JP7581031B2 - Lighting System - Google Patents

Description

The present invention relates to a lighting system. Specifically, the present invention relates to a lighting system that can achieve both energy saving and a sense of brightness.

Task/ambient lighting is gaining attention as a lighting method for office spaces. With this method, the illuminance of the ambient lighting that illuminates the entire room is reduced, and task lighting (e.g. desk lamps) is installed in the worker's work area to ensure sufficient brightness for the worker's hands. Compared to conventional general lighting methods, task/ambient lighting is easier to use for energy conservation. On the other hand, task/ambient lighting tends to give the overall impression of a dark office space.

Patent Publication 2017-020993

In recent years, there has been much research and discussion on evaluation methods using brightness perception. However, brightness perception means the impression of brightness felt by people from the field of vision, and because there are many different theories on this subject, there is currently no standardization of evaluation methods.
For example, Patent Document 1 proposes the introduction of a brightness sensation index value called the NSB (natural scale space brightness) value. The NSB (natural scale space brightness) value is defined as a value obtained by adding a "first nonuniformity (coarse luminance contrast)" and a "second nonuniformity (fine luminance contrast)" to the "average value of the amount related to brightness."
Here, the values of "average value of brightness,""firstnonuniformity," and "second nonuniformity," which are necessary for calculating the NSB value, are calculated based on the results obtained from experiments with subjects. The experiment evaluates the brightness of various spaces, but the evaluation scale is set in 13 stages, which is quite detailed, and the average value of all the answers is used. In addition, since the degree to which brightness is perceived varies from person to person, it is expected that it will be difficult to obtain answers that are consistent with the level of perception of the subjects with a scale of 13 stages.
Furthermore, for example, Patent Document 1 only aims to evaluate the sense of brightness and does not mention energy saving.

The lighting system according to claim 1 of the present invention comprises:
A lighting system that provides ambient lighting to an office space having a ceiling, walls, and a floor,
The lighting system comprises:
Equipped with multiple lighting fixtures installed on the ceiling,
Each of the plurality of lighting fixtures has a ceiling lighting unit that emits illumination light toward a ceiling side and a floor lighting unit that emits illumination light toward a floor side , the ceiling lighting unit and the floor lighting unit have their illumination surfaces facing opposite directions, and the ceiling lighting unit and the floor lighting unit are each capable of independently adjusting the luminous flux they emit,
Illuminating with the plurality of lighting fixtures with a ratio of a ceiling side luminous flux emitted from the ceiling lighting unit to a floor side luminous flux emitted from the floor lighting unit being equal to or greater than 9.5:90.5 and less than 14:86;
A ceiling area is cut out from image data of the office space captured using a camera installed to capture images of the ceiling, walls, and floor of the office space from one end of the office space toward the other end of the office space, and the brightness values of the pixels of the ceiling area in the image data are extracted. The average brightness value of the ceiling area in the image data is set as the ceiling average brightness value,
When an area division having a luminance value equal to or greater than the average luminance value of the ceiling (1.0 times or more) is defined as a high luminance division, an area division having a luminance value between 0.5 times and less than 1.0 times the average luminance value of the ceiling is defined as a medium luminance division, and an area division having a luminance value less than 0.5 times the average luminance value of the ceiling is defined as a low luminance division,
The lighting is performed so that the proportion of brightness value divisions of the ceiling area in the image data is such that the proportion of the high brightness division is 6.4% or more and less than 18.8%, the proportion of the medium brightness division is 3.0% or more and less than 33.7%, and the proportion of the low brightness division is 47.5% or more and less than 90.6%.

