucent plate hanging wall 4, and the translucent plate hanging wall 4 from the upper end surface of the translucent plate hanging wall 4. It is the illumination which shines toward the inside. As the hanging wall illumination 7, an LED line array or the like in which high-intensity LEDs are arranged in a line is used. Each illumination element such as an LED constituting the hanging wall illumination 7 is arranged such that the beam center axis direction is downward (that is, the direction toward the upper end surface of the translucent plate hanging wall 4).

In the following description, it is assumed that the horizontal direction of the room where illumination is performed is the x direction, the vertical direction is the y direction, and the vertical direction is the z direction. Further, as shown in FIGS. 1C and 1D, the width of the room to be illuminated is w _mx , w _my , the height from the floor surface 3 to the ceiling surface 1 is h _m , and the base illumination 6 is arranged. The width of the rectangular frame is w _cx , w _cy , the width of the base illumination 6 is w ₁ , the width of the translucent plate hanging wall 4 is w _2x , w _2y , and the height of the translucent plate hanging wall 4 is h ₂ , The thickness of each translucent plate 4a constituting the translucent plate hanging wall 4 is denoted by t. In a standard medical room, the height from the floor surface 3 to the ceiling surface 1 is set to about 3 _m .

FIG. 2 is a diagram illustrating the configuration of each light-transmitting plate 4 a configuring the light-transmitting plate hanging wall 4 according to the first embodiment. 2A is an overall perspective view, FIG. 2B is a front view, and FIG. 2C is a side view. In this embodiment, the translucent plate 4a is a flat plate having a rectangular shape as a whole. The translucent plate 4a has an upper end surface and a lower end surface formed in a horizontal plane or an inclined plane. In the following description, the inclination angle denoted as theta _t with respect to the horizontal plane of the upper end face of the transparent plate 4a, the inclination angle theta _t, as shown in FIG. 2 (c), the rectangular frame of the light-transmitting plate vertical wall 4 A direction inclined upward from the inside of the body to the outside is defined as a positive direction. Also, noted an inclination angle with respect to the horizontal plane of the lower end surface of the transparent plate 4a and theta _b, the inclination angle theta _b, as shown in FIG. 2 (c), the outside from the inside of the rectangular frame of the light-transmitting plate vertical wall 4 The direction inclined upward toward the top is defined as the positive direction. The width of the transparent plate 4a is _{w p,} the height _{h 2,} the thickness is referred to as t. From FIG. 1D, L _1x = 3w _p and L _1y = 4w _p .

  In the indoor lighting structure according to the present embodiment configured as described above, an indoor lighting method using the same will be described below.

  A work table (not shown) such as an operating table or a dissection table is installed on the floor 3 in the room below the frame of the translucent plate hanging wall 4. In this state, the base illumination 6 and the hanging wall illumination 7 are turned on to perform indoor illumination around the work table. Usually, the height from the floor surface 3 of a work table such as an operating table is 600 to 1000 mm. Therefore, an illuminance reference plane is virtually provided within this height range or within a range of 0 to 1.5 m depending on the purpose of use of the room, and the illuminance uniformity around the workbench is minimized on the illuminance reference plane. The illuminance of the base illumination 6 and the hanging wall illumination 7 is adjusted so that Here, “uniformity” is defined in JIS-z-9110-2011 (illumination standard general rule) as the ratio of the minimum illuminance to the average illuminance on a certain surface. Another definition may be defined as the ratio of the difference between the maximum illuminance and the minimum illuminance with respect to the average illuminance on a certain surface. When adjusting the illuminance of the base illumination 6 and the hanging wall illumination 7, the uniformity according to any definition may be used, but the latter definition is used in this specification. That is, the uniformity degree U is defined by the following equation.

Here, I (P) is the illuminance at point P on the illuminance reference plane, A is the illuminance measurement area (area on the illuminance reference plane), and max _P∈A (I (P)) is the illuminance I (P in area A ), Min _P∈A (I (P)) is the minimum value of illuminance I (P) in area A, and ave _P∈A (I (P)) is the average value of illuminance I (P) in area A It is. The homogeneity is an index representing the local shading of the room illuminance. In the following explanation, the illuminance variation coefficient RSD is used as an index representing the overall shading of the room illuminance. The coefficient of variation RSD is defined by the following equation.

  In this way, by illuminating from the upper end surface of the translucent plate hanging wall 4 with the hanging wall illumination 7 through the translucent plate hanging wall 4, the illuminance in the frame of the translucent plate hanging wall 4 is changed to the illuminance around the frame. And uniform.

  Next, the results of evaluating how much the illuminance in the room is equalized by actually illuminating with the hanging wall illumination 7 through the translucent plate hanging wall 4 of FIGS. 1 and 2 will be described. . As an evaluation method, first, the evaluation of the illuminance distribution using only the base illumination 6 and the evaluation of the illuminance distribution using only the vertical wall illumination 7 are performed. evaluate. The illuminance was evaluated by numerical calculation by the ray tracing method.

