Method for calculating brightness index of space, and lighting system

Abstract

To provide a calculation method of a brightness index of a space capable of easily calculating a brightness feeling of the space.SOLUTION: A method for calculating a brightness index of a space includes calculating a brightness index of the space by a calculation method in which a luminance value of a first region located above a reference plane is more strongly reflected in the brightness index than a luminance value of a second region located below the reference plane, the reference plane including a reference line corresponding to a reference direction from a position of an observer present in the space toward a specific region in a visual field of the observer.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present disclosure relates to a method for calculating a spatial brightness index in a space, and a lighting system using the same. [Background technology]

[0002] For example, Patent Document 1 discloses a method for defining a brightness perception index for an illumination space. In this method, a color patch whose surface luminance changes using a light source separate from the light source of the lighting fixture is provided in the illumination space, and the brightness perception index is defined as a function of the geometric mean luminance based on the correlation between the color mode boundary luminance, which is the luminance of the color patch when the color patch appears unnatural, intermediate between the luminance level at which the color patch is recognized by an observer as an object placed in the space and the luminance level at which the color patch is recognized as a light source emitting its own light, and the geometric mean luminance of a specific region of the illumination space within the observer's field of view excluding the light source luminance, and the correlation between the brightness perception index, which represents the brightness perception of the illumination space, and the color mode boundary luminance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-171055 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional method for defining a brightness sensation index for an illuminated space, a brightness sensation index that expresses the sense of brightness of the illuminated space is defined, but insufficient consideration is given to obstructing objects such as desks, chairs, and partitions installed in the illuminated space, and the brightness defined in the brightness sensation index may differ from the actual brightness of the space. In particular, when the obstructing objects are dark in color (low in brightness), the average luminance value on the upper side and the average luminance value on the lower side in the field of view differ, and the brightness defined in the brightness sensation index tends to diverge even more from the brightness of the actual space.

[0005] Therefore, it would be possible to define the brightness perception index taking into account obstructions, but since the position of obstructions changes depending on the layout change in the lighting space, it is necessary to define the brightness perception index every time the position of the obstruction is changed, which is a time-consuming task.

[0006] Therefore, an object of the present disclosure is to provide a method for calculating a spatial brightness index that can easily calculate the spatial brightness index. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a method for calculating a brightness index of a space according to one embodiment of the present disclosure calculates the brightness index in the space using a calculation method in which the brightness value of a first region located above a reference plane including a reference line corresponding to a reference direction from the position of the observer toward the specific region within the field of view of an observer present in the space is reflected in the brightness index more strongly than the brightness value of a second region located below the reference plane within the specific region.

[0008] In addition, in order to achieve the above-mentioned object, a lighting system according to one aspect of the present disclosure includes a lighting control unit that controls the lighting devices so that the brightness of the specified space meets a threshold value using a method for calculating a brightness index of the space. [Effects of the Invention]

[0009] According to the method for calculating a spatial brightness index according to the present disclosure, the spatial brightness index can be easily calculated. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a lighting system according to an embodiment. [Figure 2A] FIG. 2A is a side view showing the range of the viewer's viewing angle and the specific area. [Figure 2B]FIG. 2B is a front view showing the viewer's field of view and the specific area. [Figure 2C] FIG. 2C is a diagram showing a luminance distribution image including a specific region. [Figure 3] FIG. 3 is a diagram showing a space in which a plurality of obstructions such as desks and a plurality of lighting fixtures are installed in order to evaluate the brightness index of the space. [Figure 4] FIG. 4 is a diagram showing the coefficient of determination calculated according to the angle from the first direction to the second direction, with the first direction as the starting point. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, component arrangements and connection forms, steps, step order, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0012] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales and the like do not necessarily match in each figure. Furthermore, in each figure, substantially the same configurations are assigned the same reference numerals, and duplicate explanations are omitted or simplified.

[0013] (Embodiment) <Configuration and Function> First, a method for calculating a spatial brightness index according to this embodiment, and the configuration and functions of a lighting system 1 will be described with reference to FIGS. 1 to 2C.

[0014] FIG. 1 is a block diagram showing a lighting system 1 according to an embodiment. FIG. 2A is a side view showing a specific region in an observer's field of view. The first and second directions that define the boundaries of the specific region are indicated by solid arrows, and the reference direction that serves as the reference for the field of view is indicated by a dashed arrow. The specific region shown in FIG. 2A is not a cross-sectional view but is simply shown conceptually. FIG. 2B is a front view showing the region of the observer's field of view angle and the specific region. In FIG. 2B, the reference direction is indicated by a dashed arrow, the specific region is indicated by a two-dot chain line, and the reference plane is indicated by dotted hatching. FIG. 2C is a diagram showing a luminance distribution image including the specific region. In FIG. 2C, the closer to white the color, the higher the luminance value, and the closer to black the lower the luminance value.

