JP2003345309A - Led driving system and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED driving system and its control method in which a color tone is maintained constant while luminance is controlled even though there exists dispersion in luminance and color tone for every LED. <P>SOLUTION: The LED driving system is provided with an LED unit in which a first LED and a second LED are arranged for every pixel and a data supplying section which supplies gray scale data, that are used to determine the light emitting interval of each LED, to every LED. Moreover, the system is provided with a gray scale data converting section. The section has a first gray scale data converting means which converts gray scale data related to the color to be originally light emitted by the first LED to the gray scale data for the first LED and the gray scale data for the second LED and a second gray scale data converting means which converts the gray scale data related to the color to be originally light emitted by the second LED to the gray scale data for the second LED and the gray scale data for the first LED. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED unit having a plurality of LEDs capable of emitting different colors, and the LED unit.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED drive system having a data supply unit that supplies gradation data for determining at least a light emission period of each LED arranged in a unit and a control method thereof, and particularly to variations in light emission characteristics of each LED. Accordingly, the present invention relates to an LED drive system and a control method thereof that can collectively perform luminance correction and color tone correction.

[0002]

2. Description of the Related Art Today, with the development of high-luminance light-emitting elements such as LEDs (hereinafter, also referred to as "light emitting diodes") for RGB (red, green, blue), respectively, Large self-luminous full-color displays are being produced. Above all,
A full-color display using an LED as a light-emitting element has features such as light weight, thinness, and low power consumption. Demand is rapidly increasing as a large display that can be used not only indoors but also outdoors.

For example, in the case of a large display installed outdoors, one display is generally constructed by combining a plurality of LED units. That is, the LED unit has, for example, R on the substrate.
LEDs each including a set of GBs are arranged for each pixel, and each LED unit displays an image assigned to each LED unit. In a full color display using LEDs as light emitting elements, each pixel is generally composed of a combination of three or more types of LEDs capable of emitting RGB light.

A dynamic drive system is usually used as a drive system for the LED unit. For example, as shown in FIG. 6, pixels L are arranged in m rows and n columns.
In the case of an ED display, the anode terminals of the LEDs 20 located in each row are commonly connected to one common line 21, and the cathode terminals of the LEDs 20 located in each column are commonly connected to one current line 22. Thus m
The common line 21 with rows is sequentially turned on at a predetermined cycle, and
A drive current is supplied to the current lines 22 in n columns according to the data corresponding to the N common lines. As a result, a drive current corresponding to the data is applied to the LED 20 of each pixel (corresponding to the arrow in the figure), and an image is displayed.

In order to accurately reproduce the data on the LED display, it is necessary that the light emitting characteristics (luminance and color tone) of each LED be uniform.
This is because if the light emission characteristics are not uniform, even if the LEDs are made to emit light under the same conditions, the light emission characteristics vary from LED to LED, and it is not possible to obtain a desired color by utilizing a single color or mixed colors. However, LEDs are formed on a wafer by semiconductor technology, and variations in brightness and color tone occur depending on the manufacturing lot, wafer, or chip. For this reason, it is necessary to arbitrarily adjust the driving conditions in accordance with the variation in the light emission characteristics of the LEDs that form each pixel.

For example, the conventional correction of variation in luminance (hereinafter, also referred to as "luminance correction") has been performed by increasing or decreasing the drive current according to the variation in luminance of each LED. In other words, by adjusting the magnitude of the drive current supplied to each LED, different LEs with variations in brightness can be obtained.
Even if it was D, it was corrected so that the same brightness could be obtained.

Further, the conventional correction of color tone variations (hereinafter, also referred to as “color tone correction”) uses, for example, LEDs of other colors in accordance with the color tone variations of each LED and a correction drive current. It was realized by turning on the light. Specifically, depending on the color tone variation of each LED, an LED that mainly emits light and a correction L that corrects the light emission by the LED
Driving currents of different magnitudes were applied to the ED. As a result, the same color tone as a whole can be obtained even with different LEDs having different color tones.

[0008]

However, in the conventional brightness correction or color tone correction, it was very difficult to accurately reproduce the input information on the LED unit.

That is, in the conventional luminance correction, the luminance can be corrected but the color tone cannot be corrected. Specifically, since the color tone of the LED changes depending on the magnitude of the drive current, the brightness can be controlled by adjusting the magnitude of the drive current, but the color tone is completely controlled. There was a problem that it was difficult.

In the conventional color tone correction, the LED
The mainstream method is not to correct the variation in color tone but to emphasize the color reproducibility of the LED display. In addition, due to the characteristics of the LED, it is impossible to perform accurate color tone correction due to the change in the emission color of the LED itself by performing the brightness correction using the current.

The present invention has been made in view of such a problem, and by performing the brightness correction and the color correction at the same time regardless of the variation in the brightness and the color of each LED,
It is an object of the present invention to provide an LED drive system and a control method thereof that can control the brightness while keeping the color tone constant.

[0012]

The LED drive system of the present invention is an LED unit in which at least a first LED emitting a first color and a second LED emitting a second color are arranged in each pixel. And the first L connected to the LED unit
At least each LED for each of the ED and the second LED
And a data supply unit that supplies grayscale data that determines the light emitting period of. In particular, this LED drive system further has a gradation data conversion unit connected to the LED unit and the data supply unit, and the gradation data conversion unit emits light by the originally first LED supplied from the data supply unit. Gradation data relating to a color to be reproduced, gradation data for the first LED, and a second data for correcting light emission from the first LED.
First gradation data converting means for converting into the gradation data for the LED, and gradation data regarding a color which should be originally emitted by the second LED, which is supplied from the data supply unit, as gradation data for the second LED. It is characterized in that at least one of the second gradation data conversion means for converting the gradation data for the first LED for correcting the light emission by the second LED is provided. Thereby, the correction of the brightness and the color tone can be collectively performed with a simple configuration.

Further, the LED driving system of the present invention may have a gradation data conversion unit and a gradation data addition unit connected to the LED unit. The gradation data addition unit includes a gradation data conversion unit that includes both first gradation data conversion means and second gradation data conversion means, and gradation data regarding a color that should be originally emitted by the first LED. When the colors are mixed for each pixel by using the light emission based on the gradation data regarding the color that should be originally emitted by the second LED,
First LED converted by the first gradation data conversion means
And the gradation data for the first LED converted by the second gradation data conversion means to obtain one gradation data, and a first gradation data addition means,
Second LED converted by the first gradation data conversion means
And the gradation data for the second LED converted by the second gradation data conversion means are added to obtain 1
It is characterized in that at least one of the second gradation data addition means for making one gradation data is provided. As a result, the structure of the LED drive system can be further simplified and the control of the gradation data can be facilitated.

