Abstract: A light source device according to an embodiment is used with a light guide member and a wavelength converting member, and includes a light-emitting element, a light sensor, and a driving unit. The light-emitting element radiates a light beam to be incident on a first end of the light guide member by being supplied with a drive current. The light sensor detects signal light, which has been incident on a second end of the light guide member and transmitted to the first end. The driving unit supplies the drive current to the light-emitting element and controls the drive current based on a result of detection of the signal light.

Abstract: A light source device according to an embodiment is used with a light guide member and a wavelength converting member, and includes a light-emitting element, a light sensor, and a driving unit. The light-emitting element radiates a light beam to be incident on a first end of the light guide member by being supplied with a drive current. The light sensor detects signal light, which has been incident on a second end of the light guide member and transmitted to the first end. The driving unit supplies the drive current to the light-emitting element and controls the drive current based on a result of detection of the signal light.

Abstract: A target identification system includes: one or more optical receivers (at least one of a first optical receiver or a second optical receiver) which receive outgoing light from a moving body, the outgoing light including an optical signal indicating identification information (first information) for identifying the moving body; a controller connected to the one or more optical receivers; and a wireless communicator connected to the controller.

Abstract: An illumination light communication apparatus to be connected to a light source that emits illumination light due to a current from a constant current generation device, and that modulates the illumination light includes: a switch connected in series to the light source; a signal generator circuit that generates a binary communication signal which controls ON and OFF states of the switch to modulate the illumination light; a current suppression circuit that is connected in series to the light source and the switch, and that suppresses the current flowing in the light source so that a current setting value corresponding to a reference value is not exceeded; and a controller that can change an ON duty ratio of the switch through the communication signal. The controller changes the ON duty ratio of the switch during a transition period in which a current flowing in the current suppression circuit changes.

Abstract: A visible light communication device includes: a light emitting device that emits visible light when current flows thereto; a power supply circuit that supplies the current that flows to the light emitting device; a switch that switches between ON and OFF states in which current does and does not flow to the light emitting device, respectively; a switch controller that controls the switch state; a voltage detector that detects an input voltage of the light emitting device; a threshold storage that stores information stipulating a threshold voltage; and a determiner that, when the switch is in the ON state and the voltage detector detects an ON voltage, determines whether the ON voltage satisfies a predetermined relationship with the threshold voltage stipulated by the information stored in the threshold storage. The switch controller further latches the switch in the OFF state when the determination by the determiner is affirmative.

Abstract: A visible light communication device includes: a light emitting device that emits visible light when current flows thereto; a power supply circuit that supplies the current that flows to the light emitting device; a switch that switches between ON and OFF states in which current does and does not flow to the light emitting device, respectively; a switch controller that controls the switch state; a voltage detector that detects an input voltage of the light emitting device; a threshold storage that stores information stipulating a threshold voltage; and a determiner that, when the switch is in the ON state and the voltage detector detects an ON voltage, determines whether the ON voltage satisfies a predetermined relationship with the threshold voltage stipulated by the information stored in the threshold storage. The switch controller further latches the switch in the OFF state when the determination by the determiner is affirmative.

Abstract: A mobile device includes: a communications circuit which performs wireless communication; a receiver which receives input of a destination from a user; an output which outputs guidance information for guiding the user from a current location to the destination; and a controller which causes the output to output notification information for notifying presence of a transmitting device which emits light for visible light communications, if the communications circuit receives a wireless signal from a transmitting device by the wireless communication.

Abstract: A target identification system includes: one or more optical receivers (at least one of a first optical receiver or a second optical receiver) which receive outgoing light from a moving body, the outgoing light including an optical signal indicating identification information (first information) for identifying the moving body; a controller connected to the one or more optical receivers; and a wireless communicator connected to the controller.

Abstract: A guide display device which is installed in a predetermined direction includes: a first screen which is parallel to the predetermined direction; a first light source which illuminates the first screen; a cover which is provided above the first screen in the predetermined direction and projects in a direction crossing the first screen to block light from above the guide display device and cast a shadow upon an area of the guide display device; a second light source which illuminates the area on which the shadow is cast; and a controller which causes at least the second light source to perform optical communication.

