JP4747529B2 - lighting equipment - Google Patents

Description

  The present invention relates to a lighting fixture including an illuminance sensor.

Conventionally, there has been a luminaire provided with a control unit that controls the light output ratio of a light source so as to make the illuminance of an irradiated surface constant by using an illuminance sensor. For example, the illuminance sensor outputs a voltage proportional to the detected illuminance of the irradiated surface, and the control unit stores the sensor voltage of the illuminance sensor at which the irradiated surface becomes the target illuminance, and the sensor voltage is stored. The light output ratio of the light source was controlled so as to be a voltage. (For example, see Patent Document 1)
JP 58-53187 A

  Usually, the target sensor voltage (target value) setting of the sensor voltage for adjusting the illuminance is performed after the installation of the lighting fixture. After the target sensor voltage is set, when the reflectance of the irradiated surface is changed due to a layout change or the like, it is necessary to change the target sensor voltage setting.

  FIG. 14 shows the relationship of the sensor voltage with respect to the illuminated surface illumination before and after the layout change. For example, before the layout change, as indicated by the straight line Y10, the set illuminance of the irradiated surface is set to 700 lx, and the target sensor voltage at which the illuminance is set is 3.5V. If the reflectance of the irradiated surface increases by 10% due to the layout change, the relationship of the sensor voltage to the illuminance of the irradiated surface, which is the basis for setting the target sensor voltage, is changed to a straight line Y11, and the increase in reflectance is a straight line Y10. It appears as a change to a straight line Y11 having a larger slope than that. As a result of the increase in reflectance by 10%, the illuminance sensor attached to the ceiling obtains an input that is 10% larger than before the layout change at the same illuminated surface illuminance, and the sensor voltage is also about 10% larger (3. 5V × 1.1 = 3.85V) is output. However, since the target sensor voltage setting has not been changed, the output of the light source is changed so as to be the target sensor voltage (3.5 V) before the layout change, and the illumination intensity of the irradiated surface is about 10%. It is controlled so as to decrease and darken (700 lx / 1.1 = 636 lx). In this case, it is necessary to reset the target sensor voltage to 3.85V. On the other hand, if the target sensor voltage setting is not changed when the reflectance is reduced by 10%, the brightness is controlled to be about 10% brighter. In the actual environment, the influence of the reflectance of floors, walls, ceilings, etc. is mutually affected, so this is not required by the simple calculation as described above, but the target sensor voltage setting changes each time the environment changes. If not performed, the illuminated surface illuminance is not controlled to an appropriate brightness as described above.

  The present invention has been made in view of the above-mentioned reasons, and the purpose thereof is a lighting fixture that can control the brightness of the irradiated surface to a constant level even when the reflectance of the irradiated surface changes due to a layout change or the like. Is to provide.

  The invention according to claim 1 is a light source, an illuminance sensor that measures the illuminance of the illuminated surface illuminated by the light source with reflected light, and a light source so that the illuminance of the illuminated surface is constant based on the output value of the illuminance sensor A control unit that controls the light output of the light source, the control unit corresponds to the light output ratio of the light source in the night specified by the night specifying unit, the night specifying unit specifying the night without daylight, and the light output ratio Illuminance when the light output ratio of the light source measured by the first measurement unit and the output value of the illuminance sensor are set to a predetermined light output ratio at night. A calculation unit that calculates the output value of the sensor and sets the calculation result as a target value, and controls the light output of the light source so that the output value of the illuminance sensor becomes the target value at least in the daytime. Features.

  According to this invention, it is possible to automatically set the target value of the illuminance sensor output used when controlling the light output of the light source, and moreover, it is possible to appropriately cope with the change in the reflectance of the irradiated surface. Even if the reflectance of the irradiated surface changes due to a layout change or the like, the brightness of the irradiated surface can be controlled to be constant.

  According to a second aspect of the present invention, in the first aspect, the control unit turns on the light source with the predetermined light output ratio fixed at night, and the output value of the illuminance sensor at this time is set as the target value. It is characterized by doing.

  According to the present invention, the lighting control that reacts to the fluctuation of the brightness due to the blinking of the adjacent circuit-divided lighting fixtures or the movement of the person is not performed at night. Never give to.

  A third aspect of the present invention is the second aspect of the first aspect, wherein the nighttime specifying unit measures the light output ratio of the light source and the output value of the illuminance sensor corresponding to the light output ratio a plurality of times a day. It is characterized in that the time when the value obtained by dividing the output value of the illuminance sensor measured by the measurement unit and the second measurement unit by the light output ratio of the light source is the lowest among a plurality of measurement results is specified at night.

  According to this invention, it can be configured at low cost without using a timer in the night specific part.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the predetermined light output ratio is a value corresponding to a luminous flux decay rate based on a cumulative lighting time of the light source.

  According to this invention, it is possible to prevent a decrease in brightness due to the cumulative lighting time of the light source, and to maintain the illuminance of the irradiated surface constant throughout the life of the light source.