Further, the LED driving system of the present invention includes at least a first LED that emits a first color, a second LED that emits a second color, and a third LE that emits a third color.
LED unit in which D is arranged for each pixel, first LED, second LED, and third LE connected to the LED unit
A data supply unit that supplies at least gradation data for determining the light emission period of each LED to each of the D.
In particular, this LED drive system further has a gradation data conversion unit connected to the LED unit and the data supply unit, and the gradation data conversion unit is originally the first LED supplied from the data supply unit. Grayscale data for a color to be emitted, grayscale data for a first LED, grayscale data for a second LED for correcting light emission by the first LED, and grayscale data for correcting light emission by the first LED. First gradation data conversion means for converting into the gradation data for the LED No. 3 and gradation data for the color to be emitted by the second LED originally from the data supply unit, the gradation data for the second LED. And gradation data for the first LED for correcting the light emission by the second LED and a third LE for correcting the light emission by the second LED
Second gradation data conversion means for converting the gradation data for D and originally the third LED supplied from the data supply unit
Grayscale data about the color to be emitted by the third LED
Data for the first LED and the gray data for the first LED for correcting the light emission by the third LED
It is characterized by comprising at least one means of third gradation data conversion means for converting the gradation data for the second LED for correcting the light emission by D. As a result, it is possible to obtain the same effects as the LED drive system according to the first aspect.

Further, the LED driving system of the present invention can have a gradation data conversion unit and a gradation data addition unit connected to the previous LED unit. In this gradation data addition unit, the gradation data conversion unit includes a first gradation data conversion unit, a second gradation data conversion unit, and a third gradation data conversion unit, and is originally a first LED. Light emission based on gradation data regarding colors to be emitted and originally the second LE
When at least two of the light emission based on the gradation data regarding the color to be emitted in D and the light emission based on the gradation data regarding the color to be originally emitted by the third LED are used to mix colors for each pixel, The gradation data for the first LED converted by the gradation data converting means, the gradation data for the first LED converted by the second gradation data converting means, and the third gradation data converting means. And the second LED converted by the first gradation data conversion means, the first gradation data addition means for adding the converted gradation data for the first LED into one gradation data. And the gradation data for the second LED converted by the second gradation data conversion means and the gradation data for the second LED converted by the third gradation data conversion means are added. Then one floor A second tone data adding means for the data, a third converted by the first gradation data conversion unit
Gradation data for the LED, the gradation data for the third LED converted by the second gradation data conversion means, and the gradation data for the third LED converted by the third gradation data conversion means Is added to obtain one gradation data, at least one of the third gradation data adding means is provided. This makes it possible to obtain the same effects as the LED drive system according to the second aspect.

In the light emission of each LED based on the gradation data for each LED added by each gradation data adding means, the light emitting period of the other LED is included in the light emitting period of the LED having the longest light emitting period. It is characterized by being As a result, it is possible to significantly reduce color flicker due to a shift in the light emitting period of each LED.

Further, each gradation data conversion means converts the gradation data input to itself into gradation data for a predetermined LED and gradation data for the LED for correcting light emission by the predetermined LED, The gradation data input to itself is used as a common input, and a new function is applied to each LED based on a predetermined function corresponding to the input and the first LED, the second LED, and the third LED. It is characterized by outputting various gradation data. As a result, the grayscale data input to itself can be efficiently converted into new grayscale data.

Further, the predetermined function is non-linear. As a result, other corrections such as gamma correction can be performed collectively.

The first LED, the second LED and the third LED are red LEDs that emit red light, respectively.
Green LED that emits green light and blue L that emits blue light
It is characterized by being ED. As a result, an LED driving system capable of full-color light emission can be obtained.

The control method of the LED drive system according to the present invention includes a red LED which emits red light, a green LED which emits green light, and a blue LED which emits blue light, which are arranged for each pixel on the LED unit. This is a control method in which gradation data that determines the light emitting period of the LEDs is supplied and each LED is caused to emit light based on the gradation data. Especially, the control method of this LED drive system is
The gradation data for the red LED which mainly emits the gradation data regarding the red color to be emitted by the ED, the gradation data for the green LED for correcting the light emission by the red LED, and the blue data for correcting the light emission by the red LED First gradation data conversion step of converting into gradation data, gradation data for a green LED which mainly emits gradation data regarding green which should originally be emitted by the green LED, and blue for correcting light emission by the green LED The second gradation data conversion step of converting the gradation data for the LED and the gradation data for the red LED to correct the light emission by the green LED, and the gradation data for blue, which should be originally emitted by the blue LED, are mainly emitted. Grayscale data for the blue LED and the red LED for correcting the light emission by the blue LED Characterized in that it comprises at least one of the steps of the third gradation data conversion step of converting the gradation data for the green LED for correcting the light emission by the gradation data and the blue LED. Thereby, the correction of the brightness and the color tone can be collectively performed with a simple configuration.

Further, the control method of the LED driving system of the present invention comprises a first gradation data conversion step, a second gradation data conversion step and a third gradation data conversion step, and a gradation for red color. When color mixing is performed for each pixel using at least two of the light emission based on the data, the light emission based on the grayscale data regarding green, and the light emission based on the grayscale data regarding blue, the first grayscale data conversion step is performed. The grayscale data for the red LED, the grayscale data for the red LED converted in the second grayscale data conversion step, and the grayscale data for the red LED converted in the third grayscale data conversion step are added. And a second gradation data conversion process for the green LED converted in the first gradation data conversion process Second gradation data addition step of adding the gradation data for the green LED converted in step 3 and the gradation data for the green LED converted in the third step to the single gradation data And gradation data for the blue LED converted in the first gradation data conversion step, gradation data for the blue LED converted in the second gradation data conversion step, and third gradation data conversion It is characterized by including at least one of the third gradation data addition steps of adding the gradation data for the blue LED converted in the step to obtain one gradation data. This makes it possible to further simplify the configuration of the control method and facilitate control of the gradation data.

Further, the red LE based on the gradation data for the red LED added in the first gradation data adding step
D emission and green LED emission based on the gradation data for the green LED added in the second gradation data addition step and blue LED addition in the third gradation data addition step
In the light emission of the blue LED based on the grayscale data for the
It is characterized in that it is controlled so as to include the light emission period of the ED. As a result, it is possible to significantly reduce color flicker due to a shift in the light emitting period of each LED.

Further, in each gradation data conversion step, the gradation data input to itself is corrected to L for correcting gradation data for a predetermined LED and light emission by the predetermined LED.
When converting to grayscale data for ED, the grayscale data input to itself is used as a common input, and the input and red LE
It is characterized in that new gradation data is output to each LED based on a predetermined function corresponding to each of the D, green LED and blue LED. As a result, the grayscale data input to itself can be efficiently converted into new grayscale data.

Further, the predetermined function is characterized by being non-linear. As a result, other corrections such as gamma correction can be performed collectively.

