JPH11251073A - Light modulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light modulating device that can keep the illuminance in a room constant even if natural light varies and can restrain the illuminance from varying for a while due to the movement of a human, thing or the like, in the light modulating device to modulate composite light composed of natural light and artificial illumination. SOLUTION: An external light sensor 10 to measure the illuminance intensity of natural light and interior light sensors 11 to measure the illuminance intensity of composite light composed of natural light and artificial illumination are installed. When the exterior illuminance changes and the output of the external light sensor 10 thereby changes, a light modulating device 20 responds immediately to it by regulating the luminance of artificial illumination and thereby keeping the illuminance inside a building constant. It does not respond to a temporary change of the output of the interior light sensors 11, but it works when the variation of the output of the interior light sensors 11 continues for a period not less than a predetermined time, and keeps the illuminance inside the building constant by regulating the luminance of the artificial illumination. When the output of the interior light sensors 11 varies, the luminance of the artificial illumination may be regulated in such a manner that the interior illuminance reaches a target value by taking a predetermined time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimming device for dimming combined light of natural light and artificial lighting, and more particularly to an optical duct device for guiding natural light into a building through a duct and illuminating the inside of the building. The present invention relates to a light control device suitable for application to a lighting device including artificial lighting.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for reduction of carbon dioxide emission and energy saving. In order to respond to the above demand, there has been proposed an optical duct device that guides natural light into a building through a duct and illuminates the inside of the building. The light duct device captures natural light outside the building (hereinafter, referred to as outside light) from a lighting port, and guides the natural light to the inside of the building through a duct having a high internal surface reflectance.
Since light energy is used without being converted to other energy, it is efficient, and can contribute to energy saving and reduction of carbon dioxide emission.

[0003] However, the illumination of only external light is greatly influenced by the weather and the like. In view of the above, there has been proposed a lighting device that combines lighting by the light duct device and artificial lighting by a fluorescent lamp or the like. That is, a sensor that detects the illuminance while installing artificial lighting inside the building is provided, and the sensor detects the illuminance of the combined light of the external light and the artificial illumination light supplied from the light duct device, and the illuminance is a predetermined value. By performing feedback control of the artificial lighting so as to obtain a value, the interior of the building is dimmed.

[0004]

When an illumination device combining the above-described light duct device and artificial illumination was experimentally manufactured, it became clear that the following problems occurred. The brightness of natural light is strongly affected by weather, cloud conditions, and the like, and the brightness fluctuates rapidly. For this reason, in order to control the composite light of the natural light and the artificial illumination light, it is necessary to make the response characteristics of the light control device sufficiently fast so as to be able to quickly respond to the fluctuation of the natural light. On the other hand, inside a building, there are many movements of people and things, and the light incident on the sensor fluctuates accordingly.
If the dimmer responds quickly to this change, the brightness of the room will temporarily fluctuate (flicker) due to the movement of people and objects,
I feel annoying.

For example, when a person wearing high-brightness colored clothes such as white passes near the sensor or a white object passes near the sensor, the illuminance of light incident on the sensor temporarily increases. This change in illuminance is a short-time change near the sensor, and it is not preferable to affect the light control of the whole room. However, if the light control device responds quickly to this, the room temporarily becomes dark. In other words, in the dimming of a lighting device that combines external light and artificial lighting, if a quick response is made to the fluctuation of natural light, the dimming device responds to the temporary fluctuation of sensor input in a room due to the movement of people and objects. In response, there is a problem that the brightness temporarily fluctuates (flickers) and the user feels troublesome. The present invention has been made in consideration of the above circumstances, and can always keep the brightness inside a building constant even when the brightness of external light fluctuates. An object of the present invention is to provide a light control device that is not affected by a temporary fluctuation of a sensor input due to a movement of an object.

[0006]

