JP2003150119A - Led matrix display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a LED matrix display device which can be made small in size and packaged at a high density by diving the whole LED matrix into segments and minimizing the number of wiring to the segments, and which is further facilitated in increasing and decreasing display area. SOLUTION: The LED matrix display device of this invention is configured of a plurality of segment display parts divided from the whole LED matrix into m x n segments, a corporate display control part for performing display control of the whole LED matrix, segment driving parts for performing display control of the LED matrix of each segment display part, and a power source part, and the power source part supplies currents to the corporate display control part and each segment driving part, and it is made possible to decrease the number of wiring to the segments by a chain connection wiring using a pair of communication lines from the corporate display control part to a plurality of segment driving parts, and as a result, a connector or the like can be made small in size. Moreover, the LED matrix display device facilitated in increasing and decreasing the display area in display driving part units can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED matrix display device, and in particular, enables a high density by reducing the number of control wirings necessary for display control of the LED matrix.
Furthermore, the present invention relates to an LED matrix display device in which the display area can be easily expanded.

[0002]

2. Description of the Related Art A display in which a plurality of LEDs are arranged two-dimensionally and which displays characters, charts, etc. is becoming widespread because it can have a large screen. For the display of the LED matrix, the method of selecting each row and column and sequentially displaying the LEDs corresponding to the intersections is the easiest to understand, but the whole wiring is divided into m rows and n columns because the number of wires is huge. The mainstream method is to control the display of LEDs while sequentially selecting rows and columns for each segment.

However, even in that case, the number of wires for transmitting and controlling the row and column data and the display information of each LED is not small, and therefore, the size of the connector is combined with the limitation in downsizing the drive circuit portion. there were.
Due to the demands of display technology, it is difficult to reduce the LED array pitch by pursuing delicate display.

Further, it is not always easy to increase or decrease the LED display area due to a great change in wiring and driving circuits, and it is difficult to expand or reduce the display area at the installation site.

[0005]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to divide the entire LED matrix into segments,
LE that enables the miniaturization and high-density mounting by reducing the number of wires to the segment as much as possible, and that it is easy to increase or decrease the display area
It is to realize and provide a D matrix display device.

[0006]

SUMMARY OF THE INVENTION An LED matrix display device according to the present invention comprises a plurality of segment display sections in which the entire LED matrix is divided into m rows and n columns, and a general display control for controlling the display of the entire LED matrix. Unit, a segment drive unit for controlling the display of the LED matrix of each segment display unit, a power supply unit, and the like. A current is supplied from the power supply unit to the integrated display control unit and each segment drive unit, and the integrated display control unit Thus, by connecting and connecting a plurality of segment drive parts in a chain with a pair of communication lines, it is possible to reduce the number of wires to the segment, and thus to downsize the connector and the like. Further, the segment display unit and the segment drive unit are integrated to provide an LED matrix display device in which the display area can be easily increased or decreased for each segment display drive unit.

The integrated display control unit sends a frame synchronization signal to each segment drive unit via the communication line at regular intervals and displays a segment address and an LED address together with a display instruction on the LED matrix if necessary. Information is transmitted as a serial data string.

Each segment drive section has at least a serial signal reception decoding circuit, a display information memory, a column address generation circuit, a column selection circuit, etc. The frame synchronization signal, the address, the display information, etc. are separated, the display information is stored in the display information memory according to the decoded address, and the column address generation circuit generates the column address in synchronization with the frame synchronization signal and the column selection circuit. A column line is selected by, the display information for each row is read from the display information memory in accordance with the column address, and the LEDs are sequentially displayed and controlled for each column.

[0009]

As described above, according to the LED matrix display device of the present invention, since each segment of the LED matrix is controlled by connecting and connecting a pair of communication lines in series, the number of wirings is small, and accordingly the number of wirings is small. The connector can be miniaturized, and high-density mounting of the LED matrix and further cost reduction can be easily achieved. Further, it is possible to provide an LED matrix display device in which the display area can be easily increased or decreased for each segment display drive unit.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an LED matrix display device according to the present invention will be described with reference to the drawings with reference to the accompanying drawings.