The lighting system according to claim 2 of the present invention comprises:
An office space with a ceiling, walls, and floorAmbient in betweenilluminationProvideA lighting system comprising:
The lighting system comprises:
Equipped with multiple lighting fixtures installed on the ceiling,
The aboveMultipleLighting fixturesEach is heavenA ceiling lighting unit that emits light toward the well side and a floor lighting unit that emits light toward the floor sideAndHasThe ceiling lighting unit and the floor lighting unit have their illumination surfaces facing opposite directions.The ceiling lighting unit and the floor lighting unit are each capable of independently adjusting the luminous flux emitted by each unit.
Illuminating with the plurality of lighting fixtures with a ratio of a ceiling side luminous flux emitted from the ceiling lighting unit to a floor side luminous flux emitted from the floor lighting unit being 9.5:90.5 or more and less than 14:86;
A ceiling area is cut out from image data of the office space captured using a camera installed to capture images of the ceiling, walls, and floor of the office space from one end of the office space toward the other end of the office space, and the brightness values of the pixels of the ceiling area in the image data are extracted. The average brightness value of the ceiling area in the image data is set as the ceiling average brightness value,
When an area division having a luminance value equal to or greater than the average luminance value of the ceiling (1.0 times or more) is defined as a high luminance division, an area division having a luminance value between 0.5 times and less than 1.0 times the average luminance value of the ceiling is defined as a medium luminance division, and an area division having a luminance value less than 0.5 times the average luminance value of the ceiling is defined as a low luminance division,
The ceiling area in the image data is illuminated so that the ratio of the luminance value divisions is 6.0% or more and less than 7.6%, the ratio of the medium luminance division is 0.6% or more and less than 12.2%, and the ratio of the low luminance division is 80.2% or more and less than 93.4%.
It is characterized by:

In one embodiment of the present invention,
When the office space is illuminated with a lighting system,
As a percentage of the overall luminance value category in the office space,
The proportion of high brightness categories is 4.0% or more and less than 6.5%.
The ratio of mid-luminance category is 33.0% or more and less than 42.0%.
It is preferable to illuminate the office area so that the ratio of the low luminance section is between 51.5% and 63.0%.

In addition, in one embodiment of the present invention,
When the office space is illuminated with a lighting system,
As a percentage of the overall luminance value category in the office space,
The proportion of high brightness categories is 4.5% or more and less than 6.0%.
The ratio of the mid-luminance category is 36.0% or more and less than 41.0%.
It is preferable to illuminate the office area so that the ratio of the low luminance section is between 53.0% and 59.5%.

In one embodiment of the present invention,
When the office space is illuminated with a lighting system,
As a percentage of the brightness value category of the ceiling part,
The proportion of high brightness categories is 9.2% or more and less than 15.4%.
The ratio of mid-luminance category is 13.8% or more and less than 58.3%.
It is preferable to illuminate the office area so that the ratio of the low luminance section is between 26.3% and 77.0%.

In one embodiment of the present invention,
When the lighting system illuminates the office space,
As a percentage of the brightness value category of the ceiling part,
The proportion of high brightness categories is 6.0% or more and less than 7.0%.
The ratio of mid-luminance category is 3.95% or more and less than 9.8%.
It is preferable to illuminate the working area so that the ratio of the low luminance section is between 83.2% and 90.1%.

In addition, the ratio of the ceiling-side luminous flux emitted from the ceiling lighting unit to the floor-side luminous flux emitted from the floor lighting unit may be equal to or greater than 5:95 and less than 18:82.

The lighting system according to claim 3 of the present invention comprises:
moreover,
A storage device that stores the vertical light distribution rate patterns of each lighting fixture;
a host computer that controls lighting of each of the lighting fixtures based on the up-down light distribution rate pattern of each of the lighting fixtures stored in the storage device.

The lighting system according to claim 4 of the present invention comprises:
moreover,
A camera installed to capture images of the ceiling, walls, and floor of the office space from one end to the other end of the office space;
A computer that calculates a ratio of brightness value ranges from a camera image,
The computer adjusts the dimming rate of each lighting fixture so that the rate falls within the range of the ratio of the brightness value segments described above.