[0015] When installing lighting fixtures 15 in an indoor space, lighting system 1 can achieve the desired brightness and atmosphere. To achieve this, once a space brightness index value is set to determine what kind of lighting fixtures 15 need to be installed, lighting system 1 is a system that controls lighting fixtures 15 so that the set space brightness index value is met. The space brightness index is an index of the brightness perceived by an observer when observing a space.

[0016] The space is a space in which lighting fixtures 15 are installed, and is an illumination space illuminated by the installed lighting fixtures 15. The brightness index of a space is an evaluation of the brightness perceived by an observer when observing a space illuminated by lighting fixtures 15.

[0017] The lighting system 1 includes an input unit 11, a calculation unit 12, a display unit 13, a lighting control unit 14, lighting fixtures 15, and a storage unit 16.

[0018] The input unit 11 can accept input of the size of the space, the light reflectance in the space, and information about the lighting fixtures to be installed in the space. The size of the space is the volume of the space in which the lighting fixtures 15 are installed. The light reflectance in the space is the reflectance of light irradiated on the walls, ceiling, floor, and obstructions that form the space. The lighting fixture information is information that indicates the performance of the lighting fixtures 15 to be installed in the space, including the luminous flux, type of light source, light color, color rendering properties, whether or not they have a dimming function, whether or not they have a color adjustment function, etc. The input unit 11 outputs the input information, including the size of the space, reflectance, and lighting fixture information, to the calculation unit 12.

[0019] The calculation unit 12 calculates the brightness index of a space using a calculation method in which the brightness value of a first region located above a reference plane including a reference line corresponding to a reference direction from the observer's position toward the specific region within a specific region in the field of view of the observer present in the space is reflected more strongly in the brightness index than the brightness value of a second region located below the reference plane within the specific region. Specifically, the calculation unit 12 calculates the brightness value of the specific region from input information input to the input unit 11. The size, reflectance, and lighting device information of the space included in the input information may be obtained, for example, from a luminance distribution image of the space including the size, reflectance, and lighting device information of the space. The calculation unit 12 may determine the size, reflectance, and lighting devices 15 of the space through simulation from the luminance distribution image and calculate the luminance value of the specific region. The luminance distribution image may be input to the input unit 11 by, for example, a user capturing an image of the space using an imaging unit. FIG. 2C illustrates an example of a luminance distribution image captured by an imaging unit with a fisheye lens. Alternatively, the luminance distribution image may be automatically input to the input unit 11 by an imaging unit installed in the space capturing an image of the space. Examples of simulations include Lumina Planner (registered trademark) and Lightning Flow (registered trademark).

[0020] In the calculation method, the first and second regions may be set so that a first angle formed between a first direction from the observer's position toward the upper end of the specific region and the reference direction is larger than a second angle formed between a second direction from the observer's position toward the lower end of the specific region and the reference direction. In other words, this indicates that the vertical width of the first region is larger than the vertical width of the second region.

[0021] In the calculation method, the weight of the luminance value of the first region may be set to be greater than the weight of the luminance value of the second region. A weight of the luminance value of the first region greater than the weight of the luminance value of the second region means, for example, that when the height in the first region and the height in the second region are the same, the coefficient by which the luminance value of the first region is multiplied is greater than the coefficient by which the luminance value of the second region is multiplied. Note that when the second angle is 0°, the second region is 0, so the weight of the luminance value of the second region, i.e., the coefficient by which the luminance value of the second region is multiplied, is 0.

[0022] This allows the influence of the luminance in the first region to be greater than the influence of the luminance in the second region in either calculation method.

[0023] In either calculation method, the geometric mean or arithmetic mean is calculated for the luminance values ​​of the first region and the luminance values ​​of the second region.

[0024] Here, the specific region is a region included in the field of view when the observer views the space, and is a region consisting of a first region located above the observer with the reference plane as the center and a second region located below the observer. For example, as shown in Figure 2C, when the input information is a luminance distribution image, the specific region is indicated by the region sandwiched between the upper end indicated by the dashed line and the lower end indicated by the dashed line, and between the right end indicated by the solid line and the left end indicated by the solid line.

[0025] The reference direction is the line of sight of an observer in a seated position looking along the horizontal direction. The reference line and reference plane are located approximately 1200 mm from the ground surface that forms the space. The reference line is a straight line that corresponds to the reference direction and extends along the reference direction. The reference plane is a virtual plane defined by countless reference lines. In this embodiment, the reference plane is approximately parallel to the horizontal plane.

[0026] As shown in Figures 2A and 2B, the first direction is a direction tilted vertically upward from the observer's eye with respect to the reference direction. The second direction is a direction tilted vertically downward from the observer's eye with respect to the reference direction. The first and second directions indicate specific directions that serve as boundaries when identifying a specific region, such as when the observer and the specific region are viewed from the side, as in Figure 2A.

