CN101359123B - Backlight module, liquid crystal display and control method thereof - Google Patents

Abstract

A backlight module comprises a light-emitting unit and a control unit. The control unit controls the light-emitting unit through a duty cycle, wherein, in a first time-distance, the light brightness is a first level; and in a second time-distance, the light brightness changes from the first level to a second level. The duty cycle is defined as the ratio of the second time-distance to the sum of the first time-distance and the second time-distance.

Description

Backlight module, liquid crystal indicator and control method thereof

Technical field

The present invention relates to a kind of backlight module, liquid crystal indicator and control method thereof.

Background technology

Along with showing development of science and technology; Display device and products thereof is used by people widely; And liquid crystal indicator is because of having that build is frivolous, low power consumption and advantageous characteristic such as radiationless; Replace the conventional cathode ray tube display device gradually, and be applied to the electronic product of numerous species.

In general, existing liquid crystal indicator control the luminous of a backlight module and a display panels respectively light transmittance to show different pictures.

Please with reference to shown in Figure 1, it is presented in the above-mentioned liquid crystal indicator, when light luminance and light transmittance change in time, and the time dependent relation of the pixel intensity of picture.Backlight module is controlled and driven to light luminance with 50% duty cycle (duty cycle) is example.Wherein, at time t ₁₁Before, display panels control light transmittance maintains T ₁₁, so that the pixel intensity that liquid crystal indicator showed is normal variation according to the product of light luminance and light transmittance.

And at time t ₁₁Afterwards, display panels control light transmittance is reduced to T ₁₂, also can correspondingly reduce in the hope of pixel intensity.Yet, owing to the restriction that receives the liquid crystal reaction velocity causes at time t ₁₂Afterwards, light transmittance is not reduced to T like expection yet ₁₂And the pixel intensity that causes liquid crystal indicator to show produces extra brightness L _Peak, and then make that liquid crystal indicator institute picture displayed quality is bad.

Recently, the dealer is in order to address the above problem, generally can duty cycle be controlled and to drive backlight module luminous to reduce, produce extra brightness L to reduce _PeakWherein, in order to reduce the duty cycle of light, backlight module must drive with higher current level, and causes the life-span of backlight module to be reduced.In addition, current level also can't unrestrictedly improve, and therefore can't effectively reduce to produce extra brightness L _Peak

Therefore, how to provide a kind of and can not need change control and drive the luminous duty cycle of backlight module, but still can effectively reduce backlight module, liquid crystal indicator and control method thereof that extra brightness produces, just one of important topic of current display industry.

Summary of the invention

Because above-mentioned problem the purpose of this invention is to provide a kind of duty cycle that can not need change light, but still can effectively reduce backlight module, liquid crystal indicator and control method thereof that extra brightness produces.

Edge is for reaching above-mentioned purpose, to comprise a luminescence unit and a control module according to a kind of backlight module of the present invention.Control module is exported a light with duty cycle control luminescence unit.Wherein, one first o'clock apart from, the brightness of light is one first level, one second o'clock apart from, the brightness of light is gradual by first level to be one second level.Above-mentioned duty cycle be defined as second o'clock distance with first o'clock apart from and second o'clock ratio apart from sum.

For reaching above-mentioned purpose, according to the control method of a kind of backlight module of the present invention, wherein, backlight module has a control module and a luminescence unit.Control module is exported a light with duty cycle control luminescence unit, and control method comprises the following step: at first, one first o'clock apart from, the brightness of light is one first level; Then, one second o'clock apart from, the brightness of light is gradual by first level to be one second level, wherein, duty cycle be defined as second o'clock distance with first o'clock apart from and second o'clock ratio apart from sum.

For reaching above-mentioned purpose, comprise a display panels and a backlight module according to a kind of liquid crystal indicator of the present invention.Backlight module has a luminescence unit and a control module.Control module is exported a light to display panels with duty cycle control luminescence unit.Wherein, one first o'clock apart from, the brightness of light is one first level, one second o'clock apart from, the brightness of light is gradual by first level to be one second level.Above-mentioned duty cycle be defined as second o'clock distance with first o'clock apart from and second o'clock ratio apart from sum.

For reaching above-mentioned purpose, according to the control method of a kind of liquid crystal indicator of the present invention, wherein, liquid crystal indicator has a display panels and a backlight module, and backlight module has a control module and a luminescence unit.Control module is exported a light to display panels with duty cycle control luminescence unit, and control method comprises the following step: at first, one first o'clock apart from, the brightness of light is one first level; Then, one second o'clock apart from, the brightness of light is gradual by first level to be one second level, wherein, duty cycle be defined as second o'clock distance with first o'clock apart from and second o'clock ratio apart from sum.

