JPH11126047A - Led display device and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a display screen enlargeable and changeable for high definition display, and to make a display device applicable to various screen size, by making each LED unit compare data from a control means with discrimination information of its own unit, selecting data of itself, and performing receiving processing. SOLUTION: An ATM packet transferred to a LED unit 202 from a controller 203 comprises a group ID discriminating a LED unit group 221, a module ID discriminating a LED unit module 211, and a unit ID discriminating the LED unit 202. A distributing means 214 refers to the module ID and routing-controls a corresponding module 211. A distributing means 224 refers to the unit ID and routing-controls a corresponding unit 202. Each LED unit 202 stores its own unit ID, compares the unit ID of the ATM packet with its own unit ID, when they coincides, data are received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED in which a plurality of light emitting diodes (hereinafter, also referred to as LEDs) are connected according to the size of a display device.
The present invention relates to a display device and the like, and more particularly, to an LED display device that enables more efficient and high-speed data transmission between LED units and enables more flexible display control.

[0002]

2. Description of the Related Art In recent years, high performance red, green and blue LEs have been developed.
D was developed to enable full-color LED display. Among large-sized display devices, LED display devices that utilize the features of LEDs, such as high brightness, long life, and light weight, are becoming widespread.

The screen size and pixel pitch of LED displays have been varied depending on the application and location, from large outdoor displays such as for billboards, to small and medium screens in semi-indoors such as platforms. . In addition, the conventional vertical / horizontal screen ratio (aspect ratio) also tends to change. In the case where a high-definition image represented by HDTV is displayed on an LED in the future, the amount of image data increases and the display panel becomes larger. We have to deal with screens.

For example, an LE of about 16 dots × 16 dots
D is arranged in a matrix and is modularized as one LED unit. The LED display device is configured by connecting the LED units in a matrix according to the screen size and the vertical / horizontal aspect ratio.
FIG. 8 shows an LED display device 801 as a configuration example. The plurality of distributors 804 connected to the controller 803 are LE
It is arranged for each row of the D unit 802 and supplies video data for display and various control signals to each LED unit 802.

The control signal 820 includes, for example, a video data synchronization clock, a horizontal synchronization signal, a vertical synchronization signal, a blanking signal, a gradation reference signal, and a video data latch signal. And supplies it to each LED unit 802 via the distributor 804. The display full-color video data 810 transmitted from the distributor 804 to each LED unit 802 is at least RG
Video data of each color B (red, green, blue) is required, and the bit width of the video data is determined according to the gradation resolution.

For example, when displaying with 256 gradations per color, a video data bus having an 8-bit width for three colors is required. These video data are supplied to the LED unit 802 by dividing the number of LED units × the number of display dots by time. Shift register circuit 8 in each LED unit 802
At 05, the video data 810 is bit-shifted, and when a predetermined number of data is supplied, the data is latched and the captured video data 810 can be displayed as the display video data 810.

[0007]

However, such an LED display device includes a controller 803 and a distributor 80.
4 and display video data 810 between LED unit 802
Is transmitted by a parallel bus as a signal interface, and a synchronous clock synchronized with the signal and various control signals 820 are supplied. Therefore, there is a problem that the number of signal lines increases as the definition or size of the LED display device increases. In particular, at present, where the display screen is large and the number of LED units tends to increase, if the number of signal lines increases and becomes longer, the influence on the reference signal for gradation, the pulse width of the synchronizing clock of the video data, the noise, and the noise is serious. Become.

Also, in order to comply with the HDTV specification, the aspect ratio of the screen changes, and it becomes necessary to further increase the number of LED units to be connected, and the transfer rate of video data must be increased accordingly. As the number of connected LED units increases, the pulse deterioration of each signal increases, and in particular, there is a problem that input / output timing between video data and a synchronous clock becomes more difficult.