According to the present invention, a first sensor for detecting external light and a second sensor for detecting a composite light of external light and artificial illumination light are provided in the present invention. The illuminance of artificial lighting is controlled as follows. (1) When the output of the first sensor fluctuates, the illuminance of the artificial lighting is adjusted by immediately responding to the output of the first sensor, and the fluctuation of the output of the second sensor has continued for a predetermined time or more. At this time, the illuminance of the artificial lighting is adjusted. (2) When the output of the first sensor fluctuates, the illuminance of the artificial lighting is adjusted by immediately responding to the output of the first sensor, and when the output of the second sensor fluctuates, the second The illuminance of the artificial lighting is adjusted such that the illuminance detected by the sensor reaches the target value over a predetermined time. By performing the control as described above, it is not affected by the temporary fluctuation of the sensor input due to the movement of people and objects inside the building, and immediately responds to the fluctuation of the brightness of the external light. Brightness can be kept constant.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described for the case where the present invention is applied to a lighting device including a light duct device and artificial lighting. 8 and 9 are schematic configuration diagrams of an optical duct device to which the present invention is applied. FIG. 8 shows a horizontal light duct device applied to an office or the like, FIG. 9 shows a vertical light duct device applied to an underground parking lot or the like, and FIG.
(B) is a perspective view of the duct viewed from the direction A in FIG.
FIG. 9 is a sectional configuration diagram of the vertical duct device.

8 and 9, 1 is an external light (sunlight), 2 is a daylighting opening, 3 is a reflection plate, 4 is a duct, 5 is an outer wall of a building, 6 is a room, 7 is glass, and 8 is a fluorescent lamp. Artificial lighting 9 and the like is the ground surface. As shown in FIG. 8B, the duct 4 is formed of a cylindrical body having a substantially rectangular cross section, and a light emitting port 4a is provided below the tubular body. Further, the inside of the duct 4 is formed of a member having a high reflectivity, and external light entering through the glass 7 enters the duct 4 from the lighting port 2 (a part of the external light is reflected by the reflecting plate 3). Then, the light is reflected from the inside of the duct 4 to reach the light emitting port 4a, and is radiated from the light emitting port 4a into the room 6. Further, an artificial lighting device composed of a fluorescent lamp 8 is attached to the light emission port 4a.

FIG. 10 is a detailed view of the installation of the artificial lighting device in the light duct device. FIG. 10 (a) is an overall view of the duct, and FIG. 10 (b) is a cross section taken along line XX 'of FIG. FIG. As shown in FIG. 10, the inner surface of the duct 4 is formed of a specular reflection plate 12,
A is provided with a dust-proof acrylic cover 13. A milky white acrylic board 15 is provided in an opening provided at a position corresponding to the light emission port 4a of the ceiling board 14. A fluorescent lamp fixture 8 ′ is attached to the space between the mirror reflector 12 of the duct 4 and the ceiling board 14, and the fluorescent lamp 8 attached to the fluorescent lamp fixture 8 ′ projects above the acrylic board 15. The light of the fluorescent lamp 8 is radiated into the room through the acrylic board 15. The room is n
The plurality of fluorescent lamps installed in the room are divided into groups 1 to n corresponding to the above-mentioned areas. Further, as described later, n indoor light sensors for detecting brightness are mounted in the room, and the fluorescent lamp outputs the output of the n indoor light sensors and the output of the external light sensor described later. The light is adjusted for each group based on the light intensity.

FIG. 1 is a diagram showing the overall configuration of a light control device according to an embodiment of the present invention. In the figure, reference numeral 10 denotes an external light sensor for detecting the illuminance of light introduced into the light duct device, and reference numeral 11 denotes room light for detecting a composite light of light emitted from the light duct device and light emitted from the fluorescent lamp 8. The output of the external light sensor 10 and the output of the indoor light sensor 11 are amplified by an amplifier 21 and supplied to a dimming control device 20. FIG. 2 is a view showing an example of a mounting position of the external light sensor 10 and the indoor light sensor 11, and as shown in FIG.
Is installed, for example, outside the building or near a window inside the building, and the indoor light sensor 11 is installed, for example, on the ceiling surface in the room. In addition, the mounting position of the external light sensor 10 and the indoor light sensor 11 is not limited to the position shown in FIG. 2, and may be mounted at any position as long as it can detect external light and indoor light.

Returning to FIG. 1, the dimming control device 20 includes a multiplexer 22 for taking in the outputs of the external light sensor 10 and the indoor light sensor 11 in a time-division manner, and an A / D converter 23 for converting the output of the multiplexer 22 into a digital signal. , A dimming control processor 24, and a duty signal generator 25. The duty signal generator 25 generates a pulse signal (duty signal) in which the ratio between the on time and the off time changes according to the output signal of the processor 24, and controls each of the fluorescent lamp groups 26-1 to 26-n for each group. I do. Each fluorescent lamp has a built-in inverter, and is turned on with brightness according to the duty signal.

