Lighting control system

Abstract

To provide a lighting control system that can be operated in a room equipped with a window that actually allows light to pass through. [Solution] The lighting control system (1) is installed in a room that has a light-transmitting window. The lighting control system (1) comprises a lighting fixture (20) placed in the room, a color temperature control means (31) that controls the color temperature of the lighting fixture (20) on an hourly basis, a daylight control means (32) that controls the brightness of the lighting fixture (20), and a storage means (33) that stores the color temperature for each time period corresponding to the orientation of the window.

Description

Technical Field

[0001] The present invention relates to a lighting control system, and more particularly to a lighting control system for a room provided with a translucent window.

Background Art

[0002] In a general lighting control system, for example, "daylight control" that automatically controls the brightness of lighting fixtures according to the amount of daylight incident from a window into a room, and "circadian control" that controls the brightness and color temperature of lighting fixtures according to time in consideration of the circadian rhythm are known.

[0003] As a lighting control system that combines such daylight control and circadian control, for example, Japanese Patent Application Laid-Open No. 2011-23339 (Patent Document 1) is known. The lighting system of Patent Document 1 includes a control device in which changes in illuminance according to the time of day, responses to human physiological phenomena, and changes in temperature and color temperature according to seasons are programmed in advance in order to enable control according to the human life rhythm.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventionally, a lighting system that combines daylight control and circadian control, as in Patent Document 1 above, is known. However, although the lighting system of Patent Document 1 takes into account illuminance and color temperature according to seasons and time of day, further consideration is required for practical operation in a building.

[0006] The present invention was made to solve the above-mentioned problems, and its objective is to provide a lighting control system that can be operated in a room actually equipped with a light-transmitting window. [Means for solving the problem]

[0007] A lighting control system according to one aspect of this invention is a lighting control system installed in a room with a light-transmitting window, comprising: a lighting fixture arranged in the room; a color temperature control means for controlling the color temperature of the lighting fixture on an hourly basis; a daylight control means for controlling the brightness of the lighting fixture; and a storage means for storing the color temperature for each time period corresponding to the orientation of the window.

[0008] Preferably, the lighting control system further includes a luminance sensor for detecting the illuminance near the window.

[0009] Preferably, the memory means stores the color temperature for sunny conditions and the color temperature for cloudy conditions, and the color temperature control means selects an appropriate color temperature in sunny conditions according to the illuminance near the window due to sunlight.

[0010] Preferably, the storage means stores the design color temperature without considering the color temperature due to illuminance near the window caused by sunlight. [Effects of the Invention]

[0011] The lighting control system of the present invention can be operated in a room that actually has a light-transmitting window. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic plan view showing the general configuration of a lighting control system according to an embodiment of the present invention. [Figure 2] This is a schematic vertical cross-sectional view showing the general configuration of a lighting control system according to an embodiment of the present invention, where (A) is the state before control and (B) is the state after control. [Figure 3]This is a block diagram showing the functional configuration of a lighting control system according to an embodiment of the present invention. [Figure 4] This is an example of the data structure for design illuminance and design color temperature stored in a memory device. [Figure 5] This is an example of a data structure for color temperature in sunny and cloudy conditions, stored in a memory device. [Figure 6] This flowchart shows a lighting control system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0014] (Schematic configuration) Figures 1, 2(A), and 2(B) schematically show the general configuration of the lighting control system 1 according to this embodiment; Figure 1 is a plan view, and Figures 2(A) and 2(B) are longitudinal cross-sectional views.

[0015] The lighting control system 1 controls multiple lighting fixtures 20 installed on the ceiling of room 11. Room 11 is, for example, a room in an office building, and multiple desks are installed inside room 11.

[0016] In particular, as shown in Figure 1, the room 11 is roughly rectangular (rectangular or square) in plan view, and a light-transmitting window 12 is provided in one of the walls 13-16 surrounding the room 11, for example, wall 13. In this embodiment, the wall on which the window 12 is provided is called the outer wall 13, and the wall 14 facing the outer wall 13 is called the opposing wall. Also, the pair of walls 15 and 16 that intersect (are perpendicular to) the outer wall 13 are called side walls. The opposing wall 14 and the side walls 15 and 16 are either outer walls or partition walls.

