2479 results about "Visible light communication" patented technology

A system and method for providing an in-building navigation service using VLC are provided, in which transmitters control lamp modules to generate visible light signals each in a combination of different wavelengths as information for a navigation function, a mobile terminal receives visible light signals from a plurality of lamp modules that illuminate an area where the mobile terminal is located, location information about a current location of the mobile terminal is acquired through the visible light signals received from the plurality of lamp modules, and navigation information including information that matches the location information to map information is displayed on the mobile terminal.

A method and an apparatus are provided for guaranteeing terminal mobility in a time division visible light communication system. In resource assignment in a position where the visible light communication terminal changes a cell, the terminal is assigned a resource to be used in a next cell in a cell boundary area from a communication coordinator, thereby guaranteeing the continuous mobility. The visible light communication system informs the terminal of cell boundary notice information for easily informing the terminal of the cell definition so that the terminal can recognize that the terminal is currently located in the cell boundary and is necessary to change the resource.

A visible light communication apparatus enables an operator to visually recognize a communication state during visual light communication. The apparatus includes a light emitting section which emits visible light and which includes a modulator, a visible light emitter, a light emitting element and an emission control section which includes a controller and which controls an emission state of the visible light from the light emitting section. The apparatus controls the emission state according to the communication state. It is hence possible for the operator to visually perceive the communication state during the visible light communication.

In a visible light communication system, a transmission device includes a data modulation section which assigns 1-bit information to each of visible lights of RGB, and modulates transmission data into 3-bit modulation data. An LED light emission section transmits a multiplexed visible light signal, in which the RGB visible lights are multiplexed in accordance with the modulation data.

A navigation system and a navigation method inside of a building using Visible Light Communications (VLC) are provided. The navigation system includes a map server, in which map information required to provide a navigation function is stored, for transferring the map information to each lamp, a plurality of lamps, installed in each zone inside of the building and having their respective identifiable and unique IDentifications (IDs), for receiving the map information required to provide the navigation function from the map server, and for generating a visible light signal in response to the received map information by using a VLC module, and a mobile terminal, equipped with a visible light Rx module, for being provided with the map information upon receiving the visible light signal generated from the lamp, and for displaying a map image in response to the provided map information.

A visible light communications transmitter combines a modulated carrier signal with a pulse from a pulse generator. The carrier signal is modulated according to data read from a buffer during the pulse.

A display device for providing additional information using Visible Light Communication (VLC), including a decoder for dividing an input signal into a video signal and a data signal including additional information on at least one object included in an image output through the video signal; a display; a VLC controller for receiving the data signal from the decoder and encoding the data signal in accordance with a VLC protocol to output the data signal as a visible light signal through the VLC; light source blocks, which include light sources, back light the display, and output the data signal encoded in accordance with the VLC; and a control unit for controlling the encoded data signal including the additional information on the object, to be output as the visible light signal through a light source block at a position corresponding to the object from among the light source blocks.

Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.

Method and device for exchanging messages in a VLC navigation system is provided, in which a map server generates a provision message in the form of visible light signals through all lamps in an area, using a PLC network, where a navigation service is provided, a terminal that wants to implement the navigation service among terminals that have received the provision message transmits a registration request message to the map server, the map server transmits a registration response message for the registration request message to the terminal, the terminal transmits a map request message including information about a destination to the map server, the map server transmits a map response message including information about a path to the destination to the terminal, and the terminal displays map information and the path.

A method to securely transfer data to aid in a medical procedure or to a data management system to be accessed in a medical care facility is provided that includes a set of data from a data storage system being downloaded via a network to a visible light communication (VLC) enabled device. The set of data from the VLC enabled device is then transferred to a VLC enabled device located in an operating room (OR) via point to point VLC or uploaded to a data management system. The transferred set of data is then used to aid in a medical procedure or be accessed by a medical care facility. Software executables are similarly transferred and run in an OR context.

A time-sharing Visible Light Communication (VLC) system is provided. Two or more light sources transmit data received from one or more VLC terminals located in its service area to a communication control device, and transmits data received from the communication control device to the one or more VLC terminals. The communication control device determines and groups at least one of the two or more light sources to be included in a cell according to a generated user service, maps the grouped at least one light source to the cell, allocates a time slot used to provide the user service to the cell, transmits data associated with the user service to at least one of the one or more VLC terminals through the at least one light source mapped to the cell using the allocated time slot, detects a location of the at least one VLC terminal located in a service area of the cell on a real-time basis, and remaps the cell according to the detected location.

