Abstract: A signboard apparatus includes: light panel apparatuses arranged two-dimensionally, and each having a transmission function and a light-emitting face for visible light communication; and a control apparatus that performs, with respect to the light panel apparatuses, exclusive control of the transmission function. The light panel apparatuses are arranged as a collective signboard.

Abstract: A modulation device includes a modulator circuit that causes a light source to perform light communication, storage storing an internal ID, and a control circuit that determines whether an external ID is input into the modulation device. When the control circuit determines that the external ID is input into the modulation device, the control circuit causes the input external ID to be input, as a modulation signal, into the modulator circuit. When the control circuit determines that the external ID is not input into the modulation device, the control circuit causes the internal ID stored in the storage to be input, as a modulation signal, into the modulator circuit.

Abstract: A modulation device includes: a modulation ID signal generator that generates a first ID signal including first identification information; a reception terminal capable of receiving a second ID signal including second identification information; a transmission terminal capable of transmitting the first ID signal and the second ID signal out of the modulation device; a detector that detects a received state in which the second ID signal is received by the reception terminal and an unreceived state in which the second ID signal is not received by the reception terminal; and a switch circuit that outputs the first ID signal to the transmission terminal when the detector detects the unreceived state and outputs the second ID signal to the transmission terminal when the detector detects the received state.

Abstract: A visible light communication modulation circuit includes a modulation resistance circuit configured to change a current flowing through an LED light source by changing a resistance thereof, a measurement circuit configured to simultaneously measure a voltage applied to the LED light source and the current flowing through the LED light source at least twice until the current is stabilized, an calculation circuit configured to obtain an equivalent series resistance of the LED light source based on at least two sets of voltage values and current values and determine a target resistance of the modulation resistance circuit based on the equivalent series resistance and a predetermined modulation degree, and a conversion circuit configured to change the resistance of the modulation resistance circuit based on the target resistance.

Abstract: A visible light communication apparatus includes: a light source; a power source circuit which applies a voltage to an electric path for causing the light source to emit light; a modulation circuit which causes the light source to emit light modulated by a communication signal; and a function circuit section which is connected to the electric path and performs a predetermined function by operating on a current flowing through the electric path, the function circuit section operating on a voltage lower than a first voltage value which is a lowest voltage value at which the light source emits light and higher than or equal to a second voltage value, wherein the power source circuit further applies to the electric path the voltage lower than the first voltage value and higher than or equal to the second voltage value.

Abstract: A lighting apparatus that is used in a positioning system and is locatable in plural number in a limited area is provided. The lighting apparatus for use in the positioning includes a power supplier that supplies power, a lighting unit that is lit by the power supplied by the power supplier, and a beacon transmitter. The beacon transmitter operates by the power supplied by the power supplier, and transmits a beacon that is a signal for positioning. The beacon includes a long-distance beacon transmitted with first transmission power and a short-distance beacon transmitted with a second transmission power less than the first transmission power. The beacon transmitter transmits at least the long-distance beacon intermittently.

Abstract: A visible light communication apparatus includes: a light source; a power source circuit which applies a voltage to an electric path for causing the light source to emit light; a modulation circuit which causes the light source to emit light modulated by a communication signal; and a function circuit section which is connected to the electric path and performs a predetermined function by operating on a current flowing through the electric path, the function circuit section operating on a voltage lower than a first voltage value which is a lowest voltage value at which the light source emits light and higher than or equal to a second voltage value, wherein the power source circuit further applies to the electric path the voltage lower than the first voltage value and higher than or equal to the second voltage value.

Abstract: A controller is configured, by decreasing light quantity in only a first slot that is any one of a plurality of slots into which a unit time is divided equally, and increasing light quantity in all the remaining slots except the first slot of the plurality of slots, to assign information to the first slot of the plurality of slots. The controller is furthermore configured to decrease light quantity in second slots that are three or more continuous slots starting from a head of a preamble, which indicates a frame start point, of a frame of an optical-communication signal and to increase light quantity in a slot immediately before the preamble.

Abstract: A lighting fixture for visible light communication is configured to modulate light intensity of a light source (11) comprising a light-emitting device (2) to superpose a communication signal on illumination light. The lighting fixture includes: a power supply circuit (3) configured to control light output of the light source (11) based on a dimming signal; a switch device (Q1) for modulating an output current from the power supply circuit (3) to the light source (11); an impedance element (Rx); a communication circuit (4); and an ON circuit (6). The communication circuit (4) is configured to supply a modulation signal to a side of the switch device (Q1) to superpose the communication signal on the illumination light. The ON circuit (6) is configured to turn on the switch device (Q1) by supply power from the power supply circuit (3) when the communication circuit (4) is inactivated.

Abstract: A visible light communication apparatus includes a constant current circuit and a load circuit including light emitting elements connected to output terminals of the constant current circuit. Further, the visible light communication apparatus includes a load variation circuit configured to change load characteristics of the load circuit by electrically connecting to the load circuit, the load variation circuit including a series circuit of a diode and a resistor connected in series to the load circuit and a switching element configured to electrically connect or disconnect the load variation circuit to the load circuit in response to a binary communication signal.

