Light control system, light control method and computer readable memory

1. A light control system comprising:

a plurality of lighting devices respectively arranged, on a ceiling surface, at a plurality of grid points of said ceiling surface partitioned in a grid pattern;

a sensor that detects occupancy statuses of a plurality of seats located correspondingly to positions of said plurality of grid points; and

a controller capable of communicating with each of said plurality of lighting devices, wherein

said controller

generates, for each of groups set correspondingly to occupied locations, light control information on a lighting device that becomes a dimming target in each of said groups, where a block formed of a plurality of grid points, which center around a grid point of an occupied location and include at least four grid points positioned diagonally to the grid point of the occupied location, is one group,

for each of said groups, calculates ratios of a first illuminance of the centered around grid point being turned on to second illuminances of other grid points being turned off adjacent to the centered around grid point, and

transmits said light control information derived from the calculated ratios, and

a lighting device being a dimming target among said plurality of lighting devices performs light control based on said received light control information.

2. The light control system according to claim 1 , wherein said controller determines, among said plurality of lighting devices, a lighting device at each of grid points included in each of said groups as a to-be-turned-on light; and

specifies, for each of said groups, a lighting device adjacent to another to-be-turned-on light at a grid point outside of said group as said lighting device being a dimming target among the lighting devices at grid points in each of said groups.

3. The light control system according to claim 2 , wherein in a case where a reference illuminance represents an illuminance on an illumination surface at a grid point at which a lighting device being a dimming target when said lighting device being a dimming target is turned on alone with a rated output, said controller calculates said ratios such that a composite illuminance approaches said reference illuminance, said composite illuminance being obtained by adding an illuminance on said illumination surface provided from said lighting device being a dimming target and an illuminance on said illumination surface provided from said another to-be-turned-on light adjacent to said lighting device being a dimming target.

4. The light control system according to claim 3 , wherein

said controller preliminarily stores, as first illuminance ratios, ratios of an illuminance on an illumination surface at a grid point and an illuminance on an illumination surface at each adjacent grid point adjacent to said grid point, which are obtained when a lighting device at said grid point is turned on alone with a rated output, to said reference illuminance, and obtains said composite illuminance using said first illuminance ratios to calculate said light control ratio such that said composite illuminance approaches one being said first illuminance ratios of said reference illuminance.

5. The light control system according to claim 3 , wherein

the block as said group is formed of a grid point at an occupied location and eight grid points adjacent to said grid point,

said controller judges whether or not a specific group, which is said group in which seats at the grid points included therein are all occupied, exists, calculates, in a case where said specific group exists, a light control ratio of a lighting device at a center grid point positioned at the center of said specific group as said light control information,

obtains a cumulative illuminance being an accumulation of illuminances on an illumination surface at said center grid point, said illuminances being respectively provided from to-be-turned-on lights at grid points that are adjacent to any of grid points in said specific group and are not included in said specific group, and

calculates, as a light control ratio of the lighting device at said center grid point, a ratio of a value obtained by subtracting said cumulative illuminance from said reference illuminance to said reference illuminance.

6. The light control system according to claim 5 , wherein

said controller preliminarily stores, as second illuminance ratios, ratios of an illuminance on an illumination surface at a grid point and an illuminance on an illumination surface at each of grid points that adjacently surround each adjacent grid point adjacent to said grid point, which are obtained when a lighting device at said grid point is turned on alone with a rated output, to said reference illuminance, and

obtains said cumulative illuminance using said second illuminance ratios to calculate, as a light control ratio of the lighting device at said center grid point, a value obtained by subtracting said cumulative illuminance from one being the second illuminance ratios of said reference illuminance.

7. A light control method for a plurality of lighting devices respectively arranged, on a ceiling surface, at a plurality of grid points of said ceiling surface partitioned in a grid pattern, the method comprising the steps of:

a) detecting occupancy statuses of a plurality of seats located correspondingly to positions of said plurality of grid points;

b) generating, for each of groups set correspondingly to occupied locations, light control information on a lighting device that becomes a dimming target in each of said groups, where a block formed of a plurality of grid points, which center around a grid point of an occupied location and include at least four grid points positioned diagonally to the grid point of the occupied location, is one group;

c) for each of said groups, calculating ratios of a first illuminance of the centered around grid point being turned on to second illuminances of other grid points being turned off adjacent to the centered around grid point; and

d) performing light control on the lighting device being a dimming target based on said received light control information derived from the calculated ratios.

8. A non-transitory computer-readable memory storing a program that causes a computer built in a controller of a light control system including: a plurality of lighting devices respectively arranged, on a ceiling surface, at a plurality of grid points of said ceiling surface partitioned in a grid pattern; a sensor that detects occupancy statuses of a plurality of seats positioned correspondingly to positions of said plurality of grid points; and said controller capable of communicating with each of said plurality of lighting devices, to perform the steps of:

a) determining, when a block formed of a plurality of grid points, which center around a grid point of an occupied location and include at least four grid points positioned diagonally to the grid point of the occupied location, is a constitutional unit of one group, a lighting device at each of grid points included in each of groups set correspondingly to occupied locations as a to-be-turned-on light among said plurality of lighting devices; and

b) for each of said groups, calculating ratios of a first illuminance of the centered around grid point being turned on to second illuminances of other grid points being turned off adjacent to the centered around grid point.