JP2001052879A - Lighting device and optical sensor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure that the illuminance of a surface to be illuminated is maintained at a set illuminance even when external light is present. A brightness sensor detects the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated. The control block 2 controls the lamp 4 based on the output of the brightness sensor 1.
Feedback control of the light output. The control block 2 determines the presence or absence of external light on the surface to be illuminated based on the output of the brightness sensor 1, and performs feedback control according to the presence or absence of external light so that the illuminance of the surface to be illuminated is maintained at the set illuminance. Change the value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used for office or store lighting, and detects the brightness of a surface to be illuminated and adjusts the light output of a lamp to substantially reduce the illuminance of the surface to be illuminated. The present invention relates to a lighting device and an optical sensor that are kept constant.

[0002]

2. Description of the Related Art Hitherto, there has been provided an illuminating device that detects the brightness of a surface to be illuminated by a brightness sensor and feedback-controls the light output of a lamp so as to keep the detected brightness substantially constant. As shown in FIG. 35, this type of lighting device includes a brightness sensor 1, outputs a dimming signal from the control block 2 according to the brightness detected by the brightness sensor 1, and outputs the light control signal via the lighting device 3. The dimming control of the lamp 4 as a light source is configured. The brightness sensor 1 is mounted on the ceiling surface and receives light from below to detect the brightness of a specific portion in the surface to be illuminated by the lamp 4. The control block 2 has a function of storing the output of the brightness sensor 1 in a state where the light output of the lamp 4 is set so that the illuminated surface has the set illuminance as a brightness target value Vs. Target value V
After the setting of s, the light output of the lamp 4 is feedback-controlled so that the output Vt of the brightness sensor 1 at each point in time approaches the brightness target value Vs. In short, if Vt> Vs, the light output is reduced, and if Vt <Vs, the light output is increased.

Since the light output of the lamp 4 is feedback-controlled based on the output of the brightness sensor 1 as described above,
Light whose brightness is detected by the brightness sensor 1 is a portion close to a window and is light such as natural light that is not subjected to feedback control by the brightness sensor 1 (this kind of light is hereinafter referred to as outside light). ) Is obtained, the dimming signal is output from the control block 2 so as to reduce the light output of the lamp 4 as compared with the case where the illumination is performed only by the lamp 4. As described above, when external light is obtained, power consumption is suppressed by dimming the lamp 4.
It saves energy while ensuring the required illuminance.
Further, since the light output with respect to the power supplied to the lamp 4 (that is, the luminous efficiency) decreases over time, the dimming lighting is performed immediately after the use of the lamp 4 is started, and control is performed so as to approach the full lighting as the end of the life is approached. Then, the light output of the lamp 4 can be kept substantially constant from the initial stage to the end of its life, and energy can be saved by reducing the supplied power at the initial stage.

[0004]

By the way, when setting the brightness target value Vs for the output of the brightness sensor 1, as shown in FIG.
And by adjusting the light output of the lamp 4 that is feedback-controlled using the brightness sensor 1 so that the illuminance detected by the illuminometer 5 becomes the set illuminance. When the set illuminance is obtained in this manner, the output value of the brightness sensor 1 at this time is stored as the brightness target value Vs.

The above-described setting method uses a brightness target value Vs set in an environment where no light is incident on the illuminometer 5 other than the light from the lamp 4 that is feedback-controlled, as a reference value. As shown in FIG. 36B, when the brightness target value Vs is set in an environment where external light A is incident on the illuminometer 5 such as near a window, even if the illuminance measured by the illuminometer 5 is equal, the brightness is increased. The output of the sensor 1 may be different.

[0006] Such a phenomenon is considered to occur for the following two reasons.

[0007] First, the brightness sensor 1 is shown in FIG.
The field of view F1 is set so as to detect the brightness immediately below, and light from within a limited range of the irradiated surface is detected, whereas the illuminometer 5 is positioned directly below the brightness sensor 1. It is considered that the light in the field of view F2 set above is detected with the sensitivity of cos θ to the incident angle θ (the front direction is 0 °). In other words, the output of the brightness sensor 1 is equal if the amount of reflected light from the field of view F1 is equal, but the output of the illuminometer 5 changes depending on the incident angle even when the amount of light is equal. As a result, when being affected by external light, the illuminance detected by the illuminometer 5 may be low even when the output values of the brightness sensor 1 are equal.

Second, it is considered that the spectral sensitivity characteristics of the brightness sensor 1 and the illuminometer 5 do not match. In other words, the illuminometer 5 uses a strictly adjusted optical filter in order to match the spectral sensitivity characteristics of a sensor such as a silicon photodiode with the relative luminous efficiency characteristics of a person. For this reason, it is difficult to use a strict optical filter. Here, if it is assumed that a fluorescent lamp is used as the lamp 4 and the external light is obtained by natural light, the external light includes a light component in a wide wavelength range, and the spectral sensitivity characteristic of the brightness sensor 1 generally has an illuminometer. Since the wavelength range is wider than the relative luminous efficiency characteristics according to No. 5, the output of the brightness sensor 1 is larger when external light is included.

In any case, even if the set illuminance is set to be equal to that when no external light is present, the output of the brightness sensor 1 is increased, so that the light output of the lamp 4 is reduced accordingly. Even though the illuminometer 5 has obtained the set illuminance, the light output of the lamp 4 may have decreased and the required illuminance may not be obtained. In other words,
When there is external light, the illuminance may be insufficient and a sense of darkness may be felt.

Let us consider this in more detail. Now, assuming that the illuminated surface is illuminated only by the lamp 4 that is feedback-controlled, the output of the brightness sensor 1 is the brightness (the lower surface illuminance) immediately below the brightness sensor 1 as shown in FIG. ) (A linear function for simplicity). Here, the output of the brightness sensor 1 when the lower surface illuminance is the set illuminance Is is set as the brightness target value Vs. In the figure, this state is represented by a circled number 0.

If the surface to be illuminated is illuminated by external light after setting the brightness target value Vs (state), the output of the brightness sensor 1 increases unless feedback control is performed. As described above, when external light is present, the output of the brightness sensor 1 is further increased compared to the case where there is no external light. 37 (b), and as shown in FIG. 37 (b), the output of the brightness sensor 1 approaches the brightness target value Vs by feedback control.
When the light output of the lamp 4 is reduced (state), the lower surface illuminance is lower than the set illuminance Is. Here, in the drawing, Ls is the light output (i.e., the amount of modulated light) with respect to the brightness target value Vs when there is no external light, and the light output L of the lamp 4 in the state reduced by the external light is the brightness target value Vs. It is lower than the corresponding light output Ls. FIG. 37 (c) shows a state in which the outside light is further increased. If the feedback control is not performed, the output of the brightness sensor 1 further increases,
In this state, since it is within the range of the feedback control, the lower surface illuminance becomes lower than the set illuminance Is (state).

When the outside light is further increased and exceeds the range of the feedback control (that is, when the output of the lamp 4 cannot be further reduced),
As shown in FIG. 37D, the output of the brightness sensor 1 increases by the increase in the amount of external light (state). In this case, the lower surface illuminance may be higher than the set illuminance Is.

FIG. 38 shows the operation shown in FIG. 37 on the time axis. FIG. 38A shows the output of the brightness sensor 1, and Vr indicates the output of the brightness sensor 1 when the set illuminance is obtained. Here, the circled numbers in FIG. 38 correspond to the states indicated by the circled numbers in FIG. FIG. 38 (b) shows the light output of the lamp 4,
FIG. 38C shows the lower surface illuminance, where Is is the set illuminance and I
r indicates the illuminance when the output of the brightness sensor 1 is the brightness target value Vs. As is apparent from the figure, the output of the brightness sensor 1 becomes the brightness target value Vs in the feedback control not only when the external light increases and the lower surface illuminance increases, but also in a process (see) where the external light decreases. When it has reached, the actual illuminance becomes lower than the set illuminance Is. After all, when external light exists, the set illuminance Is
Is obtained, the output of the brightness sensor 1 becomes larger than the brightness target value Vs. Therefore, when the output of the brightness sensor 1 reaches the brightness target value Vs and is stable, the actual It is highly likely that the illuminance is lower than the set illuminance Is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an illuminating device in which the presence or absence of external light is determined to suppress the lower surface illuminance from lowering than a set illuminance. An object of the present invention is to provide an optical sensor suitable for use in detecting the presence or absence of external light in a lighting device.

[0015]

According to a first aspect of the present invention, there is provided a brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and based on an output of the brightness sensor. A control block for performing feedback control of the light output of the light source, wherein the control block determines the presence or absence of external light on the illuminated surface based on the output of the brightness sensor, and the illuminance of the illuminated surface is maintained at the set illuminance. Thus, the target value of the feedback control is controlled according to the presence or absence of external light.

According to a second aspect of the present invention, in the first aspect, the control block stores the output of the brightness sensor when the set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and After the light output of the brightness sensor is stored as the output target value, when the output of the brightness sensor is larger than the reference value of the brightness target value and the light output is smaller than the output target value, the brightness target value is larger than the reference value. When the light output is larger than the output target value, the brightness target value is used as a reference value.