  As described above, in the present invention, the output value of the illuminance sensor at the predetermined light output ratio at night is calculated from the light output ratio of the light source and the output value of the illuminance sensor, and the calculation result is set as the target value. Because the light output of the light source is controlled so that the output value of the illuminance sensor becomes the target value at least during the daytime, the brightness of the irradiated surface can be improved even if the reflectance of the irradiated surface changes due to layout changes, etc. There is an effect that it is possible to provide a lighting apparatus capable of controlling the thickness to a certain level.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The lighting fixture A of the present embodiment is integrally provided with an illuminance sensor 12 and is attached to a ceiling B such as an office as shown in FIG. A voltage value (analog signal) corresponding to the amount of reflected light from the irradiated surface F is output as a sensor voltage. Here, the illuminance sensor 12 includes not only reflected light from the illuminated surface F of light output from the luminaire A but also reflected light from the illuminated surface F of external light such as daylight entering through an office window. Incident.

  In the luminaire A, the illuminance of the irradiated surface is substantially constant based on the light source 11 that illuminates the irradiated surface, the above-described illuminance sensor 12 that detects the illuminance of the irradiated surface with reflected light, and the sensor voltage of the illuminance sensor 12. The control unit 13 controls the light output ratio of the light source 11 so that

  The control unit 13 is specified by the amplification circuit 14 that amplifies the sensor voltage from the illuminance sensor 12, the night specifying unit 15 that specifies the night without daylight by recognizing the time by a timer or the like, and the night specifying unit 15 The measurement unit 16 that measures the light output ratio of the light source 11 at night and the sensor voltage of the illuminance sensor 12 through the amplifier circuit 14 and the output voltage (target sensor voltage) of the illuminance sensor 12 that is the target value for illumination control The calculation unit 17 includes a memory 18 that stores electrical signals and setting values from the measurement unit 16 and the calculation unit 17, and a dimming signal output unit 19 that outputs a dimming control signal to the light source 11.

  Hereinafter, operation | movement of the lighting fixture A of this embodiment is demonstrated. First, the dimming signal output unit 19 normally sets the light output ratio of the light source 11 so that the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 becomes the target sensor voltage calculated by the calculation unit 17 regardless of day or night. Control. In order to determine the target sensor voltage, it is necessary to grasp the sensor voltage of the illuminance sensor 12 when the light source 11 is turned on at a predetermined light output ratio in the absence of daylight. This is because if there is no daylight, the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 are in a proportional relationship.

  Here, the luminaire A is arranged and designed so that the illuminance in the room can be maintained at the end of its lifetime, and a correction coefficient is set in consideration of a decrease in luminous flux at the end of the lifetime of the light source 11 at the time of this arrangement design. The predetermined light output ratio is the maintenance rate. In the case of an exposure type incandescent lamp fixture generally used for indoor lighting, the maintenance rate is 0.88, and therefore the predetermined light output ratio is also 0.88 ( 88%).

  By using a one-day timer that can determine only the time, the night identification unit 15 identifies the time zone from the latest sunset time to the earliest sunrise time for each location throughout the year as nighttime, and grasps the state without daylight. ing. In addition, if an annual timer that can grasp the date and time is used, the time zone from the latest sunset time to the earliest sunrise time can be specified for each season for each location.

  Then, the measurement unit 16 measures the light output ratio of the light source 11 at night and the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 and stores the measurement result in the memory 18.

The calculating unit 17 calculates the light source at night from the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 stored in the memory 18 after the night specifying unit 15 specifies the night until the power is shut off. 11 and the average sensor voltage of the illuminance sensor 12 are obtained, and the target sensor voltage (set for the next day) at a predetermined light output ratio (= 88%) is obtained by the following equation, and the target sensor voltage is stored in the memory. 18.
Target sensor voltage = (average sensor voltage at night × predetermined target light output ratio (88%)) / average light output ratio at night The dimming signal output unit 19 reads the target sensor voltage from the memory 18 at the next power-on. And the dimming control is performed so that the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 becomes the target sensor voltage.

  The average light output ratio at night is calculated from the measurement result of the light output ratio stored in the memory 18 by the measurement unit 16 measuring the light output ratio from the dimming control signal output from the dimming signal output unit 19. Calculated. As the dimming control signal, for example, a pulse signal of a PWM (Pulse Width Modulation) method having an amplitude of 10 V and a cycle Tc = 1 ms as shown in FIGS. 3A and 3B is used, and a duty ratio (= per cycle). The on-time Ton / cycle Tc × 100 (%)) is changed to change the light output ratio of the light source 11. For example, the dimming control signal shown in FIG. 3A has a duty ratio larger than that of the dimming control signal shown in FIG. Therefore, by storing the relationship between the duty ratio of the dimming control signal and the light output ratio in the memory 18, the measuring unit 16 can calculate the light output ratio from the duty ratio of the dimming control signal.