FIG. 3 is a functional block diagram showing the functions of the dimming control device 20. As shown in the figure, the processor 24 includes a first control unit 20a and a second control unit 20b.
The first controller 20a and the second controller 20b perform indoor light control as follows. (a) First control means When the outdoor illuminance detected by the external light sensor 10 changes by a predetermined value or more, an average value of the indoor illuminance detected by the indoor light sensor 11 is obtained. Then, the necessity of dimming is determined from the average value of the indoor illuminance and the upper and lower limit values of the standard illuminance. If dimming is necessary, an operation amount for canceling the variation of the indoor illuminance is calculated, and the duty signal generator 25 is calculated. To send to. The duty signal generator 25 sends a duty signal corresponding to the operation amount to the first to n-th fluorescent lamp groups 26-1 to 26-n and sends the duty signal to the first to n-th fluorescent lamp groups 26-1 to 26-n. The brightness of the fluorescent lamp to which it belongs is changed to control the target illuminance. Thereby, even if the brightness of the outside light fluctuates, the brightness of the room can be always kept constant. As described above, since the brightness of the external light fluctuates rapidly, the first control means 20a responds quickly to the fluctuation of the external light.

(B) Second control means The second control means is provided for each group, and determines the fluorescent light group of the fluorescent lamp group based on the variation of the illuminance in the room detected by the indoor sensor 11 of each group. The necessity of light control is determined. Then, when dimming is required, an operation amount for canceling the variation of the indoor illuminance is calculated and sent to the duty signal generator 25. The duty signal generator 25 sends a duty signal corresponding to the operation amount to the fluorescent lamp group determined to require dimming, changes the brightness of the fluorescent lamp belonging to the group, and sets the target illuminance. Control.

As described above, inside the building, sensor inputs temporarily fluctuate due to the movement of people and objects. If the light control device responds quickly to this change, the room cannot be maintained at a constant brightness. Therefore, the second control means removes the influence of the temporary fluctuation of the input to the indoor light sensor 11 as follows. When the variation of the illuminance in the room detected by the indoor light sensor 11 has continued for a predetermined time, the brightness of the fluorescent lamp group corresponding to the indoor light sensor 11 is controlled. That is,
As shown in FIG. 4A, when the output of the indoor light sensor 11 fluctuates and continues for a predetermined time (for example, 2 to 3
The control is started at (minute), and the brightness of the fluorescent lamps belonging to the corresponding fluorescent lamp group is changed. On the other hand, when the indoor light sensor 11 fluctuates temporarily as shown in FIG.

When the illuminance in the room detected by the indoor light sensor 11 fluctuates, the illuminance detected by the second sensor reaches a target value over a predetermined time.
The brightness of the fluorescent lamp belonging to the corresponding fluorescent lamp group is changed. That is, as shown in FIG. 4B, when the output of the indoor light sensor 11 fluctuates, the control is started immediately, but the brightness of the fluorescent lamps belonging to the corresponding fluorescent lamp group is changed for a predetermined time (for example, 5 to 5). 10 minutes) to change the brightness of the room to the target value. In this case, since the control is started immediately in response to the output fluctuation of the indoor light sensor 11, when the indoor light sensor 11 temporarily fluctuates as shown in FIG. fluctuate.

FIGS. 5 to 7 are flowcharts of the processor 24 for performing the above control. A specific embodiment of the present invention will be described with reference to FIGS. (1) Embodiment 1 In this embodiment, the brightness of each fluorescent lamp group in the room is controlled by the output of the external light sensor 10, and the fluctuation of the illuminance in the room detected by the indoor light sensor 11 has continued for a predetermined time. At this time, an embodiment (corresponding to (b)) for controlling the brightness of the fluorescent lamp group corresponding to the indoor light sensor 11 is shown, and this embodiment will be described with reference to the flowchart of FIG. In step S1 of FIG.
Initial settings such as timer reset, various flag reset, and condition setting are performed, and it is checked in step S2 whether the time is up. Note that this timer uses the indoor light sensor 1
1 is a timer that determines the timing for controlling each fluorescent lamp group in the room, and can be realized by, for example, a timer interrupt. Note that the set time of the timer can be determined according to how long the fluctuation of the illuminance in the room continues when the dimming is started.
When the light control is started in about two minutes as shown in (a), the set time T of the timer can be set as follows. T = 2 minutes / n [n: number of fluorescent lamp groups]