FIGS. 1, 2 and 3 are views for explaining an LED matrix display device which is a first embodiment of the present invention and which is monochrome and has no gradation display. FIG. 1 shows the LED matrix display. 1 shows a schematic configuration of an apparatus. In the figure, L
A segment drive in which an LED matrix which is composed of a two-dimensional array of dots 11 is divided into m rows and n columns of segment display units 12 and the display control of the LEDs in the segment display units is performed in each segment display unit 12. Part 1
3, and further comprises an integrated display control unit 14 and the like for integrally controlling a plurality of segment drive units 13. Integrated display control unit 14
And a plurality of segment drive units 13 between the pair of communication lines 15
Are connected and connected in a chain. The power supply unit and the wiring from the power supply unit to each segment drive unit 13 are not shown.

The integrated display control unit 14 separately displays the display information input via a personal computer or the Internet via the communication line 15 into the segment address and L
Display information is serially transmitted together with the ED address and the like, and the segment drive unit 13 obtains the display control information and controls the display of the LEDs in the segment display unit 12. Since two lines are sufficient for the communication line 15, the wiring is not bulky and the connector in the segment driving unit 13 is also small, so that the size of the entire segment driving unit 13 can be reduced.

FIG. 2 shows an example of a data string transmitted from the integrated display control unit 14 to each segment driving unit 13 via the communication line 15. The display data switching interval of the entire LED matrix is indicated by Fj, and in the figure, a part of the data sequence configuration of the jth frame Fj and the data sequence configuration of the j + 1th frame are shown. In the figure, reference numeral 21 indicates a frame synchronization signal, which is composed of a pulse train having a predetermined pattern to indicate the beginning of the data train.
The number 22 is composed of a pulse train of a predetermined pattern with a data mark indicating that the segment address follows, the number 23 is the segment address, the number 24 after that is the dot address in the segment display unit 12, and the number 25. Indicates the display information of the LED forming the dot. When a plurality of segments are targeted, the required number of data strings from number 22 to number 25 are repeated. Number 26
Is a data mark indicating the end of the data string to be transmitted in the frame Fj.

The segment driver 13 shown in FIG. 1 receives this data string, decodes it, and fetches only the subsequent data strings 24 and 25 that match its own segment address,
Ignore other data columns. The data strings indicated by numbers 24 and 25 are sent out their addresses and display information only for the LEDs that change the display state. However, it is assumed that the arrangement of LEDs is fixed, and all the display information is sent without sending the respective addresses. It may be sent serially. The frame synchronization signal 11 is also used in the segment drive unit 13 for synchronization for display control.

In a switching control of a large number of LED matrices, it is a noisy environment and a transmission error is likely to occur. A redundant bit for error detection or a redundant bit for error detection and correction is attached to the end of the data string transmitted from the integrated display control unit 14, and if an error is found in the received data, retransmission is requested or the error is corrected. Means such as doing is effective. Since these techniques are already known, the description is omitted.

FIG. 3 shows an example of the structure of the segment drive unit 13. In the figure, the segment display unit 12 is configured to control the display of an LED matrix of 8 rows and 8 columns.
Upon receiving the data string from the integrated display control unit 14 via the communication line 15, the serial signal reception decoding unit 31 decodes and separates the frame synchronization signal, the segment address, the LED address, the display information, etc., and matches the own segment address. Only the information is fetched and the display information is stored in the display information memory 32 according to the LED address. In the first embodiment, since a single color is not used for gradation display, the memory required for each LED is 1 bit.

The column address generation unit 33 receives the frame synchronization signal via the output 39 of the serial signal reception / decoding unit 31, and generates the column address 40 in synchronization with the frame synchronization signal. The column selection circuit 34 receives the column address 40 and selects one column,
Supply a predetermined current. The number 36 indicates one current source in the column selection circuit 34, and the number 42 indicates an output line for selecting a column.

