Organization of the Thesis - 適用於色序法液晶顯示器之多主頻譜背光系統

Chapter 1 Introductions

1.6 Organization of the Thesis

The thesis is organized as following: in Charter 2, the principle of the components, the driving theory of the LEDs, and the principle of the colorimetry will be given. In Chapter 3, the hardware and the software of the backlight control system will be presented. Furthermore, the driving principle of the scanning FSC backlight will be described. In Chapter 4, the optical performances and electronic characterizations will be obtained for operating different driving methods. In Chapter 5, the issues of RGB LEDs backlight will be described. Finally, the conclusions and the future works will be described in Chapter 6.

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Chapter 2 Principle and Prior Arts

2.1 Basic Types of LED Circuits

In the electronics, the basic LED circuit consists of three components connected in series: a voltage source, a current limiting resistor and a LED, as shown in fig. 2-1.

Fig. 2-1 Basic circuit of the LED

The formula is used to calculate the correct resistor:

LED LED S

I V -) V (

resistance Ω = (2.1)

where Vs is the voltage of the power supply, VLED is the forward voltage of the LED, and ILED is the driving current of the LED.

There are two basic types of the circuit: Series type and Parallel type.

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2.1.1 Series Type

If two or more circuit components are connected end to end like a daisy chain, it is said they are connected in series. A series circuit is a single path for electric current through all of its components which have the same electric current. The series circuit of the LED is shown in Fig. 2-2

Fig. 2-2 Series circuit of the LED

2.1.2 Parallel Type

If two or more circuit components are connected like the rungs of a ladder it is said they are connected in parallel. A parallel circuit is a different path for current through each of its components. A parallel circuit provides the same voltage across all of its components. The parallel circuit of the LED is shown in Fig. 2-3.

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Fig. 2-3 Parallel circuit of the LED

2.2 Pulse Width Modulation

Pulse width modulation (PWM) is a powerful technique for controlling analog circuits with a processor's digital outputs. PWM is employed in a wide variety of applications, ranging from measurement and communications to power control and conversion. Fig. 2-4 shows an example of PWM: the supply voltage (blue) modulated as a series of pulses results in a sine-like flux density waveform (red) in a magnetic circuit of electromagnetic actuator. The smoothness of the resultant waveform can be controlled by the width and number of modulated impulses (per given cycle). In this research, the PWM method is used to control the LED and modify the LED lighting period and intensity.

Fig. 2-4 An example of PWM

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2.3 Tristimulus Values and Chromaticity Coordinates

The tristimulus values X, Y and Z of a color stimulus Φ(λ) can be obtained by first calculating tristimulus values R, G and B by equation (2.2) [16], and then converting them into the tristimulus values X, Y and Z using equation (2.3).

where P(λ) is the spectral distribution of the illuminating light, r(λ) g(λ) b(λ) are called color matching functions, and the integral is taken in the visible wavelength region.

However, in general, they are obtained directly using the color matching functions x(λ), y(λ) and z(λ) according to equations (2.4).

where κ(λ) is a constant, and the integral is taken in the visible wavelength region.

For a reflecting object, the color stimulus is Φ(λ) = R(λ) P(λ), and for the transparent object it is Φ(λ) = T(λ) P(λ), where R(λ) is the spectral reflectance of the reflecting object, and T(λ) is the spectral transmittance of the transmitting object. For example, the tristimulus values X, Y and Z of a reflecting object can be expressed as

- 13 - The constant κ is selected such that the tristimulus values Y yields a value of 100 for a perfect reflecting object. In general, R(λ) < 1 for any real object color, and Y is therefore < 100.

As with the RGB system, the chromaticity coordinates x and y are established by the intersection of the color vector (X, Y, Z) with the unit plane X + Y + Z = 1 as

A two-dimensional xy chromaticity diagram is often used to plot colors.

However, since three pieces of information are needed to specify color, a third must be added to x and y for a complete specification. Any of the tristimulus values X, Y and Z could be used, but in general, the photometric quantity Y is chosen and colors are expressed by (x, y, Y).

2.4 Color Mixing

The phenomenon of generating a new color stimulus through the interaction of multiple other color stimuli is called color mixing. Color mixing can be either additive or subtractive. Additive mixing occurs when the component color stimuli are simultaneously incident on the eye. The stimuli may be superimposed optically, they may occur in rapid temporal alternation (flicker), or they may be interlaced in a spatial pattern not visible to the eye. Because the physical intensity of the color stimulus that results from the mixture is obtained as the sum of the components, the mixture is called ‘additive’ color mixture.

