JP2002108286A - Display device and driving control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving controller and a driving control system for normally driving a light emitting element through the display device of a final stage from the display device subsequent to a display device whose display function is stopped due to any problem of a power source and a control circuit. SOLUTION: In a driving part 303 which drives the light emitting element and a display device 300 receiving data required for driving the light emitting element through a first line L, and which transmits it to the other display device through a second line and controls the driving part based on received data, the first line and the second line are put in non-connection state at the time of a regular operation. The first line and the second line are put in connection state when communication is impossible. The above-mentioned data are data packet whose communication destination is designated by identification information. A line connection part connects the first line with the second line when power is not supplied to the display device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for driving a light emitting element such as an LED (light emitting diode) and a drive control system used for an LED display, an LED lighting device and the like.

[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 displays, which take advantage of the characteristics of LEDs, such as high brightness, long life, and light weight, are rapidly spreading.

Such a display is, for example, 16
LEDs of about 16 dots × 16 dots are arranged in a matrix, and these are modularized as one LED unit (display device), and the LED units are connected in a matrix according to the screen size and the vertical / horizontal aspect ratio. It is configured together. FIG. 1 shows an LED display 801 as a configuration example. A plurality of distributors 804 connected to the drive control device 803 are disposed for each row of the LED unit 802, and transmit display image data and various control signals.
Each LED unit 8 connected in series from the distributor 804
02 is supplied.

[0004] Further, as shown in FIG.
2 is provided with a drive circuit 813 that can individually drive each LED. The display device 802 includes a distributor 804 for transferring image data and a plurality of display devices 802 connected in a one-to-many relationship. The image data sent from the distributor 804 is transferred to the display device 1 and then to the display device 2. This is repeated and transferred to the last stage. The larger the LED display, the greater the number of connected display devices. For example, a large-sized LED display is constituted by a combination of a display device of 300 × 400.

The control signal 820 includes, for example, a synchronization clock for image data, a horizontal synchronization signal, a vertical synchronization signal, a blank signal, a gradation reference signal, and a latch signal for image data. Is generated and supplied to each display device 802 via the distributor 804. The display full-color image data 810 transmitted from the distributor 804 to each display device 802 requires at least image data of each color of RGB (red, green, blue), and the bit width of the image data is determined according to the gradation resolution.

For example, when displaying with 256 gradations per color, an image data bus having an 8-bit width is required for three colors. These image data are supplied to the display device 802 by dividing the number of display devices × the number of display dots by time. The image data 810 is bit-shifted by the shift register circuit 805 in each display device 802, and when a predetermined number of data is supplied, the data is latched.
As 10, the captured image data can be displayed.

[0007]

However, in such an LED display, when power is not supplied to a certain display device, or when a control circuit of the display device cannot operate normally, the last stage of the display device is located behind the display device. The display up to the display device is stopped. For example, in FIG. 2, when power is not supplied to the display device 2 due to some problem, the flow of image data is cut off by the display device 2, and the display devices from the display device 3 to the last stage are
The display stops even though the power is normally supplied. At this time, even if the display device 2 is skipped and the signal lines of the display device 1 and the display device 3 are connected, the image data for displaying the display device 2 is transferred to the display device 3 so that the display is shifted, Data cannot be transferred to the display device, and the entire LED display is seriously affected.

[0008] Such a problem is caused by the image data transfer method. This is a method in which the image data transferred from the control device is taken in while being sequentially shifted from the top by a clock synchronized with the image data by the drive circuit of the display device. In this case, since the image data is continuous data from the display device 1 to the last stage, if the data is interrupted somewhere, the image data from there to the last stage display device becomes invalid. Therefore, when power is not supplied to a certain display device or a control circuit of the display device does not operate normally, display from the display device to the last stage is stopped. Further, since the image data is sequentially taken into the drive circuit from the top, it becomes impossible to transfer any image data for each display device, which causes a display shift.

The present invention has been made to solve such a problem, and even if a display function of a display device such as a certain display device is stopped due to a problem of a power supply, a control circuit, or the like, It is an object of the present invention to provide a display device and a drive control system capable of normally driving a light emitting element from a subsequent display device to a final display device.