(1) Evaluation of illuminance distribution by base illumination 6 In calculating illuminance, assuming the size of a standard medical room, the size of the room to be illuminated is set as w _mx × w _my = 6. 5 × 8 m, the height from the floor surface 3 to the ceiling surface 1 is h _m = 3 m, the width of the rectangular frame in which the base lighting 6 is arranged is w _cx × w _cy = 4.79 × 5.24 m, The width is w ₁ = 0.3 m, the width of the frame of the translucent plate hanging wall 4 is w _2x × w _2y = 1.6 × 2.4 m, and the height of the translucent plate hanging wall 4 is h ₂ = 0.3 m. The thickness of each translucent plate 4a constituting the translucent plate hanging wall 4 was t = 10 mm. The light distribution distribution curve of the base illumination 6 varies depending on the luminaire to be used. Here, as a standard model, the base illumination 6 is an ideal surface light source, and the orientation curve is I _s (θ) = I _s0 cos θ. It was. Here, θ represents an angle with respect to a normal vector (a vector pointing vertically downward) of the base illumination 6. As the illuminance reference plane, a horizontal plane with a height of 70 cm from the floor surface (horizontal plane with a distance of 2 m from the lower end surface of the translucent plate hanging wall 4) was used as the illuminance reference plane. In addition, the reflection by the peripheral wall surface and floor surface of the room varies depending on the material constituting the wall surface and floor surface, so that the reflection by the peripheral wall surface and floor surface is not considered in this evaluation.

  FIG. 3 is a diagram showing a calculation result of the illuminance distribution by only the base illumination 6. In FIG. 3, in the frame lines indicated by black lines, the outer frame line indicates the position of the base illumination 6 on the ceiling surface, and the inner rectangular frame line indicates the position of the translucent plate hanging wall 4. (See FIG. 1 (d)). From FIG. 3, it can be seen that when the illumination is performed only by the base illumination, a dark portion is generated in the frame of the translucent plate hanging wall 4. At this time, the degree of uniformity U (A) in the region A (the region surrounded by the alternate long and short dash line in FIG. 3) within the frame of the base illumination 6 (within the convex hull including all outer sides of the frame of the base illumination 6) and The coefficient of variation RSD (A) was U (A) = 0.619, RSD (A) = 0.163.

(2) Evaluation about illuminance distribution by single translucent plate 4a Next, the result of evaluating the illuminance distribution by the single translucent plate 4a will be described. FIG. 4 is a diagram illustrating an evaluation model of a single translucent plate 4a. The shape of the transparent plate 4a is the same as FIG. 2, above the upper end surface of the transparent plate 4a, an interval of distance d _s, placing a surface light source having the same width as the transparent plate 4a. Here, the light distribution curve of the surface light source is a constant value (isotropic light source) in all directions. Further, a shielding plate was set instead of the socket 5 between the surface light source and the upper end surface of the translucent plate. The illuminance reference plane was a horizontal plane where the distance hm from the lower end of the translucent plate 4a was 2 _m . On this illuminance reference plane, as shown in FIG. 4B, the origin is a point just below the center point of the translucent plate 4a, and the direction perpendicular to the width direction of the translucent plate 4a is the x-axis and vertical. A coordinate axis with the direction as the z-axis was set, and the illuminance was calculated along the x-axis. The inclination angle theta _t of the upper end surface of the transparent plate 4a is set to 0 degrees.

FIG. 5 is a diagram showing the calculation result of the illuminance distribution on the measurement line with respect to each lower end surface inclination angle θ _b when the distance d _s between the upper end surface of the translucent plate 4a and the surface light source is 0.1t, t, 2t, 5t. It is. As shown in FIG. 5, as the distance d _s between the upper end surface of the translucent plate 4a and the surface light source increases, the peak of the illuminance value moves to the inner side (x <0) from the position directly below the translucent plate 4a (x = 0). You can see the shift. In addition, on the outside of the light transmitting plate (x> 0), there is a tendency that the vibration of the illuminance value is large. The reason is considered as follows.

FIG. 6 is a diagram illustrating an optical path that enters the translucent plate from the upper end surface of the translucent plate. As shown in FIG. 6A, the incident angle of the light incident on the upper end of the translucent plate from the surface light source is maximized, as shown in FIG. 6A, at the end opposite to the upper end surface of the translucent plate. The incident angle at this time is θ _s0 . From FIG. _6A , θ _s0 = arctan (t / d _s ). When this light ray enters the light transmitting plate, the optical path is refracted and the transmission angle becomes θ _s . When the refractive index of the transparent plate and n _1, transmission angle theta _s is expressed by the following equation.

Here, θ _c = asin (1 / n ₁ ) is a critical angle. After this light ray penetrates into the translucent plate, it enters the inner surface of the translucent plate. Assuming that the incident angle (hereinafter referred to as “minimum side surface incident angle”) at this time is θ ₁ , θ ₁ = π / 2−θ _s from FIG. If the critical angle θ _c is smaller than π / 4, θ ₁ > θ _{c is} always established, and all the optical paths are totally reflected by the inner surface of the light transmitting plate. Therefore, the maximum number of reflections N that is reflected on the inner surface of the light transmissive plate from the upper end surface to the lower end surface of the light transmissive plate is expressed by the following equation.