According to a third aspect of the present invention, in the first aspect of the present invention, the control block stores an output of the brightness sensor when a set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and After storing the light output as an output target value, a set of a set of the reference value and the output target value of the brightness target value and a set of the output of the brightness sensor and the light output of the light source on a straight line passing through the origin are tabulated. When the actual output of the brightness sensor was larger than the output of the brightness sensor obtained by comparing the light output with the table, the brightness target value was set to be larger than the reference value, and the light output was obtained by checking the table. When the output of the brightness sensor is substantially equal to the actual output of the brightness sensor, the brightness target value is used as a reference value.

According to a fourth aspect of the present invention, in the first aspect, the control block stores an output of the brightness sensor when a set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and Is stored as an output target value, and then the brightness on a straight line passing through a set of a reference value of the brightness target value and the output target value and at least one set of the output of the brightness sensor and the light output. When a set of the sensor output and the light output of the light source is tabulated, and the actual output of the brightness sensor is larger than the output of the brightness sensor obtained by comparing the light output with the table, the brightness target value is set to the reference value. Is set large, and when the output of the brightness sensor obtained by comparing the light output with the table is substantially equal to the actual output of the brightness sensor, the brightness target value is used as the reference value.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the control block stores an output of a brightness sensor when a set illuminance is obtained in a predetermined state as a brightness target value, and controls a light output of a light source. Is stored as the output target value, and if the light output when stable is smaller than the output target value, the brightness target value is increased, and if the light output when stable is larger than the output target value, the brightness target value is increased. It lowers the value.

According to a sixth aspect of the present invention, in the second to fifth aspects of the invention, the brightness target value is changed by a constant value irrespective of the difference between the light output and the output target value.

According to a seventh aspect of the present invention, in the second to fifth aspects of the present invention, the brightness target value is set in a plurality of stages according to a difference between the light output and the output target value. .

According to an eighth aspect of the present invention, in the invention of the second to fifth aspects, the brightness target value has an upper limit value and a lower limit value, and the target of the brightness target value is changed with the median value. At least one of the upper limit value and the lower limit value.

According to a ninth aspect of the present invention, in the second to fifth aspects of the present invention, the reference value of the brightness target value is set such that the surface to be irradiated is not irradiated with external light and the brightness sensor output during feedback control. Is stored in at least one of a stable state.

According to a tenth aspect of the present invention, there is provided a brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and a feedback of an optical output of a light source based on an output of the brightness sensor. And a control block for controlling,
The control block determines a change in light color on the surface to be illuminated based on the output of the brightness sensor, and determines whether or not there is external light so that the illuminance on the surface to be illuminated is maintained at the set illuminance regardless of the light color. This is to perform feedback control.

According to an eleventh aspect of the present invention, in the tenth aspect of the present invention, a plurality of brightness sensors having mutually different spectral sensitivity characteristics are provided, and a light output of a light source is determined based on a difference between outputs of the brightness sensors. It is set.

According to a twelfth aspect of the present invention, in the eleventh aspect of the present invention, a relationship between the output of the brightness sensor and the light output of the light source is set in the control block in advance. The light output of the light source is set by applying the above relationship.

According to a thirteenth aspect of the present invention, in the tenth aspect of the present invention, a plurality of brightness sensors having mutually different spectral sensitivity characteristics are provided, and a light output of a light source is determined based on a ratio of outputs of the brightness sensors. It is set.

According to a fourteenth aspect, in the thirteenth aspect, a relationship between the output of the brightness sensor and the light output of the light source is set in the control block in advance, and the relationship between the output of the brightness sensor and The light output of the light source is set by applying the above relationship.

According to a fifteenth aspect of the present invention, in the tenth aspect of the present invention, a plurality of brightness sensors having mutually different spectral sensitivity characteristics are provided, and a feedback control is performed by comparing a difference between outputs of the brightness sensors. Is selected.

According to a sixteenth aspect of the present invention, in the tenth aspect of the present invention, a plurality of brightness sensors having mutually different spectral sensitivity characteristics are provided, and a feedback control is performed by comparing the output ratio of each brightness sensor. Is selected.

According to a seventeenth aspect, in at least one of the eleventh to sixteenth aspects, at least one brightness sensor has a spectral sensitivity characteristic similar to a human's relative luminous efficiency characteristic.

According to an eighteenth aspect of the present invention, in the invention of the eleventh to sixteenth aspects, a sensor having high sensitivity to a specific wavelength is used as a brightness sensor that does not perform feedback control.

According to a nineteenth aspect, in the eleventh to sixteenth aspects, the brightness sensor has a spectral sensitivity characteristic having high sensitivity to a light component to be detected.

According to a twentieth aspect of the present invention, in accordance with the eleventh to sixteenth aspects of the present invention, a plurality of light sources having different emission colors are provided as the light source, and a difference between light spectrum components of each light source is large as the brightness sensor. Those having high sensitivity to wavelength components are used.

According to a twenty-first aspect of the present invention, there is provided an optical sensor for receiving reflected light from a surface to be irradiated to detect the presence or absence of external light irradiation. It is provided.

According to a twenty-second aspect of the present invention, in the twenty-first aspect of the present invention, in the spectral sensitivity characteristics of each of the brightness sensors, wavelength ranges where the sensitivity is near the maximum overlap with each other.

According to a twenty-third aspect of the present invention, in the twenty-second aspect, at least one brightness sensor has a sensitivity equivalent to that of another brightness sensor on a shorter wavelength side than a wavelength at which an output is maximized in spectral sensitivity characteristics. And has higher sensitivity on the long wavelength side than other brightness sensors.

According to a twenty-fourth aspect of the present invention, in the twenty-second aspect, at least one brightness sensor has the same sensitivity as the other brightness sensors on a longer wavelength side than the wavelength at which the output becomes maximum in the spectral sensitivity characteristics. And the sensitivity is higher on the short wavelength side than on other brightness sensors.

According to a twenty-fifth aspect of the present invention, in the twenty-second aspect, at least one brightness sensor has another brightness on both the long wavelength side and the short wavelength side of the wavelength at which the output becomes maximum in the spectral sensitivity characteristic. The sensitivity is higher than that of the sensor.

According to a twenty-sixth aspect, in the twenty-third aspect to the twenty-fifth aspect, the other brightness sensor has a spectral sensitivity characteristic similar to a human relative luminous efficiency characteristic.

According to a twenty-seventh aspect, in the twenty-second to twenty-sixth aspects, the wavelength at which the sensitivity is maximum in the spectral sensitivity characteristics of each of the brightness sensors is in a visible light region.

According to a twenty-eighth aspect of the present invention, in the twenty-first aspect, in the spectral sensitivity characteristics of each of the brightness sensors, the wavelength ranges where the sensitivity is near the maximum do not overlap each other.

According to a twenty-ninth aspect of the present invention, in the twenty-eighth aspect, the wavelength ranges having sensitivity in the spectral sensitivity characteristics of the brightness sensors do not overlap each other.

The invention of claim 30 is characterized in that, in the invention of claims 21 to 28, a part of the wavelength ranges having sensitivity in the spectral sensitivity characteristics of the respective brightness sensors overlap with each other.

According to a thirty-first aspect of the present invention, there is provided an optical sensor according to any one of the twenty-first to twenty-third aspects, and a control block for feedback-controlling the optical output of the light source based on the output of the optical sensor. The block determines the presence or absence of external light on the irradiated surface based on the output of the optical sensor, and controls the target value of the feedback control according to the presence or absence of external light so that the illuminance of the irradiated surface is maintained at the set illuminance. Things.

According to a thirty-second aspect, in the thirty-first aspect, the control block determines the presence or absence of external light by comparing the outputs of the brightness sensors.

According to a thirty-third aspect, in the thirty-first aspect, the control block determines the presence or absence of external light by comparing the ratio of the outputs of the brightness sensors.

According to a thirty-fourth aspect, in the thirty-first aspect, the control block determines the presence or absence of external light based on a change in a gradient of a ratio between outputs of the brightness sensors.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of a lighting device used in each of the following embodiments will be briefly described. As shown in FIG.
The illumination device used in the following embodiments also has a configuration basically similar to the conventional configuration, and is provided with a brightness sensor 1 that is arranged on the ceiling and detects light from within a predetermined area set below. A light control signal is output from the control block 2 in accordance with the brightness detected by the brightness sensor 1, and the light control of the lamp 4 is performed via the lighting device 3. That is, the brightness sensor 1 is configured to detect the brightness of a specific portion in the surface to be illuminated by the lamp 4. The control block 2 stores the output value of the brightness sensor 1 in a predetermined state as the reference value Vs of the brightness target value, and stores the light output of the lamp 4 in the same state as the output target value Ls. Calculation for setting the dimming amount such that the lower surface illuminance is maintained at or above the set illuminance based on the relationship between the reference value Vs of the brightness target value and the output target value Ls stored in the storage unit 2a. A part 2b is provided. Here, the output target value Ls
Uses not the actual light output from the lamp 4 but the amount of light that is applied to the lighting device 3 to obtain a predetermined light output from the lamp 4.