[0009] Furthermore, the required level of image quality in the image display of the LED display device has been increasing year by year, and together with the miniaturization of the LED, the technical development of an LED display capable of fine display has been urgently required. In order to realize a high-definition display of an image, it is necessary to increase the gradation resolution. Specifically, it is necessary to change the bus specification such as changing the conventional display video data bus width from 8 bits to 10 bits. Also, in order to realize a fine display, L
It is also necessary to reduce the ED and the dot pitch width. When the dot pitch is reduced, the LED unit size is reduced in proportion thereto. For this reason, there is a problem that the ratio of the mounting area of components such as connectors is increased due to the increase in the width of the video data bus.

Therefore, when designing the LED unit, there is a trade-off relationship between the enlargement of the display screen and the fine display in the mounting conditions. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a large display screen in an LED display and an L display applicable to various screen sizes.
It aims at ED display devices and high definition.

[0011]

According to the present invention, a plurality of light emitting diodes are arranged and each light emitting diode is controlled.
The present invention relates to an LED display device having an ED unit and control means for transmitting video data to a plurality of LED units.
In particular, while the control means transmits data formatted in the form of an ATM packet to each LED unit,
The ED unit has storage means for storing identification information provided for each LED unit, and comparison means for comparing data from the control means with the identification information of each LED unit, selecting its own data, and performing reception processing. LED display device.

In the LED display device according to a second aspect of the present invention, the control means serially transfers at least the data signal and the strobe signal. Further, the LED unit has a clock signal generating unit that autonomously generates a control signal by taking an exclusive OR of the data signal and the strobe signal.

According to a third aspect of the present invention, there is provided a driving method, wherein a plurality of light emitting diodes are arranged and a plurality of LED units each of which controls each light emitting diode by processing data from the control means. The present invention relates to a driving method of an LED display device having an LED unit group.

Particularly, in the present invention, a step of serially transferring data in the form of an ATM packet from the control means to each LED unit side, a step of performing a routing switch by the distribution means and distributing the data to a desired LED unit, and a step of receiving the data Then, the method includes a step of comparing the identification information of each LED unit to determine whether the data is the LED unit data of itself, and a step of performing a reception process only for the data of the LED unit.

According to a fourth aspect of the present invention, there is provided a driving method, wherein an ATM packet including common control data for commonly controlling an LED unit group is transmitted by a control means for each LED lighting cycle, and the common control data is transferred. Transmitting an ATM packet composed of LED unit individual control data for individually controlling each LED unit within a cycle.

The driving method according to the fifth aspect of the present invention is characterized in that:
Autonomously generating an LED driver circuit and a common driver control signal by the ED unit.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present inventor has found that it is possible to achieve a large display screen and a high definition display in an LED display device by using an LED display device utilizing a specific data transfer method. It came to accomplish.

More specifically, the present invention employs an asynchronous transfer method (hereinafter referred to as ATM (ATM)) for data transmission between a controller serving as control means for transferring data and each LED unit.
nous transfer mode). In particular, it is an LED display device that multiplexes display video data and various control signals into data units called ATM packet cells and performs high-speed serial communication between each LED unit and between the LED unit and a video source. is there.

LED of the Present Invention Utilizing ATM Packet
FIG. 2 shows an example of the display device. An example of the format of an ATM packet transferred from the controller 203 to the LED unit 202 is described below with reference to FIG. The format of the ATM packet is composed of two types of data: common control data and LED unit individual control data. The common control data includes an Hdr part (head data), a control data part,
It is composed of an Eop section (end data). Hdr part is L
Group ID and LED for identifying ED unit group
It is composed of identification information for identifying a unit module (hereinafter, also referred to as a module ID). The control data part is
The information includes the selection information of the scanning driver when performing dynamic lighting control of the LED unit, or various control information for the gradation driver.

On the LED unit 202 side, such an AT
A control signal is autonomously generated by referring to data using M packets. The LED blanking cycle is performed by transmitting common control data at a predetermined cycle on the controller side. LED that controls a certain period
In lighting control or the like, an ATM packet cell generates an event at a fixed cycle. On the other hand, the LED unit 202
The side autonomously generates various control signals in accordance with the control data reception cycle. The Eop section of the ATM packet cell containing the common control data indicates the end of the packet. This makes it possible to shift to the next data reception process.