The display information memory 32 receives the column address 40, reads the display information in units of rows, and outputs the display information to the row drive circuit 35, and the row drive circuit 35 opens and closes the gate according to the output. The number 37 indicates one switching element in the row drive circuit 35, and the number 43 indicates a row line. Also, number 4
Reference numeral 4 denotes a timer, which sends an output to the row drive circuit 35 so that the gate can be opened for a certain period of time in accordance with a preset instruction or an instruction sent from the general display control unit 14. Although the brightness of the LED can be considered to be substantially uniform in the unit of the segment display units 11, there are variations among the segment display units 11.
It is used for correction in that case.

In this embodiment, a data string is received from the integrated display control unit 14 and writing to the display information memory 32 is performed within a short time between display frames. However, when the amount of data becomes large due to the gradation display or color display of each LED, the writing time to the display information memory becomes long. The display information memory 32 is provided with two sets of memories so that reading and reading from each other will not be congested, and writing and reading are performed simultaneously in different memories, and are alternately switched by a frame synchronization signal.

The second embodiment of the present invention is an embodiment which enables gradation display of each LED. In the second embodiment,
The overall structure, the data string structure, and the structure of the segment driving unit are the same as those of the first embodiment shown in FIGS. 1, 2, and 3, respectively, and are different in that gradation display data of LEDs are added. That is, each LED has a memory of 1 bit, but in the second embodiment, 4 to 8 bits required for gradation display are required.

FIG. 4 shows a method for gradation display of the brightness of each dot of the LEDs, and shows that gradation is realized by changing the width of the current flowing while keeping the current flowing through each LED constant. In addition to the configuration of the segment drive unit 13 shown in FIG. 3, each row has at least one timer, and the timer is set according to the gradation information in the display information memory 32, and the gate time in the row drive circuit 35 is set. Control and realize gradation.

In FIG. 4, [Li] indicates the lighting state of each column that can be switched on the time axis in the same row. Numbers 51, 52, 53, and 54 are column switching timings, respectively, and [Li] between the numbers 52 and 53 indicates a situation in which the i-th column is selected by the column selection circuit 34. Numbers 55, 56 and 57 indicate the lighting times of the LEDs in the same row in the i-1, i, i + 1 columns, respectively. Lighting time 5
5, 56 and 57 are column switching timings 51,
Lighting is started from 52 and 53, and the lighting is stopped at the time points Wi-1, Wi, Wi + 1 proportional to the respective gradations. Since there is a timer for each row, a segment of an LED matrix of 8 rows and 8 columns has 8 timers.

In the case of implementing color display by appropriately mixing the primary colors in the LED matrix, if the different primary colors are treated as independent LEDs on the same column line, the color display can be controlled in the second embodiment. Is.

In the third embodiment of the present invention, primary color LEDs R (red), G (green), and B (blue) are arranged in a matrix, and individual primary color LEDs are displayed in multicolor by gradation display. It is an embodiment that realizes. In the third embodiment, the overall structure, the data string structure, and the structure of the segment driving unit are the same as those in the first embodiment shown in FIGS. The added points are different. That is, if each primary color LED forming each dot is regarded as an independent dot, each LED requires 4 to 8 bits required for gradation display in the third embodiment. However, the dot matrix of 8 rows and 8 columns is treated as an LED matrix of 24 rows and 8 columns in the three primary color display.

FIG. 5 shows primary color LEDs R (red) and G.
(Green) and B (blue) are realized by controlling the lighting time width on the time axis as in the second embodiment shown in FIG. In the present embodiment, the lighting start time and the lighting end time of each primary color LED are designated to control the lighting time width. In the embodiment shown in FIG. 4, only the time width is
In this embodiment, the lighting start time and the lighting end time are specified because there is a time delay difference in perceptual recognition for each primary color. Similar to FIG. 4, the numbers 52, 53, 54 are i, i + 1,
The timing of switching to the i + 2th column is shown. In the i-th column, the number 61 indicates the R lighting time, the number 63 indicates the G lighting time, and the number 65 indicates the B lighting time. At those lighting times, RSi and REi respectively indicate the start and end of lighting of R. GSi and GEi are G, B
Si and BEi indicate the start and end of lighting of B, respectively. Therefore, each LED forming a row has two timers.