FIG. 2 is a diagram illustrating an example of an experimental space prepared for an experiment. FIG. 2 is a diagram illustrating an example of an experimental space prepared for an experiment. FIG. FIG. 1 is a diagram showing specifications of a lighting fixture. FIG. 13 is a diagram showing a light distribution pattern prepared for an experiment. 11A and 11B are diagrams illustrating combinations of light distribution patterns. FIG. 13 is a diagram showing a result of image processing applied to image data of a light distribution pattern 4. FIG. 13 is a diagram showing a result of image processing applied to image data of a light distribution pattern 7. 11 is a diagram showing a result of image processing performed on image data of a light distribution pattern 11. FIG. 13 is a diagram showing a result of image processing applied to image data of a light distribution pattern 12. FIG. FIG. 11 is a diagram showing the results of calculating the ratio of luminance value sections for each light distribution pattern. FIG. 11 is a diagram showing the results of calculating the ratio of luminance value sections for each light distribution pattern. FIG. 13 is a diagram showing a result of comparing reference light distribution patterns with each other. FIG. 11 is a diagram showing a result of comparing a test light distribution pattern with a reference light distribution pattern. FIG. 13 is a diagram showing the results of a comparison between a test light distribution pattern and a reference light distribution pattern, with the luminance contrast (horizontal axis) being “background luminance.” 15 is an enlarged view of the vicinity of a background luminance ratio of 1.0 in FIG. 14 . FIG. 13 is a diagram showing the results of grouping light distribution patterns by upward dimming rate and recalculating the ratios of brightness value sections. FIG. 13 is a diagram showing the proportions of suitable luminance value segments.

The present invention provides a lighting system for illuminating an office space that is energy-saving yet provides a feeling of sufficient brightness to people in the room, and proposes a lighting distribution (optimal ratio of luminance value categories) for this purpose.
The following describes an experiment on brightness perception that led to the determination of the light distribution (preferable ratio of luminance value segments) of the lighting according to the present invention.
(Experimental Method)
Figures 1 and 2 show the experimental space prepared for this experiment. The experimental space has a ceiling, walls, and floor, just like a normal office space, and the ceiling height is about the same as a normal office space (2.6 m). To eliminate the effects of daylight, the windows are covered with screens.

Several lighting fixtures are placed on the ceiling.
This luminaire is intended to provide ambient lighting.
The luminaire 10 is shown in FIG.
The lighting fixture 10 includes a ceiling lighting section 11 and a floor lighting section 12 .
The ceiling lighting unit 11 is provided to emit light (illumination light) toward the upper side of the lighting fixture 10, i.e., toward the ceiling. The floor lighting unit 12 is provided to emit light (illumination light) toward the lower side of the lighting fixture 10, i.e., toward the floor surface.
The ceiling lighting unit 11 and the floor lighting unit 12 can be dimmed independently, that is, the lighting device 10 can adjust the light distribution (light distribution rate) of the illumination light toward the ceiling and the illumination light toward the floor. In the lighting device 10 used in this experiment, the ceiling lighting unit 11 and the floor lighting unit 12 have the same specifications except that the illumination surfaces face in opposite directions. Figure 4 is a diagram showing the specifications of the lighting device 10.

Here, the experimental space was 12m in length and width, and 30 lighting fixtures 10 were placed on the ceiling.

The subject was asked to sit in a chair placed at one end of the room. A ring (here, a red ring) 20 was placed as a mark at the other end of the room opposite the subject's seat. The subject was then asked to fix his or her gaze in the direction of the ring 20 and look around the entire room as much as possible.

A camera was also installed at one end of the room, allowing it to capture an image of the entire room, including the ring 20. Luminance was extracted from the camera's image data and calculations and other processing was carried out, which will be described later.