Further, a driving current larger than the driving current required to obtain a predetermined brightness is made to flow by using the respective gradation data regarding red, green and blue, and the emission characteristics of the red LED, the green LED or the blue LED are changed. Measure each,
It is characterized in that a predetermined function corresponding to each LED is determined based on the measurement result. This makes it possible to obtain a desired brightness without lengthening the gradation data more than necessary.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below are for embodying the technical idea of the present invention, and the present invention is not limited to the following. In addition, the size and positional relationship of the constituent parts shown in each drawing are exaggerated for clarity.

FIG. 1 shows an example of the configuration of an LED drive system according to the present invention. The LED drive system according to the present embodiment includes at least the first LED that emits the first color and the second LED that emits the first color.
The second LED which emits the color of the third and the third which emits the color of the third
LED unit 5 (hereinafter also referred to as “DU (Display Unit)”) in which each LED is arranged for each pixel, and gradation data that determines at least the light emission period of each LED connected to the LED unit 5 A data supply unit 2 (hereinafter, also referred to as “TA (Terminal Adapter)”) to be supplied, an LED unit 5 and a gradation data conversion unit 3 connected to the data supply unit 2 are provided. Here, the first
Red LED that emits red light as the second LED, the second LE
An example will be described in which a green LED that emits green light is used as D, a blue LED that emits blue light is used as the third LED, and each pixel is composed of RGB (red, green, blue) LEDs.

As shown in FIG. 1, the LED of the present embodiment
The drive system includes a data control unit 1 (hereinafter, "CU (Cont
rol Unit) "is also called). The data control unit 1
Control data and gradation data for driving the LEDs input from the outside are supplied to each LED via the data supply unit 2.
It is supplied to the unit 2. In the present specification, the control data is various data for controlling and driving each LED, for example, vertical synchronization data indicating the start and end of one image frame (hereinafter, also referred to as “VSYNC”), Horizontal synchronization data indicating the line breaks (hereinafter,
"HSYNC"), a gradation reference clock (hereinafter also referred to as "GCLOCK") indicating a gradation reference, etc., and the gradation data is each LE based on the gradation reference clock.
It is data for determining the light emission period of D.

Further, the LED drive system of the present embodiment is provided with the gradation data addition section 4 as will be described later, and the gradation data addition section 4 has the gradation data conversion sections 3 and L.
It is connected to the ED unit 5. That is, the LED drive system according to the present embodiment includes the data control unit 1, the data supply unit 2, the gradation data conversion unit 3, the gradation data addition unit 4,
The LED units 5 are sequentially connected. Here, the LED drive system according to the present embodiment includes the data supply unit 2
Includes a gradation data conversion unit 3 and a gradation data addition unit 4.

As shown in FIG. 1, the LED of the present embodiment
In the drive system, a plurality of data supply units 2 are connected to the data control unit 1 via a communication line L2, and a plurality of LED units 1 are connected to each data supply unit 2 via a communication line L1. That is, in this embodiment, the TA serving as the data supply unit 2 has a function as a distributor that distributes the data input from the CU serving as the data control unit 1 to each of the plurality of DUs connected to itself. With this structure, a larger display 10 can be formed. Further, in FIG. 1, in order to simplify the description, the data control unit 1 is a CU and the data supply unit 2 is
Is represented by TA, and the LED unit 5 is represented by DU. Here, in order to perform smoother communication, it is preferable that the communication on the communication line L2 is performed at a higher speed than the communication on the communication line L1.

On the other hand, reference numeral 10 denotes the entire display for displaying based on the control data and the gradation data, and the display 10 is divided into a plurality of TA blocks 11. That is, one TA is arranged in each TA block 11, and TA1 to TA in this embodiment.
The display 10 is composed of 24 TA blocks 11 in which 24 are arranged. Furthermore, each TA block 11 is composed of a plurality of DUs, and in this embodiment, each TA block 11 has 12 DUs (DU1 to DU).
12). That is, in this embodiment, the display 10 is composed of 24 × 12 288 DUs in total.

Here, in the LED driving system and the control method thereof according to the present invention, a plurality of gradation data which should originally correspond to an LED of one color are generated in the gradation data converting section 3 or the gradation data converting step described later. It is characterized in that it is converted into gradation data for the LED. When converting the gradation data that should originally correspond to the LED of one color into the gradation data for the LEDs of a plurality of colors and driving the corresponding LEDs based on this new gradation data, The magnitude of the drive current supplied to the LEDs is always equal at least for each color LED. That is, the brightness is determined by the magnitude of the drive current and the length of the light emission period, but in the present invention, the drive supplied to the LED corresponding to each new grayscale data converted by the grayscale data conversion unit 3. It is characterized in that the magnitude of the current is kept constant and the overall brightness is arbitrarily controlled by the new gradation data converted by the gradation data converter 3. In other words, by adjusting the light emitting period of each LED according to the gradation data without changing the magnitude of the drive current, it is possible to arbitrarily adjust the brightness while keeping the color tone constant. It should be noted that the magnitude of each drive current supplied to the LED of each color may be determined in consideration of the target predetermined color (for example, white).

It should be noted that in the present specification, "the LE which originally has one color"
The "gradation data that should correspond to D" refers to "gradation data that has not been substantially satisfactorily subjected to the luminance correction and the color correction in consideration of the light emission characteristics of the LED". That is,
In the present invention, even when at least one of the luminance correction and the color tone correction is performed by a known method, if it is necessary to substantially further correct the tone data, the gradation data is replaced with another new one. It is possible to perform more excellent brightness correction and color tone correction by converting the gradation data.

The flow of control data and gradation data will be described in more detail below with reference to FIGS. First, for example, control data is input to a data control unit 1 from a computer such as a PC, and gradation data is input to a data control unit 1 from a video reproducing device such as a video player. Here, in the present specification, as shown in FIGS. 2 and 3, the gradation data regarding the red color which should be originally emitted by the red LED is “r”, and the gradation data regarding the green color which is originally caused by the green LED is “g”. The grayscale data regarding the blue color that should be originally emitted by the blue LED is expressed as “b”. That is, the gradation data r, g, and b mean the gradation data of each color that is not directly corrected and is directly input from the CU to the TA.