[0010]

In order to achieve the above object, a display device according to the present invention comprises: a driving unit for driving a light emitting element;
A drive control unit that receives data necessary for driving the light emitting element via a first line and transmits the data to another display device via a second line, and controls the drive unit based on the received data. In the display device having: the first line and the second line are disconnected from each other during a normal operation, and when the drive control unit cannot communicate, the first line is disconnected from the first line.
And a line connecting portion for connecting the second line to the second line.

Further, in the display device according to the present invention, the data is a data packet in which a communication destination is specified by identification information.

Further, in the display device according to the present invention, the line connection section connects the first line and the second line when power is not supplied to the display device.

Further, the drive control system according to the present invention includes a drive unit for driving a light emitting element, data required for driving the light emitting element received via a first line, and a second unit.
A plurality of display devices having a drive control unit that transmits to another display device via the line and controls the drive unit based on the received data, and a display device at one end connected in series A drive control system for transmitting data necessary for driving the light emitting element, wherein each of the display devices disconnects the first line and the second line during a normal operation. age,
A line connection unit that connects the first line and the second line when the drive control unit cannot communicate;

The drive control system according to claim 4, wherein the data is a data packet whose communication destination is specified by identification information.

Further, in the drive control system according to the present invention, the line connection unit connects the first line and the second line when power is not supplied to the display device.

In the drive control system according to the present invention, a second line of the display device at the other end connected in series is connected to the drive control device.

Further, in the drive control system according to the present invention, the second line of the display device at the other end connected in series is connected to the drive control device, and the display device is connected to the first line. When it is determined that the data received via the first line is abnormal, communication abnormality notification data indicating that transmission from the display device connected to the first line is abnormal is transmitted from the second line to the drive control device. When the drive control device receives the communication abnormality notification data, the drive control device connects the first line and the second line to the line connection portion of the transmission abnormality display device based on the communication abnormality notification data. The connection switching instruction data for instructing the connection state is transmitted.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The LE of the embodiment of the present invention
FIG. 3 shows an example of a display device for driving a light emitting element such as D (light emitting diode), and a drive control system used for an LED display, an LED lighting device, and the like. Each of the display devices 300 receives a driving unit (a driving circuit 303) for driving a light emitting element, data necessary for driving the light emitting element via one of the lines L (first line), and the other of the lines L. A control circuit (drive control unit 304) that controls the drive unit (drive circuit 303) based on the data transmitted to another display device via the (second line). The drive control system according to the embodiment of the present invention has a plurality of display devices 300 and transmits data necessary for driving the light emitting elements to display device 300 at one end of line L connected in series. And an LED unit control device 200. During normal operation, each display device 300 has a first line and a second line.
Line and the control circuit (drive control unit 3)
04) is unable to communicate, the first line and the second line
Line connection part (switch 31
5).

It is preferable that the data necessary for driving the light emitting element is a data packet in which a communication destination, in this case, a display device to be transmitted is specified by ID by identification information (ID). As a result, even when a certain display device becomes incapable of communication, the light-emitting state by driving the light-emitting element, for example, the light emission of the light-emitting element to be driven normally by another display device without the display image being shifted. Can be performed. In this case, the display device 300 has its own identification information (I
D), and receives a data packet indicating its own ID.

Preferably, the line connection unit connects the first line and the second line when power is not supplied to the display device. This is because each of the display devices can autonomously eliminate a problem such as an image display due to a communication error without requiring another control unit.

Further, in the drive control system according to the embodiment of the present invention, the second line of the display device 300 at the other end connected in series may be connected to the LED unit control device 200. . In this case, even when the line L performs only one-way communication, the display device on the downstream side of the communication error display device determines the communication error and notifies the LED unit control device 200 of the communication error. It becomes possible to do.

In particular, when the display device 300 determines that data received via the first line is abnormal, a communication error indicating that transmission from the display device connected to the first line is abnormal. The notification data is transmitted from the second line to the LED unit control device 200. When the LED unit control device 200 receives the communication abnormality notification data, the LED unit control device 200 displays the transmission abnormality display device 300 based on the communication abnormality notification data. By configuring the line connection unit to transmit connection switching data for instructing the first line and the second line to be connected, the communication abnormality display device can receive the data. Therefore, even if there is an abnormality only in transmission, it is possible to eliminate a problem such as image display due to an abnormality in communication.