AT including LED unit individual control data
The Hdr portion of the M packet includes identification information for identifying the LED unit 202 (hereinafter, also referred to as a unit ID). Each LED unit 202 has its own unit I
It has a storage unit for storing D, and compares the unit ID of the Hdr unit with the unit ID of the LED unit itself by the comparison unit, and receives the same if they match.

The data area of the LED unit individual control data may include display video data and / or display video data. The amount of display video data varies depending on conditions such as the number of dots of the LED unit 202, the lighting cycle, the number of display colors, the number of LEDs per unit lighting cycle, etc., but is freely set by the system design side according to specifications. can do. The display video data includes an instruction to turn on and off the LED of each LED unit 202, a setting of frequency division of a gradation clock, a control of an LED driver, and an operation of the LED unit 2.
02 internal circuits can be controlled. Finally,
The EOP part of the ATM packet containing the LED unit individual control data indicates the end of the data and can take the next action.

The common control data is all LED units 202
In the LED unit individual control data, only the data that matches the unit ID of the Hdr section is received by the LED unit 202. The LED unit individual control data may be transferred in the LED unit module 211 by the number of the maximum LED units 202.
Note that a plurality of LED units 202 are connected,
When only one of the LED units 202 is displayed, only the LED unit individual control data can be transferred.

In FIG. 2, the LED units 202 are arranged in a matrix and constitute an LED unit module 211 as one module. Further, a plurality of LED unit modules 211 are arranged, and an LED unit group 221 is configured as one group. Each L
The ED unit group 221, the LED unit module 211, and the LED unit 202 are combined according to the screen size to configure an LED display device that displays data from the video source 200 via the controller 203. Module of each LED unit 202 and each LED
LEs are provided by distributing means 214 and 224 for distributing data to the group of unit modules 211, respectively.
A D display device is configured.

The distribution means 214 performs routing control to the corresponding LED unit module with reference to the module ID of the Hdr part of the common control data, which is an ATM packet cell. Hd of the common control data in the distribution means 224 of the next stage
The routing control to the corresponding LED unit is performed with reference to the unit ID of the r section. On the other hand, the LED unit 20
On the second side, the common control data is received and the LED unit 202
It is used as control data.

The LED unit individual control data is also L
If the unit ID of the ED unit 202 matches, the display control of the LED unit 202 is similarly performed according to the received and control data. The group ID, module ID and unit ID indicating the transfer destination address can be determined on the controller 203 side of the LED display device. When the data strobe system is used, various clock signals and the like can be generated on the LED unit 202 side only by using the data transfer timing. Hereinafter, the configuration of the present invention will be described in detail.

(ATM packet format data 100) By using the ATM packet format data used in the present invention, each LED unit can independently generate a control signal such as a clock signal.
The data for driving the LED unit can be formed using a certain coding method (such as a Data / Strobe coding method or a 10B1C coding method).

FIG. 3 shows a specific example of the format of an ATM packet cell. FIG. 3 shows a packet configured by combining at least three parts, an “Hdr” part indicating a header or a transfer destination address, a data part, and an “EOP” part indicating the end of the packet. Each part can constitute data without any restriction on its length. FIG. 4 shows an example of the data strobe coding method.

For example, in the present invention, when a plurality of LED unit groups 221, a plurality of LED unit modules 211, and a plurality of LED units are provided, a group ID and an LED unit are used as identification factors for identifying a group of LED displays in the Hdr section. A module ID for identifying a module, a unit ID for identifying an LED unit, and the like can be assigned. The data to be transferred is the LED unit 20.
The data length can be determined according to the number of dots in 2, the lighting period, and the number of LED units 202. Therefore,
The size of the ATM packet that can be set to a variable length can be effectively used.

