KR101587059B1 - Apparatus and method for visible light communication using direct lit backlight - Google Patents

Abstract

The present invention relates to an apparatus and a method for high-speed visible light communication using a direct-lit backlight. The apparatus for high-speed visible light communication using a direct-lit backlight comprises: a direct-lit backlight which is divided into a plurality of blocks and can control brightness of each block; a dimming control unit to control whether to dim each block based on a dimming signal; and a data decoder unit to generate the dimming signal based on inputted transmission data. The transmitted data are converted into an image pattern to improve transmission efficiency of visible light communication. The direct-lit backlight included in a display device is used in visible light communication to simplify a structure of a visible light communication device included in the display device and reduce manufacturing costs.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-speed visible light communication apparatus and method using a direct-type backlight,

The present invention relates to a high-speed visible light communication apparatus and method using a direct-type backlight, and more particularly, to a high-speed visible light communication apparatus and method using a direct-type backlight that improves transmission efficiency by converting transmitted data into an image pattern .

Light Emitting Diode (LED) is a light emitting device with stability and high efficiency, it replaces existing lighting fixtures at a high speed and is easy to control by electric circuit, so it can be used not only for lighting but also for communication .

As a result, Visual Light Communication (VLC) using LED light has received much attention since its proposal is being standardized. Visible light communication is a technology that synthesizes communication signals modulated by visible light of wavelengths of 380 ~ 780nm generated by LEDs and transmits information while maintaining the brightness as illumination by using the fact that human eyes can not detect visible light which changes rapidly Technique. That is, in the visible light communication, the transmitted signal is modulated by the optical signal and is emitted through the LED. The optical signal transmitted from the receiving side is detected and converted into an electrical signal, and the demodulated electrical signal is demodulated The communication is performed in such a manner that Such a visible light communication has a problem that transmission speed is limited because data of one channel is transmitted through one light source.

Recently, an LED display using LED as a backlight which is a light source of a liquid crystal display device has been widely used, and a direct lit backlight in the backlight of the LED display is characterized in that the LED light source is illuminated in the display direction .

Korean Patent Laid-Open No. 10-2011-0063365 (published on June 10, 2011, entitled: Apparatus and Method for Adjusting Brightness of Light Sources Used for Data Transmission, Claim 1).

An object of the present invention is to provide a high-speed visible light communication apparatus and method using a direct-type backlight which improves transmission efficiency by converting transmitted data into an image pattern.

A high-speed visible light communication device using a direct-type backlight according to an aspect of the present invention includes a direct-type backlight divided into a plurality of blocks, and capable of controlling light emission and dimming according to optical signal modulation for each block, A dimming control unit for performing at least one of control of dimming based on a dimming signal and control of light emission based on a modulation signal indicating the optical signal modulation, and a control unit for controlling the modulation signal and the dimming And a data encoder section for generating at least one of the signals.

Preferably, the optical signal modulation is at least one of on-off keying, variable pulse position modulation, and color shift keying.

Preferably, the data encoder unit includes a block information processor for determining the number of used blocks based on the input video signal and the serial data, a data converter for converting the serial data into as many parallel data as the number of used blocks, And a block allocator for allocating one of the blocks to the parallel data.

Preferably, the data conversion unit converts a part of the serial data into an image pattern composed of as many blocks as the used blocks, and the block allocation unit allocates the image pattern to as many blocks as the used blocks .

Preferably, the dimming control unit controls dimming of each block to which the image pattern is allocated based on an image pattern assigned to each block as many as the number of used blocks.

According to another aspect of the present invention, there is provided a high-speed visible light communication method using a direct-view type backlight, the method comprising: a backlight unit including a number of used blocks based on at least one of serial data, which is a bit string representing a communication signal to be transmitted, Wherein the data encoder unit converts the serial data into as many pieces of parallel data as the number of used blocks, and the data encoder unit allocates the parallel data to as many blocks as the number of used blocks Generating a modulated signal based on the optical signal modulation result of the parallel data; and controlling the light emission of the block to which the parallel data is allocated, based on the modulated signal.