Abstract: A Lighting device, which performs visible light communication with a receiver including an image sensor, includes: a dividing unit that divides identification information assigned to the lighting device into N packets (where N is a natural number greater than or equal to 2); a block generator that generates signal blocks each of which includes M packets (where M is a natural number greater than or equal to N) that include at least one of each of the N packets; and a light source that sequentially transmits the signal blocks in (i) each frame cycle of the image sensor or in (ii) each cycle substantially equal to an integral multiple of the frame cycle, by superimposing each of the signal blocks onto illumination light. The block generator generates the signal blocks so that an order of arranging the M packets is different between consecutive signal blocks in the signal blocks.

Abstract: A lighting device includes: a first light source which emits light that includes a visible light communication signal indicating first information; and a second light source which is disposed at a position different from a position of the first light source, and emits light that includes a visible light communication signal indicating second information different from the first information.

Abstract: An illumination light communication apparatus includes: a light source which emits illumination light; a power supply circuit for supplying constant current to the light source; a switch which is connected in series to the light source, and intermittently interrupts current which flows through the light source; a signal generating circuit which generates a binary communication signal which controls on and off of the switch to modulate the illumination light; and a current limiting circuit which is connected in series to the light source and the switch, and limits the current which flows through the light source to prevent the current from exceeding a current set value which is variable.

Abstract: A worker management device that manages a worker wearing workwear includes: a main body; a light receiver that is provided on a part of the main body that is exposed when the main body is attached to the workwear, and receives light including predetermined identification information; a controller connected to the light receiver; and a communication unit connected to the controller.

Abstract: Provided is a guidance display device which transmits predetermined information by visible light communications, the guidance display device including: a light source which emits light for visible light communications, the light including the predetermined information; a housing covering the light source and having a first light-exit surface which transmits the light emitted by the light source; a first guidance display on the first light-exit surface; and a first mark on the first light-exit surface, wherein the first mark has a shape corresponding to a total number of light-exit surfaces, including the first light-exit surface, of the guidance display device through which the light for visible light communications emitted by the light source exits.

Abstract: A guide display device which is installed in a predetermined direction includes: a first screen which is parallel to the predetermined direction; a first light source which illuminates the first screen; a cover which is provided above the first screen in the predetermined direction and projects in a direction crossing the first screen to block light from above the guide display device and cast a shadow upon an area of the guide display device; a second light source which illuminates the area on which the shadow cast; and a controller which causes at least the second light source to perform optical communication.

Abstract: An illumination light communication apparatus includes: a light source which emits illumination light; a power supply circuit for supplying constant current to the light source; a switch which is connected in series to the light source, and intermittently interrupts current which flows through the light source; a signal generating circuit which generates a binary communication signal which controls on and off of the switch to modulate the illumination light; and a current limiting circuit which is connected in series to the light source and the switch, and limits the current which flows through the light source to prevent the current from exceeding a current set value which is variable.

Abstract: A luminaire includes an electric light source, a light source driver configured to turn on the light source, and a controller configured to control the light source driver. The controller is configured to control the light source driver to transmit, with a probability lower than 50% at a prescribed time interval, an optical signal with light of the light source as a medium while the light source is in ON. The prescribed time interval is longer than a time period during which the optical signal is transmitted.

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 mobile device includes: a communications circuit which performs wireless communication; a receiver which receives input of a destination from a user; an output which outputs guidance information for guiding the user from a current location to the destination; and a controller which causes the output to output notification information for notifying presence of a transmitting device which emits light for visible light communications, if the communications circuit receives a wireless signal from a transmitting device by the wireless communication.

Abstract: Provided is a guidance display device which transmits predetermined information by visible light communications, the guidance display device including: a light source which emits light for visible light communications, the light including the predetermined information; a housing covering the light source and having a first light-exit surface which transmits the light emitted by the light source; a first guidance display on the first light-exit surface; and a first mark on the first light-exit surface, wherein the first mark has a shape corresponding to a total number of light-exit surfaces, including the first light-exit surface, of the guidance display device through which the light for visible light communications emitted by the light source exits.