The arithmetic unit 2b basically performs the same feedback control as in the conventional configuration, and performs feedback control so that the output Vt of the brightness sensor 1 at each time approaches the brightness target value. However, when the output target value Ls is a condition described in each of the following embodiments, the light output of the lamp 4 is controlled so as to change the brightness target value and give priority to maintaining the lower surface illuminance.

(First Embodiment) In the present embodiment, the relationship between the output Vt of the brightness sensor 1 and the reference value Vs of the brightness target value during the feedback control is being performed, and the light output of the lamp 4 Light control amount Lt and output target value L for controlling
Using the relationship with s, the operation unit 2b of the control block 2 operates as follows. Here, it is assumed that the reference value Vs and the output target value Ls of the brightness target value are set such that the lower surface illuminance becomes the target illuminance Is in a state where there is no external light. If Vt ≧ Vs and Lt <Ls, the brightness target value is raised from the reference value Vs to the correction value Vm. Lt
> Ls, the brightness target value is changed from the correction value Vm to the reference value V
Return to s.

Next, the operation will be specifically described with reference to FIG. If the illumination target surface is illuminated only by the feedback-controlled lamp 4, the output of the brightness sensor 1 is a monotonically increasing function of the lower surface illuminance as shown in FIG. As described above, when the lower surface illuminance is the set illuminance Is, the output of the brightness sensor 1 is set to the reference value Vs of the brightness target value.
Is set as In the figure, this state is indicated by a circled number 0.
It is represented by

If the illuminated surface is illuminated by external light after setting the reference value Vs of the brightness target value (state), the output of the brightness sensor 1 increases unless feedback control is performed. I do. As described above, when external light is present, the output of the brightness sensor 1 is further increased compared to the case where there is no external light. The arithmetic unit 2b controls the light output of the lamp 4 in a direction in which the light output of the lamp 4 is reduced. Here, FIG.
As shown in (b), when the light output of the lamp 4 is controlled so that the output of the brightness sensor 1 becomes the reference value Vs, the light output of the lamp 4 becomes lower than when the output target value Ls is set. That is, since Vt ≧ Vs and Lt <Ls,
This is to raise the brightness target value from the reference value Vs to the correction value Vm. That is, the output of the brightness sensor 1 is the correction value Vm
The light output of the lamp 4 is controlled so as to satisfy the condition (state), and the amount of decrease in the light output is smaller than when the brightness target value is set to the reference value Vs. It is possible to prevent a large decrease from Is (the lower surface illuminance is slightly higher than the set illuminance Is in the figure).

In short, using the reference value Vs and the output target value Ls of the target brightness value set in the state where there is no external light,
When the light output of the lamp 4 is lower than the output target value Ls, it is determined that there is external light. If there is external light, the brightness target value is raised to the correction value Vm (> Vs).
The lower illuminance is prevented from lowering. Thus, it is possible to prevent the lower surface illuminance from lowering than the set illuminance Is when there is external light.

When the external light further increases, as shown in FIG. 2C, the output of the brightness sensor 1 increases (state), and the light output of the lamp 4 is maintained so that the brightness target value is maintained at the correction value Vm. Although the dimming is performed, since the correction value Vm is fixedly set, the lower surface illuminance may be lower than the set illuminance Is. However, the degree is small compared to the conventional configuration,
The lower surface illuminance is kept close to the set illuminance Is, and the lower surface illuminance is prevented from dropping significantly (state).

FIG. 3 shows the operation shown in FIG. 2 on the time axis.
become that way. The circled numbers in FIG. 3 correspond to the states of the circled numbers in FIG. 2 (the same applies to the following embodiments).
FIG. 3A shows the output of the brightness sensor 1. As described above, the brightness target value becomes the reference value Vs during the period in which the light output shown in FIG. 3B is the output set value Ls. During a period in which the light output Ls is lower than the output set value Ls, the brightness target value becomes the correction value Vm. By such an operation, FIG.
The lower surface illuminance shown in (c) is kept substantially higher than the set illuminance Is, and it is possible to avoid the inconvenience that the lower surface illuminance is significantly lower than the set illuminance Is as in the conventional configuration. 3 indicates a case where the brightness target value is fixed to the reference value Vs as in the conventional configuration.

In short, the set illuminance Is in the absence of external light
By setting the correction value Vm of the brightness target value when the set illuminance Is is obtained in a state of external light higher than the reference value Vs of the brightness target value when the Even at a certain time, the lowering of the illuminance of the lower surface can be suppressed.

Further, even when external light decreases while the brightness target value is set to the correction value Vm, the correction value Vm of the brightness target value is set higher than the reference value Vs. The lower surface illuminance does not become lower than the set illuminance Is. When the external light is further reduced, the lower surface illuminance becomes much larger than the set illuminance Is when the brightness target value is the correction value Vm, so that the energy saving effect is reduced. Therefore, as described above, when Lt> Ls, the brightness target value is returned to the reference value Vs, and it is possible to prevent the lower surface illuminance from significantly increasing beyond the set illuminance Is.

In the above example, the reference value Vs of the brightness target value is set to a constant value, but may be set with a certain width. For example, when the reference value of the brightness target value is set to Vs ± ΔVs with an upper limit value and a lower limit value before and after the median value, when the external light is present as shown in FIG. For the correction value Vm of the brightness target value, the median value Vs is increased, the upper limit value is increased (the upper limit value is set to Vs + ΔVs ′ using ΔVs ′ (> ΔVs)), and the lower limit value is increased ( Using ΔVs ′ (<ΔVs), the lower limit is set to VS−
ΔVs ′), or a combination thereof.

The storage of the reference value Vs of the brightness target value and the light output Ls for the set illuminance Is in the storage unit 2a may be performed only once without external light. In the stable state of the target value Vs, it may be reset in the storage unit 2a.

(Second Embodiment) In this embodiment, a table in which the output of the brightness sensor is associated with the light output is set in the storage unit 2a, and the light output is controlled using this table. Things. That is, similarly to the first embodiment, the reference value Vs of the brightness target value and the output target value Ls are set such that the lower surface illuminance becomes the target illuminance Is without external light. Here, assuming that the output of the brightness sensor 1 becomes linear with respect to the light output of the lamp 4, a set of the reference value Vs of the brightness target value and the output target value Ls and the origin (that is, the brightness sensor 1) (The point where the output is 0 and the light output is 0) are set, and a plurality of sets of the output of the brightness sensor 1 and the light output of the lamp 4 are taken out on this straight line to set a table. The calculation unit 2b calculates a calculated value Vc of the output of the brightness sensor 1 with respect to the light output of the lamp 4 at each time based on this table, and controls the light output of the lamp 4 under the following conditions. That is, using the relationship between the output Vt of the brightness sensor 1 at each time and the calculated value Vc of the output of the brightness sensor 1 obtained from the table, if Vt ≧ Vc,
The brightness target value is raised from the reference value Vs to the correction value Vm. If Vt ≒ Vc, the brightness target value is returned from the correction value Vm to the reference value Vs.

FIG. 5 shows the operation of this embodiment. The meaning of each symbol in FIG. 5 is the same as that in FIG. 2. If it is assumed that the target surface is illuminated by external light after setting the target value Vs (state), the feedback control must be performed. The output of the brightness sensor 1 increases. When external light is present, the calculation unit 2b performs feedback control of the light output of the lamp 4 in a direction to reduce the light output of the lamp 4. Here, as shown in FIG.
When the light output of the lamp 4 is controlled so that the output of the lamp 4 becomes the reference value Vs, the light output of the lamp 4 becomes lower than when the output target value Ls is set. The calculated value Vc of the output of the brightness sensor 1 obtained from the equation (1) is Vt ≧ Vc with respect to the actual output Vt of the brightness sensor 1. As a result, the brightness target value is raised from the reference value Vs to the correction value Vm. That is, the light output of the lamp 4 is feedback-controlled so that the output of the brightness sensor 1 becomes the correction value Vm (state), and the light output is compared with the case where the brightness target value is set to the reference value Vs. Is small, and as a result, the lower surface illuminance can be prevented from greatly decreasing from the set illuminance Is (the lower surface illuminance is slightly higher than the set illuminance Is in the figure).

When the external light further increases, as shown in FIG. 5C, the output of the brightness sensor 1 increases (state), and the light output of the lamp 4 is maintained so that the brightness target value is maintained at the correction value Vm. Although the dimming is performed, since the correction value Vm of the brightness target value is fixedly set, the lower surface illuminance may be lower than the set illuminance Is. However, the degree is smaller than that of the conventional configuration, the lower surface illuminance is kept close to the set illuminance Is, and the lower surface illuminance is prevented from dropping significantly (state).

The operation shown in FIG. 5 is shown on the time axis in FIG.
become that way. FIG. 6A shows the output of the brightness sensor 1, and as described above, during the period when the light output shown in FIG. 6B is the output set value Ls, the brightness target value becomes the reference value Vs. During a period in which the light output Ls is lower than the output set value Ls, the brightness target value becomes the correction value Vm. By such an operation, the lower surface illuminance shown in FIG. 6C is kept substantially higher than the set illuminance Is, and the inconvenience that the lower surface illuminance is significantly lower than the set illuminance Is as in the conventional configuration is reduced. Can be avoided. 6 indicates a case where the brightness target value is fixed to the reference value Vs as in the conventional configuration.