[0027] The first angle is an acute angle formed between the reference direction and the first direction, and the second angle is an acute angle formed between the reference direction and the second direction.

[0028] The second angle may be 0° or 10°. In this case, the vertical width of the first region is greater than the vertical width of the second region. In this case, the first angle may be 35° or less.

[0029] Furthermore, when the second angle is 0°, the specific region is made up of a first region where the first angle is 35° or less, and a second region where the second angle is 0° is 0.

[0030] The specific region may also be a region in which the first angle is 35° or less, and the angle between the right direction from the observer's position toward the right edge of the specific region and the left direction from the observer's position toward the left edge of the specific region relative to a reference line from the observer is 180° or less. An angle of 180° or less between the right direction and the left direction means, for example, that the angle between the reference direction from the observer is 90° or less and the angle between the reference direction and the left direction is 90° or less, with the reference direction from the observer as the center. In particular, the specific region may have a first angle of 35° or less, an angle between the reference direction from the observer and the right direction from the observer's position toward the right edge of the specific region is 50° or less, and an angle between the reference direction from the observer and the left direction from the observer's position toward the left edge of the specific region is 50° or less. In these cases, the angles between the right direction and the left direction in the first region and the second region are equivalent.

[0031] As shown in Figures 2A and 2B, the right direction is a direction tilted to the right from the observer's eye relative to a reference direction. The left direction is a direction tilted to the left from the observer's eye relative to a reference direction. The right direction and the left direction indicate specific directions that serve as boundaries when identifying a specific region, such as when viewing the observer and the specific region from above, as shown in Figure 2B.

[0032] Furthermore, in the first region, the angle from the right direction from the observer's position toward the right edge of the specific region relative to the reference line to the left direction from the observer's position toward the left edge of the specific region may be larger than the angle from the right direction from the observer's position toward the right edge of the specific region to the left direction from the observer's position toward the left edge of the specific region in the second region. That is, the first region and the second region are set so that the angle between the right direction and the left direction in the first region is larger than the angle between the right direction and the left direction in the second region. For example, by setting the angle between the right direction and the left direction in the first region to 180° and setting the angle between the right direction and the left direction in the second region to 100°, the influence of luminance in the first region can be made larger than the influence of luminance in the second region.

[0033] Furthermore, the calculation unit 12 outputs the calculated brightness index of the space to the display unit 13. Note that the calculation unit 12 may also output the calculated luminance value to the display unit 13.

[0034] The display unit 13 displays the brightness index of the space calculated by the calculation unit 12. The display unit 13 may also display the calculated luminance value.

[0035] Furthermore, when the brightness of a space is specified, calculation unit 12 can calculate the luminous flux of lighting fixtures 15 and the arrangement of lighting fixtures 15 to satisfy the specified brightness of the space. For example, when the user specifies the brightness of a space, calculation unit 12 can calculate the luminous flux of lighting fixtures 15 and the arrangement of lighting fixtures 15 to satisfy the specified brightness of the space based on the size of the space input to input unit 11, the light reflectance in the space, and information about lighting fixtures to be installed in the space.

[0036] Storage unit 16 stores the computer program executed by calculation unit 12, the spatial brightness index calculated by calculation unit 12, and various control instructions required to output control signals to lighting fixtures 15. Storage unit 16 is specifically realized by a semiconductor memory or the like.

[0037] Illumination control unit 14 can use the brightness index calculation method to control lighting device 15 so that the brightness of the specified space satisfies a threshold value. In other words, illumination control unit 14 outputs a control signal to lighting device 15 to control lighting device 15 based on the brightness index of the space calculated by calculation unit 12 so that the specified threshold value is satisfied.

[0038] Lighting fixture 15 is installed in a space and can illuminate the indoor space. Lighting fixture 15 includes a plurality of LED (Light Emitting Diode) modules mounted on a board and a power supply unit. The power supply unit supplies power (current) to the plurality of LED modules to cause the LED modules to emit light based on a control signal output from lighting control unit 14.

[0039] Furthermore, lighting fixture 15 has a dimming function and a color-adjusting function. The dimming function is realized by a dimming circuit, and the color-adjusting function is realized by a color-adjusting circuit.

[0040] In this way, by calculating a spatial brightness index that estimates the brightness evaluation of the space, it is possible to reduce the discrepancy between the brightness of the space indicated by this spatial brightness index and the actual brightness of the space, even if an obstruction is present in the space.

[0041] <Verification results> Next, a method for calculating a space brightness index that estimates a space brightness evaluation will be described with reference to FIGS.