  Next, the specific operation of the lighting fixture A will be described with reference to FIG. First, since the target sensor voltage is not stored in the memory 18 at the time of lighting fixture installation (the first day), the dimming signal output unit 19 does not perform dimming control by the sensor voltage output by the illuminance sensor 12, The light source 11 is turned on at a fixed light output ratio of 88% regardless of day or night. However, in order to determine the target sensor voltage on the second day, the sensor voltage of the illuminance sensor 12 is measured by the measuring unit 16 and stored in the memory 18 only at night specified by the night specifying unit 15. Then, the calculation unit 17 reads out the sensor voltage stored in the memory 18 after the night specifying unit 15 specifies the night until the power is shut off, and calculates the average sensor voltage at night. In the present embodiment, the average sensor voltage at night is 3.5 V with respect to the average light output ratio of 88% at night on the first day, and the calculation unit 17 sets the target sensor voltage on the second day to [night on the first day] Average sensor voltage (3.5V) × target predetermined light output ratio (88%) / day 1 night average light output ratio (88%) = 3.5V], and the calculation result (3 .5V) is stored in the memory 18. On the second day, the dimming signal output unit 19 reads out the target sensor voltage (the calculation result at night of the first day: 3.5 V) stored in the memory 18 when the power is turned on, and the target sensor on the second day. Set as voltage.

  On the (N + 1) th day after the second day, the dimming signal output unit 19 usually changes the light output ratio of the light source 11 regardless of day and night, and the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 is set when the power is turned on. The light output control of the light source 11 is performed only in the time period specified by the night specifying unit 15 to be night time in order to determine the target sensor voltage on the (N + 2) th day. The ratio and the sensor voltage of the illuminance sensor 12 are measured by the measuring unit 16 and stored in the memory 18. Then, the calculation unit 17 reads the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 stored in the memory 18 after the night is specified by the night specifying unit 15 until the power is turned off. The average sensor output voltage and the average sensor voltage are calculated, and the target sensor voltage on the (N + 2) th day is calculated by [N + 1 day night average sensor voltage × target predetermined light output ratio (88%) / N + 1 day night] The average light output ratio] is calculated, and the calculation result is stored in the memory 18. On the N + 2 day, the dimming signal output unit 19 reads out the target sensor voltage (the calculation result at night on the N + 1 day) stored in the memory 18 when the power is turned on, and sets it as the target sensor voltage on the N + 2 day.

  In FIG. 4, the nighttime average sensor voltage is 3.5 V with respect to the average light output ratio of 93% on the second day, and the calculation unit 17 sets the target sensor voltage on the third day to [ Average sensor voltage (3.5V) × target predetermined light output ratio (88%) / 2 day night average light output ratio (93%) = 3.3V], and the calculation result (3. 3V) is stored in the memory 18 and set to the target sensor voltage on the third day.

  Next, a case where the layout is changed on the (N + 1) th day and the reflectance of the irradiated surface is increased as compared with the Nth day will be described. FIG. 5 shows the relationship of the sensor voltage to the light output ratio before and after the layout change. The relationship before the layout change (Nth day) is represented by a straight line Y1, and the relationship after the layout change (N + 1 day) is represented by a straight line Y2. Then, the change in the reflectance of the irradiated surface appears in the difference in inclination between the straight lines Y1 and Y2. As a result of the layout change, when the reflectance of the irradiated surface increases on the (N + 1) th day, the dimming signal output unit 19 controls to keep the sensor voltage constant at 3.5 V, so that the average light output ratio at night Decreases from 88% the previous day to 60% and is controlled in the direction of darkening.

  However, as shown in FIG. 4, at night on the (N + 1) th day, the calculation unit 17 sets the target sensor voltage on the (N + 2) th day as [average sensor voltage (3.5V) at night on the (N + 1) th day × target light]. Output ratio (88%) / N + 1 day night average light output ratio (60%) = 5.1V], the calculation result (5.1V) is stored in the memory 18, and dimming on the N + 2 day The signal output unit 19 reads out the target sensor voltage (N + 1 day nighttime calculation result: 5.1 V) stored in the memory 18 when the power is turned on and sets it as the target sensor voltage on the (N + 2) th day. On the day, the dimming signal output unit 19 controls to keep the sensor voltage constant at 5.1 V, so dimming control is performed so that the light output ratio is about 88%.

  As described above, the target sensor voltage setting operation is performed almost every day in a normal office by performing the target sensor voltage setting operation when the power is turned on. Therefore, it is possible to control the brightness of the room such as the office so that the target brightness remains constant almost every day, and the brightness of the illuminated surface even if the reflectance of the illuminated surface changes due to layout changes, etc. Can be controlled constant.

  Further, when setting the target brightness, the conventional lighting fixture adjusts the light output ratio of the light source while measuring the illuminance on the desk surface in the office or the like, and sets the target sensor voltage for each illuminance sensor. If the interior, desk specifications, layout, etc. are changed, the target sensor voltage must be set again. In this embodiment, the target sensor voltage is automatically set. Therefore, labor required for setting is reduced as compared with the conventional case.