The transfer of image data and control data necessary for driving the light-emitting elements is performed by a serial packet transfer method. Identification information (ID) is allocated by adopting the method shown in 11-23235. The signal line L of each of the display devices 300 is provided with a line connection unit that includes a switch 315 in which a switch when the power is off is a normally-on type.

At the time of normal operation, the switch 315 is in an open state under the control of the control circuit 304 when the power is turned on.
The image data and the control data are sent to all the control circuits 304 from the control circuit 304 of the display device 1 to the control circuit 304 of the last display device in order, as in the related art. Identification information added to the image data and the control data;
When the identification information stored in the storage unit 4 matches, the image data and the control data are taken into the drive circuit 303, and the corresponding display operation is performed.

When the display function of the display device 2 is stopped due to a problem with the power supply or the control circuit, for example, the input power of the switch 315 is turned off and closed, and the image data and control data transferred from the display device 1 are transferred. Is the switch 3 of the display device 2
15 to the display device 3 (FIG. 3).
Middle bold line). Therefore, normal data transfer from the display device 3 to the final stage can be secured, and since the identification information is allocated, image data and control data can be transferred to the subsequent display device, and the display of the image may be shifted. Absent.

[0026]

(Embodiment 1) FIG. 4 shows an embodiment of connection of display devices in a drive control system according to the present invention. The drive control system of the present invention has a plurality of LED units 30 (display devices), and the respective LED units 30 are connected in series, and one end of the LED units 30 connected in series has a light emitting element. An LED unit control device 20 (drive control device) for transmitting data necessary for driving. Further, in the present embodiment, the second line of the LED unit 10 at the other end connected in series is connected to the LED unit control device 20, and the one-way communication is used for the communication of the line L. Although an example is shown, it is also possible to use two-way communication.

FIG. 5 is a block diagram schematically showing an LED unit 30 as one embodiment of the display device of the present invention. The LED unit 30 shown in this figure has the following configuration. (A) A display section 1 in which a plurality of light emitting elements are arranged in a matrix of M rows × N columns. (B) A vertical drive unit 2 for applying a current to each row of the display unit 1 while selecting each row. (C) A horizontal drive unit 3 (drive unit) that supplies a drive current to each column of the display unit 1 according to the image data corresponding to the selected row. (D) The drive control unit 4 (drive control unit) including the communication unit 8, the DMA control unit 6, and the control unit 5. (E) A correction data storage unit 9 storing correction data for correction.

The operation of each component is controlled by the drive control unit 4. The LED unit receives only data for controlling the LED unit from the LED unit control device 20 that supplies image data, and generates a signal necessary for driving the inside of the LED unit autonomously within the LED unit to perform lighting display. The drive circuit of this embodiment shows a method of driving a light emitting element by current control.

The display section 1 has a plurality of light emitting elements arranged in a matrix of M rows × N columns on a substrate on which a conductive pattern is formed. As the light emitting element, an LED or the like is used. In this embodiment, three light emitting diodes capable of emitting light of red, green, and blue (RGB) are disposed adjacent to each other in units of three to constitute one pixel. An LED with RGB adjacent to each pixel can realize full color display. However, the present invention is not limited to this configuration, and two colors can be arranged close to each other, or two or more LEDs can be arranged for one color.

As the light emitting diode, a semiconductor light emitting device capable of emitting various lights can be used. As a semiconductor element, GaP, GaAs, GaN, InN, AlN, G
aAsP, GaAlAs, InGaN, AlGaN, A
An example in which a semiconductor such as lGaInP or InGaAlN is used for a light emitting layer is given. Also, the structure of the semiconductor is MI
Homostructures, heterostructures, and double heterostructures having an S junction, PIN junction, or PN junction can be given.

The emission wavelength of the semiconductor light emitting device 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. Furthermore, in order to provide a quantum effect, a single quantum well structure or a multiple quantum well structure in which the light emitting layer is a thin film 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 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.