[0042] FIG. 3 is a diagram showing a space in which multiple luminaires 15 and multiple obstructions such as desks and people are installed to evaluate the brightness index of the space. In FIG. 3, the obstructing people are indicated by diagonal hatching. FIG. 4 is a diagram showing the coefficient of determination calculated according to the angle from the first direction to the second direction (the sum of the first angle and the second angle) starting from the first direction. Excluding the light source luminance in a specific area, FIG. 4 shows the values ​​obtained by multiplying the geometric mean luminance to the power of 0.7 by 1.5 for the cases with and without obstructions in the space, and for the cases where the space with and without obstructions is combined. The light source luminance in a specific area is the luminance of light emitted by a light source included in the specific area.

[0043] As shown in Figure 3, multiple desks and other obstructions were placed in the space, and multiple lighting fixtures 15 were placed on the ceiling of the space. The multiple lighting fixtures 15 included multiple recessed lighting fixtures 15 and multiple base lights. When the multiple lighting fixtures 15 illuminated the space, an observer evaluated the brightness index of the space in a specific area. The size of the space was 7.5 m length x 9.7 m width x 2.6 m height.

[0044] Excluding the light source luminance in a specific area, the value obtained by multiplying the geometric mean luminance to the power of 0.7 by 1.5 is 1.5×Lg 0.7 (Formula 1) It can be calculated based on the following.

[0045] Lg is the geometric mean luminance of the region in the induced visual field where the angle from the first direction to the second direction is 85° or less, and the angle from the right direction to the left direction is 100° or less. The angle from the first direction to the second direction of 85° or less is, for example, the sum of the first angle of 35° or less and the second angle of 50° or less, when the first direction is taken as the starting point. The geometric mean luminance is 1000 cd / m 2 The relative tendency in the coefficient of determination is not limited to the coefficients used in (Equation 1), so this is true not only for the geometric mean but also for the arithmetic mean.

[0046] In this case, as shown in FIG. 4, the coefficient of determination (R ) of the regression line was calculated for each of the sum of the first angle 35° and the second angle 50°, the sum of the first angle 35° and the second angle 40°, the sum of the first angle 35° and the second angle 30°, the sum of the first angle 35° and the second angle 20°, the sum of the first angle 35° and the second angle 10°, the sum of the first angle 35° and the second angle 0°, the sum of the first angle 25° and the second angle 0°, and the sum of the first angle 15° and the second angle 0°. 2 ) was calculated.

[0047] As described above, the coefficients of determination were calculated for the cases with and without an obstruction in the space, and for the cases with and without an obstruction in the space combined, as shown in (1) to (6) below. Note that, hereinafter, the angle from the first direction to the second direction will be simply referred to as the angle.

[0048] (1) When there is an obstruction in the space, the coefficient of determination when multiple lighting fixtures 15 arranged in the space are lit evenly and when multiple lighting fixtures 15 are lit unevenly combined is 0.51 when the first angle is the sum of 35° and the second angle is 50°, 0.56 when the first angle is the sum of 35° and the second angle is 40°, 0.59 when the first angle is the sum of 35° and the second angle is 30°, 0.61 when the first angle is the sum of 35° and the second angle is 20°, 0.64 when the first angle is the sum of 35° and the second angle is 10°, 0.67 when the first angle is the sum of 35° and the second angle is 0°, 0.66 when the first angle is the sum of 25° and the second angle is 0°, and 0.63 when the first angle is the sum of 15° and the second angle 0°.

[0049] (2) When there is an obstruction in the space, the coefficient of determination when multiple lighting fixtures 15 arranged in the space are uniformly lit is 0.73 when the sum of the first angle is 35° and the second angle is 50°, 0.73 when the sum of the first angle is 35° and the second angle is 40°, 0.73 when the sum of the first angle is 35° and the second angle is 30°, 0.72 when the sum of the first angle is 35° and the second angle is 20°, 0.72 when the sum of the first angle is 35° and the second angle is 10°, 0.71 when the sum of the first angle is 35° and the second angle is 0°, 0.71 when the sum of the first angle is 25° and the second angle is 0°, and 0.72 when the sum of the first angle is 15° and the second angle is 0°.

[0050] (3) When there are no obstructions in the space, the coefficient of determination when multiple lighting fixtures 15 arranged in the space are lit evenly and when multiple lighting fixtures 15 are lit unevenly combined is 0.63 when the first angle is the sum of 35° and the second angle is 50°, 0.67 when the first angle is the sum of 35° and the second angle is 40°, 0.70 when the first angle is the sum of 35° and the second angle is 30°, 0.72 when the first angle is the sum of 35° and the second angle is 20°, 0.72 when the first angle is the sum of 35° and the second angle is 10°, 0.72 when the first angle is the sum of 35° and the second angle is 0°, 0.72 when the first angle is the sum of 25° and the second angle is 0°, and 0.69 when the first angle is the sum of 15° and the second angle is 0°.