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Let us consider the case of three-stimulus mixture. The tristimulus values for unit amount (for example, 1W) of the color stimuli are given by (XR, YR, ZR), (XG, YG, ZG), and (XB, YB, ZB) respectively, and the chromaticity coordinates are given by (xR, yR), (xG, yG), and (xB, yB) respectively. The tristimulus values (XF, YF, ZF) of the color stimulus [F] obtained by additive mixing of amounts R, G, and B of these three color stimuli are expressed by the following equations according to Grassmann’s Laws.

These equations can be expressed in matrix form：

The three component stimuli that used are for the additive mixing are called additive primaries, and in order to achieve a large gamut, are most often red [R], green [G], and blue [B].

For example, the tristimulus values and chromaticity coordinates of color stimuli [R], [G] and [B] are measured, as shown in equation (2.10).

0.040

A stimulus having the same chromaticity coordinates as those of standard illuminant D65 with a luminance of YD = 10 can be calculated as an additive mixture of [R], [G], and [B]. Such a stimulus will be metameric to D65. Because D65 has chromaticity coordinates xD and yD given by

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From equation (2.9), the following is obtained

⎥⎥

By multiplying both sides of the equation by the inverse of the first matrix of the left-hand side, the following can be obtained

Thus, 0.2934, 0.6571 and 0.0496 are the desired amounts of [R], [G], and [B]

respectively. In the unit plane (R + G + B = 1), the luminance of the color obtained by additive mixing is intermediate between the luminances of the primaries. The actual luminance of any color within the RGB triangle depends on its position in the triangle or on its chromaticity coordinates.

2.5 Summary

The driving methods of the LEDs circuit and the principle of the colorimetry are presented in this chapter. In the following chapter, we will use the hardware combining with the software to accomplish the control circuit of the backlight system.

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Chapter 3 Circuit Design

3.1 Introduction

In this chapter, the main stress will fall on the control circuit of the backlight system. The backlight system consists of the optomechanical setup and the control circuit. The optomechanical setup is designed by the condisciple. The BLM is proposed for a scanning field-sequential-color liquid-crystal display (FSC LCD). The specification of the backlight system will be briefly introduced. Moreover, the design of the circuit combines the software with the hardware will be described in detail. The tree diagram of the backlight system is shown in Fig. 3-1.

Fig. 3-1 Tree diagram of the backlight system

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3.2 Specification of the FSC LCD Backlight System

Coupling with the optically-compensated-bend (OCB) mode LC and full color LEDs, a FSC LCD can be realized without the color filter. However, due to the response time of the LC is slow, the duty cycle of the LEDs is restricted. The backlight will be not bright enough. In order to improve the issue of the LC response time in FSC LCD application, a specific configuration of the backlight system is required: spatial-temporal partitioned scanning backlight driven by the FSC method.

The structure of the spatial-temporal scanning backlight for an OCB-mode FSC-LCD is shown in Fig. 3-2 (a). The backlight consists of

(1) Tandem wedge shaped light guides have prismatic micro-bump structures over the bottom, as shown in Fig. 3-2 (b). The light guides control the direction of the light extraction as well as the uniformity and efficiency.

(2) 4-in-1 full color LEDs light bar is setin front of the incident surface of the corresponding LG and under the end of the previous one.

(3) A diffuser on the top of the wedge shaped light guides that diffuses light and illuminates local dim regions.

(4) A brightness enhanced film (BEF) with a saw-tooth cross-section guide light toward the front direction in order to increase the normal component of the light toward the LCD.

(a)

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(b)

Fig. 3-2 (a) Structure of the FSC scanning BLM (b) wedge shaped light guide unit

Table 3-1 Specifications and criterions of proposed BLM

The specification of the developed prototype OCB mode FSC LCD is shown in Table 3-1. The tandem wedge shaped light guides are assembled into 32-inch diagonal panel size with aspect ratio 16:9. The entire BLM is divided into 12 horizontal blocks in several considerations such as LC response time, optical efficiency and the panel resolution. The vertical pixel numbers should be divided into an integer by scanning divisions. Otherwise, the pixel will be located across the boundary of two isolated LG plates. Moreover, if we try to increase the numbers of the scanning blocks, the optical performance of LG unit is difficult to be maintained,

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and some technical problems may occur during fabrication process. Therefore, the 12 scanning divisions is an adequate choice for our model.

The criterions of the uniformity for full panel and efficiency per light guide unit are 80% and 70%, respectively. The thickness of the overall BLM is less than 30mm without any shields.

3.3 Software for the Circuit of the Scanning FSC BLM

The C programming language is the most popular programming language in the control signals of the circuit, so we use the C programming language to implement the control signals and download the contral signals in the micro controller chip.