[0017] The window 12 is provided in a wide range leaving both end portions in the vertical width direction of the outer wall 13. Further, as shown in FIGS. (A) and 2(B), the upper end of the window 12 is located near the height of the ceiling. The window 12 has translucency, and specifically, solar radiation can be taken into the room. Although not shown, when it is desired to block the solar radiation from the window 12, a shielding member (blind) capable of covering the entire indoor surface of the window 12 may be provided on the indoor side of the window 12.

[0018] As shown in FIG. 1, in the present embodiment, the window 12 is arranged facing one side (one direction) of the room 11, but it may be provided on two sides (two directions) or more. However, when the window 12 is provided on two sides or more, it is preferable that it is arranged facing only one side because the interior of the room becomes too bright due to solar radiation.

[0019] In a plan view, the plurality of lighting fixtures 20a to 20d are arranged in alignment, for example, at a pitch of about 2 m along the lateral width direction (hereinafter referred to as the "X direction") of the side walls 15 and 16 and the vertical width direction (hereinafter referred to as the "Y direction") of the outer wall 13 and the facing wall 14. Note that at least a plurality of lighting fixtures 20 may be provided along the X direction. The shape of the lighting fixture 20 is not limited to the rectangular shape having a length in the Y direction as shown in the drawing. Further, the number of the lighting fixtures 20a to 20d may be increased or decreased according to the size of the room 11 or the like.

[0020] In the following description, when it is necessary to distinguish the lighting fixtures 20a to 20d, the lighting fixtures 20 near the window 12 (near the window 12) are referred to as the lighting fixtures 20a and 20b at the window edge, and the lighting fixtures 20 outside the window edge (on the indoor side) are referred to as the lighting fixtures 20c and 20d on the indoor side. Note that the vicinity of the window means the window edge, for example, up to a location about 5 m away from the window 12.

[0021] As shown in FIG. 1, a luminance sensor 40 is arranged between the lighting fixtures 20. The luminance sensor 40 is arranged facing downward (the upper surface of the desk). The luminance sensor 40 detects the amount of light in the installed vicinity, and senses the four lighting fixtures 20 located in its four directions with one luminance sensor 40.

[0022] Furthermore, the placement of the brightness sensors 40 is not limited; they may be placed between each of the lighting fixtures 20 located at a distance in the vertical direction (for example, sensing two lighting fixtures 20). The placement and number of sensors are not limited, but they should at least detect the illuminance near the window 12.

[0023] (Functional Configuration) Figure 3 is a block diagram showing the functional configuration of the lighting control system 1. The lighting control system 1 includes a control device 30 electrically connected to a plurality of lighting fixtures 20 and a plurality of luminance sensors 40. The control device 30 is implemented by a processor such as a CPU (Central Processing Unit). The control device 30 includes a color temperature control means 31, a daylight control means 32, and a storage means 33.

[0024] The color temperature control means 31 controls the color temperature of the lighting fixture 20 on an hourly basis. Preferably, the indoor color temperature is set to 2500K to 7000K, which approximates sunlight. By setting such a value, work efficiency can be improved even in an indoor environment, and lighting that is less strenuous on the body can be achieved. The color temperature control means 31 is intended to realize so-called "circadian control."

[0025] In this embodiment, the color temperature control means 31 controls the color temperature to be in the range of 3500K to 6000K, as shown in Figure 4. Specifically, it is at a maximum of 6000K until noon, and after 2 PM, it gradually decreases by 500K every hour, to 5000K, 4500K, and so on. The design color temperature is the ideal color temperature, for example, the color temperature when sunlight does not reach the room through the window 12, such as when blinds are blocked and sunlight does not reach the room, or when it is cloudy. Note that the design color temperature shown in Figure 4 is just one example, and various design color temperatures can be adopted depending on the season, month, latitude, etc.

[0026] Furthermore, the color temperature control means 31 selects an appropriate color temperature in sunny conditions according to the illuminance near the window 12 due to sunlight. Specifically, the color temperature control means 31 outputs the color temperature for cloudy conditions if the ratio of the illuminance near the window 12 due to sunlight to the design illuminance is less than or equal to a predetermined ratio, and outputs the color temperature for sunny conditions if it exceeds the predetermined ratio. The color temperatures for cloudy and sunny conditions will be described later.