When the external light decreases while the brightness target value is set to the correction value Vm, the output Vt of the brightness sensor 1 is calculated by the calculated value Vt obtained from the table.
When the calculated value becomes substantially equal to c (an appropriate range is determined for the calculated value Vc and Vt falls within the range), it is regarded that the external light has disappeared, and the brightness target value is returned to the reference value Vs. . Other configurations and operations are the same as those of the first embodiment.

(Third Embodiment) In the present embodiment, the second embodiment
Similarly to the embodiment, a table in which the output of the brightness sensor is associated with the light output is set in the storage unit 2a, and the light output is controlled using this table. That is, similarly to the first embodiment, the reference value Vs of the brightness target value and the output target value Ls are set such that the lower surface illuminance becomes the target illuminance Is without external light. Here, assuming that the output of the brightness sensor 1 has a specific functional relationship (linearly in the simplest case) with respect to the light output of the lamp 4, the reference value Vs of the brightness target value and the output target value Ls are calculated. Set up a table containing tuples. That is, at least one other set of the output value of the brightness sensor 1 and the light output of the lamp 4 is obtained, and a table is set so that a specific functional relationship is obtained from the combination of the plurality of sets. Subsequent processing is the same as that of the second embodiment. The calculation unit 2b calculates a calculation value Vc of the output of the brightness sensor 1 with respect to the light output of the lamp 4 at each time based on this table. The light output of the lamp 4 is controlled under the following conditions. That is, using the relationship between the output Vt of the brightness sensor 1 at each time and the calculated value Vc of the output of the brightness sensor 1 obtained from the table, if Vt ≧ Vc,
The brightness target value is raised from the reference value Vs to the correction value Vm. If Vt ≒ Vc, the brightness target value correction value Vm is returned to the reference value Vs.

FIG. 7 shows the operation of this embodiment. The meanings of the respective symbols in FIG. 7 are the same as those in FIG. 2. If it is assumed that the target surface is illuminated by external light after setting the target value Vs (state), the feedback control must be performed. The output of the brightness sensor 1 increases. FIG.
Determines two other sets of the output of the brightness sensor 1 and the light output of the lamp 4. That is, (Vs, Ls), (V
Since a combination of three sets of (1, L1) and (V2, L2) is obtained, a functional relationship is set so as to satisfy these sets. In the simplest case, a linear prediction formula is obtained by applying a least square method or the like so as to have a linear relationship, and a table corresponding to the linear prediction formula is set. Subsequent processing is the same as that of the second embodiment.
b feedback-controls the light output of the lamp 4 in a direction to reduce the light output of the lamp 4. That is, as shown in FIG. 7B, when the light output of the lamp 4 is controlled so that the output of the brightness sensor 1 becomes the reference value Vs, the light output of the lamp 4 becomes lower than when the output target value Ls is set. Therefore, the calculated value Vc of the output of the brightness sensor 1 obtained from the table with respect to the light output of the lamp 4 at this time is Vt ≧ Vc with respect to the actual output Vt of the brightness sensor 1. As a result, the brightness target value is raised from the reference value Vs to the correction value Vm. That is, the output of the brightness sensor 1 is the correction value Vm
So that the light output of the lamp 4 is feedback-controlled (state), and the brightness target value is set to the reference value Vs.
As compared with the case of, the lowering amount of the light output is small, and as a result, the lower surface illuminance can be prevented from greatly decreasing from the set illuminance Is (the lower surface illuminance is slightly higher than the set illuminance Is in the figure). ).

When the external light further increases, as shown in FIG. 7C, the output of the brightness sensor 1 increases (state), and the light output of the lamp 4 is maintained so that the brightness target value is maintained at the correction value Vm. Although the dimming is performed, since the correction value Vm of the brightness target value is fixedly set, the lower surface illuminance may be lower than the set illuminance Is. However, the degree is smaller than that of the conventional configuration, the lower surface illuminance is kept close to the set illuminance Is, and the lower surface illuminance is prevented from dropping significantly (state).

FIG. 8 shows the operation shown in FIG. 7 on the time axis.
become that way. FIG. 8A shows the output of the brightness sensor 1. As described above, the brightness target value becomes the reference value Vs during the period in which the light output shown in FIG. 8B is the output set value Ls. During a period in which the light output Ls is lower than the output set value Ls, the brightness target value becomes the correction value Vm. By such an operation, the lower surface illuminance shown in FIG. 8C is kept substantially higher than the set illuminance Is, and the disadvantage that the lower surface illuminance is significantly lower than the set illuminance Is as in the conventional configuration is solved. Can be avoided. A chain line in FIG. 8 indicates a case where the brightness target value is fixed to the reference value Vs as in the conventional configuration.

When the external light decreases while the brightness target value is set to the correction value Vm, the output Vt of the brightness sensor 1 is calculated by the calculated value Vt obtained from the table.
When the value substantially coincides with c (when an appropriate range is determined for Vc and Vt falls within the range), it is regarded that external light has disappeared, and the brightness target value is returned to Vs. Other configurations and operations are the same as those of the first embodiment.

(Fourth Embodiment) In this embodiment, the arithmetic unit 2b performs the following control while performing feedback control. That is, similarly to the other embodiments, first, the reference value Vs of the brightness target value and the output target value Ls are set so that the lower surface illuminance becomes the target illuminance Is in the absence of external light, and the reference value of the brightness target value is set. The storage unit 2 stores the value Vs and the output target value Ls.
Stored in a. Next, when the light output of the lamp 4 can be considered to be stable during the feedback control (when the light output of the lamp 4 is within a specified range within a specified time), the light output Lt at that time and the memory are stored. The output target value Ls stored in the unit 2a is compared. In the present embodiment, in addition to the above-described reference value Vs, an upper correction value Vm higher than the reference value Vs and a lower correction value Vn lower than the reference value Vs are set as the brightness target values (FIG. 9A )reference). Thus, if Lt <Ls, the brightness target value becomes the reference value Vs
If so, the brightness target value is raised from the reference value Vs to the upper correction value Vm, and if the brightness target value is the lower correction value Vn, the brightness target value is raised from the lower correction value Vn to the reference value Vs. Lt
If> Ls, the brightness target value is reduced from the reference value Vs to the lower correction value Vn if the brightness target value is the reference value Vs, and the brightness target value is raised to the upper correction value if the brightness target value is the upper correction value Vm. Vm is reduced to the reference value Vs.

FIG. 9 shows the operation of this embodiment on the time axis. The meaning of each symbol in FIG. 9 is the same as in FIG.
After setting the reference value Vs of the brightness target value (indicated by a circle 0), if the illuminated surface is illuminated by external light, the output of the brightness sensor 1 becomes output unless feedback control is performed. Increase (state). here,
The arithmetic unit 2b performs feedback control in a direction to reduce the light output of the lamp 4, and outputs the brightness sensor 1 with the reference value Vs
The light output of the lamp 4 is controlled so as to be as follows (state).
At this time, since the light output of the lamp 4 is lower than when the output target value Ls is set, Lt <Ls, and the brightness target value is raised to the upper correction value Vm. That is, the light output of the lamp 4 is feedback-controlled so that the output of the brightness sensor 1 becomes the brightness upper correction value Vm,
Compared to the case where the brightness target value is set to the reference value Vs, the amount of decrease in the light output is small, and as a result, it is possible to prevent the lower surface illuminance from greatly decreasing from the set illuminance Is (state).

When the external light decreases from this state, if the target brightness value is maintained at the upper correction value Vm, the lower surface illuminance may become higher than the set illuminance Is (state). Here, since Lt> Ls, the brightness target value is reduced from the upper correction value Vm to the reference value Vs. Even if the brightness target value is reduced in this way, Lt
When> Ls, the brightness target value is reduced from the reference value Vs to the lower correction value Vn (state), and as a result, a state in which the lower surface illuminance is higher than the set illuminance Is is avoided.
Other configurations and operations are the same as those of the first embodiment.

(Fifth Embodiment) In each of the embodiments described above, the brightness target value is fixedly set to one or two levels. In the present embodiment, the lamp 4 at each time is set. The brightness target value is changed stepwise based on the difference between the light output Lt and the output target value Ls. For example, the reference value Vs of the brightness target value used in the first embodiment, etc.
A plurality of levels of brightness target values are set between the correction value Vm and the correction value Vm, and one of the brightness target values is selected according to the magnitude of (Ls-Lt). In the present embodiment, the brightness target value is set in five steps from Vs to Vm.
Control is performed so that the brightness target value approaches the correction value Vm as (Ls-Lt) increases. That is, since the change width of the brightness target value can be made smaller than that in the first embodiment, it is possible to prevent the lower surface illuminance from becoming too higher than the set illuminance Is when the external light is small.
In other words, it becomes easier to maintain the set illuminance Is. Other configurations and operations are the same as those of the first embodiment. Also,
The configuration of the present embodiment can be applied to other than the first embodiment.