The experimental procedure will be explained.
A subject is asked to sit and evaluate the sense of brightness when the room is illuminated with the first light distribution pattern and when the room is illuminated with the second light distribution pattern for each case.
The room is illuminated for three seconds with the first light distribution pattern, and then the room is illuminated for three seconds with the second light distribution pattern.
Repeat this twice.
Then, the subjects were asked to answer how the latter (second light distribution pattern) compared to the former (first light distribution pattern), i.e., to choose from three options: "brighter,""notbrighter," or "exactly the same" as the latter (second light distribution pattern) compared to the former (first light distribution pattern).
When tallying the responses, "bright" was given +1 point, "not bright" was given -1 point, and "exactly the same" was given 0 point.

Forty-eight subjects, ranging in age from their 20s to their 60s, participated in the experiment.

The prepared light distribution pattern is shown in FIG.
In FIG. 5, 14 light distribution patterns are shown.
In the table of FIG. 5, the second column labeled "Reference" refers to a reference light distribution pattern.
The reference light distribution pattern is the same as the lighting in a normal room, and is the light distribution pattern when only the floor lighting unit 12 is used for lighting. (That is, in the reference light distribution pattern, the dimming rate of the ceiling lighting unit (upward luminous flux) 11 is 0%.)
Here, light distribution patterns 1, 2, and 6 correspond to reference light distribution patterns.

In the table in Figure 5, the second column labeled "Test" refers to a test light distribution pattern. A test light distribution pattern is a light distribution pattern that uses not only the floor lighting unit 12 but also the ceiling lighting unit 11.

The light distribution pattern was selected by performing a prior simulation using lighting simulation software (here, "DIALux evo" (registered trademark) and "REALAPS" (registered trademark)).
The selection criteria were: (1) satisfy the illuminance standards of the Illuminating Engineering Institute of Japan's Office Lighting Design Technical Guidelines (offices), which are a ceiling illuminance of 100 (lx) and a wall illuminance of 200 (lx); (2) provide a sense of brightness equal to or greater than that of a space with a desk illuminance (0.8 m) of 500 (lx) (upper luminous flux 0%), and consume the same or less power.

The experiment was carried out for a total of 78 cases (cases No. 1 to No. 78).
Of these, the latter 39 cases (cases No. 40 to No. 78) were performed in the reverse order of the first 39 cases (cases No. 1 to No. 39).
For example, among the first 39 cases, light distribution pattern No. 2 is set as the first light distribution pattern (the former), and light distribution pattern No. 7 is set as the second light distribution pattern (the latter).
In this case, among the latter 39 cases, the light distribution pattern No. 7 is set as the first light distribution pattern (the former), and the light distribution pattern No. 2 is set as the second light distribution pattern (the latter).

When the experimental results are compiled, a score is obtained for each combination condition (combination number) of light distribution patterns, as shown in Figure 6. (Figure 6 shows selected main results that will also be used in the following explanations.)

At the same time as conducting the subject experiment, images were taken with a camera when the room was illuminated with each light distribution pattern.Then, the brightness values of the pixels in the image data were extracted, and the images were analyzed, while the ratios according to the brightness value categories were calculated.
7 to 10 show examples of the results of image analysis and image processing of image data.
FIG. 7 shows light distribution pattern 4.
FIG. 8 shows a light distribution pattern 7.
FIG. 9 shows a light distribution pattern 11.
FIG. 10 shows the result of image processing applied to image data of the light distribution pattern 12.

Image analysis is carried out as follows.
First, the ratio of the luminance value division to the whole is calculated as follows.
The average luminance value of the entire image data is calculated.
Then, pixels in the image data having a luminance value equal to or greater than the average luminance value (1.0 times or greater) are determined to be high-luminance pixels, and the high-luminance pixels are colored white.
In the image data, pixels having a luminance value that is 0.5 times or more and less than 1.0 times the average luminance value are determined as mid-luminance pixels, and the mid-luminance pixels are colored gray.
Pixels in the image data that have a luminance value less than 0.5 times the average luminance value are designated as low-luminance pixels, and the low-luminance pixels are colored black.
7 to 10 show the results of coloring each pixel (image processing) according to the above rules.
The results of calculating the ratio of the luminance value divisions to the whole for each light distribution pattern are shown in the tables of FIGS.