There is provided a visible light control apparatus including: a modulation unit (corresponding to a PPM signal generation circuit, a subcarrier generation circuit, and a first AND circuit) that modulates a subcarrier and thereby generates a modulated signal; a visible light control unit (corresponding to a driving circuit) that controls blinking of visible light which contains information based on the modulated signal modulated by the modulation unit and allows the visible light to be emitted at a predetermined emission time ratio; and an emission time ratio control unit (corresponding to a dimming signal generation circuit, an inverting circuit, a second AND circuit, and an OR circuit) that changes the predetermined emission time ratio and allows the visible light to be emitted at the changed emission time ratio.

An information display apparatus performs a visual light communication and superimposes light source information transmitted from a light source onto images captured in time sequence for display on a screen. The information display apparatus includes an imaging section for capturing an image in an imaging range, a cache memory sequentially caching the light source information transmitted from the light source in the image, a priority level setting section for setting a higher priority to the light source information, cached in the cache memory, in order starting from a light source closest to a current imaging range, and a communications information processing section for deleting the light source information cached in the cache memory in order starting from light source information having the lowest priority level.

A visible ray communication system and method that improve transmission rate and remove an influence of inter-color interference to improve the communication quality. A transmission apparatus included in the visible ray communication system allocates each carrier signal component of an OFDM signal, which is modulated into transmission information, to a plurality of LEDs of different colors. The information is added to a combination of a carrier frequency and an LED wavelength, when a carrier signal is allocated to an, in addition to each carrier signal being modulated into the information.

The invention relates to a detection system for determining data embedded into the light output of a light source in a form of a repeating sequence of N symbols. The detection system includes a camera and a processing unit. The camera is configured to acquire a series of images of the scene via specific open / closure patterns of the shutter. The processing unit is configured to process the acquired series of images to determine the repeating sequence of N symbols. By carefully triggering when a shutter of the camera is open to capture the different symbols of the encoded light within each frame time of a camera, a conventional camera with a relatively long frame time may be employed. Therefore, the techniques presented herein are suitable for detecting the invisible “high frequency” coded light while using less expensive cameras as those used in the prior art.

A Visible Light Communication (VLC) method in a VLC terminal, in which the VLC terminal requests initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame, sends an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame, and transmits data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot.

A system, remote control device and method are provided herein for communicating with and controlling various devices using visible light communication (VLC). According to one embodiment, a method is provided for extending a communication range of a visible light communication system comprising a remote control device and a plurality of controlled devices. Such a method may include, for example, transmitting a communication message from a remote control device to a first controlled device located within range of the remote control device, wherein the communication message is transmitted through free space using visible light, and extending the communication range of the visible light communication system to a second controlled device, which is located outside of the range of the remote control device, by using the first controlled device to retransmit the communication message through free space using visible light to the second controlled device.

The present invention provides a camera-equipped cellular terminal capable of receiving visible light communication. In order to receive information from visible light, a light receiving unit (24) for visible light pointing to the same direction as a light receiving lens of the camera (21) is provided other than a camera (21) of a conventional camera-equipped cellular terminal (20). This light receiving unit (24) receives information from the visible light. This light receiving unit (24) may be configured by a photodiode or the like. When the camera (21) is used as a finder to display an illuminating device conducting visible light communication in a display of the camera, whether the light receiving unit 24 can receive information through visible light communication is determined.

A transmitting apparatus using visible light communication generates a light source control signal from color information representing additional information and transmits additional information with a color of light that is emitted by a light source by controlling an on / off time of a plurality of LEDs according to the light source control signal. Therefore, a user can intuitively know additional information from a color of light that is emitted by the light source.