[0051] (4) When there are no obstructions in the space, the coefficient of determination when multiple lighting fixtures 15 arranged in the space are uniformly lit is 0.71 when the sum of the first angle is 35° and the second angle is 50°, 0.71 when the sum of the first angle is 35° and the second angle is 40°, 0.72 when the sum of the first angle is 35° and the second angle is 30°, 0.72 when the sum of the first angle is 35° and the second angle is 20°, 0.72 when the sum of the first angle is 35° and the second angle is 10°, 0.73 when the sum of the first angle is 35° and the second angle is 0°, 0.72 when the sum of the first angle is 25° and the second angle is 0°, and 0.72 when the sum of the first angle is 15° and the second angle is 0°.

[0052] (5) The coefficient of determination for the cases where there was an obstruction in the space and the cases where there was no obstruction in the space, and for the cases where multiple lighting fixtures 15 arranged in the space were lit evenly and the cases where multiple lighting fixtures 15 were lit unevenly, was 0.54 when the first angle was 35° and the second angle was 50°, 0.60 when the first angle was 35° and the second angle was 40°, 0.63 when the first angle was 35° and the second angle was 30°, 0.65 when the first angle was 35° and the second angle was 20°, 0.67 when the first angle was 35° and the second angle was 10°, 0.69 when the first angle was 35° and the second angle was 0°, 0.67 when the first angle was 25° and the second angle was 0°, and 0.65 when the first angle was 15° and the second angle was 0°.

[0053] (6) When multiple lighting fixtures 15 arranged in a space are uniformly lit, the coefficient of determination, combining the cases where there is an obstruction in the space and the cases where there is no obstruction in the space, is 0.73 when the sum of the first angle is 35° and the second angle is 50°, 0.74 when the sum of the first angle is 35° and the second angle is 40°, 0.74 when the sum of the first angle is 35° and the second angle is 30°, 0.74 when the sum of the first angle is 35° and the second angle is 20°, 0.74 when the sum of the first angle is 35° and the second angle is 10°, 0.74 when the sum of the first angle is 35° and the second angle is 0°, 0.73 when the sum of the first angle is 25° and the second angle is 0°, and 0.74 when the sum of the first angle is 15° and the second angle is 0°.

[0054] In the case of (1), the coefficient of determination is close to 0.7 when the sum of the first and second angles is 25° and 35°, and there is a correlation between the spatial brightness index and (Equation 1).

[0055] In the case of (2), the coefficient of determination was 0.7 or more in all cases, so there is a correlation between the spatial brightness index and (Equation 1).

[0056] In the case of (3), the coefficient of determination was 0.7 or more when the sum of the first angle and the second angle was between 25° and 65°, so there is a correlation between the brightness index of the space and (Equation 1).

[0057] In the case of (4), the coefficient of determination was 0.7 or more in all cases, so there is a correlation between the spatial brightness index and (Equation 1).

[0058] In the case of (5), the coefficient of determination is close to 0.7 when the sum of the first angle and the second angle is between 25° and 45°, and there is a correlation between the brightness index of the space and (Equation 1).

[0059] In the case of (6), the coefficient of determination was 0.7 or more in all cases, so there is a correlation between the spatial brightness index and (Equation 1).

[0060] From this, it was found that the sum of the first angle and the second angle of 25° and 35° was preferable.

[0061] In addition, evaluations were performed with only multiple recessed lighting fixtures 15 uniformly lit so that the illuminance on the desk surface of a desk placed in the space was 1000 lx, 750 lx, 600 lx, 500 lx, 300 lx, and 100 lx. Evaluations were also performed with only multiple base lights uniformly lit so that the illuminance on the desk surface of a desk placed in the space was 600 lx, 500 lx, 300 lx, and 100 lx. Evaluations were also performed with only recessed lighting fixtures 15 installed other than behind the observer lit unevenly, only recessed lighting fixtures 15 installed other than in front of the observer lit, only recessed lighting fixtures 15 installed other than to the right of the observer lit, and only recessed lighting fixtures 15 installed other than to the left of the observer lit, so that the illuminance on the desk surface of a desk placed in the space was 300 lx. The reference condition is a case where only the plurality of built-in lighting fixtures 15 are lit uniformly so that the illuminance on the desk surface of the desk placed in the space is 500 lx.

[0062] This evaluation was conducted on approximately several dozen subjects, both with and without obstructions in the space. The subjects rated the brightness of the space they perceived on a 13-point scale, with "very dark" being the lowest at 1, between "very dark" and "dark" at 2, "dark" at 3, between "dark" and "slightly dark" at 4, "slightly dark" at 5, between "slightly dark" and "neither" at 6, "neither" at 7, between "neither" and "slightly bright" at 8, "slightly bright" at 9, between "slightly bright" and "bright" at 10, "bright" at 11, between "bright" and "very bright" at 12, and "very bright" at the highest at 13.

[0063] When the subjects looked straight ahead without turning their heads, they evaluated the brightness of the space in a specific area, i.e., the illuminance on each desk surface when only the multiple built-in lighting fixtures 15 were turned on, the illuminance on each desk surface when only the multiple base lights were turned on, and the illuminance on each desk surface when the lighting position of the built-in lighting fixtures 15 was changed, as described above.