[0027] The daylight control means 32 controls the brightness of the lighting fixture 20. Similar to the color temperature control means 31, the daylight control means 32 controls the brightness of the lighting fixture 20 on an hourly basis. In particular, near windows, the illuminance is high due to sunlight, so the illuminance of the lighting fixture 20 near windows can be reduced compared to lighting fixtures 20 located elsewhere. On the other hand, in order to achieve the circadian control described above, it is necessary to make it bright (high illuminance) in the morning and gradually dim (low illuminance) as evening approaches.

[0028] Therefore, in this embodiment, as shown in Figure 4, the daylight control means 32 controls the daylight to a maximum of 750 lx until 2 PM, and then gradually decreases to 600 lx, 550 lx, and 500 lx every hour thereafter. The design illuminance is the illuminance set for each time period and is set for each lighting fixture 20. The design illuminance shown in Figure 4 is merely an example, and various design illuminances can be adopted depending on the season, month, latitude, etc.

[0029] The storage means 33 stores the color temperature for each time period corresponding to the orientation of the window 12. The storage means 33 is composed of non-volatile memory. The storage means 33 stores an example of the data structure near the window shown in Figure 5. Figure 5 shows the hourly color temperature near the window for sunny and cloudy days, and in particular for sunny days, the color temperature for each of the four orientations, such as the east, south, west, and north sides, is listed.

[0030] Furthermore, the storage means 33 may also store the design illuminance and design color temperature from Figure 4, in addition to the color temperature near the window shown in Figure 5. The design color temperature in Figure 4 is the color temperature that does not take sunlight into consideration, and is therefore the color temperature of lighting fixtures 20c and 20d that illuminate areas other than near the window.

[0031] Here, the area near the window is the region that is affected by sunlight during the time of day when there is sunlight, and the area outside the window is the region that is not significantly affected by sunlight, even during the time of day when there is sunlight. In this embodiment, the area near the window is the region illuminated by lighting fixtures 20a and 20b, and the area outside the window is the region illuminated by lighting fixtures 20c and 20d.

[0032] (An example of lighting control) Figures 2(A) and 2(B) are explanatory diagrams showing specific examples of lighting control in room 11. Before describing the operation of the lighting control system 1 of this embodiment, specific examples of lighting control will be explained with reference to Figures 2(A) and 2(B). Figure 2(A) shows the state of room 11 before lighting control, and Figure 2(B) shows the state of room 11 after lighting control.

[0033] The environment of room 11 shown in Figure 2(A) is, for example, sunny weather, a window facing west, and a time of 9 o'clock. Therefore, the lighting control system 1 is set to west for the window direction and 9 o'clock for the time.

[0034] Next, a switch is used to select one of three modes: "No Daylight," "Cloudy," and "Sunny." In "No Daylight" mode, the daylight control means 32 does not operate, and only the color temperature control means 31 operates. In "Cloudy" and "Sunny" modes, both the daylight control means 32 and the color temperature control means 31 operate. Since the weather is "Sunny" in this case, the switch is turned to "Sunny" mode. This mode switching can be done manually each time the weather changes, automatically each time the weather changes by detecting the presence or absence of sunlight using the brightness sensor 40, or automatically every hour.

[0035] As shown in Figure 2(A), the color temperature of all lighting fixtures 20 is 6000K, while the color temperature of sunlight (natural light) is 8000K. Since the area near the window is affected by sunlight, the color temperature of the area illuminated by lighting fixture 20a closest to window 12 is 6500K, which is higher than the color temperature of lighting fixture 20a alone (6000K). The illuminance of all lighting fixtures 20 is 750lx.

[0036] The areas illuminated by lighting fixtures 20b and 20c, which are located more indoors than lighting fixture 20a, are also affected by solar radiation. Therefore, the color temperature of the areas illuminated by lighting fixtures 20b and 20c becomes 6200K, which is higher than the color temperature of lighting fixture 20a alone (6000K). The area illuminated by lighting fixture 20d, which is located furthest indoors, is hardly affected by solar radiation, so its color temperature remains the same as that of lighting fixture 20d, at 6000K.