Although the serial signal receiving / decoding unit, the column address generating circuit, the timer and the like are treated as independent circuits in the above-mentioned embodiment, the same function can be realized by the built-in program processing if the processing speed permits. It is important that the function sharing by software or hardware is realized in an optimal form according to the environment in consideration of the size of hardware, cost, processing time, etc., and the description of the embodiment limits the content of the present invention. Do not mean.

The fourth and fifth embodiments of the present invention are LED matrix display devices in which the display portion can be easily expanded by arranging the segment display portion and the segment driving portion in a unit of the segment display driving portion. And in FIG.
These examples will be described with reference to FIG.

FIG. 6 shows the adjacent segment display driving unit 7
A fourth embodiment of the present invention will be shown in which connectors arranged in the vicinity of the boundaries facing each other between 0s are connected and connected in a chain as connecting means. As shown in the figure, the segment display unit 12 and the segment drive unit 13 are laminated and integrated to form a segment display drive unit 70. The segment display drive unit 70 is arranged and connected to complete the LED display portion. The segment display driving unit 70 is a connector unit 71, 72 as a connecting means for connecting to the segment display driving unit 70 adjacent to two opposite sides.
The signal and power from the integrated control unit 14 are connected to one of the segment display drive units 70 as a signal power supply cable 74. Between the segment display drive units 70, these connector units 71 and 72 are connected by connecting them in a chain by a signal feeding cable 73.

As described above, according to the fourth embodiment, the required number of segment display driving units 70 are arranged in a building block manner, and the pair of communication lines and the power feeding line 2 are provided between the adjacent segment display driving units 70. A flexible and expandable LED matrix display device can be realized by simply connecting and connecting with a signal power supply cable 73 having a built-in about four conducting wires composed of a book.

In FIG. 7, the segment display drive unit 70 has male and female connectors 75 and 76 as connecting means at the boundary between the two opposite sides, and the signal feeding between the adjacent segment display drive units 70 shown in FIG. A fifth embodiment of the present invention will be described in which wiring is connected in series without using the cable 73. In FIG. 7, the male connector 75 is shown in the segment display drive unit 70, and only the position of the female connector 76 is shown. In the figure, a signal feeding cable 77 is used between the male and female connectors 75 and 76 to connect the upper and lower segment display drive units 70. By arranging the male and female connector parts 75 and 76 or equivalent, the configuration can be achieved without using the signal feeding cable 77. However, if the signal feeding cable 77 is also used as shown in FIG. 7, the overall cost can be reduced, and the configuration in which the upper and lower display blocks are arranged separately can be applied.

[0031]

As described above with reference to the embodiments, according to the LED matrix display device of the present invention, the total L
The ED matrix is divided into m rows and n columns, and a pair of conducting wires are connected and connected in a chain to the segment drive unit that controls the display of each segment, so the number of wires is small, and therefore the connector is also small and the segment drive unit is small. Since it can be made compact, it is suitable for realizing an LED matrix display of high density arrangement and for realizing an LED matrix display device in which the display area can be easily increased or decreased for each segment display drive unit.

[Brief description of drawings]

FIG. 1 shows an overall configuration of a first embodiment of the present invention.

FIG. 2 shows an example of a data string sent from a central display control unit to a segment drive unit.

FIG. 3 shows a configuration example of a segment drive unit in the first embodiment.

FIG. 4 shows a lighting current waveform in a second embodiment in which gradation display of each LED is performed.

FIG. 5 shows a lighting current waveform for gradation display of primary color LEDs for multicolor display in the third embodiment.

FIG. 6 shows a fourth embodiment in which the segment display driving unit is connected by a cable.

FIG. 7 shows a fifth embodiment connected by a connector built in a segment display drive unit.