Further, various types of light emitting diodes can be used. More specifically, a light emitting element that electrically connects an LED chip as a light emitting element to a lead terminal and uses a light emitting element itself, such as a shell type, a chip type LED, or the like, which is covered with a mold resin or the like, may be used.

The drive control unit 4 includes a communication unit 8, a DMA control unit 6, and a control unit 5. The communication unit 8 transmits and receives various data to and from the LED unit control device 20 and the communication unit 8 of another LED unit connected to the next stage, and further gives an instruction to the DMA control unit 6. The DMA control unit 6 corrects the image data (IMDATA) input from the outside in accordance with the variation in the light emitting element characteristics of each pixel, and outputs the corrected image data to the horizontal drive unit 3. On the other hand, the horizontal drive unit 3 includes a DMA control unit 6
And a horizontal drive side communication unit 8 for performing data reception processing. Reference numeral 13 denotes an identification information storage unit for storing its own identification information (ID), and reference numeral 12 denotes a normally open switch (line connection unit).

During normal operation, the switch 12 is opened to disconnect the left side line L (first line) and the right side line L (second line) from the left side of the figure. The input data is output to the right line L through the communication unit 8 without passing through the switch 12. At this time, when the identification information (ID) stored in the identification information storage unit 13 matches the identification information (ID) added to the input data, the communication unit 8 captures the input data, and does not capture the data unless they match.

When communication is impossible due to the occurrence of an abnormality in the communication section 8 or power supply abnormality, the control section 5 senses this and outputs a control signal through the line connection section control line Lc to close the switch 12. In the figure, the left line L (first line) and the right line L (second line) are connected to each other, and the data input from the left line L is transmitted to the switch 12 without passing through the communication unit 8. And is output to the right-hand line L.

If the communication unit 8 is abnormal, the switch 1
At the same time as closing 2, a specific display pattern may be transferred to the drive-side communication unit 9 in the figure, and an abnormality may be notified by the display. Also, communication abnormality notification data indicating that transmission from the display device connected to the first line is abnormal is transmitted from the second line to the drive control device. When the data is received, a connection switching data is transmitted which instructs the line connection unit of the transmission abnormality display device to connect the first line and the second line based on the communication abnormality notification data. It is good also as a structure which performs. When the switch 12 is closed, the input data is output as it is via the switch 12. At this time, the data input to the communication unit 8 becomes invalid. When the abnormality of the communication unit or the abnormality of the power supply is restored, the switch 12 is opened again by a signal from the control unit 5 and returns to the normal operation. If reception is possible and only transmission is abnormal, a normal operation may be performed based on the input data.

The DMA controller 6 has a memory (RAM) for temporarily storing image data. In order to exchange a lot of data at high speed, the DMA controller 6
Directly reads the contents of the RAM by hardware at a high speed, and transfers data to the horizontal drive unit 3.

The control section 5 switches the current source for each row of the vertical drive section 2. In addition, it also functions as a timing generation unit that generates a gradation reference clock as a reference clock for controlling the lighting gradation. The gradation reference clock is sent from the control unit 5 to each horizontal drive unit 3. In the present embodiment, the control unit 5 is provided in the drive control unit 4 to transmit the grayscale reference clock. However, the horizontal drive unit 3 is provided with a timing generation unit to generate the timing autonomously. You can also.

The drive control section 4 further includes an image data correction section and an image data storage section. The image data input from the outside is corrected by the image data correction unit according to the variation in the light emitting element characteristics of each pixel, and is output from the DMA control unit 6 to each horizontal drive unit 3. Correction data for this correction is stored in the correction data storage unit 9. The image data correction unit reads information data for correction from the correction data storage unit 9 and performs data correction. The correction data storage unit 9 is a memory element such as a ROM, preferably an E ² P
It is composed of ROM.

The correction data for correcting the variation for each light emitting element is stored in the correction data storage unit 9. The correction data storage unit 9 is configured by a ROM that stores correction data calculated in advance. In the drive circuit shown in FIG. 5, the image data correction unit is provided separately from the drive control unit 4, but can be incorporated in the drive control unit 4. The correction data includes, for example, luminance correction data for correcting luminance for each light emitting element.