(Sixth Embodiment) This embodiment is different from FIG.
As shown in FIG. 1, a plurality of (two in the illustrated example) brightness sensors 1a and 1b having different spectral sensitivity characteristics are used, and the amount of external light is determined based on the relationship between the outputs of the two sensors 1a and 1b. The light output of the lamp 4 is controlled according to the amount of external light.

Assuming that two brightness sensors 1a and 1b are provided, the directional sensitivities Sa and Sb of the brightness sensors 1a and 1b are set as shown in FIG. That is, they are set so as to substantially match each other, or set so that one is included in the other. In FIG. 11B, the lighting equipment 5
The lighting device 3 and the lamp 4 shown in FIG. 1 are attached to a fixture body.

In this embodiment, the sensitivity is adjusted by the control block 2 so that the outputs of the brightness sensors 1a and 1b become substantially equal in the absence of external light, and thereafter, a desired illuminance (set illuminance) is obtained. Lighting control of the lighting apparatus 5 is performed as described above. When the desired illuminance is obtained, the outputs of the brightness sensors 1a and 1b are stored in the control block 2,
Thereafter, feedback control is performed so that the output of the brightness sensor 1a maintains the value stored in the control block 2. However, the feedback control in the present embodiment is performed under the following conditions. However, it is assumed that the brightness sensor 1a has higher sensitivity to daylight.

That is, when there is external light, there is a difference between the outputs Va and Vb of the brightness sensors 1a and 1b.
a-Vb is compared with a threshold value Ta, and when Va-Vb ≧ Ta, it is assumed that external light (natural light) has increased, and the output value of the brightness sensor 1a is corrected so that the lower surface illuminance does not fall below the set illuminance. It is. The correction amount is obtained by any one of the following arithmetic processing. 1. Correction amount = (Va−Vb) × k1 2. Correction amount = (Va−Vb) × k2 + k3 A table for (Va-Vb) is used. However, k1, k2, and k3 are constants.

As described above, the presence or absence of external light and the amount of external light can be detected by using the two brightness sensors 1a and 1b having different spectral sensitivity characteristics. By doing so, it is possible to keep the light output of the lighting fixture 5 at the set illuminance.

The correction amount for the output value of the brightness sensor 1a may be obtained as follows. That is, the output Va and Vb of the two brightness sensors 1a and 1b are
Conditions are set, and when these conditions 1 and 2 are satisfied, it is determined that the outside light has increased, and the correction amount is obtained as follows. Condition 1: Va−Vb ≧ T1 Condition 2: Vb−Va ≧ T2 When the condition 1 is satisfied, the correction amount is A, and when the condition 2 is satisfied, the correction amount is B. Where A ≧ 0, B
≧ 0 or A ≧ 0, B ≦ 0. 2. When one of the conditions 1 and 2 is satisfied, the correction amount =
| Va−Vb | × k4 3. When the condition 1 is satisfied, the correction amount = | Va−Vb
| × k5 When the condition 2 is satisfied, the correction amount = | Va−Vb | ×
k6 + k7, where k5, k6 and k7 are constants.

Further, when obtaining the correction amount, Va /
When Vb ≠ 1, it is also possible to determine that the external light has increased, and determine the correction amount as follows. 1. A table for (Va / Vb) is used. 2. (Va / Vb) × k8 × Vs + Vs where k8 is a constant and Vs is the output of the brightness sensor 1a with respect to the set illuminance when there is no external light. That is, the reference value of the brightness target value in the first embodiment.

In the above example, the feedback control is performed using only the output of the brightness sensor 1a. However, the feedback control is performed using the larger output of the outputs of the brightness sensors 1a and 1b, or the feedback control is performed using the smaller output. Feedback control may be performed using this output.

For example, since the spectral spectrum of natural light is different between morning and evening, the brightness sensor 1a has a spectrum which is significantly different from the spectral luminous efficiency when comparing the spectral spectrum of natural light in the morning with the spectral luminous efficiency. A component that does not respond to the component is used, and a sensor that does not respond to a spectral component that is significantly different from the spectral luminous characteristic when the spectral spectrum of natural light in the evening is compared with the spectral luminous characteristic is used for the brightness sensor 1b. Used. In this combination, if the brightness sensors 1a and 1b having the smaller output are used for feedback control, it is difficult to detect a light component far away from the relative luminous efficiency characteristic, and the illuminance according to the relative luminous efficiency characteristic is reduced. It will be easier to keep.

As shown in the above example,
It is desirable to use at least one of the brightness sensors 1a and 1b having a spectral sensitivity characteristic similar to the relative luminous efficiency characteristic. In the above example, two brightness sensors 1
Although a and 1b are used, three or more brightness sensors may be used. In this case, it is possible to maintain the lower surface illuminance at the set illuminance by appropriately using the various correction amounts described above for the output of each brightness sensor.

(Seventh Embodiment) This embodiment is different from the embodiment shown in FIG.
As shown in FIG. 2, a plurality of sets of the brightness sensors 1, 1a, 1b, the control block 2, and the luminaire 5 are provided, and data transmission between the respective sets via the signal line 6 is enabled. This is an example of the case. In the case of using such a configuration, if the external light is detected in one of the sets, the information can be transmitted to another set. Therefore, the amount of the external light can be detected in only one set. For example, in other sets, feedback control according to the amount of external light can be performed. In the example shown in the figure, the amount of external light is detected by providing two brightness sensors 1a and 1b at the set near the window. It is possible to do. Other configurations and operations are the same as those of the sixth embodiment.

(Eighth Embodiment) This embodiment relates to a sixth embodiment.
As in the embodiment, an illumination device using two brightness sensors having different spectral sensitivity characteristics and mixing two lamps having different spectral spectra (emission colors) of light output as lamps will be described. I do. The lamps used in the present embodiment each have the light output of the spectral spectrum shown in FIG. 13, and the brightness sensors have the spectral sensitivity characteristics shown in FIG. Now
The lamps shown in FIG. 13 are called lamps 1 and 2, respectively, and the brightness sensors shown in FIG. 13 are called sensors 1 and 2, respectively. When light from the lamp 1 enters the brightness sensor, When the output of the sensor 1 becomes larger than the output of the sensor 2 and the light from the lamp 2 enters the brightness sensor, the output of the sensor 2 becomes larger than the output of the sensor 1.

With such a relationship,
The outputs of the sensors 1 and 2 change as shown in FIGS. 14 to 22 according to the ratio of the light output of the lamps 1 and 2. Here, indicates sensor 1 and sensor 2, and the ratio in the upper right of each figure indicates the ratio of the light output of lamp 1 and lamp 2. Here, when the light output of the lamp 2 is controlled to be constant, the ratio occupied by the light output of the lamp 1 is plotted on the horizontal axis, and the ratio of the output of the sensor 2 to the output of the sensor 1 is plotted on the vertical axis. As described above, a constant relationship is obtained between the ratio of the light output of the lamp 1 and the lamp 2 and the ratio of the output of the sensor 1 and the sensor 2.

In this embodiment, the light output of the lamp 2 is controlled to be constant, and only the light output of the lamp 1 is feedback-controlled. Further, based on the light output before the end of the life of the lamp, the initial light output of the lamp is adjusted so as to obtain the light output. By dimming the initial light output of the lamp in this way, it is possible to keep the light output of the lamp substantially constant over time, and it is possible to save energy by dimming at the beginning of the lamp. it can. Light output of lamp 1 and sensor 1 and sensor 2
Is stored at the beginning of the lamp. By storing the relationship in this way, the ratio of the light output of the lamp 1 and the light output of the lamp 2 can be known from the output of the sensor 1 and the sensor 2.

Here, the light output of the lamp 2 is kept constant, but if used for a long time, the light output will be lower than at the beginning. When the light output decreases in this manner, when the stored output ratio of the sensor 1 and the sensor 2 is compared, the sensor 2
It can be seen that the output of is reduced. In such a state, if the target value of the feedback control is maintained in the original state, in order to compensate for the decrease in the light output of the lamp 2 by the lamp 1, the amount of the decrease in the light output of the lamp 1 is larger than the decrease in the light output of the lamp 1. Power will be consumed.

Therefore, in the present embodiment, when a decrease in the light output of the lamp 2 is detected based on the output ratio of the sensor 1 and the sensor 2, the target value of the feedback control is reduced according to the decrease. Here, the target value is reduced by a fixed value or is reduced until the ratio between the outputs of the sensors 1 and 2 reaches the stored value. In particular, if the latter control is performed, it is possible to easily return the feedback control target value to the original uncorrected target value when the lamp 2 is replaced. Other configurations and operations are the same as those of the sixth embodiment, and also in this embodiment, it is possible to suppress a change in the set illuminance due to external light.

(Ninth Embodiment) In the sixth embodiment, a plurality of brightness sensors 1a, 1a having different spectral sensitivity characteristics are provided.
The example using b was shown. In the following embodiments, specific examples of combinations of these brightness sensors 1a and 1b will be described.