On the other hand, as described above, the LED drive system of the present embodiment has the data control unit 1, the data supply unit 2, the gradation data conversion unit 3, the gradation data addition unit 4, and the LED.
The units 5 are sequentially connected. FIG. 2 is a block diagram showing the LED drive system of the present embodiment, focusing on the gradation data conversion unit 3. As shown in FIG. 2, in the present embodiment, the gradation data conversion unit 3 includes a first gradation data conversion unit 3r, a second gradation data conversion unit 3g, and a third gradation data conversion unit 3b. Prepare

That is, the first gradation data conversion means 3r
The grayscale data r input to is “Rr”, “Gr”, “B
r ”is converted into gradation data. Here, Rr is gradation data for the red LED, and Gr is green L for correcting light emission of the red LED based on Rr.
Gradation data for ED, Br is red L based on Rr
Refers to the gradation data for the blue LED for correcting the light emission of the ED. Similarly, the gradation data g input to the second gradation data conversion means 3g is “Gg”, “Bg”, “R”.
g ”is converted into grayscale data. Here, Gg is the gradation data for the green LED, and Gb is the blue L for correcting the emission of the green LED based on Gg.
Gradation data for ED, Gr is green L based on Gg
It refers to the gradation data for the red LED for correcting the light emission of the ED. Similarly, the gradation data b input to the third gradation data conversion means 3b is "Bb", "Rb", "G".
b ”is converted into grayscale data. Here, Bb is gradation data for the blue LED, and Rb is red L for correcting the light emission of the blue LED based on Bb.
Grayscale data for ED, Gb is blue L based on Bb
It indicates the gradation data for the green LED for correcting the light emission of the ED.

In the present invention, the LED of originally one color is used.
The step of converting the gradation data that should correspond to the gradation data into gradation data for a plurality of LEDs is called a gradation data conversion step. Specifically, the gradation data conversion step in the control method of the LED driving system according to the present embodiment includes a first gradation data conversion step, a second gradation data conversion step, and a third gradation data conversion step. Including. That is, in the first gradation data conversion step, the gradation data r is the above-mentioned “Rr”, “Gr”,
Each is converted into gradation data represented by “Br”.
Similarly, in the second gradation data conversion step, the gradation data g is converted into the gradation data represented by "Gg", "Bg", and "Rg", respectively, and the third gradation data conversion step is performed. Then, the gradation data b is the above-mentioned “Bb”, “Rb”, “G”.
b ”is converted into grayscale data.

Further, when the gradation data r, g, b are respectively converted by the gradation data converter 3, the input gradation data r, g, b and the predetermined gradation data preliminarily provided in itself. Grayscale data for each LED is output based on the function. That is, a predetermined function is stored in advance in the gradation data conversion unit 3, and the output that becomes new gradation data is determined by associating the function with the input of the gradation data. This matter will be described in more detail below.

FIG. 4 shows the gradation data conversion unit 3 of this embodiment.
2 is a schematic drawing for explaining in more detail. As shown in FIG. 4, in the present embodiment, the gradation data conversion unit 3
Includes a first gradation data conversion unit 3r, a second gradation data conversion unit 3g, and a third gradation data conversion unit 3b, each of which has a red LED and a green LED,
A total of three functions corresponding to each blue LED are stored. That is, the function 3r (R) corresponding to the red LED and the function 3r corresponding to the green LED having the grayscale data r as a common input to the first grayscale data conversion means 3r.
(G), the function 3r (B) corresponding to the blue LED is stored in advance. Similarly, the second gradation data conversion means 3g
Is the function 3g (R) corresponding to the red LED and the function 3g corresponding to the green LED with the grayscale data g as a common input.
(G), the function 3g (B) corresponding to the blue LED is stored in advance, and the function 3b ((b) corresponding to the red LED having the grayscale data b as a common input is stored in the third grayscale data conversion unit 3b. R), the function 3b (G) corresponding to the green LED, and the function 3b (B) corresponding to the blue LED are stored in advance. In each function shown in FIG. 4, the horizontal axis represents gradation data r, g, b.
(Corresponding to “IN” in the figure) and the vertical axis corresponds to output of gradation data for each LED (corresponding to “OUT” in the figure).

Here, paying attention to the first gradation data conversion means 3r, the gradation data r for red is commonly input to each of the functions 3r (R), 3r (G), 3r (B) provided in itself. Then, new gradation data is output by each function. That is, the function 3r (R) outputs new gradation data Rr for the red LED based on the gradation data r input to itself. Similarly, the function 3r (G) outputs new grayscale data Gr for the green LED based on the grayscale data r input to itself, and the function 3r (B) is the grayscale data r input to itself. Based on this, new gradation data Br for the blue LED is output.

Next, paying attention to the second gradation data converting means 3g, the gradation data r relating to green color is common to each of the functions 3g (R), 3g (G), 3g (B) provided in itself. It is input, and new gradation data is output by each function. That is, the function 3g (R) outputs new grayscale data Rg for the red LED based on the grayscale data g input to itself. Similarly, the function 3g (G) outputs new grayscale data Gg for the green LED based on the grayscale data g input to itself, and the function 3g (B) is the grayscale data g input to itself. Based on this, new gradation data Bg for the blue LED is output.

Next, paying attention to the third gradation data converting means 3b, the gradation data b relating to blue color is common to each of the functions 3b (R), 3b (G) and 3b (B) provided in itself. It is input, and new gradation data is output by each function. That is, the function 3b (R) outputs new grayscale data Rb for the red LED based on the grayscale data b input to itself. Similarly, the function 3b (G) outputs new grayscale data Gb for the green LED based on the grayscale data b input to itself, and the function 3b (B) is the grayscale data b input to itself. Based on this, new gradation data Bb for the blue LED is output.

In this embodiment, each function is made non-linear in consideration of gamma correction and the like. With such a configuration, it is possible to perform not only the brightness correction and the color tone correction but also the gamma correction by changing only the gradation data. Further, in the present embodiment, each function is non-linear,
It is also possible to make each function linear, that is, a linear function.

Next, a method of obtaining each function stored in advance in the gradation data conversion unit 3 will be described. An object of the present invention is to use gradation data to arbitrarily change the luminance while keeping the color tone constant. Here, paying attention to the gradation data r relating to red, the gradation data r
Is converted into grayscale data Rr, Gr, Br for each LED, so that the functions 3r (R) and 3r that can arbitrarily change the luminance while keeping the color tone constant.
A method of determining (G) and 3r (B) will be described as an example.

First, it is assumed that the target red color tone / luminance is "(xo, yo), Yo", and the CIE tristimulus values are converted into "Xo, Yo, Zo". The target red CIE tristimulus values “Xo, Yo, Z
"o" varies depending on the gradation data. This is because if the color tone is constant (the height of the drive current is constant) and the luminance is changed by the gradation data r, “Xo, Yo, Zo” respectively change. Here, red LED, green L
LE is the magnitude of the drive current supplied to the ED and blue LED
The change of the CIE tristimulus value in one gradation of the red LED to be corrected is set to be constant for each D, and the change is expressed as “ΔXR, ΔYR, Δ
ZR ”, a change in the CIE tristimulus value at one gradation of the green LED is“ ΔXG, ΔYG, ΔZG ”, and a change in the CIE tristimulus value at one gradation of the blue LED is“ ΔXB, ΔYB,
Assuming ΔZB ”, the gradation data to be output to the red LED is“ Rr ”, the gradation data to be output to the green LED is“ Gr ”, and the gradation data to be output to the blue LED is“ Rr ”. Gr ”(Rr, Gr, Br correspond to FIG. 4), the target red CIE tristimulus value“ X ”
o, Yo, Zo "

It can be represented by [Formula 1].