  In this embodiment, the target sensor voltage is set every night. However, this may be appropriate, and even if it is once every two days or once a week, it does not give a great change to the control result. Absent. Further, although the target sensor voltage is obtained from the average sensor voltage and the average light output ratio, it may be the median value or the minimum value of the sensor voltage and the light output ratio.

  In addition, when the memory 18 does not have a capacity capable of storing all of the light output ratio and the sensor voltage measured between the start of the night and the power shutdown, the old measurement result is deleted every time a new measurement result is stored. As a result, even if the target sensor voltage is calculated using only the latest storable measurement result, the same calculation as described above can be performed.

(Embodiment 2)
The structure of the lighting fixture A of this embodiment is shown by FIG. 1, FIG. 2 similarly to Embodiment 1, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted.

  Hereinafter, operation | movement of the lighting fixture A of this embodiment is demonstrated. First, in the dimming signal output unit 19, the sensor voltage of the illuminance sensor 12 through the amplifier circuit 14 becomes the target sensor voltage calculated by the calculation unit 17 during the daytime when the nighttime specifying unit 15 does not specify the nighttime. Thus, the light output ratio of the light source 11 is controlled, and the light source 11 is turned on at a predetermined light output ratio (88%) at night specified by the night specifying unit 15. In other words, the lighting control that reacts to changes in brightness due to blinking of adjacent circuit-equipped lighting fixtures or movement of people at night is given to give occupants discomfort due to subtle flickering. Is preventing.

  The measurement unit 16 measures the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 when the light source 11 is turned on at a predetermined light output ratio (88%) at night, and the measurement result is stored in the memory 18. Store. The calculation unit 17 obtains the average sensor voltage of the illuminance sensor 12 at night from the sensor voltage of the illuminance sensor 12 stored in the memory 18 after the night is specified by the night specifying unit 15 until the power is shut off. The average sensor voltage is stored in the memory 18 as the target sensor voltage.

  The dimming signal output unit 19 reads the target sensor voltage from the memory 18 at the next daytime power-on, and performs dimming control so that the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 becomes the target sensor voltage.

  Next, the specific operation of the lighting fixture A will be described with reference to FIG. First, since the target sensor voltage is not stored in the memory 18 at the time of lighting fixture installation (the first day), the dimming signal output unit 19 does not perform dimming control by the sensor voltage output by the illuminance sensor 12, The light source 11 is turned on at a fixed light output ratio of 88% regardless of day or night. However, in order to determine the target sensor voltage on the second day, the sensor voltage of the illuminance sensor 12 is measured by the measuring unit 16 and stored in the memory 18 only at night specified by the night specifying unit 15. Then, the nighttime sensor voltage stored in the memory 18 after the nighttime nighttime identification unit 15 identifies the nighttime until the power is shut off is read from the memory 18 by the calculation unit 17 to calculate the nighttime average sensor voltage. Then, the calculation result (3.4 V) is stored in the memory 18 as the target sensor voltage. On the second day, the dimming signal output unit 19 reads the target sensor voltage (the calculation result at night on the first day: 3.4 V) stored in the memory 18 when the power is turned on, and the target sensor on the second day. Set as voltage.

  On the N + 1 day after the second day, the dimming signal output unit 19 changes the light output ratio of the light source 11 during the daytime, and the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 is set when the power is turned on. The dimming control is performed so as to be a voltage, but in order to determine the target sensor voltage on the (N + 2) th day, the sensor voltage of the illuminance sensor 12 is measured only during the time period specified by the night specifying unit 15 as night. Measured at 16 and stored in the memory 18. Then, the calculation unit 17 reads the sensor voltage of the illuminance sensor 12 stored in the memory 18 after the night is specified by the night specifying unit 15 until the power is shut off, and calculates the average sensor voltage, The calculation result is stored in the memory 18 as the target sensor voltage. On the N + 2 day, the dimming signal output unit 19 reads out the target sensor voltage (the calculation result at night on the N + 1 day) stored in the memory 18 when the power is turned on, and sets it as the target sensor voltage on the N + 2 day.

  In FIG. 6, since the average sensor voltage at night on the second day is 3.7 V, the calculation result (3.7 V) is stored in the memory 18 and set as the target sensor voltage on the third day.

  Next, a case where the layout is changed on the (N + 1) th day and the reflectance of the irradiated surface is increased as compared with the Nth day will be described. FIG. 7 shows the relationship of the sensor voltage to the light output ratio before and after the layout change. The relationship before the layout change (Nth day) is represented by a straight line Y3, and the relationship after the layout change (N + 1 day) is represented by a straight line Y4. Then, the change in the reflectance of the irradiated surface appears in the difference in inclination between the straight lines Y3 and Y4. As a result of the layout change, when the reflectivity of the irradiated surface increases on the (N + 1) th day, the average sensor voltage at night increases from 3.4 V to 5.1 V on the previous day.