As part of the image analysis, the brightness value division ratio for each part is also obtained.
Areas in the image data are classified into parts.
Here, the parts refer to the ceiling area, wall area, and floor area (or areas other than the ceiling and walls).
For example, only the ceiling region is cut out from the image data, and the average brightness value of the ceiling region is calculated for the ceiling region alone.Then, the brightness values of the pixels in the ceiling region are divided into 1.0 times or more, 0.5 times or more and less than 1.0 times, and less than 0.5 times the average brightness value of the ceiling region, and classified into high brightness pixels, medium brightness pixels, and low brightness pixels when viewed from the ceiling region.The calculation results of the brightness value division ratio for each region are shown in the tables of Figures 11 and 12.

(Discussion of Experimental Results)
By analyzing the scores of each light distribution pattern obtained in the experiment, we will find a light distribution pattern that is energy-efficient while still providing a sense of sufficient brightness.
13 shows a comparison between the reference light distribution patterns. In other words, it shows the results of subjects comparing the sense of brightness of combinations of light distribution patterns 1, 2, and 6.
(To repeat, the reference light distribution pattern is the same as the lighting in a normal room, and is the light distribution pattern when only the floor lighting unit 12 is used for lighting. In other words, in the reference light distribution pattern, the dimming rate of the ceiling lighting unit (upward luminous flux) 11 is 0%.)

The horizontal axis represents the ratio of the overall average luminance value between the contrasting light distribution patterns.
Luminance ratio=(overall average luminance value of the second light distribution pattern (latter))/(overall average luminance value of the first light distribution pattern (former))
The vertical axis is the score, that is, the score result of the second light distribution pattern (the latter) among the compared combinations.

As can be seen from FIG. 13, the higher the overall average luminance ratio, the higher the brightness score.
This is natural, but it also proves that the brightness scores in this experiment are valid. When a regression line was calculated for the points on the graph, which generally shows an upward trend to the right, the slope was 173.48.

FIG. 14 shows the results of comparing the test light distribution pattern with the reference light distribution pattern.
As can be seen from FIG. 14, as the overall average luminance ratio increases, the brightness score also increases.
This is natural, but when compared with the results in FIG. 13, it can be seen that the test light distribution pattern is more likely to have a higher brightness score.
When a regression line is calculated for the points on the graph in Fig. 14, the slope is 357.69. This means that the slope of the regression line is approximately twice as large as in the case of the comparison between the reference light distribution patterns in Fig. 13.

In FIG. 14, attention is focused on points with scores near 0 (arrow A in FIG. 14).
A score close to 0 means that the subject felt that there was no difference in brightness between the contrasting light distribution patterns.
In FIG. 14, the luminance ratio of the point with a score of around 0 (arrow A in FIG. 14) is smaller than 1.0. In other words, the calculated luminance of the test light distribution pattern is lower, but there is no difference in the perceived brightness from the subject's perspective.

Also, in FIG. 14, attention is focused on the vicinity of the luminance ratio of 1.0 (arrow B in FIG. 14).
A luminance ratio of approximately 1.0 means that the luminance calculated for the contrasting light distribution patterns is approximately the same, that is, the energy consumption (for example, power consumption) is approximately the same.
Looking at the scores for points where the luminance ratio is around 1.0 (arrow B in Fig. 14) in Fig. 14, they are around 45 to 50, and although the calculated luminance is almost the same, the test light distribution pattern appears to be much brighter to the subject. This suggests that the test light distribution pattern is capable of achieving both energy saving and a sense of brightness.