[0046]

[Formula 1]

[Equation 1] is expressed in matrix form

[Equation 2]

[0047]

[Formula 2] What is needed here is the output grayscale data Rr, G
Since they are r and Br, multiplying them by the inverse matrix

[Equation 3]

[0048]

[Formula 3] The gradation data Rr, Gr, Br obtained in this way
Can be focused on the target red CIE tristimulus values “X ₀ , Y ₀ , Z ₀ ” by outputting to each corresponding LED. That is, here, in the same space, C
Since the IE tristimulus values are present, not only chromaticity correction but also brightness correction can be performed collectively.

More specifically, in the first stage, ΔX
R, ΔYR, ΔZR, ΔXG, ΔYG, ΔZG, ΔX
When calculating B, ΔYB, and ΔZB respectively, that is, when measuring “Xo, Yo, Zo” for each gradation data r with a constant color tone, the gradation data r becomes an input, and “Xo, Yo, Zo” for that input Is the target CIE tristimulus value. And the output for each of the red LED, the green LED and the blue LED necessary to realize the CIE tristimulus value is

It is obtained by [Equation 3]. That is, the gradation data r when measuring “Xo, Yo, Zo” for each gradation data r is input and Rr, Gr,
By using Br as the output for each LED and plotting each output, the functions 3r (R), 3r (G), 3r
(B) can be obtained. Note that here, focusing on the gradation data r, the functions 3r (R), 3r (G), 3r
(B) is explained, but the functions 3g (R), 3g
(G), 3g (B), 3b (R), 3b (G), 3b
The same can be obtained for (B). When measuring the target color "Xo, Yo, Zo", it can be arbitrarily performed for each pixel, each LED unit, or a unit larger than that. In addition, the “Xo, Yo, Zo” of the target color is measured, that is, the magnitude of the drive current passed through the LED of each color when obtaining the predetermined function and the LED of each color when actually driving the LED. By making the magnitude of the drive current to flow the same for each LED,
It can be driven without a change in color tone between the time of measurement and the time of driving. Specifically, for example, each of the red LED, the green LED, and the blue LED is measured, a predetermined function for each LED is determined based on the measurement result, and the driving current of the same magnitude as the driving current at the time of measurement is determined. The current can be used to actually drive each LED. Further, in the present invention, as will be described later, the magnitude of the current at the time of measurement can be determined in consideration of the target luminance range obtained by actually driving the LED. In addition, how many colors of LED to measure, and how many colors of LE based on the measurement
Whether the gradation data is converted to D can be arbitrarily set by the setter side.

Further, for example, when the red CIE tristimulus values "X _o , Y _o , Z _o " are measured, the red LED is originally used.
It is possible to measure the light emission characteristics of the red LED, the green LED, or the blue LED by applying a driving current larger than the driving current required to obtain a predetermined luminance by using the gradation data regarding the red color corresponding to. Good That is, the measurement can be performed in consideration of driving each LED by increasing the drive current. Below, the gradation data r,
The reason will be described by taking the light emission of the red LED based on g and b as an example.

In the present embodiment, paying attention to the gradation data for the red LED, the gradation data Rr, Rg, R for the red LED based on the gradation data r, g, b.
b is output. And the gradation data Rr, Rg, Rb
Is provided with a gradation data addition unit (gradation data addition step) as described later, one gradation data “Rr + R
“G + Rb” is output to the red LED. Here, the grayscale data “Rr + Rg + Rb” is once written in the corresponding memory and read out to read the red LE.
Although D emits light, it may be too large for the memory provided with the gradation data “Rr + Rg + Rb”.

That is, in order to obtain a desired image, the LED
It is necessary to shorten the repetition period of blinking and make the image appear to be constantly illuminated (fusion),
Because of this, it is not possible to obtain a certain brightness or more only by controlling the gradation data. If the light is turned on for a certain time or longer in order to obtain a certain brightness or more, the image may have flicker, and in the worst case, the brightness may be adversely decreased. Therefore, it becomes impossible to obtain the brightness required for lighting in consideration of the brightness correction and color tone correction of the present invention.

Therefore, in consideration of use with a large driving current in advance, the “large driving current” at the time of measurement is actually flowed to cause each LED to emit light, and thereby a shorter gradation is obtained without a change in color tone. It is possible to obtain a predetermined brightness with data, and it is possible to perform brightness correction and color tone correction without flicker of an image. It should be noted that the color tone naturally changes when a "large drive current" is applied, but since the measurement is performed by applying the same drive current, it is possible to obtain the desired brightness and color tone after correction. That is, the present invention is the magnitude of the drive current passed through each of the LEDs of each color when measuring the emission characteristics of the LED to determine the predetermined function,
By setting the magnitude of the drive current to be applied to the LEDs of each color when the LEDs are actually driven to be constant for each of the LEDs of each color, it is possible to drive the LEDs without any change in color tone between measurement and driving. Therefore, in the present invention, the magnitude of the current at the time of measurement is determined in consideration of the target range of brightness obtained by actually driving the LED. It should be noted that, here, the "large drive current" is used for the purpose of obtaining a larger brightness, but it is sufficient that the current at the time of measurement and the current at the time of driving are the same as described above. For example, the predetermined function can be determined by using a “small drive current” that is smaller than the current value that is normally used. It should be noted that, as described above, how many colors of LED should be measured, and how many colors of LED should be measured based on the measurement.
On the other hand, whether or not the gradation data is converted can be arbitrarily set by the setter.

FIG. 3 is a block diagram showing the LED drive system of the present embodiment, paying attention to the gradation data adding section 4. As shown in FIG. 3, in the present embodiment, the gradation data addition unit 4 includes a first gradation data addition unit 4R, a second gradation data addition unit 4G, and a third gradation data addition unit 4B. Prepare That is, the gradation data addition unit 4 has nine new gradation data Rr, G converted by the gradation data conversion unit 3.
r, Br, Rg, Gg, Bg, Rb, Gb, and Bb are added for each corresponding red LED, green LED, and blue LED and output as one gradation data to each LED.

Specifically, three gradation data Rr, Rg for the red LED converted by the gradation data converter 3 are
Rb is added by the first gradation data addition unit 4R to form one gradation data “Rr + Rg + Rb”. Similarly, the three gradation data Gr, Gg, and Gb for the green LED converted by the gradation data conversion unit 3 are added by the second gradation data addition unit 4G to obtain one gradation data “Gr + Gg + G”.
b ”, and the blue LE converted by the gradation data conversion unit 3
The three gradation data Br, Bg, and Bb for D are added by the third gradation data addition unit 4B to form one gradation data “Br + Bg + Bb”. In this way, the gradation data addition unit 4 newly generates the gradation data “Rr + Rg +” for each of the red LED, the green LED, and the blue LED.
Rb ”,“ Gr + Gg + Gb ”,“ Br + Bg + Bb ”
Is output, and the red LED, the green LED, and the blue LED are caused to emit light based on the gradation data.