The address of the transfer destination can be freely set on the system design side of the LED display device. Further, the data section can be composed of display video data and / or control data. The display video data is LE
The number of dots of the D unit 202, the lighting cycle, the number of display colors,
The amount of data varies depending on conditions such as the number of LEDs per unit lighting cycle, but can be set freely by the system design side according to specifications.

Similarly, the control data can be used to instruct the LED units to turn on and off the LEDs, set the frequency division of the gradation clock, control the LED driver, and control the LED unit circuit. Therefore, horizontal sync, vertical sync,
The LED blanking cycle can be performed by transmitting control data at a predetermined cycle on the controller 203 side. In the LED lighting control that performs control at a fixed cycle, an ATM packet cell containing control data is generated at a fixed cycle. In particular, in the present invention, according to the type of control data received on the LED unit 202 side,
Various control signals can be generated autonomously.

(Control means 103, 203) Control means 10
Numerals 3 and 203 are for transmitting video data and control data for controlling each LED unit 202 to the LED unit 202 side. Therefore, it can be configured independently of the video source 200 or can be configured integrally. For example, in the case where video data from a video device, a DVD device, or the like is used independently and used, video data from the video device or the DVD device is used as a video source 200 to control the video data.
AD (analog to digital) received at 3, 203 side
Convert. After the conversion, the control means 103 and 203 can format and transmit the digital data as RGB digital data in the form of an ATM packet. On the other hand, when the video source for outputting digital data and the control means are integrally formed, the digital data formatted in the ATM packet format can be directly transmitted to the LED unit side 202.

By controlling the timing of the data transmitted from the control means 103 and 203 to the LED unit 202, various clock signals such as blanking for receiving the LED and controlling the lighting of the LED by the LED unit 202 are controlled. Can be generated. Specifically, the control unit 103 or 203 transmits an ATM packet including common control data for commonly controlling the LED unit group 221 every LED lighting cycle. On the other hand, the LED unit 202 can autonomously generate various clock signals by transmitting an ATM packet including LED unit individual control data that is individually controlled for each LED unit 202 within the transfer cycle of the common control data.

(LED Unit 202) The LED unit 202 can be formed using two or more light emitting diodes such as a dot matrix. When used for an LED display, for example, a light-emitting diode capable of emitting light of each of RGB is combined into one pixel as 16 pixels.
It can be configured by disposing them in a × 16 matrix.

Further, a driving means for driving the wiring and each light emitting diode provided on the substrate, a storage means for temporarily storing transmitted data, and identification information previously provided for each LED unit are stored. Storage means, comparing means for comparing the transmitted data with the identification information of each LED unit to determine that the data is its own LED unit data;
It is electrically connected to a calculating means for calculating the power to be supplied to each light emitting diode based on the data received and processed after the comparison and a synchronous clock signal generating means for generating a synchronous clock signal based on the obtained data. Have been. These various means can be constituted by utilizing a semiconductor memory, a logic circuit and a central processing unit.

(Synchronous Clock Generating Means) The synchronous clock generating means can generate a synchronous clock by taking the exclusive OR of the data signal and the strobe signal in the decoder 602 on the LED unit side. Various signals such as a blanking signal (BLANK), a data latch signal (LATCH), a shift clock signal (SCLK), and a gradation reference clock signal (GDCK) can be generated by the timing generation circuit 605 based on the synchronous clock. it can. The driving means is capable of driving only a desired light emitting diode by supplying power to the light emitting diode or the like. When LEDs arranged in a dot matrix are dynamically driven, a desired emission color can be obtained by selecting and controlling the LED group arranged in each segment at a fixed cycle by a common driver and adjusting the time of current flow by the segment driver. Can be.