In particular, when d _s = 0, θ _s = θ _c and the minimum side surface incident angle is θ ₁ = π / 2−θ _c . From equations (3) and (4), when d _s increases, θ _s decreases, the minimum side surface incident angle θ ₁ increases, and the maximum number of reflections N decreases. This means that as d _s increases, the directivity of the apparent light source of incident light increases. Therefore, since the dispersion of the optical path due to reflection in the light transmissive plate is reduced, the influence due to the zigzag reflection inside the light transmissive plate is reduced, and it is considered that only the influence of the light path directed downward is left. In the case of a light path traveling vertically downward, as shown in FIG. 6 (b), the light is refracted inward (leftward in FIG. 6 (b)) at the lower end surface of the light-transmitting plate and then toward the floor. Irradiated. At this time, when the lower end surface of the translucent plate is inclined upward (in the case of θ _b > 0) from the inner side (left side of FIG. 6B) toward the outer side (right side of FIG. 6B). The light rays are refracted in the inward direction. Accordingly, when d _s increases and directivity increases, and the influence of the optical path traveling in the vicinity of the vertically downward direction increases, the illuminance peak shifts inward as shown in FIG. Further, as d _s increases, the zigzag optical path with a small side reflection angle decreases, and only a limited zigzag optical path with a large side reflection angle remains. Therefore, the vibration in the illuminance distribution increases as d _s increases. It is done.

7, the refractive index n ₁ of 1.5 transparent plate 4a, 1.6, 1.7, in the case of 1.8, a diagram representing the calculation result of the illuminance distribution measuring line for each lower end face inclination angle theta _b. From FIG. 7, as the refractive index of the light transmissive plate 4a increases, the peak of the illuminance value may shift to the inside (x <0) from the position directly below the light transmissive plate 4a (x = 0). I understand. In addition, on the outside of the light transmitting plate (x> 0), there is a tendency that the vibration of the illuminance value is large. This tendency is more widened distance d _s of the transparent plate 4a upper surface and the surface light source appears large, it appears larger as the inclination angle theta _b of the transparent plate 4a bottom surface increases.

(3) Evaluation of illuminance distribution by entire translucent plate hanging wall 4 (3.1) Evaluation of influence of inclination of upper end surface and lower end surface of translucent plate Next, the shape of the translucent plate 4a is the translucent plate droop. The influence on the illuminance distribution by the entire wall 4 will be described. Figure 8 is a graph showing a change in the illuminance distribution when changing the upper end face inclination angle theta _t and the lower end face inclination angle theta _b of the transparent plate 4a in the translucent plate vertical wall 4 of FIG. 1 and FIG. 2 . Each illuminance distribution chart in the table of FIG. 8 is shown in the same size as FIG. In FIG. 8, the refractive index n ₁ of the translucent plate 4a is 1.5, and the distance d _s between the upper end surface of the translucent plate 4a and the surface light source is 0.1t. Further, as the illuminance reference plane, a horizontal plane having a height of 70 cm from the floor surface (horizontal plane having a distance of 2 m from the lower end surface of the translucent plate hanging wall 4) is used as the illuminance reference plane. The upper end face inclination angle theta _t and the lower end face inclination angle theta _b is a direction inclined upward positive and negative direction which is inclined down towards the outside the frame from the frame of the transparent plate vertical wall 4 (FIG. 2 ( c)). Further, the light distribution distribution curve of the vertical wall illumination 7 is assumed to be LED illumination, and the illuminance is Gaussian curve (I (θ _s0 ) = I ₀ · exp (−) with respect to the direction of the angle θ _s0 from the irradiation axis direction. αθ _s0 ² )). From FIG. 8, by changing the upper end face inclination angle theta _t and the lower end face inclination angle theta _b of the transparent plate 4a, it can be seen that it is possible to control the illuminance distribution on the illumination reference plane.

Next, it is considered to minimize the uniformity by superimposing the illumination by the vertical wall illumination 7 (hereinafter referred to as “auxiliary illumination”) through the translucent plate vertical wall 4 and the illumination of the base illumination 6. Now, assume that the illuminance of the base illumination at the point P (x, y) on the illuminance reference plane is I ₀ (P), and the illuminance of the auxiliary illumination is I ₁ (P). When the base illumination and the auxiliary illumination are turned on at the same time, it is assumed that the linear overlap is established, assuming that the interference of light due to both illuminations is small enough to be ignored. At this time, the total illuminance I (P) at the point P (x, y) is expressed by the following equation.

Here, w ₀ and w ₁ are weighting factors. As an index for measuring the uniformity of illuminance on the illuminance reference plane, the uniformity U in Expression (1) and the variation coefficient RSD in Expression (2) are used. As the area A for measuring the uniformity U and the coefficient of variation RSD, in order to eliminate the influence of the vicinity of the room wall, within the frame of the base illumination 6 as shown by the one-dot chain line frame in FIG. The convex hull including the outer side of the region. For simplicity, w ₀ = 1 and the weight coefficient w ₁ is changed to obtain the weight coefficient w _{1, min} that minimizes the illuminance uniformity U or the variation coefficient RSD in the area A. The uniformity U (w _{1, min} ) or coefficient of variation RSD (w _{1, min} ) is obtained. The uniformity U (w _{1, min} ) is called “optimized uniformity”, and the coefficient of variation RSD (w _{1, min} ) is called “optimized variation coefficient”.

