JPH04241384A - Color led display device - Google Patents

Abstract

PURPOSE:To solve such problems that it is hard to lead out terminals since the terminals are too many in a static driving system so it comes to hard to constitute a driving circuit since a current value is large in a dynamic driving system, when driving the color LED display device on which light emitting diodes are arranged in the row and column direction. CONSTITUTION:Dot signals DS1-DS256 corresponding to the dots of a color LED display unit are provided and chrominance signal lines R, G, and B corresponding to light emission colors are provided; and light emission diodes which emit light of the same colors are driven at a time while a period is divided by the light emission colors.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a color LED display device in which dots are arranged in both row and column directions, and each dot is composed of a plurality of light emitting diodes that emit light of a different color. Regarding.

0002

2. Description of the Related Art One of the methods conventionally adopted for driving a matrix type color LED display unit in which each dot is composed of two light emitting diodes that emit red and green lights respectively is as follows. As shown in FIG. 4, the anodes of all the light emitting diodes 91 are connected to the positive power supply P91, and the cathodes are connected to the data driver 92, thereby making each light emitting diode 91 statically emit light. be.

A second method, as shown in FIG. 5, is to provide a scan drive unit 93 having a line output L91 corresponding to the number of lines of dots, and also provide a scan drive unit 93 corresponding to each color of red and green. The data driving units 94 and 95 output column outputs L92 and L93 corresponding to the number of columns, and the row output L91
This is a method of dynamically causing the light emitting diodes 96 to emit light by connecting the light emitting diodes 96 to each of the intersections of the column outputs L92 and L93.

0004

[Problem to be Solved by the Invention] Currently, there is a color LED in which 16 dots are arranged in both row and column directions, and each dot is composed of light emitting diodes that emit red, green, and blue colors. When trying to drive a display unit, if you try to adopt the first method, color LED
The number of terminals of the display unit is 769, which is extremely large, so when the color LED display unit is miniaturized, it is difficult to draw out all the terminals to the outside.

[0005] When the second method is adopted, the drive system is dynamic, so the instantaneous current flowing is large, but the blue light emission requires a large current to flow because the brightness is low. When driving the diodes, the current value of the row output is about several tens of amperes, so there has been a problem that the configuration of the scan driving section 93 is difficult.

The present invention was created to solve the above problems, and its purpose is to provide a color LED display that can prevent an increase in the flowing current without increasing the number of terminals of the color LED display unit. The goal is to provide equipment.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a color LED display device according to the present invention provides a color LED display device in which when a plurality of light emitting diodes that emit light of different colors are used as a light emitting diode group, Each of the dots arranged in both directions is composed of a group of light emitting diodes, and the dot signal line provided corresponding to each dot has a
The first terminals of all the light emitting diodes of the light emitting diode group constituting the dot corresponding to this dot signal line are connected, and the color signal line provided corresponding to each color of light emitted from the light emitting diode is A color LED to which the second terminals of all light emitting diodes emitting the corresponding color are connected.
The display unit is connected to a color signal line, and a color signal scanning unit that sequentially sends scanning signals to this color signal line is connected to a dot signal line, which corresponds to the color signal line scanned by the color signal scanning unit. and a data drive unit that sends dot data to the dot signal line, and when the first terminal is used as an anode, the second terminal is used as a cathode, and when the first terminal is used as a cathode, the second terminal is used as a cathode. is used as an anode, and the scanning time of the color signal line is made to correspond to the brightness of the light emitting diode.

[0008]

Embodiment FIG. 2 is a partial schematic diagram showing the appearance of a color LED display unit according to an embodiment of the present invention.

In the figure, a color LED display unit 1
1 is a unit main body 111 and this unit main body 111
16 in the row direction (indicated by arrow A) on the display side of the
In the column direction (indicated by arrow B) there are 16 256 dots (
All dots are indicated by a symbol 112, and if it is necessary to specify one dot among these dots, an alphabet is added to the end of the symbol 112). A light emitting diode element 113 is attached to each dot 112, and a light emitting diode group consisting of three light emitting diodes that emit red, green, and blue colors is incorporated in the light emitting diode element 113. It is.