  Therefore, the average sensor voltage (5.1V) is stored in the memory 18 as the target sensor voltage, and the dimming signal output unit 19 on the N + 2 day, the target sensor voltage (5.1V) stored in the memory 18 is stored. When the power is turned on and set as the target sensor voltage on the (N + 2) th day, the dimming signal output unit 19 controls to keep the sensor voltage constant at 5.1V on the (N + 2) th day. Dimming is controlled to be around%.

  As described above, the target sensor voltage setting operation is performed almost every day in a normal office by performing the target sensor voltage setting operation when the power is turned on. Therefore, it is possible to control the brightness of the room such as the office so that the target brightness remains constant almost every day, and the brightness of the illuminated surface even if the reflectance of the illuminated surface changes due to layout changes, etc. Can be controlled constant.

  Further, when setting the target brightness, the conventional lighting fixture adjusts the light output ratio of the light source while measuring the illuminance on the desk surface in the office or the like, and sets the target sensor voltage for each illuminance sensor. If the interior, desk specifications, layout, etc. are changed, the target sensor voltage must be set again. In this embodiment, the target sensor voltage is automatically set. Therefore, labor required for setting is reduced as compared with the conventional case.

  In this embodiment, the target sensor voltage is set every night. However, this may be appropriate, and even if it is once every two days or once a week, it does not give a great change to the control result. Absent. Moreover, although the target sensor voltage is calculated | required from the average sensor voltage, the median value or minimum value of a sensor voltage may be sufficient.

  In addition, when the memory 18 does not have a capacity capable of storing all of the light output ratio and the sensor voltage measured between the start of the night and the power shutdown, the old measurement result is deleted every time a new measurement result is stored. As a result, even if the target sensor voltage is calculated using only the latest storable measurement result, the same calculation as described above can be performed.

(Embodiment 3)
The configuration of the lighting fixture A of the present embodiment is shown in FIGS. 1 and 2 as in the first and second embodiments. The same components as those in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. .

  The present embodiment is different from the first and second embodiments in that the dimming signal output unit 19 turns on the light source 11 at a light output ratio corresponding to the luminous flux reduction rate based on the cumulative lighting time of the light source 11.

  Here, FIG. 8 is a relational diagram showing the change in light source life and brightness of a general lighting fixture when a fluorescent lamp is used as a light source, and a normal lighting fixture maintains power consumption P at 100% from the beginning. . However, it is known that the luminous flux decreases according to the aging change according to the luminous flux decay curve S1, and at the end of the life, the luminous flux decreases to about 70% with respect to 100% of the power consumption. Usually, since the lighting fixture arrangement design is performed with the illuminance at the end of the life as the design illuminance, the brightness is excessive in the initial stage.

  Further, FIG. 9 shows the relationship between the light output ratio and the illuminated surface illuminance at the beginning of lighting and after 2000 hours of cumulative lighting time, and at the beginning of lighting, as shown by the straight line Y5, the light is irradiated when the light output ratio is 100%. The surface illuminance is 1000 lx, and the target brightness is, for example, a light output ratio of 70% and an illuminated surface illuminance of 700 lx (= 1000 lx × 0.7). If the luminous flux reduction rate after 2000 hours of cumulative lighting time is 10% as indicated by the straight line Y6, the illuminated surface illuminance at the light output ratio of 100% after 2000 hours of cumulative lighting time is 900 lx (= 1000 lx). × 0.9). Here, when the target brightness is 70% as in the lighting initial stage, the illuminated surface illuminance after the cumulative lighting time of 2000 hours is 630 lx (= 900 lx × 0.7), and is set to the lighting initial stage. 10% lower than the target brightness.

  For example, when setting the target brightness so as to achieve a predetermined light output ratio, if the setting is changed in about one day from the previous setting change, the brightness at the maximum light output does not decrease. There is no difference in brightness before and after the setting change. However, if a fluorescent lamp is used as the light source and the setting is changed after a cumulative lighting time of several thousand hours has passed since the previous setting change, the luminous flux is greatly reduced compared to the initial lighting state. Even if the target brightness is set so that the ratio is the same, the actual brightness becomes darker than the initial lighting. In FIG. 9, the light output ratio needs to be 78% (= 700 lx / 900 lx) in order to make the illuminated surface illuminance 700 lx which is the same as the initial lighting after the cumulative lighting time 2000 hours.

  That is, if the illuminance is to be kept constant throughout the life of the light source, as shown in FIG. 10, as the cumulative lighting time of the light source increases, the light output ratio also corresponds to the luminous flux reduction rate at that time as shown by the curve S2. It is sufficient to increase it.

  Therefore, in the present embodiment, the predetermined light output ratio (88% constant in the first embodiment) set as the target of the first embodiment is set to 88% at the time of installation, and thereafter the luminous flux based on the cumulative lighting time of the light source 11. By increasing to a value corresponding to the decline rate, it is possible to prevent a decrease in brightness due to the cumulative lighting time of the light source, and to maintain the illuminance of the irradiated surface constant throughout the life of the light source.