In this embodiment, as shown in FIG. 24, an optical sensor is configured by arranging two brightness sensors 1a and 1b adjacent to one substrate 7. That is, the two brightness sensors 1a and 1b are arranged to detect light from the same area. In the present embodiment, one brightness sensor 1a has a spectral sensitivity characteristic similar to the relative luminous efficiency characteristic as shown by a curve A in FIG. 25, and the other brightness sensor 1b is shown by a curve B in FIG. As described above, the wavelength at which the sensitivity becomes maximum (hereinafter, referred to as “peak wavelength”) substantially coincides with the brightness sensor 1a (that is, the wavelength ranges where the sensitivity is near the maximum overlap with each other), and the wavelength is longer than the peak wavelength. On the side, the sensitivity is higher than that of the brightness sensor 1a. However, the sensitivity on the short wavelength side of the brightness sensor 1b is almost the same as that of the brightness sensor 1a. Therefore, the brightness sensor 1b
Has relatively high sensitivity even in the infrared region.

When a fluorescent lamp is used as the lamp 4, the spectral distribution of the lamp 4 has, for example, a characteristic shown by a curve A in FIG. 26, and the light from the lamp 4 hardly contains components in the infrared region or the ultraviolet region. On the other hand, natural light, which is external light, contains many components in the infrared region and the ultraviolet region as shown by the curve B in FIG. Therefore, when the two brightness sensors 1a and 1b having the above-described spectral sensitivity characteristics are used as the optical sensors, the outputs of the two brightness sensors 1a and 1b are output in a space where there is no window and no external light enters or at night. When the natural light, which is external light, substantially coincides with the light in the daytime or the like, the output of the brightness sensor 1b becomes larger than the output of the brightness sensor 1a. FIG. 27 shows the relationship between external light and illumination light and the outputs of the brightness sensors 1a and 1b.
When there is no external light, as shown in the left half of FIG. 27A, and when the amount of illumination light changes as shown in FIG. 27B, the outputs of the brightness sensors 1a and 1b become the outputs of FIG.
As shown in (d), the light intensity is substantially proportional to and substantially equal to the amount of illumination light. Also, when external light is present as in the right half of FIG. 27A, as can be seen by comparing FIG. 27C with FIG. 27D, the brightness sensor increases with the increase in external light. It can be seen that the output of the brightness sensor 1a increases more than the output of the brightness sensor 1a, and that the output of the brightness sensors 1a and 1b greatly differs when the external light increases. That is, if the outputs of the brightness sensors 1a and 1b are Oa and Ob, respectively,
When there is no external light, Oa ≒ Ob, and when there is external light, Oa <Ob. From this, the output difference (= Oa−Ob) between the two brightness sensors 1a and 1b is determined, or the ratio of the output of the brightness sensor 1b to the total output of the two brightness sensors 1b and 1b (= Ob) / (Oa + Ob))
, It is possible to detect the presence or absence of external light,
It is also possible to obtain information on the external light amount. As a result, it is possible to accurately correct the brightness target value according to the presence or absence of external light.

As the output of the brightness sensor 1 when the feedback control is performed in the control block 2, the output of the brightness sensor 1a may be used alone, but the sum of the outputs of the brightness sensors 1a and 1b may be used. It may be.
Other configurations and operations are the same as those of the sixth embodiment.

(Tenth Embodiment) This embodiment uses two brightness sensors 1a and 1b having different spectral sensitivity characteristics as in the ninth embodiment. However, in the ninth embodiment, the sensitivity of the brightness sensor 1b is higher than the brightness sensor 1a on the longer wavelength side than the peak wavelength, but in the present embodiment, as shown in FIG. The sensitivity sensor 1b has a higher sensitivity on the short wavelength side than the peak wavelength than the brightness sensor 1a. That is, the brightness sensor 1a has a spectral sensitivity characteristic similar to the relative luminous efficiency characteristic as shown by the curve A in FIG. 28, and the brightness sensor 1b has a longer wavelength from the peak wavelength as shown by the curve B in FIG. On the wavelength side, it has a spectral sensitivity characteristic that substantially matches the brightness sensor 1a, but on the wavelength side shorter than the peak wavelength, it has a spectral sensitivity characteristic that extends to the ultraviolet region.

As described in the ninth embodiment, the amount of external light, which is natural light, in the ultraviolet region is sufficiently larger than that of illumination light when a fluorescent lamp is used for the lamp 4. Therefore, the outputs of the brightness sensors 1a and 1b are substantially equal for the illumination light, but the output of the brightness sensor 1b is considerably larger than the output of the brightness sensor 1a for the external light. As a result, it is possible to obtain information on the presence or absence of external light and the amount of external light by comparing the outputs of the brightness sensors 1a and 1b. Furthermore, in the configuration of the present embodiment, even when a glass that blocks infrared rays such as heat insulating glass or heat shielding glass is used for a window, the presence or absence of external light is detected by detecting the presence or absence of ultraviolet light. Becomes possible. Other configurations and operations are the same as in the ninth embodiment.

(Eleventh Embodiment) This embodiment uses two brightness sensors 1a and 1b having different spectral sensitivity characteristics as in the ninth embodiment. However, in the present embodiment, a sensor having a spectral sensitivity characteristic similar to the relative luminous efficiency characteristic as shown by a curve A in FIG. 29 is used as the brightness sensor 1a, and a brightness sensor 1b is shown by a curve B in FIG. The peak wavelength substantially coincides with the brightness sensor 1a, and the brightness sensor 1a
Use a larger one. That is, the brightness sensor 1b has a spectral sensitivity characteristic covering an ultraviolet region and an infrared region.

As described in the ninth embodiment, since the amount of external light, which is natural light, in the ultraviolet region and the infrared region is greater than the illumination light when the fluorescent lamp is used for the lamp 4, the above-described spectral When two brightness sensors 1a and 1b having sensitivity characteristics are used, the output of the brightness sensor 1b becomes larger than the output of the brightness sensor 1a when external light is present. That is, as in the ninth embodiment, it is possible to obtain information regarding the presence or absence of external light and the amount of external light by comparing the magnitudes of the outputs of the brightness sensors 1a and 1b. Further, in the present embodiment, since the sensitivity of the brightness sensor 1b is larger than that of the brightness sensor 1a in both the infrared region and the ultraviolet region, a glass (adiabatic / ultraviolet cut glass or the like) that attenuates both infrared light and ultraviolet light is used. It is possible to distinguish between external light and illumination light even when is used for a window. That is, since the brightness sensor 1b has higher sensitivity than the brightness sensor 1a in both the infrared region and the ultraviolet region, the difference between the outputs of the brightness sensors 1a and 1b with respect to external light can be made large. Therefore, even when the amounts of infrared light and ultraviolet light are both attenuated by the window, it is possible to obtain a significant difference between the outputs of the brightness sensors 1a and 1b with respect to the external light. Other configurations and operations are the same as in the ninth embodiment.

(Twelfth Embodiment) In the ninth to eleventh embodiments, the spectral sensitivity characteristic of one brightness sensor 1a constituting the brightness sensor 1 is similar to the spectral luminous efficiency characteristic. Although the peak wavelengths in the spectral sensitivity characteristics of the two brightness sensors 1a and 1b are set near the center of the visible light region, in the present embodiment, the two brightness sensors 1a and 1b are set.
The peak wavelength in the spectral sensitivity characteristic b is set near the ultraviolet region as shown in FIG. That is, a sensor having a spectral sensitivity characteristic as shown by a curve A in FIG. 30 is used as the brightness sensor 1a, and the brightness sensor 1b shown in FIG.
The one having a spectral sensitivity characteristic like the curve B in the above is used. Here, the peak wavelengths of the two brightness sensors 1a and 1b are substantially matched, and the sensitivity of the brightness sensor 1b is larger than that of the brightness sensor 1a in the visible light region longer than the peak wavelength and shorter than the peak wavelength. On the wavelength side (i.e., in the ultraviolet region), it is almost the same as the brightness sensor 1a.

When such brightness sensors 1a and 1b are used, the outputs of the brightness sensors 1a and 1b are different between the external light which is natural light and the illumination light when a fluorescent lamp is used as the lamp 4, so that Brightness sensor 1 as in the ninth embodiment.
It is possible to obtain information on the presence or absence of external light and the amount of external light based on the outputs a and 1b. Other configurations and operations are the same as in the ninth embodiment.

(Thirteenth Embodiment) In the twelfth embodiment, the peak wavelength in the spectral sensitivity characteristics of the brightness sensors 1a and 1b is set near the ultraviolet region. As shown in the figure, it is set near the infrared region. That is, a sensor having a spectral sensitivity characteristic as shown by a curve A in FIG. 31 is used as the brightness sensor 1a,
As the brightness sensor 1b, a sensor having a spectral sensitivity characteristic as shown by a curve B in FIG. 30 is used. Here, the peak wavelengths of the two brightness sensors 1a and 1b are made substantially coincident, and the sensitivity of the brightness sensor 1b is made almost coincident with the brightness sensor 1a on the longer wavelength side (that is, in the infrared region) than the peak wavelength. In the visible light region on the shorter wavelength side than the brightness sensor 1a, it is set larger.