[0064] Thus, when the subjects evaluated the results, similar to those described above were obtained.

[0065] Therefore, in the specific region, it is preferable that the first angle be 35° or less and the second angle be 0° so that the luminance value of the first region is stronger than the luminance value of the second region.

[0066] <Effects, etc.> Next, a method for calculating a brightness index of a space according to the embodiment, and the effects of the lighting system 1 will be described.

[0067] As explained above, the method for calculating the brightness index of a space according to Technology 1 of this embodiment calculates the brightness index in a space using a calculation method in which the brightness value of a first region located above a reference plane including a reference line corresponding to a reference direction from the observer's position toward the specific region within the field of view of the observer present in the space is reflected in the brightness index more strongly than the brightness value of a second region located below the reference plane within the specific region.

[0068] According to this, since the brightness value of the first region is set to be larger than the brightness value of the second region, it is possible to minimize the difference between the brightness defined by the index and the actual brightness of the space due to obstructions placed in the space. Therefore, it is possible to reduce the influence of obstructions, and it is not necessary to input (consider) information about obstructions.

[0069] Therefore, according to this embodiment, the brightness index of a space can be easily calculated.

[0070] In particular, according to this embodiment, the brightness index of a space can be easily calculated, and therefore, it is effective not only for spaces with uniform brightness but also for spaces with non-uniform brightness (non-uniform spaces).

[0071] Furthermore, a method for calculating a spatial brightness index according to Technique 2 of the present embodiment is the method for calculating a spatial brightness index according to Technique 1. In this case, in the calculation method, the first region and the second region are set so that a first angle formed between a first direction from the position of the observer toward the upper end of the specific region and a reference direction is larger than a second angle formed between a second direction from the position of the observer toward the lower end of the specific region and the reference direction.

[0072] In this way, since the first angle is larger than the second angle, the brightness value of the first region can be made larger than the brightness value of the second region, and there is no need to input (consider) information about the obstruction, which makes it possible to easily calculate the brightness index of the space.

[0073] Furthermore, the method for calculating the spatial brightness index according to Technique 3 of the present embodiment is the method for calculating the spatial brightness index according to Technique 1. In this case, in the calculation method, the weight assigned to the brightness value of the first region is set to be greater than the weight assigned to the brightness value of the second region.

[0074] In this way, the weight of the brightness value of the first region is greater than the weight of the brightness value of the second region, so the brightness value of the first region can be made greater than the brightness value of the second region, and there is no need to input (consider) information about obstructions, which makes it easy to calculate the brightness index of the space.

[0075] Furthermore, the method for calculating the spatial brightness index according to Technique 4 of the present embodiment is the method for calculating the spatial brightness index according to Technique 2. In this case, in the first region, the angle from the right direction from the observer's position relative to the reference line toward the right edge of the specific region to the left direction from the observer's position toward the left edge of the specific region is larger than the angle from the right direction from the observer's position relative to the reference line toward the left direction from the observer's position toward the left edge of the specific region in the second region.

[0076] In this case, the brightness value of the first region can be made greater than the brightness value of the second region, and there is no need to input (consider) information about the obstruction, making it possible to easily calculate the brightness index of the space.

[0077] Furthermore, the method for calculating the spatial brightness index of Technique 5 according to the present embodiment is the method for calculating the spatial brightness index described in Technique 3. In this case as well, the same effects as those of Technique 4 described above are achieved.

[0078] Furthermore, the method for calculating the spatial brightness index of Technique 6 according to the present embodiment is the method for calculating the spatial brightness index according to Technique 2 or 4. In this case, the second angle is 10°.

[0079] This allows the first angle in the first direction to be larger than the second angle in the second direction. For example, in the case of (1) above, the coefficient of determination was 0.63 or higher, so it is expected that the influence of obstructions will be suppressed. This eliminates the need to input (consider) information about obstructions, making it possible to easily calculate the brightness index of the space.

[0080] Furthermore, the method for calculating the spatial brightness index of Technique 7 according to the present embodiment is the method for calculating the spatial brightness index according to Technique 2 or 4. In this case, the second angle is 0°.

[0081] This allows the specific area to be limited to the first area. For example, in the case of (1) above, when the first angle is 35°, the coefficient of determination is 0.67, so it is expected that the influence of occlusions will be suppressed. This means that there is no need to input (consider) information about occlusions, and the brightness index of the space can be easily calculated.

[0082] Furthermore, the method for calculating the spatial brightness index according to Technique 8 of the present embodiment is the method for calculating the spatial brightness index according to Technique 4. In this case, the first angle is 35° or less, and the angle between the right direction from the observer's position toward the right end of the specific area and the left direction from the observer's position toward the left end of the specific area relative to the reference line is 180° or less.