  In the second embodiment, a predetermined light output ratio when lighting the light source 11 at night (88% constant in the second embodiment) is initially set to 88% at the time of installation, and thereafter the cumulative lighting of the light source 11 is performed. What is necessary is just to make it increase to the value corresponding to the luminous flux decline rate based on time.

(Embodiment 4)
As shown in FIG. 11, the lighting fixture A of the present embodiment is different from the configuration of the control unit 13 in FIG. 1 shown in the first embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals. Description is omitted.

  The control unit 13 includes an amplification circuit 14 that amplifies the sensor voltage from the illuminance sensor 12, a night specification unit 15 that specifies nighttime without daylight, and a light output ratio of the light source 11 at night specified by the night specification unit 15. And a measurement unit (first measurement unit) 16 that measures the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 and an output voltage (target sensor voltage) of the illuminance sensor 12 that is a target value for illumination control. The calculation unit 17 includes a memory 18 that stores electrical signals and setting values from the calculation unit 17, and a dimming signal output unit 19 that outputs a dimming control signal to the light source 11.

  The dimming signal output unit 19 normally adjusts the light output ratio of the light source 11 so that the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 becomes the target sensor voltage calculated by the calculation unit 17 regardless of day or night. Control.

  Next, the night specifying unit 15 measures the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 at the light output ratio through the measuring unit 16 a plurality of times per day (second measurement). Part) 15a, and a calculation to divide the sensor voltage by the light output ratio based on the light output ratio and the sensor voltage measured by the measurement part 15a, and the most of the results of the calculations performed several times a day It comprises a specifying unit 15b that specifies when the value is low, and a memory 15c that stores an electrical signal and a set value from the specifying unit 15b.

  The night specifying unit 15 of the present embodiment is configured at low cost by specifying the night without using a timer. From the relationship between the light output of the light source 11 and the sensor voltage of the illuminance sensor 12, a night without daylight Analogy. Hereinafter, the operation of the night specifying unit 15 of the present embodiment will be described. FIG. 12 shows the relationship between the sensor voltage of the illuminance sensor 12 from 10:00 to 22:00, the light output ratio of the light source 11, and the daylight quantity. Since there is daylight in the daytime, the target sensor voltage is controlled to 3.5V. In order to achieve this, it is necessary to lower the light output ratio. However, when the light output ratio has fallen to the lower limit of 30%, the sensor voltage rises above the target sensor voltage of 3.5V. Since there is no daylight at night, the light output ratio and the sensor voltage are substantially constant. When the sensor voltage at the time of the light output ratio of 100% is calculated from the light output ratio and the sensor voltage (= measured sensor voltage / measured light output ratio), the daylight component is included in the calculation result in the daytime. Therefore, the calculated value is higher than at night. Therefore, the sensor voltage when the light output ratio is 100% is obtained, and the time when the calculated value becomes the lowest value during the day can be specified as nighttime without daylight.

  Therefore, the measurement unit 15a measures the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 at the light output ratio a plurality of times a day from when the power is turned on to when the power is turned off. Obtains a sensor voltage at a light output ratio of 100% obtained by dividing each measured sensor voltage by the measured light output ratio, and stores the lowest value in the memory 15c among the results of the above-mentioned calculation performed a plurality of times a day. . That is, the time when the lowest value is recorded is specified as nighttime, and the lowest value stored in the memory 15 c is output from the measuring unit 15 a to the calculating unit 17 via the measuring unit 16.

Next, the calculation unit 17 stores a value obtained by multiplying the minimum value of the sensor voltage when the light output ratio is 100% by a predetermined light output ratio (88%) in the memory 18 as a target sensor voltage. That is, the target sensor voltage is obtained by the following equation.
Target sensor voltage = minimum value of sensor voltage when the light output ratio is 100% × target predetermined light output ratio (88%)
The dimming signal output unit 19 reads the target sensor voltage from the memory 18 at the next power-on, and performs dimming control so that the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 becomes the target sensor voltage.

  For example, in FIG. 12, the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 are measured three times at time t1: around 10 o'clock, time t2: around 13 o'clock, and time t3: around 18:30. At time t1: around 10 o'clock, the sensor voltage is 3.5V, the light output ratio is 50%, and the sensor voltage when the light output ratio is 100% = 3.5V / 0.5 = 7.0V. At time t2: around 13:00, the sensor voltage is 4.0V, the light output ratio is 30%, and the sensor voltage when the light output ratio is 100% = 4.0V / 0.3 = 13.3V. At time t3: around 18:30, the sensor voltage is 3.5V, the light output ratio is 70%, and the sensor voltage when the light output ratio is 100% = 3.5V / 0.7 = 5.0V. Therefore, the sensor voltage when the light output ratio is 100% becomes the lowest value at about time t3: 18: 30, and the time t3: about 18:30 is specified as nighttime.