[0037] As described above, the area near the window is affected by sunlight, causing its color temperature to deviate significantly from the design color temperature. Therefore, by reducing the output of the color temperature of the lighting fixtures 20a and 20b that illuminate the area near the window, the color temperature of the area near the window is brought closer to the design color temperature.

[0038] Specifically, as shown in Figure 2(B), the color temperature of lighting fixture 20a illuminating the window area is set to 5000K, and the color temperature of lighting fixture 20b is set to 5500K. This brings the color temperature illuminating the window area closer to the 6000K design color temperature at 9 o'clock, as shown in Figure 4.

[0039] (Operation of the lighting control system) Figure 6 is a flowchart showing a lighting control system 1 according to an embodiment of the present invention. The operation of the lighting control system 1 will be explained with reference to Figure 6. The flowchart shown in Figure 6 shows the operation of lighting fixtures 20a and 20b near the window.

[0040] As shown in Figure 6, first, the illuminance due to sunlight at that time is determined from the color temperature and design illuminance of the lighting fixture 20 (step S10). Next, the ratio of illuminance due to daylight to the design illuminance is calculated. If the ratio of illuminance due to daylight to the design illuminance is 25% or less (yes in step S12), the influence of sunlight near the window is small, so the output is "cloudy color temperature". If, after the above calculation, the ratio of illuminance due to daylight to the design illuminance is greater than 25% (no in step S12), the influence of sunlight near the window is large, so the output is "color temperature according to direction". "Color temperature according to direction" is for sunny days. Both "cloudy color temperature" and "color temperature according to direction" are output based on the example data structure for the window shown in Figure 5.

[0041] In the flowchart in Figure 6, it is shown that if the ratio of daylight illumination to the design illumination is 25% or less, the output will be set to the "cloudy" color temperature, and if it is greater than 25%, the output will be set to the "sunny" color temperature. However, 25% is merely an example, and the ratio of daylight illumination to the design illumination can be appropriately selected depending on various situations.

[0042] Furthermore, for lighting fixtures 20c and 20d other than those near windows, it is preferable to set them to the design color temperature shown in Figure 4, as they are less affected by sunlight. By doing so, it is possible to reduce the color temperature near windows, which are heavily affected by sunlight, while keeping the color temperature at the design color temperature in areas not affected by sunlight, thereby reducing the deviation from the design color temperature.

[0043] The lighting control system 1 of this embodiment includes a color temperature control means 31 that controls the color temperature for each time period, a daylight control means 32 that controls the brightness of the lighting fixture 20, and a storage means 33 that stores the color temperature for each time period corresponding to the orientation of the window 12. A room 11 with a translucent window 12 is affected by sunlight, except in cases such as cloudy days, when it is completely shielded by blinds, for example. Furthermore, because the sun is set in the south, the effect of sunlight on the area near the window differs depending on the orientation of the window 12. In this embodiment, since the storage means 33 stores the color temperature corresponding to the orientation of the window 12, it can actually be used in a room 11 with a translucent window 12.

[0044] In this embodiment, the lighting control system 1 was described as selecting three modes, "no daylight," "cloudy," and "sunny," using a switch. However, it may also be a system that selects two modes, "daylight enabled" and "no daylight."

[0045] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0046] 1 Lighting control system, 11 Rooms, 12 Windows, 13-16 Walls, 20 Lighting fixtures, 30 Control devices, 31 Color temperature control means, 32 Daylight control means, 33 Memory means, 40 Brightness sensors.

Claims

1. A lighting control system installed in a room with a light-transmitting window, The lighting fixtures arranged in the aforementioned room, A color temperature control means for controlling the color temperature of the lighting fixture on an hourly basis, A daylight control means for controlling the brightness of the aforementioned lighting fixture, A lighting control system comprising a storage means for storing color temperatures for each time period corresponding to the orientation of the aforementioned window.

2. The lighting control system according to claim 1, further comprising a luminance sensor for detecting the illuminance near the window.

3. The aforementioned storage means stores the color temperature for sunny conditions and the color temperature for cloudy conditions. The lighting control system according to claim 1, wherein the color temperature control means selects an appropriate color temperature in the case of sunny weather, according to the illuminance near the window due to sunlight.

4. The lighting control system according to claim 1 or 2, wherein the storage means stores a design color temperature that does not take into account the color temperature near the window due to solar radiation.

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