[0083] According to this, for example, in the case of (1) above, when the first angle is 35°, the coefficient of determination is 0.67 or more, so it is expected that the influence of the obstruction will be suppressed. Also, since it is expected that the user will usually turn their head left and right, it is expected that the influence of the obstruction will be suppressed even when the angle from right to left is 180° or less. Therefore, it is not necessary to input (consider) information about the obstruction, and the brightness index of the space can be easily calculated.

[0084] Furthermore, a method for calculating a spatial brightness index according to Technique 9 of the present embodiment is the method for calculating a spatial brightness index according to Technique 4. In this case, the first angle is 35° or less, the angle between the reference direction and the right direction from the observer's position toward the right end of the specific area is 50° or less, and the angle between the reference direction and the left direction from the observer's position toward the left end of the specific area is 50° or less.

[0085] According to this, for example, in the case of (1) above, when the first angle is 35°, the coefficient of determination is 0.67 or more, so it is expected that the influence of the obstruction will be suppressed. Also, since it is expected that the user will usually turn their head left and right, it is expected that the influence of the obstruction will be suppressed even when the angle between the right direction and the reference direction is 50° or less, and when the angle between the left direction and the reference direction is 50° or less. Therefore, it is not necessary to input (consider) information about the obstruction, and the brightness index of the space can be easily calculated.

[0086] Furthermore, a method for calculating a spatial brightness index according to Technique 10 of the present embodiment is the method for calculating a spatial brightness index according to any one of Techniques 1 to 9. In this case, the calculation method involves taking the geometric mean or arithmetic mean of the luminance values ​​of the first region and the luminance values ​​of the second region, respectively.

[0087] This makes it possible to easily obtain the luminance value of a specific region.

[0088] Furthermore, a method for calculating a spatial brightness index according to Technique 11 of the present embodiment is the method for calculating a spatial brightness index according to Technique 10. In this case, the brightness index is an index based on a value obtained by multiplying the geometric mean raised to the power of 0.7 by 1.5.

[0089] This makes it possible to easily calculate the brightness index.

[0090] Furthermore, a method for calculating a brightness index of a space according to Technique 12 of the present embodiment is the method for calculating a brightness index of a space according to any one of Techniques 1 to 11. In this case, the reference direction is the line of sight of an observer in a sitting position looking along the horizontal direction, and the reference line and reference plane are located approximately 1200 mm from the ground surface that forms the space.

[0091] This makes it possible to apply the system to a general office environment.

[0092] Furthermore, the method for calculating a spatial brightness index according to Technique 13 of the present embodiment is the method for calculating a spatial brightness index according to any one of Techniques 1 to 12. In this case, the luminance value is calculated by simulation.

[0093] This makes it possible to apply the lighting environment to a general office environment.

[0094] Furthermore, the method for calculating a spatial brightness index according to Technology 14 of this embodiment is the method for calculating a spatial brightness index according to Technology 13, which further includes inputting the size of the space, the reflectance of light in the space, and information on lighting devices to be installed in the space into an input unit 11, calculating a luminance value of a specific region by a simulation using the input size of the space, the reflectance, and the information on lighting devices, by a calculation unit 12, and displaying the index calculated by the calculation unit 12 by a display unit 13.

[0095] This allows the luminance value of a specific area in space to be calculated with high accuracy, which in turn allows the installation position of lighting fixture 15 to be optimized.

[0096] Furthermore, a method for calculating a spatial brightness index according to Technique 15 of the present embodiment is the method for calculating a spatial brightness index according to Technique 14. In this case, the calculation unit 12 calculates the brightness value of a specific region based on a spatial brightness distribution image including the size, reflectance, and lighting fixture information of the space.

[0097] This allows the luminance value of a specific area in space to be calculated with high accuracy based on the luminance distribution image, making it possible to easily calculate the luminance value.

[0098] Furthermore, the method for calculating a spatial brightness index of Technique 16 according to the present embodiment is a method for calculating a spatial brightness index according to any one of Techniques 1 to 15, which further includes specifying the brightness of the space based on the calculated index, and determining the luminous flux of lighting devices 15 and the arrangement of lighting devices 15 to satisfy the specified brightness of the space.

[0099] According to this, by specifying the brightness index of a space, the space can be set to a desired brightness, and therefore the brightness of the space can be easily set. Therefore, the method of calculating the brightness index of a space is highly convenient.

[0100] Furthermore, the lighting system 1 of Technology 17 according to this embodiment includes a lighting control unit 14 that controls the lighting fixtures 15 so that the specified brightness of the space satisfies a threshold value using the method for calculating the brightness index of the space described in Technology 16.

[0101] This allows the desired brightness of the space to be achieved by controlling lighting fixtures 15 so that they match the brightness index of the specified space. This makes it easy to set the brightness of the space, and is highly convenient.

[0102] (Other embodiments) Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments.