Next, we consider which of the test light distribution patterns is preferable.
FIG. 15 shows the results of comparing the test light distribution pattern with the reference light distribution pattern, like FIG. 14, but uses "background luminance" to plot the luminance contrast (horizontal axis).
The "background luminance" referred to here is the average luminance of the area other than the light-emitting portion of lighting device 10, after removing (masking) the light-emitting portion of lighting device 10 from the image data.
Since the light-emitting parts of lighting fixture 10 themselves do not affect the perceived brightness of the space, it is considered appropriate to compare the brightness excluding the light-emitting parts in order to evaluate the performance of ambient lighting.
In FIG. 15, the plotted points vary considerably, but the overall trend is upward.

In FIG. 15, attention is focused on points near the background luminance ratio of 1.0.
FIG. 16 is an enlarged view of the vicinity of a background luminance ratio of 1.0 in FIG.
In FIG. 16, when one looks at points where the background luminance ratio is in the vicinity of 1.0, there is a mixture of positive and negative scores.
Now, in Fig. 16, a combination table of points where the background luminance ratio is in the vicinity of 1.0 times is shown in Fig. 6. (The rightmost column in Fig. 6 shows which of the two contrasting light distribution patterns is more energy efficient.)
16, if we focus on the pattern with a clearly positive score, it is light distribution pattern 7. With light distribution pattern 7, there is a clear tendency for the subjects' brightness perception scores to be higher than with the reference light distribution pattern, even if the calculated background luminance values are almost the same.

In combination No. 30 (test light distribution pattern 7 and reference light distribution pattern 6), the power consumption of test light distribution pattern 7 is greater (calculated luminance is also greater), so it is natural that the score of test light distribution pattern 7 is higher in combination No. 30 (test light distribution pattern 7 and reference light distribution pattern 6) of test light distribution pattern 7.
However, in combination No. 17 (test light distribution pattern 7 and reference light distribution pattern 2), even though the power consumption of test light distribution pattern 7 is lower, the score of test light distribution pattern 7 is +14, and it can be said that test light distribution pattern 7 provides a hint for achieving both energy saving and a sense of brightness.

Now, reading the light distribution of the test light distribution pattern 7 from Fig. 5, the upward light distribution dimming rate is 5%, the downward dimming rate is 34%, and the power consumption is 274 W. For reference, the desk surface illuminance for the test light distribution pattern 7 is 350 (lx).
The reference light distribution pattern 2 has an upward light distribution dimming rate of 0%, a downward light distribution dimming rate of 43%, and a power consumption of 302W.
For reference, the desk surface illuminance is 400 (lx) in the case of the reference light distribution pattern 2. In other words, according to the light distribution of the test light distribution pattern 7, even if the power consumption is reduced within this range (even if energy saving is achieved by 30 W per 30 units), the sense of brightness can be sufficiently maintained or can be made brighter.

The light distribution pattern closest to the light distribution of the test light distribution pattern 7 is the test light distribution pattern 3.
Let's also take a look at test light distribution pattern 3.
In Fig. 16, attention will be paid to combination No. 1 (test light distribution pattern 3 and reference light distribution pattern 1).
In the case of combination No. 1 (test light distribution pattern 3 and reference light distribution pattern 1), the background luminance ratio is 0.88 times, and the score is −18.
Indeed, in the case of combination No. 1 (test light distribution pattern 3 and reference light distribution pattern 1), the score of test light distribution pattern 3 is minus 18, but when comparing the power consumption of test light distribution pattern 3 and reference light distribution pattern 1, test light distribution pattern 3 can be evaluated as performing well. In other words, although there is an energy saving of about 80 W in power consumption (per 30 units) between test light distribution pattern 3 and reference light distribution pattern 1, test light distribution pattern 3 is perceived as being somewhat bright by the subjects.

Now, if the upward dimming rate is increased, does the sense of brightness improve? This is not the case, as can be seen from Figure 16. Combinations No. 2, 9, and 21 in Figure 16 have low scores. In other words, test light distribution patterns 4, 11, and 12 have upward dimming rates of 10%, 10%, and 20%, but it cannot be said that the sense of brightness has increased.