When the timer has not expired When the timer has not expired, the dimming by the external light sensor 10 is performed as follows. In step S3, based on the output of the external light sensor 10, the current time, and the like,
Find out if it is noon. If it is not noon, the external light sensor 1
Since control by 0 is unnecessary, the process returns to step S2. In the case of noon, the process goes to step S4, and the external light sensor 1
The outdoor illuminance detected by 0 is observed. Then, in step S5, the variation of the outdoor illuminance is calculated, and the variation of the outdoor illuminance is compared with the upper and lower limits. If the variation does not exceed the upper and lower limits, the process returns from step S6 to step S2. If the variation exceeds the upper and lower limits, the process goes from step S6 to step S7, where the average value of the room illuminance detected by the room light sensor 11 is observed,
In step S8, it is determined whether dimming is necessary. The necessity of light control can be determined by, for example, checking whether the average illuminance is outside a predetermined range.

If it is not necessary, the process returns to step S2. In the case where light control is required, in step S9,
An operation amount for canceling the variation in the room illuminance is calculated, and the dimming signal is controlled. That is, when the dimming is necessary, the processor 24 calculates the operation amount and sends a signal corresponding to the calculated operation amount to the duty signal generator 25. The duty signal generator 25 outputs a duty signal corresponding to the operation amount to each of the fluorescent lamp groups 26-1 to 26-.
n, which controls the brightness of each fluorescent light group. In step S10, the indoor light sensor 11
Observe the average illuminance in the room detected by
At 11, it is checked whether the average illuminance has changed. If the average illuminance has changed, it is checked in step S12 whether the average illuminance has reached a predetermined target value. If the average illuminance has not reached the target value, the process returns to step S9 and repeats the above processing. If the average illuminance has reached the target value, the process returns to step S2, and the above processing is repeated. By performing the above-described processing, it is possible to adjust the brightness of each fluorescent lamp group in the room in response to the fluctuation of the external light, and to keep the brightness of the room constant.

When the Timer Times Up When the timer times out, the indoor light sensor 11 performs dimming for each fluorescent lamp group as follows.
Note that the processing of steps S13 to S19 in FIG. 5 is performed for each fluorescent lamp group. For example, first, the processing of steps S13 to S19 is performed for the fluorescent lamp group 26-1 to perform dimming, and then the next step is performed. Next, the processes of steps S13 to S19 are performed on the fluorescent lamp group 26-2 to perform light control, and similarly, the above process is sequentially performed on each fluorescent lamp group in the same manner (hereinafter, the control cycle corresponding to each fluorescent lamp group is set). Channel). The order of dimming the fluorescent lamp groups does not necessarily have to be ascending / descending, but may be determined in any order. In step S13 of FIG. 5, the timer is reset, and in step S14,
Change the indoor channel. That is, the fluorescent lamp group to be controlled is changed from the previous group to the next group.

In step S15, the illuminance of the indoor light sensor 11 corresponding to the fluorescent lamp group to be controlled this time is observed, and in step S16, it is checked whether light control is necessary. The determination of the necessity of dimming can be made, for example, by checking whether the average illuminance is outside a predetermined range as described above. If dimming is not required, the process returns to step S2. If dimming is required, it is determined in step S17 whether dimming was required in the previous observation of the same channel and whether the dimming was the same as the current brightness increase / decrease direction. If the previous and current conditions are the same (when the previous dimming is necessary and the direction of increase / decrease is the same), go from step S18 to step S19,
An operation amount for canceling the variation in the room illuminance is calculated, and the dimming signal is controlled. That is, a signal corresponding to the calculated manipulated variable is sent to the duty signal generator 25, and a duty signal corresponding to the manipulated variable is sent to the fluorescent lamp group to be controlled this time. Control. If the previous and current conditions are not the same, the process returns to step S2. As described above, by performing light control only when the previous and current conditions are the same, the influence of the temporary fluctuation of the output of the indoor light sensor 11 can be removed as described above.

(2) Embodiment 2 In this embodiment, when dimming each fluorescent lamp group in the first embodiment, the dimming is performed from the one having the largest absolute value of the difference between the set illuminance and the current illuminance. It was made. FIG.
5 is a flowchart showing the processing of this embodiment. In FIG. 6, the processing by the external light sensor 10 in steps S1 to S12 is the same as that in FIG.
A part of the processing by the indoor light sensor 11 is different from FIG. Here, steps S13 to S13 in FIG.
The processing of this embodiment will be described with reference to FIG.