FIG. 1 is a block diagram showing the electrical configuration of an embodiment of the present invention.

[0011] DR1, DG1, GB1 are dots 112
These are three light emitting diodes provided in the light emitting diode element 113 corresponding to a, and the light emitting diode group GR1
Configure. Also, DR2, DG2, and GB2 are dot 1
These are three light emitting diodes provided in the light emitting diode element 113 corresponding to 12b, and the light emitting diode group G
Configure R2. Similarly, a light emitting diode group consisting of three light emitting diodes is provided corresponding to each dot 112. and light emitting diodes DR1, DR2
...DR256 is a light emitting diode that emits red light, DG1, DG2...DG256 is a light emitting diode that emits green light, DB1, DB2...DB25
6 is a light emitting diode that emits blue light.

The dot signal line DS1 provided corresponding to the dot 112a has three light emitting diodes DR1, D
The cathode, which is the first terminal of G1 DB1, is connected. Further, the dot signal line DS2 provided corresponding to the dot 112b has three light emitting diodes DR2, D
The cathode, which is the first terminal of G2 DB2, is connected. Similarly, dot signal lines DS3...DS256 (DS3...
- DS255 is not shown) has three corresponding light emitting diodes DR3...DR256, DG3
...DR256, DR3...DR256 (DR3・
...DR255, DG3...DR255, DR3...
- The cathode of DR255 (not shown) is connected.

[0013] Also, a color signal line R provided corresponding to red
has 256 light emitting diodes DR1, DR2...
The anode of DR256 is connected to the color signal line G provided corresponding to green, and the anodes of 256 light emitting diodes DG1, DG2...DG256 are connected to the color signal line G provided corresponding to blue. Color signal line B has 256
The anodes of the light emitting diodes DB1, DB2...DB256 are connected.

The color signal lines R, G, B are connected to the color signal scanning section 12, and the dot signal lines DS1, DS2...D
S256 is connected to the data driver 13. Further, a scanning signal CSG indicating scanning timing is guided to the color signal scanning section 12, and a data signal DIN indicating driving data is guided to the data driving section 13, and a data signal DOUT indicating driving data is guided to the data driving section 13. It is being sent to the outside.

In the above configuration, the color signal scanning section 12 has the following functions:
The data drive section 13 is composed of a decoder that decodes the scanning signal CSG, and a switching transistor that switches current according to the output of this decoder. A configuration consisting of a 256-bit shift register for converting serial data that appears into parallel data, a latch circuit that latches the parallel output converted by this shift register, and a switching transistor that performs switching according to the output of this latch circuit. It becomes. Further, the data signal DOUT is a serial output of the shift register.

FIG. 3 is a timing chart showing the signals of the main parts. Referring to the same figure as necessary,
The operation of one embodiment of the present invention will be described below.

Scanning signal CS guided to color signal scanning section 12
G is a 2-bit signal that indicates a value of 0 to 3, and during periods t1 and t4 when the value is 0 (indicated by 51 and 55), a current is supplied to the color signal line R. be done. Further, a current is supplied to the color signal line G during a period t2 when the value of the scanning signal CSG is 1 (indicated by 52). Then, during the period t3 when the value of the scanning signal CSG is 2 (indicated by 53) and 3 (indicated by 54), the color signal line B
Current is supplied to The periods t1, t2, and t4 are equal, and the period t3 is twice as long as the period t1.

That is, during the periods t1 and t4, current is supplied to the anodes of the light emitting diodes DR1, DR2, . DG1,D
G2...A current is supplied to the anode of DG256 (
62). During period t3, which is twice as long as these periods, the light-emitting diode DB emits blue light, which requires a large average current value because the brightness is low.
1, DB2...A current is supplied to the anode of DB256 (indicated by 63).

Further, during the period t1, display data for the green light emitting diodes DG1, DG2, . . . DG256 is transmitted as a 256-bit serial signal to the data signal DI.
N is given to the data driver 13 (by 71,
(shown as data at time of display). Also, during the period t2, display data for the blue light emitting diodes DB1, DB2, .
Display data for R2...DR256 (indicated by 73 as data at the time of display) is provided to the data driver 13 in a similar manner.