The connection portion, which is a physical interface of a signal, is a means for serially transmitting data from the drive control device to the LED unit, and can be electrically connected using wiring or using an optical fiber. It can also be transmitted. 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.

The vertical drive section 2 is a common driver for applying a current in the row direction of the display section 1, and is composed of semiconductor switching elements and the like. In FIG. 5, one vertical drive unit 2 switches the common lines of each row in a predetermined order to apply a current. The row selected by the vertical drive unit 2 in one operation may be one row of the display unit 1 or a plurality of rows.

The horizontal drive unit 3 has a plurality of stages connected as shown in FIG. An LED driver constituting each horizontal control unit 3 is connected to each column of the light emitting elements, and N columns of L are connected.
ED drivers 1 to N are connected in series. Adjacent LED drivers are electrically connected by respective horizontal drive side communication units 8.

The horizontal drive unit 3 includes a horizontal drive communication unit 8,
Memory unit 17, lighting control unit 15, constant current drive unit
It consists of. The memory unit 17 includes a shift register and the like. The horizontal drive unit 3 includes LEs arranged in each column direction.
D, and sequentially supplies current to the LEDs in the vertical direction in synchronization with the switching of the vertical drive unit 2 to perform dynamic lighting. The horizontal drive unit 3 includes a semiconductor switching element and a driver IC.

The horizontal drive section 3 has a horizontal drive side communication section 8. The horizontal drive side communication unit 8 communicates with the drive control unit 4 and the horizontal drive side communication unit 8 provided in the horizontal control unit 3 at the next stage. Further, the horizontal drive communication unit 8 writes data sent from the DMA control unit 6 of the drive control unit 4 to the memory unit 17 provided in the horizontal drive unit 3.
In the example of FIG. 5, the DMA control unit 6 sends the image data to the memory unit 17, and the memory unit 17 holds the image data with a shift register. Each horizontal drive unit 3 has individual identification information I
D is assigned, and image data or the like to which the identification information ID of the destination horizontal drive unit 3 is added is transmitted from the drive control unit 4 of the LED unit. After recognizing that the data is addressed to itself, the horizontal drive unit 3 side
Perform reception processing.

On the other hand, the drive control section 4 has a communication section 8. The communication unit 8 transmits L for transmitting image display data.
Receiving control data from the ED unit control device 20,
The write and read operations of the memory, the register, and the like are performed on the DMA controller 6 of the drive controller 4. For example, the communication unit 8 receives image data from the LED unit control device 20, and the image data storage RAM included in the DMA control unit 6.
Is updated, the image display is updated. L
The control data of the ED unit includes control to the drive circuit, temperature information inside the LED unit, monitor information of the power supply voltage, detection of disconnection between the display device and the drive circuit, failure due to abnormal temperature rise of the horizontal drive unit 3, LED Processing such as checking the signal pattern wiring failure inside the unit, checking the data communication state between the control unit and the horizontal drive unit 3, and writing the brightness correction data are included. The communication unit 8 exchanges these data between the LED unit control device 20 and the LED units according to a predetermined communication method.

The DMA control section 6 performs high-speed autonomous data transfer to the horizontal drive communication section 8 in a predetermined format using image data, luminance correction data, and the like in a predetermined format. In particular, in the case of the LED unit using the LED, the image refresh rate is about 4 times higher than the image refresh rate at the normal video rate.
A double to 16 times image refresh rate is required.
For this reason, at the time of dynamic driving, it is necessary to read out image data and luminance correction data directly from the memory by hardware processing and to perform high-speed data transfer.

FIG. 6 is a time chart for a frame cycle operation at the time of 1/4 duty. In the present embodiment, LED unit IDs (here, ud1 to udN) are assigned to the LED units 30, and driver IDs (here, drv1 to drn) are assigned to the horizontal driving unit 3 in each LED unit 30.
v4) are set.