FIG. 9 is a diagram illustrating changes in the optimization uniformity degree and the optimization variation coefficient with respect to changes in the inclination angles θ _t and θ _b of the upper end surface and the lower end surface of the translucent plate 4a. 9, the refractive index _{n 1} of the transparent plate 4a is 1.5, distance _{d s} of the transparent plate 4a upper surface and the surface light source is set to 0.1 t. From FIG. 9, the optimization uniformity U and the optimization variation coefficient RSD can be kept low by setting θ _b = 0 to −40 degrees in the range of θ _t = −10 to 30 degrees. . In the case of using only the base light source, the homogeneity is 0.619 and the variation coefficient is 0.163. Therefore, from FIG. 9, by using the auxiliary light source, the uniformity is approximately 60% and the variation coefficient is approximately 40%. It can be suppressed to. Incidentally, the inclination angle theta _b of the lower end surface of the transparent plate 4a is smaller than -40 degrees, the weighting factor for the optimization increases. This means that high illuminance is required in the auxiliary light source, which is not preferable. In addition, when the inclination angle θ _t of the upper end surface of the light transmitting plate 4a is −10 to 10 degrees, the most stable and good uniformity can be obtained. In this case, the inclination angle θ _b of the lower end surface is −40 to 40 In the range of degrees, the optimized uniformity U and the optimized variation coefficient RSD can be kept low.

(3.2) Evaluation of influence of distance d _s between upper end surface of translucent plate and surface light source As described in FIGS. 5 and 6, the distance d _s between the upper end surface of translucent plate 4a and the surface light source is If it becomes larger, the apparent directivity of the light source (the hanging wall illumination 7) becomes higher, so that it is considered that the optimized uniformity and the optimized variation coefficient are also affected. Therefore, the influence of the distance d _s between the upper end surface of the translucent plate 4a and the surface light source was evaluated. FIG. 10 is a diagram illustrating the change in the illuminance distribution depending on the distance d _s between the upper end surface of the translucent plate and the surface light source. FIG. 10A shows the dependence of the illuminance distribution on the lower end surface inclination angle θ _b when d _s = 0.1 t, 1.0 t (n = 1.5, θ _t = 0 degree), and FIG. It represents the interval d _s dependence of the illuminance distribution when θ _b = θ _t = 0 degrees (n = 1.5). As shown in FIG. 10, as the distance d _s increases, the apparent directivity of the light source (the hanging wall illumination 7) increases. Therefore, the illuminance distribution has a shape of the translucent plate hanging wall 4 as the distance d _s increases. Is more strongly reflected. FIG. 11 is a diagram illustrating changes in the optimized uniformity and the optimized variation coefficient depending on the distance d _s between the upper end surface of the translucent plate and the surface light source. 11 (a) and 11 (b) show the dependence of the optimization uniformity and the optimization coefficient of variation when d _s = 0.1t, 1.0t (n = 1.5, θ _t = 0 °) on the lower end surface inclination angle θ _b. 11C and 11D show the dependence of the optimization uniformity and the optimization variation coefficient on the interval d _s when θ _b = θ _t = 0 degree (n = 1.5). From FIG. 11, it can be seen that as the distance d _s between the upper end surface of the light-transmitting plate and the surface light source increases, the optimized uniformity and the optimized variation coefficient increase, and the illuminance uniformity decreases.

  From the above results, in order to increase the uniformity of illuminance, the irradiation surface of the hanging wall illumination 7 may be disposed in close contact with the upper end surface of the translucent plate 4a. However, in order to obtain sufficient luminance, the actual vertical wall illumination 7 uses an LED array in which a large number of high-brightness LEDs are arranged in a line. Therefore, if the vertical wall illumination 7 is disposed in close contact with the upper end surface of the translucent plate 4a, the heat dissipation is deteriorated, and the vertical wall illumination 7 may be deteriorated. The LED array is a discrete light source unlike an ideal continuous surface light source, in which high-brightness LEDs are arranged at regular intervals.

Therefore, in the present invention, as shown in FIG. 12, the inner side surface of the socket 7 that covers the upper side surface of the translucent plate hanging wall 4 and fixes the translucent plate hanging wall 4 to the ceiling surface is mirror-finished. And As a result, even if the distance d _s between the upper end surface of the translucent plate 4a and the surface light source is increased, the irradiation surface of the vertical wall illumination 7 is in close contact with the upper end surface of the translucent plate 4a, and optically. Are substantially the same. Therefore, the apparent directivity of the light source (the hanging wall illumination 7) is lowered, and the optimization uniformity and the optimization variation coefficient can be kept low. Further, by separating the irradiation surface of the vertical wall illumination 7 from the upper end surface of the translucent plate 4a, the space between the irradiation surface of the vertical wall illumination 7 and the upper end surface of the translucent plate 4a can be ventilated. It is also possible to cool the hanging wall illumination 7 using the space. Furthermore, even if the vertical wall illumination 7 is a discrete light source such as an LED array, an ideal continuous surface can be obtained by separating the irradiation surface of the vertical wall illumination 7 from the upper end surface of the translucent plate 4a by a certain distance. It is possible to approach the light source. FIG. 13 shows a change in illuminance distribution when the distance d _s between the upper end surface of the translucent plate 4a and the surface light source is changed when the inner surface of the socket 7 is a non-reflective surface and a mirror surface. From FIG. 13, by making the inner surface of the socket 7 a mirror surface, even if the distance d _s between the upper end surface of the translucent plate 4a and the surface light source is large, the irradiation surface of the vertical wall illumination 7 is made to be the same as that of the translucent plate 4a. It can be seen that it can be approached when placed in close contact with the upper end surface.