3.4 Hardware for the Circuit of the Scanning FSC BLM

The hardware of the backlight module consists of the control board, the 4-in-1 full color LEDs light bar, and the LED drive IC. The details of the hardware will be depicted.

3.4.1 Control Board

Fig. 3-3 presents the control board which is designed by Chih-Yang Su. In this control board, the MCU (micro controller unit) is principal control center, and the signals of the LEDs light bar is transmitted by the control port of the LEDs light bar.

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Fig. 3-3 Circuit of the control system

3.4.2 LEDs Light Bar

Using LEDs as light source is suitable for FSC backlight application due to the response time is sufficiently rapid to switch the different color state. Moreover, the emission spectra of R, G and B LEDs are narrower than the color filters. In this experiment, the LEDs are provided by EVERLIGHT ELECTRONICS CO., LTD. The features of the LED are introduced as follow：

(A) Features

1. High efficiency, high luminosity.

2. Viewing angle: 120°

MCU Control Port of the

LEDs Light Bar Input Port of PC

Push-Butto

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3. Long operating life 4. Full color

5. Lead free

6. Soldering methods: SMT type (B) Electro-optical characteristics

The electro-optical characteristics of the LED are shown in Table 3-2 and Table 3-3.

Table 3-2 Electro-optical characteristics

Table 3-3 Electro-optical characteristics

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The LEDs light-bar are adopted as the light source, as shown in Fig. 3-4. The circuits of the R, G and B LEDs light bar are shown in Fig. 3-5 (a) (b) (c), respectively.

Fig. 3-4 LEDs light bar

VLED

Rdrop

RLED

Rdrop Rdrop

VLED

GLED

Rdrop

Rdrop Rdrop

(a) (b) (c)

Fig. 3-5 Circuit of the (a) R LEDs light bar (b) G LEDs light bar (c) B LEDs light bar

3.4.3 LED Drive IC

There are many features of the LED drive IC which is produced by MACROBLOCK INC. The features are composed of

1. 16 constant-current output channels

2. Output current adjustable through an external resistor 3. Constant output current range: 5-90mA

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4. Programmable output current gain for white balance 5. Constant output current invariant to load voltage change

3.5 Circuit Design for the Hardware of the LED

The VR, VG and VB represent the forward voltage of the R, G and B LEDs, respectively. In chapter 2, the principle of the mixing color was presented. In this experiment, the driving current are 294mA, 343mA, and 147mA in the red, green and blue LEDs light bar, respectively. Based on this condition, the voltage of the R, G and B LEDs light bar is shown in equation (3.1).

3.5.1 Selection of the External Resister (Rext)

The output current of each channel (Iout) is set by an external resistor (Rext).

After a power-on status, the relationship between Iout and Rext is shown in the following figure.

Fig. 3-6 Resistance of the external resistor, Rext (Ω)

The output current in milliamps can be calculated from the equation:

15 Rext) / (V

Iout = _Rext × (3.2)

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where the VRext is the initial value which is 1.4027 V (volt) approximately in the IC.

The constant output current of the driving IC is 49 mA in this experiment. The Rext is obtained by

≅

=(1.4027 15) / 49mA 429

Rext (3.3)

Table 3-4 shows the numbers of the constant output current channel which are computed for R, G and B LEDs light bar, respectively. The IC has 16 constant-current output channels, and the total numbers of the constant current output channel for the R, G and B LEDs light bar are 16 (6 + 7 + 3 = 16). The one horizontal block of the backlight is controlled by one driver IC. Therefore, 12 pieces of the LED driver IC is needed for the backlight module.

Table 3-4 Numbers of the constant output current channel for R, G and B LEDs light bar

Driving current Numbers of the constant output current channel

R LEDs light bar 294 mA 6

G LEDs light bar 343 mA 7

B LEDs light bar 147 mA 3

Fig. 3-7 Terminal function of the IC for the R, G and B LEDs light bar

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The terminal function of the IC is described in Fig.3-7 and Table 3-5. The current output channels in the R, G and B LEDs light bar are 6, 7 and 3, respectively.

Table 3-5 Terminal function of the IC for the LEDs light bar

Pin No. Pin name Function

1 GND Ground terminal for control logic and current sink 2 SDI Serial-data input to the Shift Register

3 CLK Clock input terminal for data shift on rising edge

4 LE Serial data is transferred to the respective latch when LE (CA1) is high. The data is latched when LE (CA1) goes low.

5~10 Output 0~5 Provide current for R LEDs light bar 11~13 Output 6~8 Provide current for G LEDs light bar 14~20 Output 9~15 Provide current for B LEDs light bar

21 /OE When (active) low, the output drivers are enabled; when high, all output drivers are turned OFF (blanked).