When the image is switched at a video rate (for example, 60 Hz), the LED unit controller 20
For each Vsync indicating a frame synchronization signal, a frame cycle start packet csp indicating the start of a frame cycle, which is a command packet for performing frame synchronization control, is all L.
Transmit to ED unit 30. Subsequently, an image data packet ud, which is command data in which image data to be displayed in each LED unit 30 is attached to a data portion, is transmitted to the LED units L constituting the display.
U1, N2, U3,..., U1 are sequentially assigned as image data packets ud1, ud2, ud3,.
Transmit within the frame period. Here, each of the image data packets ud1, ud2, ud3,... UdN transmitted from the LED unit control device 20 includes an LED.
Identification information according to the connection mode of the unit 30 is attached.

Each LED unit 30 receiving the frame cycle start packet csp performs frame synchronization. At this time, each LED unit 30 does not perform a response process to the frame cycle start packet csp and does not transmit the response data res. The response data res transmitted from the LED unit 30 to the LED unit control device 20 includes the second line of the LED unit 10 at the other end connected in series as in the present embodiment. 20
When the one-way communication is used for the communication of the line L connected to the (drive control device), the command data is transmitted in the same direction as the command data. In the system, the command data is transmitted in the opposite direction. Next, each LED unit 30 that has received the image data packet ud transmits the identification information and its own LE.
The receiver unit is collated with the D unit ID, and if they match, a reception process is performed. The image data received by each LED unit 30 is stored in the RAM of the DMA control unit 6 in each LED unit 30, and is displayed and controlled in the next frame period.

FIG. 6 is a timing chart showing an example of display control in the LED unit. When the LED unit receives the frame cycle start packet csp, it raises the frame synchronization signal Vsync. The display unit 1 responds to the rising of the frame synchronization signal Vsync.
A blank signal blank corresponding to the lighting cycle of each line is generated. In accordance with the blank signal blank, the address com adr 0,
Based on the data of 1, 2, and 3, each LED is controlled to be turned on by the common driver 2 and the corresponding horizontal drive unit 3, and an image is displayed.

In each LED unit 30, an identification information ID is given to each horizontal drive unit 3, and writing to a memory in the horizontal drive unit 3 and synchronization control are performed by the drive control unit 4 in a packet format. And shows a communication method. The identification information ID to be given is, for example, an identification number unique to an IC constituting each horizontal drive unit 3.

In the image display device, the DMA controller 6
The control data sent to the horizontal drive unit 3 from the line Ld to the horizontal driving unit 3 is data_0 to data_3. data_0
To data_3 are common lines adr_0 to adr_
3 is control data corresponding to the common line adr in each of the control data data_0 to data_3.
Control data drv1_data to drv4_data to be supplied to the horizontal drive unit 3 corresponding to _0 to adr_3 are included. Further, in FIG. 6, vsync is generated in the image display device according to the vertical synchronization detection data csp. This data determines the cycle of a packet for transmitting each frame data, and is used as a frame synchronization of each horizontal drive unit 3 and as a data latch trigger.

The drive controller 4 receives the vertical synchronization detection data csp sent from the LED unit controller 20, recognizes the head of the image frame data, and performs vertical synchronization. By this synchronization detection, a lighting control signal (BLA) indicating switching of each drive line in the image display device.
NK), a vertical drive unit control address indicating the address of the drive line is generated based on a predetermined display double speed. FIG. 6 shows an example of quadruple-speed lighting with respect to a vertical synchronization period of 60 Hz, and one vertical drive period for performing one screen display of one image display device is 240 Hz. In this case, one frame packet section (about 16 ms) of the vertical synchronization cycle of 60 Hz
In contrast, the drive duty ratio is 1/4, and the control is performed under four common lines. In this embodiment, the variable function of the refresh rate is realized by making the lighting double speed variable. In addition, various data such as image data and luminance adjustment data are transferred by N (ud1 to udN), which is the number of the horizontal drive units 3 to be controlled, during one cycle of the vertical synchronization detection data csp. After receiving the data in each horizontal drive unit 3, the data is reflected in the next vertical cycle. Therefore, during reception of various data, writing to the memory in each horizontal drive unit 3 is performed, and the image data currently displayed is the data transferred in the previous vertical cycle.