(3.3) to evaluate the end of the influence of refractive index n ₁ of the transparent plate, a refractive index n ₁ of the transparent plate 4a will be described influence on the illuminance distribution. As described in FIG. 7, when the lower end face of the transparent plate 4a is inclined, the refractive index n ₁ of the transparent plate 4a increases, illuminance toward the direction opposite to the inclined surface and the maximum The peak that shifts. Therefore, in the case where the translucent plate hanging wall 4 is configured by using the translucent plate 4a as a rectangular frame, when the lower end surface of the translucent plate 4a is inclined upward in the outward direction of the frame, the translucent plate 4a is formed. If the refractive index n ₁ of the optical plate 4a becomes larger, considered light is focused more toward the center of the frame. 14, the refractive index n ₁ = 1.5 of the transparent plate, 1.6, 1.7, for 1.8 shows the change in the illuminance distribution when changing the lower end face inclination angle theta _b. 15, the refractive index n ₁ = 1.5 of the transparent plate, 1.6, 1.7, for 1.8 shows the change in the optimization uniformity and optimization variation coefficient with respect to a change in the lower end face inclination angle theta _b. Optimization in uniformity and optimization coefficient of variation, but does not appear significantly difference due to a refractive index in the range of the lower end surface inclination angle theta _b is smaller _{-30 ° ≦ θ b ≦ 30 °} , the absolute value of the lower end surface inclination angle When | θ _b | exceeds 30 °, the difference due to the refractive index becomes remarkable. When | θ _b | exceeds a certain size, the light traveling downward in the translucent plate 4a is totally reflected by the inner surface of the lower end of the translucent plate 4a and transmitted through the side surface near the lower end of the translucent plate 4a. It is thought that this is because it will be emitted outside. The condition under which light traveling vertically downward in the translucent plate 4a is totally reflected by the inner surface at the lower end of the translucent plate 4a is | θ _b | ≧ θ _c = arcsin (1 / n ₁ ). Here, [theta] _c is a critical angle of the translucent plate 4c. The critical angles θ _c when n ₁ = 1.5, 1.6, 1.7, and 1.8 are 41.81 °, 38.68 °, 36.03 °, and 33.74 °, respectively. Therefore, as shown in FIG. 15, on the negative side of θ _b (when tilting downward from the inner side to the outer side of the translucent plate wall 4), the optimized uniformity and the optimized variation coefficient start to increase rapidly. angle, it is understood that the vicinity of approximately the critical angle theta _c. Therefore, it can be seen that the inclination angle of the lower end surface of the translucent plate 4c may be set so that 0 ≧ θ _b > −θ _c . On the other hand, the side of θ _b > 0 is somewhat complicated. For simplicity, given the light traveling transparent plate within 4c vertically downward, when the critical angle theta _c is greater than 45 °, the theta _{b <45} when °, proceeds transparent plate within 4c downwardly The light is reflected and refracted by the lower end surface of the translucent plate 4c, and the transmitted light is emitted from the lower end surface of the translucent plate 4c and travels toward the inner side of the translucent plate hanging wall 4 (see FIG. 6B). At this time, since the reflected light travels horizontally or upward, it is not related to the illuminance distribution on the illuminance reference plane. In the case of 45 ° ≦ θ _b <θ _c , the reflected light is also refracted on the inner surface near the lower end of the light transmitting plate 4c and then goes to the inner side of the light transmitting plate hanging wall 4, so depending on the angle after being refracted The illuminance distribution on the illuminance reference plane may be related. In the case of θ _c ≦ θ _b , the light traveling vertically downward in the translucent plate 4c is totally reflected by the inner surface at the lower end of the translucent plate 4c and refracted by the inner surface near the lower end of the translucent plate 4c. Then, it goes to the inside of the translucent plate hanging wall 4. At this time, the incident angle θ ₁ when the light reflected by the inner surface of the lower end of the translucent plate 4 c is refracted by the inner surface of the translucent plate 4 c is θ ₁ = 90 ° −θ _b , and the refraction angle θ ₂ is θ _2. = Arcsin (n ₁ cosθ _b ). And, if tanθ ₂ <h _b / w (h _b is the height from the lower end of the translucent plate 4a to the illuminance reference plane, and w is the horizontal or vertical width of the frame of the translucent plate 4), the transmitted light Is dispersed out of the opposite frame beyond the position of the translucent plate facing the radiation source translucent plate, and when tan θ ₂ > h _b / w, the transmitted light enters the frame of the translucent plate hanging wall 4. Focused. That is, considering only the light traveling transparent plate within 4c vertically downward, the lower end face inclination angle theta _b

In the range of the light is distributed to the outside the frame of the transparent plate vertical wall 4, the lower end face inclination angle theta _b

In this range, the light is collected toward the inside of the translucent plate hanging wall 4. Actually, the angle θ _{o with} respect to the vertical downward direction vector of the light traveling from the upper end surface to the lower end surface in the translucent plate is distributed within a range of −θ _s ≦ θ _o ≦ θ _s (where θ _s is Therefore, the range dispersed outside the frame of the translucent plate hanging wall 4 and the range condensed into the frame of the translucent plate hanging wall 4 are shifted by the extent of the angle θ _o. To do. As a result, as shown in FIG. 15, the optimized uniformity and the optimized variation coefficient show complex changes depending on the refractive index n ₁ in the vicinity of θ _b = θ _c . 9 and 15, regardless of the refractive index n ₁ of the translucent plate 4 c, when the lower end surface inclination angle θ _b is θ _b <0, compared to the case where the lower end surface of the translucent plate 4 c is horizontal, The optimization uniformity and the optimization coefficient of variation become smaller. Therefore, from the above examination, when the light transmitting plate 4c having the shape of FIG. 2 is used, the inclination angle θ _b of the lower end surface of the light transmitting plate 4c is −θ _c = arcsin (1 / n ₁ ) <θ _b A range of <0 is considered suitable.