In the present invention, the gradation data newly output in each of the first gradation data conversion step, the second gradation data conversion step and the third gradation data conversion step is converted into a red LED, The process of adding each of the green LED and the blue LED to obtain one gradation data is called a gradation data adding process. That is, in the present embodiment, the red LED converted in each gradation data conversion process
Of the three gradation data Rr, Rg, and Rb are added in the first gradation data adding step to obtain one gradation data “Rr.
+ Rg + Rb ”. Similarly, three gradation data G for the green LED converted in each gradation data conversion process
r, Gg, and Gb are added in the second gradation data addition step to form one gradation data “Gr + Gg + Gb”, and the three gradation data Br and Bg for the blue LED converted in the gradation data conversion step. Bb is added in the third gradation data addition step to obtain one gradation data “Br + Bg + B
b ”.

FIG. 5 is a schematic time chart for explaining the relationship of the light emitting period of each LED by the added new gradation data. Here, the red LED emits light in the period w (Rr + Rg + Rb) by the grayscale data “Rr + Rg + Rb” with reference to a predetermined grayscale reference clock.
With the gradation data “Gr + Gg + Gb”, the green LED emits light during the period w (Gr + Gg + Gb), and the gradation data “Br
+ Bg + Bb ”means that the blue LED is in the period w (Br + Bg
One embodiment of emitting light at + Bb) will be described.

In each of the time charts corresponding to the LEDs in FIG. 5, the horizontal axis represents the temporal flow and the vertical axis represents the magnitude of the drive current. In the present invention, when each LED is made to emit light as described above, the magnitude of the drive current in each LED is always constant. By the way, for example, when a driving current is supplied to each of the RGB LEDs at a predetermined ratio to emit light and the magnitude of the driving current supplied to each LED is changed while maintaining the ratio of the driving current supplied, the driving current is supplied. The color tone changes even though the ratio is constant. This is because, as described above, when the magnitude of the drive current changes in one LED, the color tone also changes. When the driving current is constant, the color tone does not change and only the luminance can be changed by increasing or decreasing the light emitting period. The present invention has been made in consideration of these, and the magnitude of the drive current supplied to each LED of each color when the LED is made to emit light is always constant for each LED of each color, and only the length of gradation data is set. By taking this into consideration, it is possible to arbitrarily control the brightness while keeping the color tone constant.

As shown in FIG. 5, 3 for the red LED.
New gradation data “Rr +” in which two gradation data are added
Rg + Rb ”, the period w (Rr
Focusing on + Rg + Rb), the period w (Rr + Rg + R
b) is substantially the light emission period w (R
r) and the light emission period w (Rg) based on the gradation data Rg and the light emission period w (Rb) based on the gradation data Rb. That is, in the present invention, LE of each color is
Since the drive current is set to a constant magnitude for each D and only the gradation data that determines the light emission period of each LED is changed by the gradation data conversion unit 3, the addition of the gradation data is the addition of the light emission period, In other words, it has the same meaning as luminance addition.

Similarly, paying attention to the period w (Gr + Gg + Gb) in which the green LED emits light based on the gradation data “Gr + Gg + Gb” for the green LED, the period w (Gr +
Gg + Gb) is substantially the light emission period w (Gr) based on the grayscale data Gr and the light emission period w (G) based on the grayscale data Gg.
g) and the light emission period w (Gb) based on the grayscale data Gb. Further, focusing on the period w (Br + Bg + Bb) in which the blue LED emits light based on the gradation data “Br + Bg + Bb” for the blue LED, the period w
(Br + Bg + Bb) is substantially the light emission period w (Br) based on the gradation data Br, the light emission period w (Bg) based on the gradation data Bg, and the light emission period w (Bb) based on the gradation data Bb.
You can think by dividing into. Note that the time chart shown in FIG. 5 is divided into three light emitting periods for each LED in order to facilitate the description, and there is actually no boundary in the light emitting period of each LED.

Here, the gradation data "Rr + R" shown in FIG.
g + Rb ”based red LED light emitting period, grayscale data“ Gr + Gg + Gb ”based green light emitting period, and grayscale data“ Br + Bg + Bb ”based blue LE
Focusing on the light emission period of D, the red light L having the longest light emission period
It is preferable that the emission period of the green LED and the emission period of the blue LED are included in the emission period of the ED. That is, it is preferable that the light emission of the LED having the longest light emission period and the light emission of the other LEDs temporally overlap with each other. This causes color flicker (hereinafter also referred to as "color flicker").
It is possible to effectively reduce the occurrence of. In addition, in FIG. 5, the example in which the light emission of each LED is started at the same time has been described, but the light emission may be started at a time difference.

Further, in this embodiment, in order to reduce color flicker to the maximum, the LED with the longest light emission period is used.
The example in which the light emitting period of the other two LEDs is included in the light emitting period of 2 is explained. Of course, comparison is made when the light emitting period of the other two LEDs is included in the light emitting period of the LED having the longest light emitting period. Although the effect of reducing the color flicker is somewhat lowered, it is possible to include only the light emitting period of the other one LED.

Further, the gradation data addition unit 4 does not add the gradation data for each LED, and the gradation data r, g,
Similarly, when the light emission of each LED based on each b is performed individually, it is preferable that the light emission period of the LED having the longest light emission period also includes the light emission period of another LED for correction. For example, consider an example in which the gradation data addition unit 3 is not provided in FIG. 2 and each gradation data converted by the gradation data conversion unit 3 is directly input to the red LED, the green LED, and the blue LED. That is, in the light emission of each LED based on the gradation data r, the gradation data Rr
It is preferable to perform control so that the green LED emits light based on the gradation data Gr and the blue LED emits light based on the gradation data Br while the red LED emits light. Similarly, in the light emission of each LED based on the gradation data g, the green LED based on the gradation data Gg.
Is controlled so that the blue LED emits light based on the gradation data Bg and the red LED emits light based on the gradation data Rg within a period in which L is emitted.
In the light emission of the ED, the red LED emits light based on the grayscale data Rb and the green LE based on the grayscale data Gb within a period in which the blue LED emits light based on the grayscale data Bb.
It is preferable to control so that light emission of D is performed. This makes it possible to easily reduce color flicker even when light is emitted in a single color without adding the gradation data in the gradation data addition unit 4.

Although the double speed display is not mentioned here, the double speed display may of course be performed in order to reduce the flicker of the image. That is, the 1VSYNC period is divided into a plurality of periods, and the same image is displayed for each divided period, whereby flickering of the image can be effectively reduced. When the present invention is applied to double-speed display, an LED that mainly emits light for each divided period based on gradation data regarding a color that should originally be emitted by an LED of one color and the emission of the LED that corrects the emission of that LED Is done within the split period. As a result, not only the flicker of the image but also the occurrence of color flicker can be effectively reduced. Further, the gradation data (luminance) can be increased or decreased for each divided period in which the same image is displayed. With this configuration, it is possible to increase the apparent gradation (gray scale).