  The measuring unit 15a measures the light output ratio from the dimming control signal output from the dimming signal output unit 19 via the measuring unit 16, and for example, the relationship between the duty ratio of the dimming control signal and the light output ratio. Is stored in the memory 15c, the light output ratio can be calculated from the duty ratio of the dimming control signal.

  Next, the specific operation of the lighting fixture A will be described with reference to FIG. First, since the target sensor voltage is not stored in the memory 18 at the time of lighting fixture installation (the first day), the dimming signal output unit 19 does not perform dimming control by the sensor voltage output by the illuminance sensor 12, The light source 11 is turned on at a fixed light output ratio of 88%. However, in order to determine the target sensor voltage on the second day, the sensor voltage of the illuminance sensor 12 is measured by the measurement unit 16 and stored in the memory 18 via the calculation unit 17. And the calculating part 17 reads the sensor voltage stored in the memory 18 until a power supply is interrupted, and calculates an average sensor voltage. In the present embodiment, the average sensor voltage is 3.5 V with respect to the average light output ratio of 88% on the first day, and the calculation unit 17 sets the target sensor voltage on the second day as [average sensor on the first day at night. Voltage (3.5V) x Target predetermined light output ratio (88%) / Day 1 night average light output ratio (88%) = 3.5V], and the calculation result (3.5V) Is stored in the memory 18. On the second day, the dimming signal output unit 19 reads out the target sensor voltage (the calculation result at night of the first day: 3.5 V) stored in the memory 18 when the power is turned on, and the target sensor on the second day. Set as voltage.

  The dimming signal output unit 19 usually changes the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 via the amplifier circuit 14 is set when the power is turned on on the (N + 1) th day after the second day. The dimming control is performed so as to be a voltage, but in order to determine the target sensor voltage on the (N + 2) th day, the measurement unit 15a determines the light output ratio of the light source 11 and the sensor voltage of the illuminance sensor 12 via the measurement unit 16. Then, the specifying unit 15b divides the sensor voltage by the light output ratio based on the light output ratio and the sensor voltage measured by the measuring unit 15a to obtain a sensor voltage (= N + 1 day) when the light output ratio is 100%. (Sensor voltage measured in (1) / (light output ratio measured on day N + 1)). And the sensor voltage at the time of the lowest light output ratio of 100% among the results of the calculations performed a plurality of times a day is stored in the memory 15c.

  Next, the calculation unit 17 reads the minimum value of the sensor voltage when the light output ratio is 100% from the memory 15c, and sets the target sensor voltage on the (N + 2) th day to [the sensor voltage when the light output ratio is 100% on the (N + 1) th day. The minimum value × target predetermined light output ratio (88%)] is calculated, and the calculation result is stored in the memory 18. On the N + 2 day, the dimming signal output unit 19 reads the target sensor voltage stored in the memory 18 when the power is turned on, and sets it as the target sensor voltage on the N + 2 day.

  In FIG. 13, the minimum value of the sensor voltage at the time of the light output ratio of 100% calculated on the second day is (3.5V / 0.93), and the calculation unit 17 sets the target sensor voltage on the third day to [ 2nd day light output ratio 100% minimum sensor voltage (3.5V / 0.93) x target predetermined light output ratio (88%)], the calculation result (3.3V) Stored in the memory 18 and set to the target sensor voltage of the third day.

  Next, as a result of the layout change, when the reflectance of the irradiated surface increases on the (N + 1) th day, the dimming signal output unit 19 sets the sensor voltage to 3.5 V as shown in FIG. Since the control is performed to keep it constant, the average light output ratio at night falls from 88% of the previous day to 60%, and is controlled to become darker.

  However, as shown in FIG. 13, on the (N + 1) th day, the calculation unit 17 sets the target sensor voltage on the (N + 2) th day to [the minimum value (3.5V / 0.6 ) × target predetermined light output ratio (88%)], and the calculation result (5.1 V) is stored in the memory 18, and the dimming signal output unit 19 is stored in the memory 18 on the N + 2 day. The target sensor voltage (5.1V) is read when the power is turned on and set as the target sensor voltage on the (N + 2) th day. On the (N + 2) th day, the dimming signal output unit 19 keeps the sensor voltage constant at 5.1V. Therefore, dimming control is performed so that the light output ratio is about 88%.

  As described above, the target sensor voltage setting operation is performed almost every day in a normal office by performing the target sensor voltage setting operation when the power is turned on. Therefore, it is possible to control the brightness of the room such as the office so that the target brightness remains constant almost every day, and the brightness of the illuminated surface even if the reflectance of the illuminated surface changes due to layout changes, etc. Can be controlled constant.

  Further, when setting the target brightness, the conventional lighting fixture adjusts the light output ratio of the light source while measuring the illuminance on the desk surface in the office or the like, and sets the target sensor voltage for each illuminance sensor. If the interior, desk specifications, layout, etc. are changed, the target sensor voltage must be set again. In this embodiment, the target sensor voltage is automatically set. Therefore, labor required for setting is reduced as compared with the conventional case.