Abstract: A modulation device includes a modulator circuit that causes a light source to perform light communication, storage storing an internal ID, and a control circuit that determines whether an external ID is input into the modulation device. When the control circuit determines that the external ID is input into the modulation device, the control circuit causes the input external ID to be input, as a modulation signal, into the modulator circuit. When the control circuit determines that the external ID is not input into the modulation device, the control circuit causes the internal ID stored in the storage to be input, as a modulation signal, into the modulator circuit.

Abstract: A modulation device includes: a modulation ID signal generator that generates a first ID signal including first identification information; a reception terminal capable of receiving a second ID signal including second identification information; a transmission terminal capable of transmitting the first ID signal and the second ID signal out of the modulation device; a detector that detects a received state in which the second ID signal is received by the reception terminal and an unreceived state in which the second ID signal is not received by the reception terminal; and a switch circuit that outputs the first ID signal to the transmission terminal when the detector detects the unreceived state and outputs the second ID signal to the transmission terminal when the detector detects the received state.

Abstract: A lighting device includes: a drive circuit that supplies power to a light source; a switch connected in series with the light source; and a controller that controls pulse modulation for visible light communication executed through switching ON and OFF of the switch in a first interval, and stops the pulse modulation in a second interval. The controller controls a peak value, which is a high value of a pulsed current supplied from the drive circuit to the light source, to match an average current value in the first interval with an average current value in the second interval.

Abstract: A signboard apparatus includes: light panel apparatuses arranged two-dimensionally, and each having a transmission function and a light-emitting face for visible light communication; and a control apparatus that performs, with respect to the light panel apparatuses, exclusive control of the transmission function. The light panel apparatuses are arranged as a collective signboard.

Abstract: A lighting device includes: a drive circuit that supplies power to a light source; a switch connected in series with the light source; and a controller that controls pulse modulation for visible light communication executed through switching ON and OFF of the switch in a first interval, and stops the pulse modulation in a second interval. The controller controls a peak value, which is a high value of a pulsed current. supplied from the drive circuit to the light source, to match an average current value in the first interval with an average current value in the second interval.

Abstract: An illumination light communication apparatus includes: a light source; a power supply circuit; a switching element which modulates an output current supplied from the power supply circuit to the light source; a visible light communication signal circuit which controls ON and OFF of the switching element to output a modulating signal for superimposing a visible light beacon signal including a unique ID onto the illumination light emitted from the light source; a control power supply circuit which supplies power to the visible light communication signal circuit; a wireless module which transmits a radio wave beacon signal including a unique ID; and a radio wave beacon controlling and transmitting circuit which controls the radio wave beacon signal transmitted from the wireless module, wherein the radio wave beacon controlling and transmitting circuit is supplied with power from the control power supply circuit.

Abstract: A variable impedance circuit (2) has an impedance device and is connected in series with a light source (A1). A switch circuit (Q1) is connected in parallel with the variable impedance circuit (2). A first controller (3) is configured to perform ON and OFF control of the switch circuit (Q1) and thereby to modulate an intensity of an illumination light emitted from the light source (A1). An impedance-varying circuit (Q2) is connected with the variable impedance circuit (2). The second controller (4) is configured to control the impedance-varying circuit (Q2) to change the impedance of the variable impedance circuit (2). The first controller (3) and the second controller (4) share a common hardware.

Abstract: The visible light communication device includes a control circuit configured to repeat a transmission process of transmitting a communication signal through modulating an intensity of visible light to be emitted from a light source. The control circuit is configured to, in the transmission process, arbitrarily select a time slot for transmission from a plurality of time slots set within a predetermined time period allocated to the transmission process, and transmit the communication signal in the time slot for transmission.

Abstract: A lighting fixture is configured to modulate light intensity of a light source (11) comprising a light-emitting device (2) to superpose a communication signal on illumination light of the light source (11). The fixture includes: a main power supply (3) configured to control light output of the light source (11) based on a dimming signal; a switch device (Q1) for modulating an output current supplied from the main power supply (3) to the light source (11); an impedance element (Rx); a communication circuit (7); and a control power supply (8). The communication circuit (7) is configured to control the switch device (Q1) to superpose a modulation signal on illumination light from the light source (11). The control power supply (8) is configured to supply electric power to the communication circuit (7). One end of two input ends of the control power supply (8) is connected to one end of the impedance element.

Abstract: A visible light communication modulation circuit includes a modulation resistance circuit configured to change a current flowing through an LED light source by changing a resistance thereof, a measurement circuit configured to simultaneously measure a voltage applied to the LED light source and the current flowing through the LED light source at least twice until the current is stabilized, an calculation circuit configured to obtain an equivalent series resistance of the LED light source based on at least two sets of voltage values and current values and determine a target resistance of the modulation resistance circuit based on the equivalent series resistance and a predetermined modulation degree, and a conversion circuit configured to change the resistance of the modulation resistance circuit based on the target resistance.