According to the present invention, transmission efficiency of visible light communication can be improved by converting transmitted data into an image pattern, and a direct-type backlight included in a display device can be used for visible light communication, And the manufacturing cost can be reduced.

1 is a block diagram of a high-speed visible light communication device using a direct-type backlight according to an embodiment of the present invention.
2 is a diagram illustrating an example of a backlight block for generating an image pattern by a high-speed visible light communication device according to an embodiment of the present invention.
3 is a diagram illustrating an example of an image pattern of a high-speed visible light communication apparatus according to an embodiment of the present invention.
4 is a flowchart of a high-speed visible light communication method using a direct-type backlight according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a bicycle locking device and method using a wireless charging authentication according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

1 is a block diagram of a high-speed visible light communication device using a direct-type backlight according to an embodiment of the present invention.

1, a high-speed visible light communication device using a direct-type backlight according to an embodiment of the present invention may include a direct-type backlight 100, a dimming control unit 200, and a data encoder unit 400 .

The direct-type backlight 100 is divided into a plurality of blocks 110, and control of light emission according to optical signal modulation and control of dimming of each block 110 can be performed.

As described above, in the natural light communication, the communication signal is modulated and transmitted to the optical signal emitted by the light emitting body such as the LED, thereby transmitting the communication signal. At this time, the communication signal can be modulated by modulating an optical signal emitted by the light emitting means such as an LED functioning as a backlight of the display 600 included in the direct type backlight 100. On-off keying (OOK), variable pulse-position modulation (VPPM), and color shift keying (CSK) are examples of methods for modulating and loading a communication signal on an optical signal. Or the like can be used. In this case, OOK and VPPM can be used for PHY I physical layer providing communication at 11.67 to 266.6 kb / s and PHY II physical layer providing 1.25 ~ 96 Mb / s speed, CSK for 12-16 Mb / lt; RTI ID = 0.0 > PHY < / RTI > Through the above-described modulation method, the flicker generated by emitting the optical signal modulated by the communication signal in the direct-type backlight 100 can be minimized to a level that can not be recognized by a person, and the optical signal can be transmitted to the receiving side . In this case, the direct-type backlight 100 is divided into a plurality of blocks 110, each of which is capable of controlling light emission and dimming, so that different communication signals can be modulated into optical signals for each block 110 and transmitted .

The dimming control unit 200 performs at least one of the control of dimming based on the dimming signal and the control of light emission based on the modulation signal indicating optical signal modulation for each of the blocks 110. [ The degree of dimming of each block 110 included in the entire backlight 100 may be differentiated from that of the backlight 100 by modulating different communication signals into optical signals for each block 110, It is possible to transmit information through the image pattern formed according to the position of the blocks 110 and the degree of dimming.

The power supply unit 700 can supply power to each part of the high-speed visible light communication device.

FIG. 2 is a diagram illustrating an example of a block of a backlight for generating an image pattern by a high-speed visible light communication device according to an embodiment of the present invention. FIG. Fig.

Each part of the backlight shown as p ₁ to p ₁₀ in FIG. 2 represents each block of the backlight. As shown in the screen screen item of FIG. 3, the dimming status of each block may individually change, and the dimming status of each block may represent at least one bit of information. Therefore, in the case where there are ten blocks as in the example of FIG. 2 and FIG. 3, the dimming state of all the blocks can display 10 bits of information, and the difference in the dimming states of the respective blocks is the difference . Accordingly, the number of possible image patterns in the example of FIGS. 2 and 3 is 1024 in all.

The data encoder unit 400 generates at least one of a modulation signal and a dimming signal based on the serial data received. At this time, the serial data can be generated by converting the externally input communication signal by the data decoder 300. That is, the serial data may be serial data, which is a bit sequence indicating a communication signal that is a signal to be transmitted by the user through the visible light communication device. The modulation signal may be a signal indicating a variation in brightness or light amount of each backlight block 110 generated by modulating a communication signal by optical signal modulation as described above. The dimming signal may be a signal indicating the degree of dimming of each backlight block 110.