(Storage means 607) The storage means 607
A unit ID for identifying each LED unit 202 is stored. Such storage means 607 can be configured by utilizing various semiconductor memories and the like. Each unit ID may be stored individually for each LED unit 202, or a setting instruction and setting data of identification information may be transmitted from the control unit to the first LED unit 2.
02, the identification value from the first LED unit 202 may be incremented by one, and then transferred to the next LED unit. In the method of sequentially incrementing the identification value, the individual LED units 202
The identification information can be automatically assigned under the control of the control means 103 and 203 without assigning a unit ID by providing a constant storage means such as a dip switch. Specifically, the control unit 607 for controlling the generation of a video source and each LED unit 202 etc. sends a unit ID.
A control command for shifting to the setting mode is transferred to all the LED units 202. Accordingly, each LED unit 202 switches the output selector from the through mode to the unit ID count-up mode.

Thereafter, the initial data of the unit ID is sent from the control means 103 and 203 to the first-stage LED unit 2.
02. Each LED unit can store the sequentially incremented unit ID in the storage means as its own unit ID.

It is to be noted that the through mode is defined as LE through the control means.
In this mode, the LED unit individual control data received by the D unit is directly transmitted from the first-stage LED unit to the next LED unit. In the count-up mode, the LED unit does not transmit the data but receives it once and changes the data contents (count-up)
To transmit to the next LED unit.

(Comparison means 608) The comparison means 608 is composed of the unit ID in the Hdr part of the data in the form of the ATM packet transmitted from the control means 103 and 203 and the respective LEs.
The unit ID is compared with the unit ID stored in the storage unit of the D unit. As a result of the comparison, if they match, the data is selectively received as data of its own LED unit, and can be constituted by a comparison circuit such as an exclusive OR or a central processing unit.

(Light Emitting Diode) As the light emitting diode, a semiconductor light emitting element capable of emitting various lights can be used. As semiconductor elements, GaP, GaAs, GaN,
InN, AlN, GaAsP, GaAlAs, InGa
One using a semiconductor such as N, AlGaN, AlGaInP, or InGaAlN for the light emitting layer is given. Also,
The structure of the semiconductor may be a homostructure having a MIS junction, a PIN junction or a PN junction, a heterostructure, or a double heterostructure.

The emission wavelength can be variously selected from ultraviolet light to infrared light depending on the material of the semiconductor layer and the degree of mixed crystal thereof.
Further, a single quantum well structure or a multiple quantum well structure in which a light emitting layer is thin to provide a quantum effect can be used.

In addition to the three primary colors of RGB, a light emitting diode using a combination of light from an LED chip and a fluorescent substance excited and emitted by the LED chip can be used. In this case, by using a fluorescent substance that is excited by light from the light emitting diode and converts it to a long wavelength, a light emitting diode that can emit white light with high linearity using one type of light emitting element can be obtained.

Light emitting diodes of various shapes can be used. Specifically, an LED that is a light emitting element
Examples thereof include a bullet-type or chip-type LED in which a chip is electrically connected to a lead terminal and coated with a mold resin or the like, or a device using a light-emitting element itself.

(LED unit module 211 and L
ED unit group 221) LED unit module 211 and LED unit group 221
The screen constituting the display device can be used for various selections according to a desired size. Specifically, when the screen is large, an LED display including a plurality of LED units 102 and 202 may be configured as one LED unit module 211. When configuring a larger screen, a plurality of LED units 102 and 202 may be collected up to the size of the screen, or a plurality of LED unit modules 211 may be configured as an LED unit group 211.

(Distributing Means 214, 224) Distributing Means 21
4 and 224 are LEs having a plurality of LED units 202.
It is suitably used for distributing the D unit group 221 and the LED unit modules 211. The distribution means 214 and 224 receive the data (ATM packet)
The Hdr section is read and the LED unit 202 to which the group or module is to be distributed is determined and transmitted. Therefore, the arithmetic means for reading the Hdr of the ATM packet and the AT
It has a function of selectively delivering M packets. Such distributing means 214 and 224 can be relatively easily constituted by a CPU or the like. Distribution means 214 and 224 are LEDs
It can be provided separately from the unit 202 or can be arranged in the LED unit 202.