[Explanation of symbols]

11 ... LED, 12 ... Segment display section, 13 ... Segment drive section,
14 ... Overall display control unit, 15 ... Communication line, 21 ...
..Frame sync signal, 22 ... Data mark preceding segment address, 23 ... Segment address, 24 ... Dot address, 25 ... Display information, 26 ... Data indicating end of data string Mark, 31 ... Serial signal receiving / decoding unit,
32 ... Display information memory, 33 ... Column address generation unit, 34 ... Column selection circuit, 35 ... Row drive circuit, 36 ... Current source, 37 ...
.Switching element, 38 ... Output line, 39
... Frame synchronization signal, 40 ... Column address, 41 ... Output line, 42 ...
Output line, 43 ... Row line, 51, 52, 53, 54 ...
Row switching timing, 55, 56, 57 ... LED
Lighting time, 61, 62 ... R lighting time, 6
3,64 ... G lighting time, 65,66 ... B lighting time 70 ... Segment display drive unit, 71,72.
・ Connector part, 73, 74, 77 ・ ・ Signal feeding cable, 75 ・ ・ ・ Male connector, 76 ・ ・ ・
Female connector

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 633 G09G 3/20 633P 680 680E 680G

Claims (10)

[Claims] 1. A plurality of segment display sections in which an LED matrix arranged two-dimensionally is divided into segments of m rows and n columns, a general display control section for controlling display of the entire LED matrix, and a segment display section of each segment display section. It is composed of a segment drive unit for controlling the display of the LED matrix, a power supply unit, and the like. A current is supplied from the power supply unit to the integrated display control unit and each segment drive unit, and the integrated display control unit supplies a plurality of segment drive units. An LED matrix display device, which is connected and connected by a pair of communication lines to control the display of an LED matrix. 2. The LED matrix display device according to claim 1, wherein the integrated display control unit displays display information at regular intervals based on a display instruction on the LED matrix, and transmits a frame synchronization signal via the communication line. An LED matrix display device characterized in that it is sent to a segment drive unit and, when necessary, segment information, LED address, and display information are transmitted as a serial data string. 3. The LED matrix display device according to claim 2, wherein each segment drive unit has at least a serial signal reception decoding unit, a display information memory, a column address generation unit, a column selection circuit, etc. The decoding circuit separates the frame synchronization signal, the address, the display information, etc. from the data string serially sent from the integrated display control unit, stores the display information in the display information memory according to the decoded address, and the column address generation circuit stores the frame information. A column address is generated in synchronization with a synchronization signal, a column line is selected by a column selection circuit, display information for each row is read from a display information memory in accordance with the column address, and LEDs are sequentially controlled for each column. LED matrix display device 4. The LED matrix display device according to claim 3, wherein the display information serially sent by the integrated display control unit includes brightness adjustment information for each segment, and each segment drive unit has a timer. LED matrix display device characterized in that the lighting time of the LEDs constituting the 5. The LED matrix display device according to claim 3, wherein the display information serially transmitted by the integrated display control unit includes gradation display information of each LED, and each segment drive unit forms an LED forming a row. LE having a lighting timer for each to control the lighting time and perform gradation display
D matrix display device 6. The LED matrix display device according to claim 5, wherein the lighting timer for each row has a timer for designating a lighting start time and a lighting end time.
Matrix display 7. The LED matrix display device according to claim 3, wherein the column selection circuit is driven by a constant current, and the brightness is kept constant even when the power supply voltage changes. 8. The LED matrix display device according to claim 1, wherein the entire display unit is arranged in units of segment display drive unit in which a segment display unit and a segment drive unit are integrated. Also, a pair of communication line and power supply line from the power supply unit to each segment display drive unit is configured as a chain connection wiring between adjacent segment display drive units, and it is possible to easily increase / decrease in LED display drive unit units. LED matrix display device characterized in that 9. The LED matrix display device according to claim 8, further comprising connecting means for connecting the communication line and the power supply line on at least two opposite sides of the segment display drive section, and connecting between adjacent segment display drive sections. LED matrix display device, characterized in that the connection means are connected to each other 10. The LED matrix display device according to claim 9, wherein the connecting means of each segment display driving section is a connector having one male type and the other female type, and the segment display driving section is arranged. The connectors are connected to each other between the adjacent segment display drive units, and the communication line and the power supply line are connected and connected in a chain.
ED matrix display device