When such brightness sensors 1a and 1b are used, the outputs of the brightness sensors 1a and 1b are different between the external light which is natural light and the illumination light when a fluorescent lamp is used as the lamp 4, so that Brightness sensor 1 as in the ninth embodiment.
It is possible to obtain information on the presence or absence of external light and the amount of external light based on the outputs a and 1b. Other configurations and operations are the same as in the ninth embodiment.

(Fourteenth Embodiment) In the ninth to thirteenth embodiments, the two brightness sensors 1
Although the peak wavelengths of the two brightness sensors 1a and 1b are substantially matched, in the present embodiment, as shown in FIG.
The peak wavelength of 1b is different. In the illustrated example, a sensor having a spectral sensitivity characteristic shown by a curve A in FIG. 32 is used as the brightness sensor 1a, and a sensor having a spectral sensitivity characteristic shown by a curve B in FIG. 32 is used as the brightness sensor 1b. That is, the peak wavelength of the brightness sensor 1a is near the ultraviolet region, and that of the brightness sensor 1b is near the infrared region. In the illustrated example, both the brightness sensors 1a and 1b are set so as to have an area having sensitivity near the center of the visible light area. However, this is not essential, and the spectral sensitivity characteristics of the brightness sensors 1a and 1b do not need to overlap each other.

When the brightness sensors 1a and 1b having the spectral sensitivity characteristics shown in FIG. 32 are used, the outputs as shown in FIGS. 33 (c) and 33 (d) are obtained for the outputs of the brightness sensors 1a and 1b. Can be That is, when there is no external light as in the left half of FIG. 33A, when the amount of illumination light changes as shown in FIG.
The output of 1b is substantially proportional to and substantially equal to the amount of illumination light as shown in FIGS. FIG. 33 (a)
When external light exists as in the right half of FIG.
Assuming that the illumination light is constant as shown in FIG.
As can be seen from a comparison between FIG. 33C and FIG. 33D, the output of the brightness sensor 1a increases more than the output of the brightness sensor 1b as the external light increases. A large difference occurs between the outputs of the brightness sensors 1a and 1b. In short, the sensitivity of the brightness sensor 1a is higher than that of the brightness sensor 1b with respect to external light that is natural light,
By using the relationship between the outputs of the brightness sensors 1a and 1b, it is possible to obtain information on the presence or absence of external light and the amount of external light. Other configurations and operations are the same as in the ninth embodiment.

Incidentally, the brightness sensors 1a, 1a described in the present embodiment in the sixth embodiment shown in FIG.
FIG. 34 shows an operation example when b is applied. As shown in FIG. 34A, the outputs of the brightness sensors 1a and 1b (the outputs of the brightness sensors 1a are indicated by a curve A and the brightness sensors 1b Output is indicated by the curve b) are both small,
At the time when the external light, which is natural light, increases at dawn (in the illustrated example, about 5:00 am), the output of the brightness sensor 1b increases more than the output of the brightness sensor 1a because the amount of incident infrared light increases. FIG. 34B shows the brightness sensor 1a.
Ratio of the output of the brightness sensor 1b to the output of ((= (output of brightness sensor 1b) / (output of brightness sensor 1a))
It can be seen that this ratio increases during the daytime when there is more external light than at night. Therefore, the brightness sensors 1a,
The presence or absence of external light can be determined based on the ratio between the absolute value of the output of 1b and the outputs of the brightness sensors 1a and 1b. In this way, the presence or absence of external light is determined, and the brightness target value is changed in accordance with the presence or absence of external light, so that the lower surface illuminance can be maintained in a favorable state throughout the day regardless of the change in external light. It is. Further, since the output ratio of each of the brightness sensors 1a and 1b changes as shown in FIG. 34B, it is possible to know the increase or decrease of the external light by the change rate of the output ratio (change of inclination). The presence or absence of external light may be determined based on the rate of change.

In the sixth to fourteenth embodiments, an example is shown in which two brightness sensors 1a and 1b are used. However, even if the number of brightness sensors 1a and 1b is three or more, Good.

[0107]

According to the first to twentieth aspects of the present invention, a brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and an output from the brightness sensor are provided. A control block for performing feedback control of the light output of the light source, wherein the control block determines the presence or absence of external light on the illuminated surface based on the output of the brightness sensor, and the illuminance of the illuminated surface is maintained at the set illuminance. As described above, the target value of the feedback control is controlled according to the presence or absence of external light, so that when external light such as natural light is obtained, it is possible to suppress the illuminance of the irradiated surface from falling below the set illuminance. It is possible to suppress the sense of darkness that has occurred when natural light is obtained.

According to a sixth aspect of the present invention, in the second to fifth aspects of the present invention, the brightness target value is changed by a constant value regardless of the difference between the light output and the output target value. When external light is obtained, it is possible to suppress the illuminance of the irradiated surface from falling below the set illuminance, and to suppress the sense of darkness that occurred when natural light was obtained. it can. Further, since the brightness target value is changed by a constant value, control is easy.

According to a seventh aspect of the present invention, in the second to fifth aspects of the present invention, the brightness target value is set in a plurality of stages according to a difference between the light output and the output target value.
When external light such as natural light is obtained, it is possible to suppress the illuminance of the irradiated surface from being lower than the set illuminance,
It is possible to suppress the sense of darkness that has occurred when natural light is being obtained. Moreover, since the brightness target value is set in multiple steps based on the difference between the light output and the output target value,
The illuminance is easily maintained by the set illuminance, and especially when the external light is small, the illuminance does not greatly exceed the set illuminance, and the effect of energy saving by the feedback control can be maintained.

According to a tenth aspect of the present invention, there is provided a brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and a feedback of an optical output of a light source based on an output of the brightness sensor. And a control block for controlling,
The control block determines a change in light color on the surface to be illuminated based on the output of the brightness sensor. It performs feedback control and can suppress the illuminance of the illuminated surface from dropping below the set illuminance when external light such as natural light is obtained, which occurs when natural light is obtained. The sense of darkness that has been occurring can be suppressed. In particular, the set illuminance can be maintained even when the light color of the irradiated surface changes.

The invention according to claims 21 to 30 is an optical sensor for receiving reflected light from a surface to be irradiated which is to detect the presence or absence of external light irradiation, wherein a plurality of light sensors having spectral sensitivity characteristics different from each other are provided. Since the brightness sensors are provided, it is possible to detect the presence or absence of external light on the surface to be illuminated by utilizing the difference in spectral sensitivity characteristics between the brightness sensors.

According to a thirty-first to thirty-fourth aspect of the present invention, there is provided an optical sensor according to any one of the twenty-first to thirty-fourth aspects, and a control block for feedback-controlling the optical output of the light source based on the output of the optical sensor. The control block determines the presence or absence of external light on the illuminated surface based on the output of the optical sensor, and sets the target of feedback control according to the presence or absence of external light so that the illuminance of the illuminated surface is maintained at the set illuminance. By controlling the value, it is possible to easily determine the presence or absence of external light by using the optical sensor according to any one of claims 21 to 30, and it is possible to easily determine the presence or absence of external light. Light output can be controlled accurately. That is, when external light such as natural light is obtained, it is possible to suppress the illuminance of the illuminated surface from lowering than the set illuminance, and to reduce the sense of darkness that occurred when natural light was obtained. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is an operation explanatory diagram showing the first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the above.

FIG. 4 is an operation explanatory diagram showing another example of the above.

FIG. 5 is an operation explanatory view showing a second embodiment of the present invention.

FIG. 6 is an operation explanatory view of the above.

FIG. 7 is an operation explanatory view showing a third embodiment of the present invention.

FIG. 8 is an operation explanatory view of the above.

FIG. 9 is an operation explanatory view showing a fourth embodiment of the present invention.

FIG. 10 is an operation explanatory view showing a fifth embodiment of the present invention.

11A and 11B show a sixth embodiment of the present invention, wherein FIG. 11A is a schematic configuration diagram, and FIG. 11B is a block diagram.

FIG. 12 is a block diagram showing a seventh embodiment of the present invention.

FIG. 13 is an operation explanatory view showing an eighth embodiment of the present invention.

FIG. 14 is an operation explanatory view of the above.

FIG. 15 is an explanatory diagram of the operation of the above.

FIG. 16 is an operation explanatory view of the above.

FIG. 17 is an operation explanatory view of the above.

FIG. 18 is an operation explanatory view of the above.

FIG. 19 is a diagram illustrating the operation of the above.

FIG. 20 is an explanatory diagram of the operation of the above.

FIG. 21 is an explanatory diagram of the above operation.

FIG. 22 is an explanatory diagram of the above operation.

FIG. 23 is an explanatory diagram of the operation of the above.

FIG. 24 is a front view showing a brightness sensor used in a ninth embodiment of the present invention.

FIG. 25 is an explanatory diagram of the operation of the above.

FIG. 26 is a diagram illustrating a relationship between illumination light and external light.

FIG. 27 is an explanatory diagram of the operation of the above.

FIG. 28 is an operation explanatory diagram of the tenth embodiment of the present invention.

FIG. 29 is an operation explanatory diagram of the eleventh embodiment of the present invention.

FIG. 30 is an operation explanatory diagram of the twelfth embodiment of the present invention.