FIG. 16 is a diagram illustrating the translucent plate hanging wall and the translucent plates constituting the translucent plate hanging wall in the indoor lighting structure according to the second embodiment of the present invention. 16A is an overall perspective view of the translucent plate hanging wall 4, FIG. 16B is a plan view of the translucent plate hanging wall 4, and FIG. 16C is a plan view of the translucent plate 4a. In FIG. 16, for convenience of explanation, the socket 5 and the hanging wall illumination 7 are not shown. Moreover, the whole structure of an indoor lighting structure shall be the same as that of FIG. The translucent plate hanging wall 4 in the indoor lighting structure of the present embodiment is formed by arranging a plurality of flat translucent plates 4a in a rectangular frame shape. The left and right end surfaces of each translucent plate 4a are formed as inclined surfaces, and the inclined surfaces (hereinafter referred to as "side edge inclined surfaces") are arranged and formed so as to face the outside of the rectangular frame of the translucent plate hanging wall 4. Has been. As shown in FIGS. 16B and 16C, the angle formed by the side edge inclined surface with respect to the normal of the wide surface (front surface and back surface) of the translucent plate 4a is denoted as θ _s, and the inclination angle of the side edge inclined surface Call it. Hereinafter, the influence of the inclination angle θ _s of the side edge inclined surface on the optimized uniformity and the optimized variation coefficient will be described.

FIG. 17 shows the change in the illuminance distribution with respect to the change in the inclination angle θ _s of the side edge inclined surface when θ _t = θ _b = 0 ° and n ₁ = 1.5 in the light transmitting plate vertical wall 4 in FIG. FIG. FIG. 18 shows (a) optimized uniformity and (b) optimization variation with respect to changes in the inclination angle θ _s of the side edge inclined surface when θ _t = θ _b = 0 ° and n ₁ = 1.5. It is a figure showing the change of a coefficient. From FIG. 17, when the inclination angle θ _s of the side edge inclined surface is 55 degrees, the illuminance is concentrated most in the center. The overall illuminance distribution is maintained in a state of broadening around the center. As shown in FIG. 18, the optimized uniformity and the optimized variation coefficient are minimized when the inclination angle θ _s is 52 ° to 57 °. This is because light traveling diagonally in the width direction of the light transmissive plate 4 a through the inside of the light transmissive plate 4 a is totally reflected by the side edge inclined surface of the light transmissive plate 4 a and enters the rectangular frame of the light transmissive plate hanging wall 4. This is because can be changed.

  As described above, the left and right end surfaces of each light transmissive plate 4a constituting the light transmissive plate hanging wall 4 are formed as inclined surfaces (side edge inclined surfaces), and the side edge inclined surface is a rectangular frame of the light transmissive plate hanging wall 4. The interior illumination is performed by combining the base illumination 6 and the auxiliary illumination using the hanging wall illumination 7 as a light source, thereby further reducing the illuminance uniformity in the room and improving the uniformity of illumination. It becomes possible to raise. In the present embodiment, the number of translucent plates 4a constituting the translucent plate hanging wall 4 is 2 × 3, but the number of translucent plates 4a is not limited to this. By increasing the number of translucent plates 4 a constituting the translucent plate hanging wall 4, it is possible to enhance the light collection effect of the side edge inclined surface and further improve the uniformity of the interior lighting.

FIG. 19 is a diagram illustrating the translucent plate hanging wall and the translucent plates constituting the translucent plate hanging wall in the indoor lighting structure according to the third embodiment of the present invention. 19A is a perspective view of the entire translucent plate hanging wall 4, FIG. 19B is a perspective view of each translucent plate 4a constituting the translucent plate hanging wall 4, and FIG. 19C is a translucent plate. It is sectional drawing of the lower end part of 4a. In FIG. 19, for convenience of explanation, the socket 5 and the hanging wall illumination 7 are not shown. Moreover, the whole structure of an indoor lighting structure shall be the same as that of FIG. In the present embodiment, the lower end portion of the translucent plate 4a is formed so that the cross section has an inclined arc shape. As shown in FIG. 19 (c), referred to as the tangent of the angle of the inclined circular arc in the lowermost end of the transparent plate 4a and the inclined angle theta _b. It is assumed that the tangent of the upper end portion of the inclined arc is parallel to the side surface of the translucent plate 4a. Also, if the inclined arc surface of the lower end of the transparent plate 4a is arranged KakuToruhikariban 4a to face outside the frame of the light-transmitting plate vertical wall 4, it represents the inclination angle theta _b a positive value, the transparent plate 4a If inclined arcuate surface of the lower end is arranged KakuToruhikariban 4a to face the frame of the light-transmitting plate vertical wall 4, and represent the tilt angle theta _b negative value. Hereinafter, the inclination angle theta _b of the inclined arc surface of the transparent plate 4a bottom to describe the effect on the optimization uniformity and optimization coefficient of variation.