  In this embodiment, the target sensor voltage is set every night. However, this may be appropriate, and even if it is once every two days or once a week, it does not give a great change to the control result. Absent. Further, although the target sensor voltage is obtained from the average sensor voltage and the average light output ratio, it may be the median value or the minimum value of the sensor voltage and the light output ratio.

  In addition, when the memory 18 does not have a capacity capable of storing all of the light output ratio and the sensor voltage measured between the start of the night and the power shutdown, the old measurement result is deleted every time a new measurement result is stored. As a result, even if the target sensor voltage is calculated using only the latest storable measurement result, the same calculation as described above can be performed.

(Embodiment 5)
The structure of the lighting fixture A of this embodiment is shown by FIG. 2, FIG. 11 similarly to Embodiment 4, the same code | symbol is attached | subjected to the structure similar to Embodiment 4, and description is abbreviate | omitted.

  The present embodiment is different from the fourth embodiment in that the dimming signal output unit 19 turns on the light source 11 with a light output ratio corresponding to the luminous flux reduction rate based on the cumulative lighting time of the light source 11. That is, as described in the third embodiment, in order to keep the illuminance constant throughout the life of the light source, as shown in FIG. 10, the light output ratio also becomes as shown by the curve S2 as the cumulative lighting time of the light source increases. It is increased so as to correspond to the luminous flux decline rate at that time.

  Therefore, in this embodiment, the predetermined light output ratio (88% constant in the fourth embodiment) set as the target of the fourth embodiment is set to 88% at the time of installation, and thereafter the light flux based on the cumulative lighting time of the light source 11. By increasing to a value corresponding to the decline rate, it is possible to prevent a decrease in brightness due to the cumulative lighting time of the light source, and to maintain the illuminance of the irradiated surface constant throughout the life of the light source.

It is a block diagram which shows the structure of the lighting fixture of Embodiment 1 of this invention. It is a block diagram which shows a use condition same as the above. It is a wave form diagram which shows a dimming control signal same as the above, (a) shows a bright state, (b) shows a dark state. It is a figure which shows the setting procedure of the target sensor voltage same as the above. It is a figure which shows the relationship between the optical output ratio before and behind a layout change same as the above, and a sensor voltage. It is a figure which shows the setting procedure of the target sensor voltage of Embodiment 2 of this invention. It is a figure which shows the relationship between the optical output ratio before and behind a layout change same as the above, and a sensor voltage. It is a figure which shows the relationship between the light source lifetime and brightness of a general lighting fixture. It is a figure which shows the relationship between the light output ratio of the life initial stage of a general lighting fixture, 2000 hours of cumulative lighting, and irradiated surface illumination. It is a figure which shows the relationship between the light source lifetime of Embodiment 3 of this invention, and light output ratio. It is a block diagram which shows the structure of the lighting fixture of Embodiment 4 of this invention. It is a figure which shows the relationship between a sensor voltage same as the above, light output ratio, and daylight quantity. It is a figure which shows the setting procedure of the target sensor voltage same as the above. It is a figure which shows the relationship between the to-be-irradiated surface illumination intensity before and after the conventional layout change, and a sensor voltage.

Explanation of symbols

A lighting fixture 11 light source 12 illuminance sensor 13 control unit 14 amplifier circuit 15 night specifying unit 16 measurement unit 17 calculation unit 18 memory 19 dimming signal output unit

Claims (4)

A light source, an illuminance sensor that measures the illuminance of the illuminated surface illuminated by the light source with reflected light, and a control that controls the light output of the light source so that the illuminance of the illuminated surface is constant based on the output value of the illuminance sensor A night time specifying unit that specifies nighttime without daylight, a light output ratio of a light source at night specified by the night specifying unit, and an output value of an illuminance sensor corresponding to the light output ratio, Calculating the output value of the illuminance sensor when a predetermined light output ratio is obtained at night from the light output ratio of the light source measured by the first measurement unit and the output value of the illuminance sensor. And a calculation unit that sets the calculation result as a target value, and controls the light output of the light source so that the output value of the illuminance sensor becomes the target value at least in the daytime. 2. The illumination according to claim 1, wherein the controller turns on the light source with the predetermined light output ratio fixed at night, and sets the output value of the illuminance sensor at this time as the target value. Instruments. The night specifying unit measures the light output ratio of the light source and the output value of the illuminance sensor corresponding to the light output ratio by a second measuring unit and a second measuring unit that measure the light output ratio a plurality of times a day. The lighting apparatus according to claim 1, wherein the time when the value obtained by dividing the output value of the illuminance sensor by the light output ratio of the light source is the lowest among a plurality of measurement results is specified at night. The lighting apparatus according to claim 1, wherein the predetermined light output ratio is a value corresponding to a luminous flux reduction rate based on a cumulative lighting time of the light source.

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