[0020] Therefore, during periods t1 and t4, display is performed by red light emitting diodes DR1, DR2, . , during the period t2, the green light emitting diodes DG1, DG2...DG256 display the display, and during the period t3, the blue light emitting diode DB1,
DB2...Display by DB256 will be performed.

The above operation is an explanation of the operation when only one color LED display unit 11 is used.
When more than one color LED display unit 11 is used, a color signal scanning section and a data driving section are provided for each color LED display unit. The scanning signal CSG is also common. Regarding the data driver, the data signal DOUT from the data driver corresponding to the color LED display unit in the previous stage is converted into the data signal DI.
Make a series connection to be introduced as N. Also each color LE
Since 256 bits of data are required for each D display unit, display data of the number of bits obtained by multiplying the color LED display unit by 256 is transferred during each period t1 to t4.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the case where the first terminal is the cathode and the second terminal is the anode has been described, but the first terminal is the anode and the second terminal is the anode.
A configuration in which the terminal of is used as a cathode is also possible, and in this case, current is supplied from the data driver and flows into the color signal scanning section.

Regarding the number of dots of the color LED display unit 11, a configuration in which 16 dots are arranged in each of the row and column directions has been described.
Other configurations include, for example, a configuration in which 128 dots are arranged in the row direction and 32 dots in the column direction.

Further, although the case where the light emitting diode group is constituted by three light emitting diodes has been described, it is possible to have a configuration including other numbers of light emitting diodes, for example, a configuration including two light emitting diodes.

[0025]

[Effects of the Invention] The color LED display device according to the present invention has the following features:
Each of the dots arranged in the row direction and the column direction is constituted by a light emitting diode group consisting of a plurality of light emitting diodes, and the dot signal line corresponding to the dot has the first signal line of all the light emitting diodes constituting the dot. The color signal lines that connect the terminals and correspond to the respective colors of emitted light are
The second terminals of all the light emitting diodes that emit the corresponding color are connected, and the color signal scanning section to which the color signal line is connected and the data driving section to which the dot signal line is connected are used to control the light emission of the light emitting diodes. Since this control is performed, it is possible to prevent an increase in the flowing current without causing an increase in the number of terminals.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of an embodiment of the present invention.

FIG. 2 is a partial schematic diagram showing the appearance of a color LED display unit according to an embodiment of the present invention.

FIG. 3 is a timing chart showing the state of signals in main parts.

FIG. 4 is a circuit diagram showing an electrical configuration of a conventional technique.

FIG. 5 is a circuit diagram showing the electrical configuration of the prior art.

[Explanation of symbols]

11 Color LED display unit GR1, GR2...GR256 Light emitting diode group DR1, DR2...DR256 Light emitting diode DG1, DG2...DG256
Light emitting diode DB1, DB2...DB256
Light emitting diodes R, G, B Color signal lines DS1, DS2...DS256 Dot signal line 12 Color signal scanning section 13 Data driving section

Claims (1)

[Claims] 1. When a set of a plurality of light emitting diodes emitting light of different colors constitutes a light emitting diode group, each of the dots arranged in both the row direction and the column direction is constituted by the light emitting diode group, The first terminals of all the light emitting diodes of the light emitting diode group constituting the dot corresponding to this dot signal line are connected to the dot signal line provided corresponding to each of the dots, and the light emission of the light emitting diode is The color signal line provided corresponding to each color is connected to a color LED display unit to which second terminals of all light emitting diodes that emit light of the corresponding color are connected, and the color signal line is connected to the color signal line provided corresponding to each color. The dot signal line is connected to a color signal scanning unit that sequentially sends scanning signals to the color signal line, and the dot data corresponding to the color signal line scanned by the color signal scanning unit is transferred to the dot signal line. when the first terminal is an anode, the second terminal is a cathode; when the first terminal is a cathode, the second terminal is an anode; A color LED characterized in that the scanning time of the color LED corresponds to the brightness of the light emitting diode.
Display device.