Fig. 17 shows the light distribution patterns grouped by upward dimming rate and the ratios of the brightness value sections recalculated (in other words, the data in Figs. 11 and 12 are grouped by upward dimming rate and edited).
Test light distribution patterns 3 and 7 with an upward dimming rate of 5% are desirable light distribution patterns, and test light distribution patterns 4 and 11 with an upward dimming rate of 10% are considered to be slightly outside the desirable range.
When changing the upper and lower light distribution by adjusting the upward dimming rate, if we look at the ratio of brightness value categories, the ratio of the brightness value categories for the walls and floor does not change the balance significantly even if there is a difference in the upward dimming rate.
On the other hand, the overall luminance value division ratio and the ceiling luminance value division ratio change due to the adjustment of the upward dimming rate.

Therefore, the present inventors propose a lighting system that achieves both energy saving and a sense of brightness by illuminating an office space in accordance with the ratio of the luminance value divisions shown in FIG.
As a percentage of the overall luminance value category in the office space,
The proportion of high brightness categories is 3.3 to 7.6%.
The ratio of mid-luminance range is 31.2-43.3%,
The office area is then illuminated so that the remaining portion (area) is in the low luminance range (i.e., the proportion of the low luminance range is 49.1 to 65.5%).

In addition, by focusing on the ceiling portion of the office space, the office space may be illuminated so as to have the following brightness value division ratios.
In other words, when the average luminance value of the entire ceiling area of the office space is used as the standard,
The proportion of high-luminance areas in the ceiling area is 6.4 to 18.8%.
The percentage of mid-luminance areas in the ceiling area is 3.0 to 33.7%.
The office area is then illuminated so that the remaining portion (area) of the ceiling is in the low luminance zone (i.e., the proportion of the low luminance zone is 47.5 to 90.6%).

Alternatively, when the average luminance value of the ceiling part of the office space (average luminance value of the ceiling part) is used as the standard,
The proportion of high-luminance areas in the ceiling area is 6.0% to 7.6%.
The percentage of mid-luminance areas in the ceiling area is 0.6% to 12.2%.
The office area is then illuminated so that the remaining portion (area) of the ceiling is in the low brightness zone (i.e., the proportion of the low brightness zone is 80.2 to 93.4%).

As a lighting system, a building designer can set several patterns of arrangement of lighting fixtures 10 and vertical light distribution rate (dimming rate) of each lighting fixture 10 so that the lighting system can be designed in accordance with the present invention, and these set patterns can be stored in a storage device.
Each lighting fixture 10 in the lighting system may be connected to a designated host computer, which may read the setting pattern and adjust the dimming of each lighting fixture 10.

Alternatively, a camera may be installed at an appropriate position in the office space, and a computer may be configured to obtain the luminance division ratios from the camera image in almost real time.
The user may be allowed to manually operate a knob or lever to adjust the brightness of the office space, and in this case, it is preferable for the computer to automatically adjust the dimming rate (up and down light distribution) of each lighting fixture 10 so that the brightness falls within the range of the luminance division ratio of the present invention, even when the office space becomes brighter or darker overall.
However, this method is not very effective if daylight comes in through the windows, so it is best to set the dimming rate at night or with the window blinds closed.
The dimming rate setting pattern for each lighting fixture 10 obtained by the adjustment may be stored in a storage device so as to be read out.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention.
For example, it is not necessary for all lighting fixtures installed on the ceiling of an office space to have both a ceiling lighting section and a floor lighting section.
There may be a separate lighting fixture for ceiling lighting having only a ceiling lighting portion and a lighting fixture for floor lighting having only a floor lighting portion.