Further, in the present embodiment, the data supply unit 2 includes the gradation data conversion unit 3 and the gradation data addition unit 4.
However, the present invention is not limited to this. That is, the gradation data conversion unit 3 and the gradation data addition unit 4 may be included in the data supply unit 1 or the LED unit 5. Further, for example, the data supply unit 2 may include the gradation data conversion unit 3, and the LED unit may include the gradation data addition unit 4. That is, the gradation data conversion unit 3 and the gradation data addition unit 4 can be configured separately. Further, TA which is a distributor is not necessarily required in the LED driving system of the present invention, and CU to D
You can also enter data directly into U. In this case, C
U corresponds to the data supply unit of the present invention.

In the present embodiment, the communication line L2 is a higher-level communication line, and the communication line L1 is a lower-level communication line. May be composed of a plurality of layers. In this case, TAs corresponding to the layers are arranged. Needless to say, the number of TAs and DUs and the connection form of TAs and DUs are not limited to this. That is,
As shown in FIG. 1, in the present embodiment, TAs are arranged in a Z shape and DUs are arranged in a Z shape in each TA, but the present invention is not limited to this, and each TA is, for example,
May be arranged in a straight line, and the DUs in each TA may be arranged in a different direction from the TA arrangement direction (for example, the TA arrangement direction and the DU arrangement direction are perpendicular to each other).

Further, in the present embodiment, the first LED emitting the first color and the second L emitting the second color.
The configuration in which a total of three types of LEDs including the ED and the third LED that emits the third color is arranged in the LED unit 5 has been described, but the present invention is not limited to this. That is,
The LED driving system of the present invention emits different colors.
It suffices if there are more than one kind of LED, for example, a total of two kinds of LEDs consisting of a first LED emitting a first color and a second LED emitting a second color, or a total of four kinds or more. The LEDs may be arranged in the LED unit. In this case, the gradation data conversion unit and the gradation data addition unit are respectively configured in consideration of the number of LEDs that emit different colors.

Further, here, each LED of a plurality of colors has one kind of function with respect to the gradation data which is originally supposed to be emitted by one kind of LED, but the LEDs of a plurality of colors are used.
It is also possible to set a predetermined function in advance by using drive currents of a plurality of magnitudes and set a plurality of functions for the drive currents of the respective magnitudes. This allows
For example, by determining each function using a relatively large drive current, it is possible to easily secure a relatively large luminance for daytime, and by determining each function using a relatively small drive current, a comparison for nighttime is performed. It is possible to secure an extremely small brightness without causing color flicker. In any case, by setting the same magnitude of the driving current at the time of measurement and the magnitude of the driving current at the time of driving in each of the LEDs of a plurality of colors, each LED can emit light without a change in color tone.

[0069]

As described above, according to the present invention, luminance correction and color tone correction can be collectively performed. That is, in general, it is preferable that the luminance can be adjusted and the color tone can always be kept constant in the light emission based on the gradation data that should originally correspond to the LED of one color. However, considering that there are variations in brightness and chromaticity depending on the LEDs and that the color tone changes when the magnitude of the drive current is changed, the brightness can be adjusted arbitrarily while keeping the color tone constant. Is not easy.

However, according to the LED driving system and the control method thereof of the present invention, the driving current is always made to be a constant value and each LE is actually emitted.
Despite the relatively simple configuration of using the gradation data for D, it is possible to achieve both luminance correction and color tone correction simultaneously and efficiently.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an LED drive system of the present embodiment.

FIG. 2 is a schematic diagram focusing on a gradation data conversion unit of the LED driving system shown in FIG.

FIG. 3 is a schematic diagram focusing on a gradation data addition unit of the LED driving system shown in FIG.

FIG. 4 is a schematic diagram showing a function stored in a gradation data conversion unit of the LED driving system of the present embodiment.

FIG. 5 is a schematic diagram showing a light emitting period of each LED in the present embodiment.

FIG. 6 is a schematic diagram for explaining a state in which a drive current is supplied to an LED.

[Explanation of symbols]

1 ... Data control unit 2 ... Data supply unit 3 ... Gradation data converter 3r ... First gradation data conversion means 3g ... Second gradation data conversion means 3b ... Third gradation data conversion means 4 ... Gradation data addition unit 4R ... First gradation data adding means 4G ... Second gradation data adding means 4B ... Third gradation data adding means 5 ... LED unit 10 ... Display 11 ... TA block 20 ... LED 21 ... Common line 22 ... Current line L1, L2 ... communication line

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 33/00 H01L 33/00 JF term (reference) 5C080 AA07 BB05 CC06 DD01 DD05 DD06 EE28 EE29 FF12 GG09 JJ02 JJ04 JJ05 5F041 AA10 AA11 BB06 BB12 BB13 BB33 FF01

Claims (14)