22 SDO Serial-data output to the following SDI of next driver IC

23 Rext Input terminal used to connect an external resister for setting up all output current

24 VDD 5V supply voltage terminal

3.5.2 Selection of the LED Current Limiting Resistor

The current limiting resistor can be calculated by the Kirchhoff’s Voltage law (KVL) circuit equation:

DS bar light drop

S I R V V

V = × + + (3.4) where Rdrop is the current limiting resistor, Vlight bar is the forward voltage of the LED

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3.6 Software Design & Driving Signals for the Scanning FSC Backlight

Each color sub-frame takes about 1/180 sec. The duty cycle of the illumination pulse is limited to about 50%. From the specification, the total number of gate lines is 768. If a BLM is divided into 12 scanning partitions, each single block has 64 gate lines of the TFT pixel array correspondingly, and the scanning duration over those lines is about 0.13 ms, which is the acceptable tolerance for the LC response time. Fig.

3-8 shows the simple timing relation on the scanning of LC, the TFT-array cell and the LED flash time. Moreover, the time can be calculated by the following equation:

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Fig. 3-8 Timing chart for multi-flashing method

Fig. 3-9 Timing relation for the duty of the R, G and B LED

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Fig. 3-9 presents the timing relation for the duty cycle of the R, G and B LEDs.

The horizontal axis is time scales, and the vertical axis is the position of the LED light bar in the backlight module. There are 12 time scales in every sub-frame, and the interval between the two time scales is 0.463 ms approximately.

The truth table is designed by the space and time domain from Fig. 3-9, as shown in Table 3-6. “0” represents to turn on the LED, and “1” represents to turn off.

Table 3-6 Truth table for the deductive method of the scanning FSC backlight

Space domain (NO. division)

12^th 11^th 10^th 9^th 8^th 7^th 6^th 5^th 4^th 3^rd 2^nd 1^st

R G B R G B R G B R G B R G B R G B R G B R G B R G B R G B R G B R G B

1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0

8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0

9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0

10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0

11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0

12 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0

Time domain (NO.)

13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0

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14 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0

15 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0

16 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0

17 ^{0 0 0 1} ^{0 0} ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 0 0 0

18 ¹ ^{0 0 1} ^{0 0} ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 0 0 0

19 ¹ ^{0 0 1} ^{0 0} ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ⁰ 20 ¹ ^{0 0 1} ^{0 0} ¹ ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ 21 ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ⁰ 22 ¹ ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0 1} ^{0 0 1} ⁰ ⁰ ¹ ⁰ 23 ¹ ^{0 0 0 0 0} 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0

24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0

25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0

26 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0

27 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0

28 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0

29 ^{0 0 0 0 1} ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 0 0 0

30 ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 0 0 0

31 ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ 32 ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ⁰ ⁰ ¹ 33 ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0 1} ⁰ ⁰ ¹ 34 ⁰ ¹ ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0 1} ^{0 0 1} ⁰ ⁰ ¹ 35 ⁰ ¹ ^{0 0 0 0} 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1

36 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1

37 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0

38 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0

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39 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0

40 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0

41 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

42 ^{0 0 1} ^{0 0 1} ^{0 0 1} ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 0 0 0

43 ^{0 0 1} ^{0 0 1} ^{0 0 1} ^{0 0 1} ⁰ ⁰ ¹ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ 0 0 0 0 0 0 0 1 0 0

44 ^{0 0 1} ^{0 0 1} ^{0 0 1} ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0} ¹ ⁰ ⁰ 45 ^{0 0 1} ^{0 0 1} ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ 46 ^{0 0 1} ^{0 0 1} ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ⁰ ¹ ⁰ ⁰ ¹ ^{0 0 1} ^{0 0} ¹ ⁰ ⁰ 47 ^{0 0 1} ^{0 0 0} 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0

At the beginning, the LEDs (consist of R, G and B LED) aren’t turned on because the time domain NO.1~NO.6 consist of the TFT addressing time and the LC response time in the 1^st division of the backlight. At NO.7, the R LED is turned on in the 1^st division, the others LEDs are turned off, as shown in Table 3-6-1. At NO.8, the R LEDs are turned on in the 1^st and 2^nd division, the others LEDs are turned off. And so on, as shown in Table 3-6-2. When the action is completely finished at NO.47, the next action makes a fresh start at NO.12. Then, the action repeats the foregoing actions between NO.12 with NO.47, as shown in Table 3-6-3. Fig. 3-10 presents the block chart for the scanning FSC backlight.

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Table 3-6-1 Truth table for time domain NO.1~NO.6