In this case, the data encoder 400 includes a block information processor 430 for determining the number of used blocks based on the input video signal and serial data, a data conversion unit 430 for converting the serial data into as many parallel data as the number of used blocks, And a block allocation unit 420 for allocating one of blocks to each parallel data. That is, the data conversion unit 410 converts input serial data into as many parallel data as the number of used blocks, so that each block 110 can transmit a communication signal independently of each other. As described above, parallel data independent of each block 110 can be converted into an optical signal by optical signal modulation and transmitted through visible light communication through each block 110. The block allocation unit 420 can determine which block 110 each of the converted parallel data is transmitted.

At this time, the block allocation unit 420 can determine how each block 110 is dimmed according to the dimming information for each block 110 indicated by the image pattern, and can generate a dimming signal indicating the dimming, A parallel signal generated by the block allocator 420 and assigned to a specific block may be optically modulated to generate a modulated signal that is transmitted to the block 110 of the actual backlight 100. [

Here, the data conversion unit 410 may convert a part of the serial data into an image pattern composed of as many blocks as used blocks, and the block allocation unit 420 may allocate the image pattern to the number of blocks . ≪ / RTI > That is, in the example of FIGS. 2 and 3, the information of up to 10 bits can be transferred by the image pattern at a time, so that the data conversion unit 410 converts the image pattern of the backlight 100 into serial It is possible to convert information of the number of used blocks having a maximum of 10 bits from the data into image patterns and convert the remaining information into parallel data so that each block 110 can transmit by optical signal modulation. The block allocation unit 420 may allocate such image patterns to as many blocks as the number of used blocks. For example, in the example of FIG. 2 and FIG. 3, if the number of used blocks is eight, an image pattern for transmitting 8 bits of information can be allocated to eight blocks actually used among the ten blocks 110.

The dimming control unit 200 controls the dimming of each block 110 to which an image pattern is assigned based on the image pattern assigned to each block 110 as many as the number of used blocks. For example in Figure 2 and Figure 3, if the image pattern is s _2, dimming for the p ₁₀ block is 1, and dimming for the rest of the block is zero, in which case p ₁₀ block only may be weaker than the control a dimming Alternatively, only p ₁₀ blocks can control dimming more strongly.

4 is a flowchart of a high-speed visible light communication method using a direct-type backlight according to another embodiment of the present invention.

According to the high-speed visible light communication method using the direct-type backlight according to another embodiment of the present invention, the data encoder 400 acquires the block information of the backlight including the number of used blocks based on the input video signal and serial data (S110). That is, the block encoder 430 included in the data encoder 400, in particular, the data encoder 400, determines how many of the blocks of the backlight 100 based on the state of the displayed image and the contents of the serial data It is possible to decide whether to use it for visible light communication. At this time, the data encoder 400 can determine the number of used blocks based on the transmission rate, the transmission environment, the condition of the video signal, and the like.

Then, the data encoder unit 400 converts the serial data into as many parallel data as the number of used blocks. In this case, the data encoder 400 may convert the part of the serial data into an image pattern composed of as many blocks as the number of used blocks to generate an image pattern (S120).

As described above, the data conversion unit 410 included in the data encoder unit 400 converts input serial data into parallel data corresponding to the number of used blocks, and each block 110 independently transmits communication signals . The data conversion unit 410 may convert a part of the serial data into an image pattern composed of as many blocks as the number of used blocks. For example, in the example of FIGS. 2 and 3, the maximum of 10 bits of information can be transmitted by the image pattern at a time, so that the data conversion unit 410 converts the image pattern of the backlight 100 into serial It is possible to convert information of the number of used blocks having a maximum of 10 bits from the data into image patterns and convert the remaining information into parallel data so that each block 110 can transmit by optical signal modulation.