Figure 20 is a graph showing a change in the illuminance distribution on the light-transmitting plate vertical wall 4, for θ _{t =} 0 °, the change of the inclination angle theta _b of the inclined arcuate surface when the n 1 ₌ 1.5 in FIG. 19 . FIG. 21 shows changes in (a) optimized uniformity and (b) optimized variation coefficient with respect to changes in the inclination angle θ _b of the inclined arcuate lower end surface when θ _t = 0 ° and n ₁ = 1.5. FIG. In FIG. 21, “outer arc” data is data when each light-transmitting plate 4 a is arranged so that the inclined arc surface faces out of the frame of the translucent plate hanging wall 4, and “inner arc” data is inclined arc This is data in a case where each light transmitting plate 4 a is arranged so that the surface faces the inside of the light transmitting plate hanging wall 4. The “inclined plane” data is data in the case where the translucent plate 4a has the inclined surface shape of FIG. 2 and is provided for comparison. From FIG. 21, it can be seen that even when the lower end surface of the translucent plate 4a is an inclined circular arc surface, the optimized uniformity and the optimized variation coefficient can be reduced and the illuminance uniformity can be further improved. In particular, the inclined arc surface is arranged KakuToruhikariban 4a to face outside the frame of the light-transmitting plate vertical wall 4, the inclination angle theta _b of the inclined arc surface With 30 to 40 °, the optimization uniformity and The optimization coefficient of variation can be reduced most, and the uniformity of illumination is most improved.

FIG. 22 is a cross-sectional view of the lower end portion of each light transmissive plate 4a constituting the light transmissive plate hanging wall 4 in the indoor lighting structure according to the fourth embodiment of the present invention. The structure of the lower end portion is the same as in FIGS. In this embodiment, the lower end surface is formed in a horizontal arc shape. In Figure 22, denoted a radius of curvature of the horizontal arcuate surface _E b1 _E b0 _{E b2} of the lower end and _{r b.} r _b can take range is _{r b ∈ [0.5t, ∞)} . When r _b = ∞, the lower end surface of the translucent plate 4a is a horizontal plane, and when r _b = 0.5t, the lower end surface of the translucent plate 4a is a semicircular arc surface. Further, a value t / r _b obtained by multiplying the curvature 1 / r _b of the horizontal circular arc surface E _b1 E _b0 E _b2 by the thickness t of the translucent plate 4a is referred to as “relative curvature” and is denoted as κ _b . The range that the relative curvature κ _b can take is κ _b ∈ [0, 2]. When κ _b = 0, the lower end surface of the translucent plate 4a is a horizontal plane, and when κ _b = 2, the lower end surface of the translucent plate 4a. Is a semicircular arc surface. FIG. 23 shows changes in (a) optimized uniformity and (b) optimized variation coefficient with respect to changes in relative curvature κ _b of the horizontal arcuate lower end surface when θ _t = 0 ° and n ₁ = 1.5. FIG. From FIG 23, when the lower end surface horizontally arcuately, about 2 relative curvature kappa _b, i.e., by a semicircular, reduces the optimized uniformity and optimization variation coefficient, uniform illuminance It can be seen that the sex can be further improved.

FIG. 24 is a cross-sectional view of the lower end portion of each light transmissive plate 4a constituting the light transmissive plate hanging wall 4 in the indoor lighting structure according to the fifth embodiment of the present invention. The structure of the lower end portion is the same as in FIGS. In the present embodiment, the lower end surface is formed in a folded surface shape that is folded halfway around a fold line parallel to the width direction of the light-transmitting plate 4a. The shape of the lower end folding surface may be either convex upward or convex downward. In FIG. 24, the side of x <0 (left side) is the inner side (inside) of the translucent plate hanging wall 4 and the side of x> 0 (right side) is the outer side (outside) of the translucent plate hanging wall 4. Referred the two single slope surface forming a lower refracting surface, _b1 inclination angle with respect to the horizontal plane theta inner piece inclined surface _E b0 _{E b1,} and the inclination angle with respect to the horizontal plane of the outer single slope surface _E b0 _{E b2} θ _b2 . For the inclination angles θ _b1 and θ _b2 , the upward direction is a positive direction and the downward direction is a negative direction, as shown in FIG. Further, the horizontal width of the inner side inclined surface E _b0 E _b1 is denoted by x ₁ , and the horizontal width of the outer side inclined surface E _b0 E _b2 is denoted by x ₂ .

FIG. 25 is a diagram illustrating changes in (a) optimized uniformity and (b) optimization coefficient of variation with respect to changes in the outer inclination angle θ ₂ of the folded bottom end surface of the translucent plate 4a in FIG. In Figure 25, the upper end face of the transparent plate 4a is a horizontal surface, the refractive index _{n 1} is set to 1.5. When θ _b1 = θ _b2 = 0, the lower end surface is a horizontal plane, and when θ _b1 = θ _b2 , the lower end surface is the inclined plane of the first embodiment. From FIG. 25, it can be seen that the optimized uniformity and the optimized variation coefficient can be reduced as a whole by setting the inner inclination angle θ _b1 to a range greater than 0 degree and less than or equal to 30 degrees. Further, as compared with the case where the lower end surface is a horizontal plane, the optimization uniformity and the optimization variation coefficient can be reduced by setting the outer inclination angle _θb2 to be smaller than 0 degree and larger than −40 degrees. Further, even when the inner inclination angle θ _{b1 is set} to 20 degrees or less and the outer inclination angle θ _b2 is set to a range of 60 ° ≦ θ _b2 ≦ 72 °, the optimization uniformity and the optimization variation coefficient can be greatly reduced. it can. In this case, the outer side inclined surface E _b0 E _b2 becomes a total reflection surface, and most of the light traveling downward in the translucent plate 4a is totally reflected by the outer side inclined surface E _b0 E _b2 , and the inner side inclined surface. E _b0 towards the E _b1, is reflected and refracted by the inside piece inclined surface _E b0 _{E b1,} the light transmitted through the inner piece inclined surface _E b0 _{E b1} is radiated to the outside of the transparent plate 4a, the transparent plate vertical wall 4 It is thought that the light is collected within the frame. FIG. 26 is a diagram illustrating changes in (a) optimized uniformity and (b) optimized variation coefficient in a range of 55 ° ≦ θ _b2 ≦ 77.5 °. From FIG. 26, it is understood that the range of −20 ° ≦ θ _b1 ≦ 20 ° is appropriate as the range of the inner inclination angle θ _b1 , and in particular, the range of 0 ° ≦ θ _b1 ≦ 20 ° is optimal.