Claims (4)

A lighting system that provides ambient lighting to an office space having a ceiling, walls, and a floor,
The lighting system comprises:
Equipped with multiple lighting fixtures installed on the ceiling,
Each of the plurality of lighting fixtures has a ceiling lighting unit that emits illumination light toward a ceiling side and a floor lighting unit that emits illumination light toward a floor side , the ceiling lighting unit and the floor lighting unit have their illumination surfaces facing opposite directions, and the ceiling lighting unit and the floor lighting unit are each capable of independently adjusting the luminous flux they emit,
Illuminating with the plurality of lighting fixtures with a ratio of a ceiling side luminous flux emitted from the ceiling lighting unit to a floor side luminous flux emitted from the floor lighting unit being 9.5:90.5 or more and less than 14:86;
A ceiling area is cut out from image data of the office space captured using a camera installed to capture images of the ceiling, walls, and floor of the office space from one end of the office space toward the other end of the office space, and the brightness values of the pixels of the ceiling area in the image data are extracted. The average brightness value of the ceiling area in the image data is set as the ceiling average brightness value,
When an area division having a luminance value equal to or greater than the average luminance value of the ceiling (1.0 times or more) is defined as a high luminance division, an area division having a luminance value between 0.5 times and less than 1.0 times the average luminance value of the ceiling is defined as a medium luminance division, and an area division having a luminance value less than 0.5 times the average luminance value of the ceiling is defined as a low luminance division,
A lighting system characterized by illuminating the ceiling area in image data so that the ratio of the brightness value divisions is 6.4% or more and less than 18.8%, the ratio of the high brightness division is 3.0% or more and less than 33.7%, and the ratio of the low brightness division is 47.5% or more and less than 90.6%. A lighting system that provides ambient lighting to an office space having a ceiling, walls, and a floor,
The lighting system comprises:
Equipped with multiple lighting fixtures installed on the ceiling,
Each of the plurality of lighting fixtures has a ceiling lighting unit that emits illumination light toward a ceiling side and a floor lighting unit that emits illumination light toward a floor side, the ceiling lighting unit and the floor lighting unit have their illumination surfaces facing opposite directions, and the ceiling lighting unit and the floor lighting unit are each capable of independently adjusting the luminous flux they emit,
Illuminating with the plurality of lighting fixtures with a ratio of a ceiling side luminous flux emitted from the ceiling lighting unit to a floor side luminous flux emitted from the floor lighting unit being 9.5:90.5 or more and less than 14:86;
A ceiling area is cut out from image data of the office space captured using a camera installed to capture images of the ceiling, walls, and floor of the office space from one end of the office space toward the other end of the office space, and the brightness values of the pixels of the ceiling area in the image data are extracted. The average brightness value of the ceiling area in the image data is set as the ceiling average brightness value,
When an area division having a luminance value equal to or greater than the average luminance value of the ceiling (1.0 times or more) is defined as a high luminance division, an area division having a luminance value between 0.5 times and less than 1.0 times the average luminance value of the ceiling is defined as a medium luminance division, and an area division having a luminance value less than 0.5 times the average luminance value of the ceiling is defined as a low luminance division,
A lighting system characterized by illuminating the ceiling area in image data so that the ratio of the brightness value divisions of the high brightness division is 6.0% or more and less than 7.6%, the ratio of the medium brightness division is 0.6% or more and less than 12.2%, and the ratio of the low brightness division is 80.2% or more and less than 93.4%. In a lighting system according to claim 1 or claim 2 ,
moreover,
A storage device that stores a vertical light distribution rate pattern of each lighting fixture that is set to realize claim 1 or claim 2 ;
a host computer that controls the lighting of each of the lighting fixtures based on the vertical light distribution ratio pattern of each of the lighting fixtures stored in the storage device. In a lighting system according to claim 1 or claim 2 ,
A camera installed to capture images of the ceiling, walls, and floor of the office space from one end to the other end of the office space;
A computer that calculates a ratio of brightness value ranges from a camera image,
A lighting system comprising: a computer that adjusts the dimming rate of each lighting fixture so that the dimming rate falls within a range of the ratio of the luminance value segments according to claim 1 or 2 .

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