FIG. 31 is an operation explanatory diagram of the thirteenth embodiment of the present invention.

FIG. 32 is an operation explanatory diagram of the fourteenth embodiment of the present invention.

FIG. 33 is an explanatory diagram of the operation of the above.

FIG. 34 is an explanatory diagram of the above operation.

FIG. 35 is a block diagram showing a conventional example.

FIG. 36 is an explanatory diagram of the above operation.

FIG. 37 is an explanatory diagram of the operation of the above.

FIG. 38 is an explanatory diagram of the operation of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brightness sensor 1a, 1b Brightness sensor 2 Control block 2a Storage part 2b Calculation part 3 Lighting device 4 Lamp 5 Lighting fixture

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Yamaguchi 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. Term (reference) 3K073 AA67 AA83 BA26 BA27 BA28 CF13 CG01 CG02 CG42 CH21 CJ16 CJ22

Claims (34)

[Claims] 1. A brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and a control block for feedback-controlling the light output of a light source based on the output of the brightness sensor. The control block determines the presence or absence of external light on the illuminated surface based on the output of the brightness sensor, and performs feedback control according to the presence or absence of external light so that the illuminance of the illuminated surface is maintained at the set illuminance. A lighting device for controlling a target value of the lighting device. 2. The control block stores an output of a brightness sensor when a set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and stores an optical output of a light source as an output target value. When the output of the brightness sensor is larger than the reference value of the brightness target value and the light output is smaller than the output target value, the brightness target value is set to be larger than the reference value, and the light output is larger than the output target value. 2. The lighting device according to claim 1, wherein the brightness target value is sometimes set as a reference value. 3. The control block stores an output of a brightness sensor when a set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and stores a light output of a light source as an output target value. A set of a reference value of the brightness target value and an output target value and a set of a brightness sensor output and a light source light output on a straight line passing through the origin are tabulated, and the brightness obtained by comparing the light output with the table is obtained. When the actual output of the brightness sensor is larger than the output of the sensor, the brightness target value is set to be larger than the reference value, and the output of the brightness sensor obtained by comparing the light output with the table is used as the actual output of the brightness sensor. 2. The lighting device according to claim 1, wherein the brightness target value is set as a reference value when the output is substantially equal to the output. 4. The control block stores an output of a brightness sensor when a set illuminance is obtained in a predetermined state as a reference value of a brightness target value, and stores a light output of a light source as an output target value. The set of the output of the brightness sensor and the light output of the light source on a straight line passing through a set of the reference value and the output target value of the brightness target value and at least one set of the output of the brightness sensor and the light output. If the actual output of the brightness sensor is larger than the output of the brightness sensor obtained by collating the light output with the table, set the brightness target value to be larger than the reference value, and compare the light output with the table. 2. The lighting device according to claim 1, wherein the target brightness value is used as a reference value when the output of the brightness sensor obtained by the calculation is substantially equal to the actual output of the brightness sensor. 5. The control block stores the output of a brightness sensor when a set illuminance is obtained in a predetermined state as a brightness target value, and stores the light output of a light source as an output target value, and then stably stores the output. 2. The brightness target value is increased when the light output when the light output is smaller than the output target value, and the brightness target value is reduced when the light output when the light output is stable is larger than the output target value. Lighting equipment. 6. The lighting device according to claim 2, wherein the brightness target value is changed by a constant value regardless of a difference between the light output and the output target value. 7. The illumination according to claim 2, wherein the brightness target value is set in a plurality of stages according to a difference between the light output and the output target value. apparatus. 8. The brightness target value has an upper limit value and a lower limit value, and the target of the brightness target value is at least one of a median value, an upper limit value, and a lower limit value. The lighting device according to any one of claims 2 to 5, wherein: 9. The reference value of the brightness target value is stored in at least one of a state in which the surface to be irradiated is not irradiated with external light and a state in which the brightness sensor output is stable during feedback control. The lighting device according to any one of claims 2 to 5, characterized in that: 10. A brightness sensor for detecting the brightness of a surface to be illuminated by receiving light reflected from the surface to be illuminated, and a control block for feedback-controlling the light output of a light source based on the output of the brightness sensor. The control block determines a change in light color on the illuminated surface based on the output of the brightness sensor, and controls external light so that the illuminance on the illuminated surface is maintained at the set illuminance regardless of the light color. An illumination device, wherein feedback control is performed according to presence or absence. 11. The brightness sensor according to claim 10, wherein a plurality of brightness sensors having different spectral sensitivity characteristics are provided, and a light output of a light source is set based on a difference between outputs of the brightness sensors. Lighting equipment. 12. The control block is preset with a relationship between the output of the brightness sensor and the light output of the light source, and the light output of the light source is applied by applying the relationship to the output of the brightness sensor. 2. The method of claim 1, wherein the setting is performed.
The lighting device according to claim 1. 13. The brightness sensor according to claim 10, wherein a plurality of brightness sensors having different spectral sensitivity characteristics are provided, and a light output of a light source is set based on a ratio of outputs of the brightness sensors. Lighting equipment. 14. The control block is preset with a relationship between the output of the brightness sensor and the light output of the light source, and the light output of the light source is applied by applying the relationship to the output of the brightness sensor. 2. The method of claim 1, wherein the setting is performed.
3. The lighting device according to 3. 15. A plurality of brightness sensors having different spectral sensitivity characteristics are provided, and a brightness sensor used for feedback control is selected by comparing a difference between outputs of the brightness sensors. Claim 10
The lighting device according to the above. 16. A brightness sensor, wherein a plurality of brightness sensors having different spectral sensitivity characteristics are provided, and a brightness sensor used for feedback control is selected by comparing an output ratio of each brightness sensor. Claim 10
The lighting device according to the above. 17. The lighting device according to claim 11, wherein the at least one brightness sensor has a spectral sensitivity characteristic similar to a human relative luminous efficiency characteristic. 18. The lighting device according to claim 11, wherein the brightness sensor that does not perform feedback control uses a sensor having high sensitivity to a specific wavelength. 19. The lighting device according to claim 11, wherein the brightness sensor has a spectral sensitivity characteristic having high sensitivity to a light component to be detected. 20. The light source, wherein a plurality of light sources having different emission colors are provided, and the brightness sensor has high sensitivity to a wavelength component having a large difference in light spectrum component between the light sources. The lighting device according to any one of claims 11 to 16. 21. An optical sensor for receiving reflected light from a surface to be irradiated to detect the presence or absence of external light irradiation, comprising a plurality of brightness sensors having mutually different spectral sensitivity characteristics. Light sensor. 22. The optical sensor according to claim 21, wherein wavelength ranges where the sensitivity is near the maximum in the spectral sensitivity characteristics of each of the brightness sensors overlap each other. 23. At least one brightness sensor has sensitivity similar to that of another brightness sensor on a shorter wavelength side than a wavelength at which output is maximum in spectral sensitivity characteristics, and has another brightness sensor on a longer wavelength side. 23. The optical sensor according to claim 22, wherein the optical sensor has higher sensitivity than the optical sensor. 24. At least one brightness sensor has a sensitivity similar to that of another brightness sensor on a longer wavelength side than a wavelength at which output is maximum in a spectral sensitivity characteristic and has another brightness sensor on a shorter wavelength side. 23. The optical sensor according to claim 22, wherein the optical sensor has higher sensitivity than the optical sensor. 25. The at least one brightness sensor is higher in sensitivity on both the long wavelength side and the short wavelength side than the wavelength at which the output in the spectral sensitivity characteristic is maximum, than the other brightness sensors. The optical sensor according to claim 22. 26. The optical sensor according to claim 23, wherein the other brightness sensor has a spectral sensitivity characteristic similar to human's relative luminous efficiency characteristic. 27. The optical sensor according to claim 22, wherein the wavelength at which the sensitivity is maximum in the spectral sensitivity characteristics of each of the brightness sensors is in a visible light region. 28. The optical sensor according to claim 21, wherein, in the spectral sensitivity characteristics of each of the brightness sensors, wavelength regions whose sensitivity is near the maximum do not overlap each other. 29. The optical sensor according to claim 28, wherein the wavelength ranges having sensitivity in the spectral sensitivity characteristics of each of the brightness sensors do not overlap with each other. 30. The optical sensor according to claim 28, wherein a part of a wavelength region having sensitivity in the spectral sensitivity characteristics of each of the brightness sensors overlaps with each other. 31. An optical sensor according to claim 21, further comprising: a control block that feedback-controls an optical output of a light source based on an output of the optical sensor, wherein the control block includes Determining the presence or absence of external light on the surface to be illuminated based on the output, and controlling the target value of the feedback control according to the presence or absence of external light so that the illuminance of the surface to be illuminated is maintained at the set illuminance. Lighting equipment. 32. The lighting device according to claim 31, wherein the control block determines the presence or absence of external light by comparing the outputs of the brightness sensors. 33. The lighting device according to claim 31, wherein the control block determines the presence or absence of external light by comparing the ratio of the outputs of the brightness sensors. 34. The lighting device according to claim 31, wherein the control block determines the presence or absence of external light based on a change in a gradient of a ratio between outputs of the brightness sensors.