[Claims] 1. A first LE that emits at least a first color.
An LED unit in which a second LED that emits D and a second color is arranged for each pixel, and an emission period of at least each LED for each of the first LED and the second LED connected to the LED unit In the LED drive system, comprising: a data supply unit that supplies gradation data for determining the LED data, the LED drive system further has a gradation data conversion unit connected to the LED unit and the data supply unit, The gradation data conversion unit supplies gradation data regarding a color that should be originally emitted by the first LED, which is supplied from the data supply unit, to the gradation data for the first LED and the first LED. Second for correcting the light emission
First gradation data converting means for converting into the gradation data for the LED, and gradation data regarding a color which should be originally emitted from the second LED, which is supplied from the data supply unit, to the second LED. Gradation data, and the second
2. An LED drive system, comprising at least one of second gradation data conversion means for converting the gradation data for the first LED for correcting light emission by the LED. 2. The LED driving system includes a gradation data conversion unit and a gradation data addition unit connected to the LED unit, wherein the gradation data addition unit includes the gradation data conversion unit. Both the first gradation data conversion unit and the second gradation data conversion unit are provided, and the light emission based on the gradation data relating to the color to be originally emitted by the first LED and the original second LED are performed. When color mixing is performed for each pixel by using light emission based on gradation data regarding a color to be emitted, the first L converted by the first gradation data conversion unit is used.
First gradation data adding means for adding the gradation data for the ED and the gradation data for the first LED converted by the second gradation data converting means into one gradation data, The grayscale data for the second LED converted by the first grayscale data conversion means and the grayscale data for the second LED converted by the second grayscale data conversion means are added. 2. The LED drive system according to claim 1, further comprising at least one of the second grayscale data adding means for setting one grayscale data. 3. A first LE that emits at least a first color.
D, a second LED that emits a second color, and a third LED that emits a third color are arranged in each pixel, an LED unit connected to the LED unit, and the first LED and the first LED. In the LED drive system, the LED drive system further includes two LEDs and a data supply unit that supplies gradation data for determining at least a light emission period of each of the third LEDs. It has a gradation data conversion unit connected to the data supply unit, and the gradation data conversion unit supplies the gradation data regarding the color that is originally to be emitted by the first LED and is supplied from the data supply unit. The grayscale data for the first LED, the grayscale data for the second LED for correcting light emission by the first LED, and the first grayscale data for the first LED.
First gradation data conversion means for converting the light emission from the third LED into gradation data for the third LED, and originally the second L supplied from the data supply unit.
The gradation data regarding the color to be emitted by the ED, the gradation data for the second LED, the gradation data for the first LED for correcting the light emission by the second LED, and the second LED. Second gradation data conversion means for converting the light emission by the third LED into gradation data for correction, and the gradation relating to the color which is originally to be emitted by the third LED and is supplied from the data supply unit. The data is gradation data for the third LED, and the first LED for correcting light emission by the third LED.
And gradation data for the second LED for correcting the light emission by the third LED, and at least one means for converting the gradation data for the second LED. LED drive system. 4. The LED driving system includes a gradation data conversion unit and a gradation data addition unit connected to the LED unit, wherein the gradation data addition unit includes the gradation data conversion unit. Light emission based on tone data relating to a color that should be originally emitted by the first LED, including first tone data conversion means, second tone data conversion means, and third tone data conversion means A pixel using at least two of the light emission based on the gradation data regarding the color to be originally emitted by the second LED and the light emission based on the gradation data regarding the color to be originally emitted by the third LED. When the colors are mixed for each color, the first L converted by the first gradation data conversion means is used.
The gradation data for the ED, the gradation data for the first LED converted by the second gradation data conversion means, and the first gradation data for the third gradation data conversion means.
First gradation data addition means for adding the gradation data for the LEDs of to obtain one gradation data, and the second L converted by the first gradation data conversion means.
The gradation data for the ED, the gradation data for the second LED converted by the second gradation data converting means, and the second data converted by the third gradation data converting means.
Second gradation data adding means for adding the gradation data for the LEDs to obtain one gradation data, and the third L converted by the first gradation data converting means.
The gradation data for the ED, the gradation data for the third LED converted by the second gradation data conversion means, and the third data converted by the third gradation data conversion means.
4. The LED drive system according to claim 3, further comprising at least one means of third gradation data adding means for adding the gradation data for the LEDs to obtain one gradation data. 5. In the light emission of each LED based on the gradation data for each LED added by each gradation data adding means, another LED is emitted within the light emission period of the LED having the longest light emission period.
5. The LED drive system according to claim 2, wherein the LED driving system includes the light emitting period of. 6. The gradation data converting means converts the gradation data input to itself into gradation data for a predetermined LED and gradation data for an LED for correcting light emission by the predetermined LED. At this time, the gradation data input to itself is used as a common input, and based on a predetermined function corresponding to the input and the first LED, the second LED, and the third LED, each LED
6. The LED drive system according to claim 1, wherein new gradation data is output to the LED drive system. 7. The LED driving system according to claim 6, wherein the predetermined function is non-linear. 8. The red LED that emits red light, each of the first LED, the second LED and the third LED.
The LED drive system according to claim 3, wherein the LED drive system is an ED, a green LED that emits green light, and a blue LED that emits blue light. 9. A red LED that emits red light, a green LED that emits green light, and a blue LED that emits blue light, which are arranged for each pixel on the LED unit, respectively.
In a method of controlling an LED driving system, which supplies gradation data for determining a light emitting period of an ED and causes each LED to emit light based on the gradation data, the control method of the LED driving system originally causes a red LED to emit light. The gradation data for the power red, the gradation data for the red LED, and the green L for correcting the light emission by the red LED.
A first gradation data conversion step of converting the gradation data for the ED, the gradation data for the blue LED for correcting the light emission by the red LED, and the gradation data for the green color to be originally emitted by the green LED; Second gradation converted to gradation data for the green LED, gradation data for the blue LED for correcting the light emission by the green LED, and gradation data for the red LED for correcting the light emission by the green LED The data conversion step, the gradation data regarding the blue color which should be originally emitted by the blue LED, the gradation data for the blue LED, and the blue LED
At least one of a third gradation data conversion step of converting the gradation data for the red LED for correcting the light emission by the green LED and the gradation data for the green LED for correcting the light emission by the blue LED. A method for controlling an LED drive system, comprising: 10. A method of controlling the LED drive system, comprising:
The first gradation data conversion step, the second gradation data conversion step, and the third gradation data conversion step,
In addition, when color mixing is performed for each pixel using at least two of the light emission based on the grayscale data regarding the red color, the light emission based on the grayscale data regarding the green color, and the light emission based on the grayscale data regarding the blue color, Red LE converted in the first gradation data conversion step
The gradation data for D, the gradation data for the red LED converted in the second gradation data conversion step, and the red LED converted in the third gradation data conversion step
A first gradation data addition step of adding the gradation data for the above to obtain one gradation data; and the green LE converted in the first gradation data conversion step.
The gradation data for D, the gradation data for the green LED converted in the second gradation data conversion step, and the green LED converted in the third gradation data conversion step
A second gradation data addition step of adding the gradation data for the above to obtain one gradation data; and the blue LE converted in the first gradation data conversion step.
The gradation data for D, the gradation data for the blue LED converted in the second gradation data conversion step, and the blue LED converted in the third gradation data conversion step
At least any one of the third gradation data adding step of adding the gradation data for
LE according to claim 9, characterized in that it comprises two steps.
Control method of D drive system. 11. A red LE based on the gradation data for the red LED added in the first gradation data adding step.
A green LED based on the grayscale data for the green LED added in the second grayscale data adding step and the light emission of D
And the emission of the blue LED based on the gradation data for the blue LED added in the third gradation data addition step, the other LED is emitted within the emission period of the LED having the longest emission period.
11. The control method of the LED drive system according to claim 10, wherein the control is performed such that the light emission period is included. 12. In each of the gradation data conversion steps, the gradation data input to itself is corrected to correct gradation data for a predetermined LED and light emission from the predetermined LED.
When converting the gradation data for the ED, the gradation data input to itself is used as a common input, and based on a predetermined function corresponding to the input and each of the red LED, the green LED and the blue LED, each LED 12. The method for controlling an LED drive system according to claim 9, wherein new grayscale data is output for the above. 13. The method of controlling an LED driving system according to claim 12, wherein the predetermined function is non-linear. 14. A red LED, a red LED, a green LED, a red LED, a green LED, a blue LED, a red LED, a red LED, a green LED, and a red LED.
The LED according to claim 12 or 13, wherein the light emitting characteristics of the green LED or the blue LED are measured, and a predetermined function corresponding to each LED is determined based on the measurement result. Drive system control method.