A navigation system and a navigation method inside of a building using Visible Light Communications (VLC) are provided. The navigation system includes a map server, in which map information required to provide a navigation function is stored, for transferring the map information to each lamp, a plurality of lamps, installed in each zone inside of the building and having their respective identifiable and unique IDentifications (IDs), for receiving the map information required to provide the navigation function from the map server, and for generating a visible light signal in response to the received map information by using a VLC module, and a mobile terminal, equipped with a visible light Rx module, for being provided with the map information upon receiving the visible light signal generated from the lamp, and for displaying a map image in response to the provided map information.

Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.

The invention provides a user device, a payment terminal, a system and a method, wherein the user device, the payment terminal, the system and the method are based on visible light communications to carry through payments. The user device comprises a payment information storage unit and a visible light emitting unit. The payment information storage unit is used for storing payment information which is relative to a user identity or an account. The visible light emitting unit comprises a coding and modulating module, a light source and a light source driving module, wherein the coding and modulation module is used for coding and modulating the information, and the light source driving module is used for driving the light source to light according to the modulated information. The user device further comprises a control unit, and the control unit is used for activating the visible light emitting unit to send the payment information to the payment terminal.

The invention relates to an indoor positioning method based on a visible light label, and belongs to the technical field of wireless communication. The method disclosed by the invention comprises the following steps: on the basis of visible light communication, emitting a visible light signal with an alignment code type by a transmitting terminal by controlling a light-emitting diode (LED) array, so that an indoor user analyzes the position from a received light signal, and each LED has a sole identity (ID) number; designing a locating data frame structure which is transmitted by the LED in a cycle; loading to an LED drive amplifying circuit; driving the LED lamp array to transmit a data light signal; and locating the user in a sub-cell with the maximal optical power when a detector identifies a frame header. The method is free of frequency band application, free of electromagnetic interference, green and safe, and higher in accuracy located on the basis of the visible light LED. In addition, green lighting also can be carried out in an indoor scene in visible light LED communication, the indoor visible light communication is located through the existing floodlight, a visible light source does not need to be arranged additionally, and achievement of indoor location is facilitated.

A method and apparatus for supporting mobility of a mobile terminal in a Visible Light Communication (VLC) system. The method includes activating only necessary light sources for VLC considering the mobility of the mobile terminal, instead of using total light sources for VLC. Consequently, power consumption can be significantly reduced.

A visible light communication system, includes a data storage apparatus, a data transmitter and a data receiver, the data transmitter includes data receiving module for receiving data from the data storage apparatus, modulating module for modulating the data received by the data receiving module, and transmitting module for transmitting the data modulated by the modulating module to the data receiver as a carrier of illumination light, the data receiver includes illumination light detecting module for detecting the illumination light received by the transmitting module in accordance with an output variation of power converting module, demodulating module for demodulating the illumination light detected by the illumination light detecting module, and displaying module for displaying the data demodulated by the demodulating module.

According to one embodiment, a photo detector-combined illuminance sensor includes a circuit for a Photo Detector (PD) function to detect the illuminance of the ambient environment. The illuminance sensor operates under the control of a controller in a visible light communication terminal. When an optical signal detected by the illuminance sensor is a visible light communication signal, the controller switches to cause the illuminance sensor to operate as the photo detector for the visible light communication in a visible light communication mode.

A method and apparatus conduct an optical clock rate negotiation to support asymmetric clock rates for visible light communication (VLC) in a VLC device. A first frame that includes a receiver clock rate supported by a first VLC device is transmitted at a predetermined clock rate. A response frame that includes a receiver clock rate supported by a second VLC device is received from the second VLC device. A transmission clock rate of the first VLC device is selected based on the response frame from the second VLC device. Subsequent frames for data communication are transmitted to the second VLC device at the selected transmission clock rate of the first device. Alternatively, when conducting optical clock negotiation in the PHY layer, multiple clock rates are supported within a single frame.

An information communication method selects between a visible light communication mode in which information is obtained from a subject using an image sensor having a plurality of exposure lines and a normal imaging mode. The method includes obtaining first image data by image capture with a first exposure time in the normal imaging mode. When an image is presented that prompts a user of a terminal device including the image sensor to move the terminal device to enable the information to be obtained, second image data is obtained by image capture with a second exposure time, shorter than the first exposure time, in the visible light communication mode. The information is obtained by demodulating data specified by a direction in a pattern of a bright line appearing in the second image data and corresponding to the exposure lines that is substantially perpendicular to the exposure lines.