In step S13 of FIG. 6, the timer is reset, and in step S14, the illuminance of all channels in the room is observed. Next, in step S15, the channel having the largest absolute value of the difference between the set illuminance and the current illuminance is set as the current processing channel. Step S
At 16, the illuminance of the indoor light sensor 11 corresponding to the fluorescent lamp group to be controlled this time is observed, and it is checked whether light control is necessary. If dimming is not required, the process returns to step S2. If dimming is required, step S
At 17, it is determined whether dimming was required in the previous observation of the same channel, and whether the dimming was the same as the current brightness increase / decrease direction. If the previous and current conditions are the same, the process goes from step S18 to step S19, in which an operation amount for canceling the variation in the room illuminance is calculated and the dimming signal is controlled. If the previous and current conditions are not the same, the process returns to step S2. As described above, by preferentially controlling the channel having the largest absolute value of the difference between the set illuminance and the current illuminance, the indoor illuminance can be quickly uniformed as compared with the first embodiment, Also,
Mutual interference between adjacent fluorescent lamp groups can be prevented.

(3) Embodiment 3 In this embodiment, the brightness of each fluorescent lamp group in the room is controlled by the output of the external light sensor 10 and the illuminance in the room detected by the indoor light sensor 11 fluctuates. , Second
An embodiment (corresponding to the above (b)) in which the brightness of the fluorescent lamps belonging to the corresponding fluorescent lamp group is changed so that the illuminance detected by the sensor reaches the target value over a predetermined period of time. This embodiment will be described with reference to the flowchart of FIG. In this embodiment, the timer is not used as described with reference to FIGS. 5 and 6, and the dimming by the external light sensor 10 and the fluorescent light in the room by the indoor light sensor 11 are performed by switching the processing channel. The dimming of the lamp group is performed sequentially.

In FIG. 7, in step S1, the initial setting is performed as described above. Then, step S2
, A processing channel is set, and in step S3, it is checked whether the current processing channel is dimming of room light by the indoor light sensor 11 or dimming by the outside light sensor 10. If the current light control is the light control by the external light sensor 10, the process proceeds to step S4. If the current processing channel is dimming of room light by the room light sensor 11, the process proceeds to step S14.

The processing channel this time is the external light sensor 1
In the case of dimming by 0 When the current processing channel is dimming by the external light sensor 10, it is the same as the processing of steps S3 to S12 in FIG. 5, and performs the following processing. In step S4, it is checked whether it is daytime based on the output of the external light sensor 10 and the like. If it is not daytime, control by the external light sensor 10 is not necessary, and the process returns to step S2. In the case of noon, the process goes to step S5, where the outdoor illuminance is observed. In step S6, the variation of the outdoor illuminance is calculated, and the variation of the outdoor illuminance is compared with the upper and lower limits. If the variation does not exceed the upper and lower limits, the process proceeds from step S7 to step S2.
Return to If the variation exceeds the upper and lower limits, the process goes from step S7 to step S8, where the average illuminance of the room is observed, and in step S9, it is determined whether dimming is necessary. If the light control is not required, the process returns to step S2. In the case where light control is required, in step S10, an operation amount for canceling the variation of the indoor illuminance is calculated, and the light control signal is controlled.

In step S11, the average illuminance in the room is observed, and in step S12, it is checked whether the average illuminance has changed. If the average illuminance has changed, step S1
In step 3, it is checked whether the average illuminance has reached a predetermined target value. If the average illuminance has not reached the target value, the process returns to step S10 to repeat the above processing. Also,
If the average illuminance has reached the target value, the process returns to step S2, and the above processing is repeated. By performing the above-described processing, it is possible to adjust the brightness of each fluorescent lamp group in the room in response to the fluctuation of the external light, and to keep the brightness of the room constant.

When the current processing channel is dimming by the indoor light sensor 11 When the current processing channel is dimming by the indoor light sensor 11, the following processing is performed. Step S1 in FIG.
In step S4, the indoor illuminance of the current processing channel is observed, and in step S15, it is checked whether the fluorescent lamp group to be controlled in the current processing channel is currently in the process of dimming. In the case of, it is determined whether the conditions need to be reset. In other words, even during the current dimming, the dimming direction is reversed or the illuminance is largely different from the target illuminance in the previous dimming. If the illuminance fluctuates due to the following factors), it is necessary to reset the conditions, and thus the already calculated operation amount is canceled. Then, from step S16 to step S1
Proceeding to 7, it is determined whether or not light control is necessary. If light control is not required, the process returns to step S2. If dimming is required, the operation amount is newly calculated in step S18. If the dimming condition does not need to be recalculated during the dimming process at present, the process proceeds from step S16 to step S19, and the dimming signal is controlled with the operation amount already calculated.