FIG. 7 shows a data format configuration in the case where communication is performed in the form of transmission data in a packet format when controlling the LED unit 30 and the horizontal drive unit 3. The data packet 50 of this format includes a control field 51 and an information field 52. The control field 51 is further divided into identification information (ID part) and control identification information (CMD part).

The control field 51 is a part for storing various kinds of identification information added to the actual data. The identification information ID is stored in the LED unit 30 or the horizontal drive unit 3.
Indicates information for identifying. Since the LED unit 30 and the horizontal drive unit 3 are individually given the LED unit ID and the driver ID as the identification information ID, it can be said that this information indicates the destination of the data to be transmitted.

The control identification information CMD is stored in the LED unit 3
This is information indicating a control type of what kind of control is performed on 0 and the horizontal drive unit 3. Data types include, for example, horizontal synchronization signal (HSYNC) data, image data, gradation data, brightness adjustment data, rewriting of brightness correction data, reading of fault data, connection switching instruction data, and the like. The communication abnormality notification data transmitted from the LED unit 30 to the LED unit control device 20 includes ID indicating the LED unit control device in the identification information,
Data indicating that transmission from the display device connected to the first line side is abnormal in the control identification information, itself or 1
The ID and the like of the LED unit on the upstream side may be configured to have control data.

In the information field 52, the control identification information C
It shows the contents of control data, which is actual data according to the MD. This enables individual control for each of the LED unit 30 and the horizontal drive unit 3.

The data packet includes data to be transmitted to all the LED units and the horizontal drive units in addition to data such as image data to be transmitted to the individual LED units and the horizontal drive units. As a data packet to be transmitted to all the horizontal driving units, for example, HSY
NC and an automatic ID assignment command. In these data packets, a common ID is set as the identification information ID.

In the LED unit of this embodiment, an example in which packet communication is used also for communication between the horizontal driving units has been described. However, as in the conventional communication between the horizontal driving units, data is transferred using a shift register or the like. A bit shifting communication method may be used.

Although the LED unit 30 has been described as a display device of the present invention, the constant current drive unit 14 of the horizontal drive unit is a drive unit, and the drive control unit is a drive communication unit 9. 1st line (one of line Ld)
And the second line (the other of the lines Ld) are disconnected, and when the drive control unit (drive-side communication unit 9) cannot communicate,
A horizontal drive unit (driver I) that further includes a line connection unit that connects the first line and the second line.
By configuring as C), the display device of the present invention can be obtained. In this case, the drive control unit 4 corresponding to a drive control device that transmits data necessary for driving the light emitting element
An LED unit (display device) having the following can be used as the drive control system of the present invention.

Further, in the present embodiment, the connection of the display devices is such that the communication directions of the display devices arranged in a matrix are switched for each row as shown in FIG. However, as shown in FIG. 8, the connection may be such that the communication direction is constant in each row. Also, a distributor is arranged like a conventional LED display, and a plurality of display devices are arranged via the distributor.
You may comprise so that it may be connected in series with a drive control apparatus. (Embodiment 2) Next, FIG. 9 shows another embodiment of the drive control system according to the present invention. As shown in the figure, a line Lt for communicating data with the drive control device 20 and the plurality of distributors 25 is provided.
The first line (one of the lines Lt) and the second line (the other of the lines Lt) are disconnected from the respective distributors 25 during normal operation, and the drive control unit ( When the distributor 25) cannot communicate, the driving unit (LED unit) that drives the light emitting element has a configuration including a line connection unit (switch 27) that connects the first line and the second line. 30) and receiving and transmitting the data necessary for driving the light emitting element to another display device (the LED unit 30 and the distributor 25) via the second line while receiving the data via the first line. A drive control unit for controlling the drive unit based on the data, a plurality of display devices having a drive control unit, and drive control for transmitting data necessary for driving the light emitting element to the display device at one end connected in series It can be a drive control system having a location 20. Here, the LED unit 30 is connected in series to the terminal 26 of the distributor 25 by a line Lu. Terminal 2 of each distributor 25
Reference numeral 6 includes an identification information storage unit, and the identification information (I) transmitted from the drive control device 20 via the line Lt.
After receiving the data with D) and storing it in the memory, the data connected to its own distributor via the line Lu is converted to L.
It is distributed to the ED unit 30.