The connection section, which is a physical interface of the signal, is a means for serially transmitting data from the controller to the LED unit, which can be electrically connected using wiring or transmitted directly using optical fibers and electromagnetic waves. You can also. In the case of wiring, the connection portion can be suitably configured by using two types of signal lines, that is, a data line and a strobe line. Hereinafter, specific examples of the present invention will be described in detail, but it is needless to say that the present invention is not limited thereto.

[0048]

【Example】

(Example 1) InGaN was used as a light emitting diode in a light emitting layer.
And those using AlGaInP were used. InGaN, which is a nitride-based compound semiconductor, has a light emitting diode emitting blue light by changing the composition of In,
A green light emitting diode was formed. AlGaI
Those using nP were used as red light emitting diodes. The LED chips on which the respective light emitting layers were respectively formed were arranged on the mount leads and wire-bonded to the inner leads using gold wires. Each LED chip was molded using an epoxy resin, thereby forming a shell-shaped light emitting diode having an elliptical shape as viewed from a light emission observation surface.

RG is formed on the substrate on which the conductive pattern is formed.
Each light emitting diode capable of emitting light from B was arranged in a dot matrix as one picture element. Also, on the substrate,
Driving means consisting of a common driver and a segment driver, which are semiconductor switching elements for driving each light emitting diode, a semiconductor memory for temporarily storing transmitted data, and identification information provided in advance for each LED unit, etc. Semiconductor memory as storage means for performing the operation, comparing the transmitted data with the identification information of each LED unit and selecting its own LED unit data, calculating the power supplied to each light emitting diode based on the selected data It is electrically connected to the substrate on which the arithmetic means is disposed by using leads.

The LED unit was constituted by housing the electrically connected components in a package formed of resin. The LED unit is connected to a controller for controlling the LED unit via distribution means. In each LED unit, 16 LED units are arranged in a matrix to constitute an LED unit module as one module.

A distribution means for distributing data to each LED unit module is arranged to constitute an LED display device. The distributing unit refers to the Hdr portion of the ATM packet cell indicating the transfer destination address, and determines which row of the LED unit module is. After routing according to the transfer destination address of the ATM packet cell, output is controlled to the corresponding port. ATM output on LED unit side
With reference to the unit ID indicated in the Hdr section of the packet cell, if the unit ID matches the own unit ID, reception processing is performed, each data is calculated, and then the driving unit of the LED unit is driven. Further, the LED unit performs an exclusive OR operation on the data signal and the strobe signal, so that a blanking signal (BLANK), a data latch signal (LATCH), a shift clock signal (SCLK), and the like are generated based on the generated synchronous clock signal. Generates a grayscale reference clock signal (GDCK) autonomously. Thus, display control of an LED display device in which a plurality of LED units are combined can be performed.

As a specific circuit configuration on the control means side, a FIFO (First In First Out) 501, a control data temporary storage memory (Control Buffer) 507, a timing generator (Timing Generator) 506, an oscillator (OSC) as shown in FIG. ) 5
05, a parallel-to-serial converter (Parallel To Serial) 502, an encoding circuit (Encorder) 503, a driver 504, and the like.

The control means receives the digital data of RGB (red, green, blue) as display video data after analog / digital conversion of the analog data from the video source, and temporarily stores it in the FIFO 501 on the control means side. I do. The control data for controlling the LED unit is written in the control data temporary storage memory 507. Control data and display video data are transmitted at predetermined timing from the FIFO 501 and the control data temporary storage memory 507 by using a blanking signal (BLANK) generated at each lighting cycle as a trigger in a timing generation circuit 506 that operates using the oscillator 505 as a basic clock. Perform reading. At this time,
Data is generated in the form of an ATM packet, and the parallel / serial converter 502 converts the parallel data into serial data.

After conversion into serial data, the encoding circuit 503 performs data strobe encoding processing. The processed signal is transferred to the LED unit via the driver 504 as a data signal and a strobe signal. The data transmission speed is determined by the basic clock frequency of the control means. The common control data is transmitted at the trigger cycle of the blanking signal, and the LED unit receives the data and reproduces the blanking signal for controlling the lighting of the LED.