It will be described effects of the horizontal width _{x 2} of the horizontal width _{x 1} and the outer piece inclined surface _E b0 _{E b2} of the inner piece inclined surface _E b0 _{E b1.} FIG. 27 shows (a) optimized uniformity and (b) optimized variation coefficient with respect to changes in the outer inclination angle θ ₂ of the folded lower end surface for each horizontal width x ₁ of the translucent plate 4a of FIG. It is a figure showing a change. t is the thickness of the translucent plate 4a. From FIG. 27, it can be seen that when x ₁ = 0.4 t to 0.5 t, the optimized uniformity is most improved, and it is optimal to set the horizontal width x ₁ within this range. .

Finally, the influence of the refractive index n ₁ of the translucent plate 4a will be described. FIG. 28 shows (a) optimized uniformity and (b) with respect to the change in the outer inclination angle θ ₂ of the folded lower end surface when the refractive index n ₁ of the light transmitting plate 4a is 1.4 to 1.8. FIG. 3 is a diagram illustrating a change in an optimization variation coefficient. From FIG. 28, the refractive index n ₁ of the transparent plate 4a is the smaller the critical angle theta _c of larger the transparent plate 4a, the optimization uniformity is minimum positions is shifted to the small side outer inclination angle theta ₂ To do. Also, the larger the refractive index n ₁ of the transparent plate 4a, the spread width of the low angle region optimize uniformity. When the refractive index n ₁ is 1 / sin (45 °) (= 1.4142 °) or less, the critical angle θ _c is 45 ° or less, and therefore the minimum angle at which light is totally reflected inside the translucent plate 4a is 45. More than °. Therefore, in this case, when θ _b2 is 45 ° or less, total reflection occurs at the outer side inclined surface E _b0 E _b2 , and the reflected light is directed upward. Therefore, it is not possible to use the refractive index n ₁ of this region. It is considered appropriate. From the above results, it is preferable that the refractive index n ₁ of the light-transmitting plate 4a is 1.5 or more, and considering the refractive indexes of various actual materials, a material with n ₁ = 1.5 to 1.7 It is considered preferable to select.

DESCRIPTION OF SYMBOLS 1 Ceiling surface 2 Room wall surface 3 Floor surface 4 Translucent board vertical wall 4a Translucent board 5 Socket 6 Base illumination 7 Vertical wall illumination

Claims (5)

An indoor lighting structure for illuminating the interior of a medical room,
A light-transmitting plate hanging wall that is vertically suspended from the ceiling surface and has a light-transmitting light-transmitting plate arranged in a rectangular frame shape;
A base illumination that surrounds the entire periphery of the translucent plate hanging wall on the ceiling surface, and is installed along a rectangular side concentric with the rectangular frame of the translucent plate hanging wall,
Vertical wall illumination that is arranged linearly along the upper end surface of the translucent plate hanging wall and illuminates from the upper end surface of the translucent plate hanging wall toward the inside of the translucent plate hanging wall. The interior lighting structure characterized by. The upper end of the translucent plate hanging wall includes a socket that covers a side surface of the upper end of the translucent plate hanging wall and fixes the translucent plate hanging wall to a ceiling surface,
The indoor lighting structure according to claim 1, wherein an inner surface of the socket is a mirror surface. The translucent plate hanging wall is formed by arranging a plurality of flat translucent plates in a rectangular frame shape,
The left and right end surfaces of each light transmissive plate constituting the light transmissive plate hanging wall are formed as inclined surfaces, and the inclined surface is formed so as to face the outside of the frame of the light transmissive plate hanging wall. The interior lighting structure according to claim 1 or 2, characterized in that:   The indoor lighting structure according to any one of claims 1 to 3, wherein a bottom surface of the translucent plate hanging wall is formed as an inclined flat surface, a curved surface, or a folded surface. An indoor lighting method for lighting a room in a medical room,
A translucent plate hanging wall in which a translucent plate that transmits light is arranged in a rectangular frame shape is vertically suspended from the ceiling surface,
On the ceiling surface, a base illumination is installed along a rectangular side concentric with the rectangular frame of the translucent plate hanging wall surrounding the entire periphery of the translucent plate hanging wall,
A hanging wall illumination that illuminates from the upper end surface of the light transmitting plate hanging wall toward the inside of the light transmitting plate hanging wall is provided between the ceiling surface and the light transmitting plate hanging wall. Arrange along the top edge,
The uniformity of the illuminance in the horizontal plane at a predetermined height between 0 m and 1.5 m from the floor surface of the space directly under the convex hull that includes the base illumination on the ceiling surface is minimized. An indoor lighting method comprising adjusting an illuminance ratio between the illuminance of the base illumination and the illuminance of the hanging wall illumination.