[0103] For example, in the above-described embodiments, each component may be realized by executing a software program suitable for that component, or by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0104] Furthermore, each component may be realized by hardware. Each component may be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or each may be a separate circuit. Furthermore, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0105] Furthermore, the general or specific aspects of the above-described embodiments may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0106] Furthermore, the above-described embodiment may be realized as a method for calculating a spatial brightness index executed by a computer, or as a program for causing a computer to execute the method for calculating a spatial brightness index, or as a computer-readable non-transitory recording medium on which such a program is recorded.

[0107] In addition, this disclosure also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art would think of, or forms realized by arbitrarily combining the components and functions of the embodiments within the scope that does not deviate from the intent of this disclosure. [Explanation of symbols]

[0108] 1. Lighting system 11 Input section 12 Calculation section 13 Display section 14 Lighting control unit

Claims

1. The brightness index in the space is calculated using a calculation method in which the brightness value of a first region located above a reference plane including a reference line corresponding to a reference direction from the position of the observer toward the specific region, among the specific regions in the field of view of the observer present in the space, is reflected in the brightness index more strongly than the brightness value of a second region located below the reference plane among the specific regions. How to calculate the spatial brightness index.

2. In the calculation method, the first area and the second area are set so that a first angle formed between a first direction from the position of the observer toward an upper end of the specific area and the reference direction is larger than a second angle formed between a second direction from the position of the observer toward a lower end of the specific area and the reference direction. The method for calculating a spatial brightness index according to claim 1 .

3. In the calculation method, a weight for the luminance value of the first region is set to be greater than a weight for the luminance value of the second region. The method for calculating a spatial brightness index according to claim 1 .

4. In the first area, an angle from a right direction from the position of the observer relative to the reference line toward the right end of the specific area to a left direction from the position of the observer relative to the reference line toward the left end of the specific area is larger than an angle in the second area from a right direction from the position of the observer relative to the reference line toward the right end of the specific area to a left direction from the position of the observer relative to the reference line toward the left end of the specific area. The method for calculating a spatial brightness index according to claim 2 .

5. In the first area, an angle from a right direction from the position of the observer relative to the reference line toward the right end of the specific area to a left direction from the position of the observer relative to the reference line toward the left end of the specific area is larger than an angle in the second area from a right direction from the position of the observer relative to the reference line toward the right end of the specific area to a left direction from the position of the observer relative to the reference line toward the left end of the specific area. The method for calculating a spatial brightness index according to claim 3 .

6. The second angle is 10 degrees. The method for calculating a spatial brightness index according to claim 2 or 4.

7. The second angle is 0°. The method for calculating a spatial brightness index according to claim 2 or 4.

8. the first angle is less than or equal to 35°; The angle formed by the right direction from the position of the observer toward the right end of the specific area and the left direction from the position of the observer toward the left end of the specific area with respect to the reference line is 180° or less. The method for calculating a spatial brightness index according to claim 4.

9. the first angle is less than or equal to 35°; an angle formed by the reference direction and the right direction from the position of the observer toward the right end of the specific area is 50° or less; The angle between the reference direction and the left direction from the position of the observer toward the left end of the specific area is 50° or less. The method for calculating a spatial brightness index according to claim 4.

10. In the calculation method, a geometric mean or an arithmetic mean is calculated for each of the luminance values ​​of the first region and the luminance values ​​of the second region. The method for calculating a spatial brightness index according to any one of claims 1 to 5.

11. The brightness index is based on the value obtained by multiplying the geometric mean of the brightness values ​​to the power of 0.7 by 1.

5. The method for calculating a spatial brightness index according to claim 10.

12. the reference direction is a line of sight direction when the observer is in a sitting position and looks along a horizontal direction, The reference line and the reference plane are located approximately 1200 mm from the ground surface that forms the space. The method for calculating a spatial brightness index according to any one of claims 1 to 5.

13. The brightness value is calculated by simulation. The method for calculating a spatial brightness index according to any one of claims 1 to 5.

14. The size of the space, the reflectance of light in the space, and information about lighting fixtures to be installed in the space are input to an input unit; a calculation unit calculating the luminance value of the specific area by the simulation using the input size of the space, the reflectance, and the lighting device information; The method further includes displaying the index calculated by the calculation unit by a display unit. The method for calculating a spatial brightness index according to claim 13.

15. The calculation unit calculates the luminance value based on a luminance distribution image of the space including the size of the space, the reflectance, and the lighting device information. The method for calculating a spatial brightness index according to claim 14.

16. Specifying the brightness of the space based on the calculated brightness index; and determining the luminous flux of lighting fixtures and the placement of the lighting fixtures to satisfy the brightness of the specified space. The method for calculating a spatial brightness index according to any one of claims 1 to 5.

17. a lighting control unit that controls the lighting devices so that the brightness of the designated space satisfies a threshold value by using the space brightness index calculation method of claim 16; Lighting system.

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