On the other hand, as a circuit configuration on the LED unit side, more specifically, as shown in FIG.
Decoder 602, timing generation circuit (Timin
g Generator) 605, serial-to-parallel converter (Serial To Paral)
lel) 603, comparison means (Comparater) 608, LED
Driver Controller (LED Driver Controlle
r) 609, address generation circuit (ADR Generator) 60
6, a common driver (Common Line Driver) 611, an oscillator (OSC) 604, and the like. The LED unit is driven as follows by a signal transferred from the control means.

The data in the ATM packet format transferred from the control means in the form of a data signal and a strobe signal is subjected to a data strobe decoding process in a decoder 602 via a receiver 601, and simultaneously a synchronous clock is generated.
Based on this synchronous clock, the timing generation circuit 605 uses a blanking signal (BLANK) and a data latch signal (LATC).
H), shift clock signal (SCLK) and gradation reference clock signal
(GDCK) and other various signals. The serial / parallel converter 603 converts the data subjected to the data strobe decoding from serial data to parallel data. The converted data is latched in a time-division manner for each type of control data and display data, and whether or not the data is used for its own LED unit is determined by comparing the unit ID stored in the storage unit 607 with the comparison unit 608. I do.

If it is the data of the own LED unit, L
The data is transferred to the controller 609 of the ED driver. Further, information of a common driver selection address (ADR0: 3) is transmitted as control data of the common control data. This information is reproduced by the address generation circuit 606 on the LED unit side and then decoded by the decoder 610. Based on the decoded data of the common driver selection address, the common driver 611 is switched in one-sixteenth cycle to perform dynamic lighting control.

Next, an example of data processing of the embodiment will be described with reference to FIG. The LED display device uses a dynamic drive lighting method at 1/16 Duty. The format of the ATM packet is composed of common control data and individual control data of the LED unit.
It is determined by the number of ED unit connection stages. In the above-described data processing example, an m-stage 16 × 16 dot matrix LED unit is connected, and dynamic lighting is performed by switching 16 common lines.

In the figure, data for one screen of the LED unit is defined as one frame period, and addresses (ADR) 0 to 15 are used.
Up to the ATM packet format.
When ADR = 2, common control data ADR = 2 is allocated at the head. Further, the LED unit individual control data for the LED units to be displayed is turned on at every lighting cycle with m ATM packet format data of units 0 to m-1. On the control means side, common control data is generated at the trigger cycle of the blanking signal.
The ED unit individual control data is transmitted until the next common control data. The data pattern of the Hdr portion of the common control data is transmitted in a specific pattern, and each LED unit recognizes this specific pattern and reproduces the blanking signal of the LED. Further, the control data of the common control data is extracted, and the common driver selection information (ADR0:
3) is identified and LED lighting control is performed. Further, by reproducing the blanking signal, the latch signal for latching the display video data of the previous cycle is also reproduced at the same time. After recognizing that the LED unit individual control data is its own unit ID possessed by each LED unit, it is taken in as display video data.

In this embodiment, the lighting timing of the LED is 1
After all the LED units receive the LED unit individual control data for the common line cycle,
Although the ED unit modules are turned on at the same time, the lighting may be started sequentially after each LED unit receives the LED unit individual control data. As described above, by adopting the configuration of the present invention, it is possible to provide an LED display device which can be increased in size and definition with relatively simple wiring.

[0061]

According to the present invention, it is possible to achieve both high definition and high image quality. In particular, a large display device arranged on a wall surface such as a billboard has a large effect by adopting the configuration of the present invention. That is, signal lines can be reduced by automatically generating various control signals inside the LED unit.

The number of signal lines can be greatly reduced by performing data transfer by high-speed serial communication. Therefore, even if the number of LED units is increased or decreased, the configuration of the connection unit can be reduced in size and simplified. Similarly, since a synchronous clock, a grayscale reference clock, and the like can be generated inside the LED, problems of signal deterioration and radiation noise can be avoided.