In the above description, the light emitting element L
Although the LED unit 30 having the matrix display in which the EDs are arranged in a plurality of pixels is shown, the display device may have a configuration in which display elements corresponding to one or more pixels are arranged. Examples of the display element include a liquid crystal, an EL element, a PDP, and an electric sign. Further, it is also possible to use illumination of a neon tube or the like as a display element and to use gradation of illumination intensity as image data.

[0065]

As described above, even when the display function of a certain LED unit or the like is stopped by the display device and the drive control system of the present invention due to the problem of the power supply, the control circuit, or the like, it does not matter. It is possible to provide a display device and a drive control system that can normally drive the light emitting elements from the subsequent display device to the last stage.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an LED display including a conventional LED unit.

FIG. 2 is a schematic diagram showing connection of a conventional LED unit.

FIG. 3 is a schematic view showing the connection of the display device of the present invention.

FIG. 4 is a schematic diagram showing one embodiment of a connection configuration of a display device in the drive control system of the present invention.

FIG. 5 is a block diagram schematically showing an LED unit as one embodiment of the display device of the present invention.

FIG. 6 is a time chart of a frame cycle operation in the drive control system of the present invention.

FIG. 7 is a format configuration example of a transmission data packet used in the drive control system of the present invention.

FIG. 8 is a schematic diagram showing another embodiment of the connection configuration of the display device in the drive control system of the present invention.

FIG. 9 is a schematic diagram showing another embodiment of the drive control system of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Display part 2 ... Common driver 3 ... Horizontal drive part 4 ... Drive control part 6 ... DMA control part 8 ... Communication part 9 ... Drive side communication part 12, 26 , 315: switch 14: constant current drive unit 15: lighting control unit 17: memory unit 13: identification information storage unit 20: LED unit control device (drive control device) 25 ... Distributor 26 ... Terminal 30 ... LED unit (display device) 200 ... Drive control device 300 ... Display device 303,813 ... Drive circuit 304,814 ... Control circuit L , Lc, Ld, Lt, Lu ... line

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/66 103 H04N 5/66 103

Claims (8)

[Claims] A driving unit for driving the light emitting element; receiving data required for driving the light emitting element via a first line and transmitting the data to another display device via a second line; A display device having a drive control unit for controlling the drive unit based on the obtained data, wherein the first line and the second line are disconnected from each other during a normal operation, and the drive control unit cannot communicate. In some cases, the display device further includes a line connection unit that connects the first line and the second line. 2. The display device according to claim 1, wherein the data is a data packet whose communication destination is specified by identification information. 3. The display device according to claim 1, wherein the line connection unit connects the first line and the second line when power is not supplied to the display device. 4. A driving unit for driving a light emitting element, receiving data required for driving the light emitting element via a first line and transmitting data to another display device via a second line. A plurality of display devices each having a drive control unit that controls the drive unit based on the data obtained, and transmitting data necessary for driving the light emitting element to the one end display device connected in series. A drive control system having a control device, wherein each of the display devices disconnects the first line and the second line during a normal operation, and when the drive control unit cannot communicate, A drive control system further comprising a line connection unit that connects the first line and the second line. 5. The drive control system according to claim 4, wherein the data is a data packet whose communication destination is specified by identification information. 6. The drive control system according to claim 4, wherein the line connection unit connects the first line and the second line when power is not supplied to the display device. . 7. The drive control system according to claim 4, wherein a second line of the display device at the other end connected in series is connected to the drive control device. 8. A second line of the display device at the other end connected in series is connected to the drive control device, and the display device abnormally receives data received via the first line. When it is determined that the transmission from the display device connected to the first line side is abnormal, communication abnormality notification data indicating that the transmission is abnormal is transmitted from the second line to the drive control device; When receiving the communication abnormality notification data, the apparatus instructs the line connection unit of the transmission abnormality display device to connect the first line and the second line based on the communication abnormality notification data. The drive control system according to claim 7, wherein the connection control instruction data is transmitted.