Then, the data encoder unit 400 allocates the parallel data to as many blocks as the number of used blocks (S130). For example, in the example of FIG. 2 and FIG. 3, if the number of used blocks is 8, an image pattern carrying 8 bits of information can be allocated to eight blocks actually used among the ten blocks 110.

Thereafter, the data encoder unit 400 generates a modulation signal based on the optical signal modulation result of the parallel data, and the dimming control unit controls the light emission of the block to which the parallel data is allocated based on the modulation signal, The block 110 transmits a signal (S140) and ends the process.

At this time, the modulated signal can be generated by at least one of optical signal modulation of on-off keying, variable pulse position modulation and color shift keying as described above. The block allocation unit 420 included in the data encoder unit 400 determines how each block 110 is dimmed according to the dimming information of each block 110 indicated by the image pattern, And modulates a parallel signal generated by the data converting unit 410 and assigned to a specific block by the block allocating unit 420 to the block 110 of the actual backlight 100 And generate a modulated signal to be transmitted.

In addition, the dimming control unit 200 can control the dimming of each block to which the image pattern is allocated based on the image pattern assigned to each block as many as the number of blocks. For example, the example in FIGS. 2 and 3 for example, if the image pattern is s _2, dimming for the p ₁₀ block is 1, and a dimming for the rest of the block is 0, in which case the more the only dimming p ₁₀ blocks weakly control Alternatively, only the p ₁₀ block can control dimming more strongly.

As described above, according to the present invention, transmission efficiency of visible light communication can be improved by converting transmitted data into an image pattern, and a direct-type backlight included in a display device is used for visible light communication, The structure of the communication device can be simplified and the manufacturing cost can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand. Accordingly, the technical scope of the present invention should be defined by the following claims.

100: direct type backlight 110: block
200: a dimming control unit 300: a data decoder
400: Data encoder 410: Data conversion unit
420: block allocation unit 430: block information processing unit
500: video signal processor 600: display
700:

Claims (10)

A direct-type backlight which is divided into a plurality of blocks and is capable of controlling light emission and controlling dimming by optical-signal-modulating serial data by allocating as many bits as the number of blocks for each block;
A dimming control unit for each of the blocks to perform at least one of dimming control based on a dimming signal and control of light emission based on a modulation signal indicating the optical signal modulation; And
And a data encoder section for generating at least one of the modulation signal and the dimming signal based on serial data which is a bit string representing a communication signal to be transmitted,
The data encoder unit
A block information processing unit for determining the number of used blocks based on the input video signal and the serial data;
A data conversion unit for converting the serial data into parallel data of the number of used blocks; And
And a block allocation unit for allocating one of the blocks to each parallel data,
Wherein the data conversion unit converts a part of the serial data into an image pattern composed of as many blocks as the number of used blocks,
Wherein the block allocation unit allocates the image pattern to as many blocks as the number of used blocks,
Wherein the dimming control unit controls dimming of each block to which the image pattern is allocated based on an image pattern assigned to each block as many as the number of used blocks.
The method according to claim 1,
Wherein the optical signal modulation comprises:
On / off keying, variable pulse position modulation, and color shift keying.
delete delete delete Obtaining block information of a backlight including the number of used blocks based on at least one of serial data which is a bit string representing a communication signal to be transmitted by the data encoder and a received video signal;
The data encoder converting the serial data into as many parallel data as the number of used blocks;
The data encoder unit allocating the parallel data to as many blocks as the number of used blocks;
Generating a modulated signal based on an optical signal modulation result of the parallel data;
Wherein the dimming control unit controls light emission of a block to which the parallel data is allocated based on the modulation signal,
Wherein the data encoder unit comprises:
Converting a part of the serial data into an image pattern composed of as many blocks as the number of used blocks in the step of converting into parallel data,
Allocating the image pattern to as many blocks as the number of used blocks,
Wherein a dimming signal for a block to which the image pattern is allocated is generated based on an image pattern allocated to each block of the number of used blocks.
The method according to claim 6,
Wherein the optical signal modulation comprises:
On-off keying, variable pulse position modulation, and color shift keying.
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