Since the display video data is transferred in the ATM packet cell, even if the bit length of the data changes, the bus does not increase or decrease between the controller and the LED unit or between the LED units, and the data bit length remains the same interface. Can be made variable. Therefore, it is possible to flexibly cope with systems having different display gradation levels.

In addition to the video data for display of the LED, various data such as brightness correction data can be provided to each LED unit as unit individual data through the same interface. Since each unit ID is assigned,
Independent lighting control of the ED unit can also be performed.

Since the display video data length of the LED unit individual control data can be made variable, the lighting method of the LED display device can be easily changed. Specifically, it is possible to flexibly cope with the drive cycle for performing the dynamic drive by controlling the selection information of the common driver on the controller side.

Even if the control circuit of the LED unit is changed,
This can be dealt with by changing the control type of the control data without changing the signal interface. That is, the functional grade of the LED unit can be changed without adding or changing a signal line.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an LED display device of the present invention.

FIG. 2 is a schematic explanatory view showing another LED display device of the present invention.

FIG. 3 is a schematic explanatory diagram illustrating a data format used in the present invention.

FIG. 4 is a schematic diagram showing a circuit configuration example of a controller used in the LED display device of the present invention.

FIG. 5 is a schematic diagram showing an example of a circuit configuration of an LED unit used in the LED display device of the present invention.

FIG. 6 is a schematic diagram showing an example of a cycle structure of an ATM packet used in the present invention.

FIG. 7 is a schematic explanatory view illustrating a driving method according to the present invention.

FIG. 8 is a schematic explanatory view of an LED display device shown for comparison with the present invention.

[Description of sign]

 100: data in ATM packet format 101: LED display 102: LED unit 103: control means 200: video source 202: LED unit 203: controllers 214, 224 ... Distribution means 221 LED unit group 501 FIFO 502 Parallel-serial converter 503 Encoding circuit 504 Driver 505 Transmitter 506 Timing generation circuit 507 Control data buffer 601 receiver 602 decoder 603 serial-parallel converter 604 transmitter 605 timing generation circuit 607 storage means 608 comparison means 609 ..LED driver controller 610 ... decoder 611 ... common dry 612: LED dot matrix display 801: LED display device 802: LED unit 803: Controller 804: Distributor 805: Drive driver 810: Video data 820: Control data

Claims (5)

[Claims] 1. An LED display device comprising: an LED unit in which a plurality of light emitting diodes are arranged and controlling each light emitting diode; and control means for transmitting image data to the plurality of LED units. The data formatted in the form of the ATM packet is transferred to each LED unit, and the LED unit stores the identification information provided for each LED unit and the data from the control unit for identifying each LED unit. An LED display device comprising a comparing means for comparing data with information, selecting its own data, and performing reception processing. 2. The control means serially transfers at least a data signal and a strobe signal, respectively, and
2. The LED display device according to claim 1, wherein the ED unit has a clock signal generating unit that autonomously generates a clock signal synchronized with the data signal by taking an exclusive OR of the data signal and the strobe signal. 3. A method for driving an LED display device having a plurality of LED unit groups each including a plurality of light emitting diodes and controlling the light emitting diodes by processing data from the control means. A step of serially transferring data in the form of an ATM packet from the control means, a step of routing switching by the distribution means and delivering the data to a desired LED unit, and a step of receiving the data and comparing it with the identification information of each LED unit. A method for driving an LED display device, comprising: a step of determining whether or not the data is its own LED unit data; and a step of receiving only the own data. 4. A step of transmitting an ATM packet comprising common control data for controlling an LED unit group in common by said control means in each LED lighting cycle, and individually for each LED unit within said common control data transfer cycle. 4. The method of driving an LED display device according to claim 3, further comprising the step of transmitting an ATM packet composed of individual control data of the LED unit to be controlled. 5. The driving method for an LED display device according to claim 4, further comprising the step of: an LED unit autonomously generating an LED driver circuit and a common driver control signal.