On the other hand, if the light control is not currently being performed, the process proceeds from step S16 to step S17 to determine whether light control is necessary. If light control is not required, the process returns to step S2. If dimming is required, in step S18,
An operation amount per operation for canceling the variation in the room illuminance over a predetermined time is calculated. For example, FIG.
As shown in (1), the variation of the indoor illuminance is canceled in 5 to 10 minutes, and the amount of operation per operation that causes the indoor brightness to reach the target illuminance is calculated. By calculating the amount of operation per time for canceling the variation of the room illuminance over a predetermined time as described above, and controlling the room brightness to reach a target value over a predetermined time, 1,
As in the second embodiment, it is possible to remove the influence of the temporary fluctuation of the output of the indoor light sensor 11. In the above embodiment, the case where the present invention is applied to a lighting device including a light duct device and an artificial lighting device has been described.
The present invention is not limited to the above embodiment, and can be applied to, for example, a case where artificial light is adjusted in an environment where external light enters through a window or the like. Further, in the above embodiment, the case of dimming an inverter type fluorescent lamp has been described. However, the present invention relates to a case of dimming an electrodeless lamp, an incandescent lamp, a dimming fluorescent lamp (transformer type) which is not an inverter type, etc. It can also be applied to

[0029]

As described above, according to the present invention, the first sensor for detecting external light and the second sensor for detecting composite light of external light and artificial illumination light are provided. The above-described control is performed by the output of the second sensor and the output of the second sensor. Therefore, the brightness of the outside light is not affected by the temporary fluctuation of the sensor input due to the movement of a person or an object inside the building. It can respond immediately to the fluctuation of the height. For this reason, it is possible to suppress the temporary fluctuation (flicker) of the brightness due to the movement of people and things inside the building, and to keep the brightness inside the building constant even if the external light fluctuates. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a light control device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a mounting position of an external light sensor and an indoor light sensor.

FIG. 3 is a functional block diagram of the dimming control device of the present embodiment.

FIG. 4 is a diagram for explaining the operation of a second control means in FIG. 3;

FIG. 5 is a flowchart illustrating a process according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating a process according to a second embodiment of the present invention.

FIG. 7 is a flowchart illustrating a process according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a schematic configuration of a horizontal light duct device applied to an office or the like.

FIG. 9 is a diagram showing a schematic configuration of a vertical light duct device applied to an underground parking lot or the like.

FIG. 10 is a detailed view of the installation of the artificial lighting device in the light duct device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 External light (sunlight) 2 Lighting opening 3 Reflector 4 Duct 5 Building outer wall 6 Room 7 Glass 8 Artificial lighting such as fluorescent lamps 8 'Fluorescent lamp fixture 9 Ground surface 4a Light emitting port 10 External light sensor 11 Indoor light sensor 12 Mirror reflector 13 Dustproof acrylic cover 14 Ceiling board 15 Acrylic board 20 Dimming control device 20a First control means 20b Second control means 21 Amplifier 22 Multiplexer 23 A / D converter 24 Processor 25 Duty signal generator 26-1 ~ 26-n Each fluorescent light group

Claims (2)

[Claims] 1. A light control device for keeping the illuminance of a composite light of external light and light supplied from artificial lighting installed inside a building constant, wherein the light control device measures the illuminance of natural light. A first sensor that measures the illuminance of the combined light of natural light and artificial light; and a second sensor that responds immediately to the output of the first sensor when the output of the first sensor fluctuates. Adjust the illumination intensity,
First control means for keeping the brightness inside the building constant, and when the output of the second sensor does not fluctuate immediately but temporarily fluctuates in the output of the second sensor for a predetermined time. A dimming device, comprising: a second control unit that operates to adjust the illuminance of the artificial lighting to keep the brightness inside the building constant. 2. A light control device for maintaining a constant illuminance of a composite light of external light and light supplied from artificial lighting installed inside a building, wherein the light control device measures the illuminance of natural light. A first sensor that measures the illuminance of the combined light of natural light and artificial light; and a second sensor that responds immediately to the output of the first sensor when the output of the first sensor fluctuates. Adjust the illumination intensity,
First control means for keeping the brightness inside the building constant, and when the output of the second sensor fluctuates, the illuminance detected by the second sensor reaches a target value over a predetermined time. And a second control means for adjusting the illuminance of the artificial lighting.