Hold the above; Because of according to backlight module of the present invention, liquid crystal indicator and control method thereof be second o'clock apart from; The brightness of light is gradual by first level to be second level; In other words, backlight module of the present invention, liquid crystal indicator and control method thereof are to change reducing the generation of extra brightness through being controlled at not simultaneously apart from the level of the brightness of interior light, and need not change the duty cycle of light; Not only can guarantee quality of display pictures, and can avoid reduce the serviceable life of backlight module.

Description of drawings

Fig. 1 shows in the available liquid crystal display device, when light luminance and light transmittance change in time, and the time dependent relation of the pixel intensity of picture;

Fig. 2 shows a liquid crystal indicator of preferred embodiment of the present invention;

In the liquid crystal indicator of Fig. 3 a to Fig. 3 i displayed map 2, the light intensity that luminescence unit is exported over time;

Fig. 4 shows another liquid crystal indicator of preferred embodiment of the present invention;

Fig. 5 shows the control method of the liquid crystal indicator of preferred embodiment of the present invention;

Fig. 6 shows the backlight module of preferred embodiment of the present invention; And

Fig. 7 shows the control method of the backlight module of preferred embodiment of the present invention.

The reference numeral explanation:

2: liquid crystal indicator

21: display panels

211: pel array

212: driver element

22: backlight module

221: luminescence unit

222: control module

23: the frame load module

24: the frame buffer module

25: analysis module

26: the over-drive value generation module

27: the frame output module

B ₂₀: light

D ₂₀: duty cycle

G ₂₁: show the GTG value

G ₂₂: GTG value to be shown

L ₂₁: first level

L ₂₂: second level

L ₂₃: the 3rd level

L _Peak: extra brightness

P ₂₀: pixel

S ₂₀: relation

S ₂₁(t): part

S ₂₂(t): another part

S100-S110: step

S200-S210: step

t ₁₁, t ₁₂: the time

t _I1: first o'clock distance

t _I2: second o'clock distance

t _I21: a part

t _I22: another part

t _I0: the time distance

t _I4: the time distance

T ₁₁, T ₁₂, T ₂₀: light transmittance

V ₂₀: over-drive value

Embodiment

Below will backlight module, liquid crystal indicator and control method thereof according to preferred embodiment of the present invention be described with reference to correlative type.

[liquid crystal indicator of preferred embodiment]

Please with reference to shown in Figure 2, the liquid crystal indicator 2 of preferred embodiment comprises a display panels 21 and a backlight module 22.

Display panels 21 has a pel array 211 and a driver element 212, wherein, but the rotation of the liquid crystal of driver element 212 driving pixels arrays 211, so that light transmittance T ₂₀Change.

Backlight module 22 has a luminescence unit 221 and a control module 222, and wherein, control module 222 is with a duty cycle D ₂₀ Control luminescence unit 221 outputs one light B ₂₀Pel array 211 to display panels 21.

Please be simultaneously with reference to shown in Fig. 2 and Fig. 3 a, duty cycle D ₂₀Be defined as at one second o'clock apart from t _I2With one first o'clock apart from t _I1Reach at second o'clock apart from t _I2The ratio of sum

At first o'clock apart from t _I1In, the brightness of light is one first level L ₂₁, and at second o'clock apart from t _I2In, the brightness of light concerns S according to one ₂₀By the first level L ₂₁Gradual is one second level L ₂₂, in the present embodiment, the first level L ₂₁Less than the second level L ₂₂Wherein, concern S ₂₀Different designs can be arranged according to actual state, for example, please, concern S with reference to shown in Fig. 3 a to Fig. 3 h ₂₀Can be a linearity (shown in Fig. 3 a), one stepped (shown in Fig. 3 b) or an arc shaped (shown in Fig. 3 c and Fig. 3 d).Certainly, also can under different time, apply mechanically different relationships S ₂₀, for instance, shown in Fig. 3 e, wherein, the time apart from t _I0In, the brightness of light is according to concerning S ₂₀(linearity) is by the first level L ₂₁Gradual is the second level L ₂₂The time apart from t _I2In, the brightness of light is according to concerning S ₂₀(stepped) is by the first level L ₂₁Gradual is the second level L ₂₂The time apart from t _I4In, the bright foundation of light concerns S ₂₀(arc shaped) is by the first level L ₂₁Gradual is the second level L ₂₂

In addition, concern S ₂₀Also can constitute, wherein, concern S by two parts ₂₀A part of S ₂₁(t) brightness that makes light is by the first level L ₂₁Gradual is the second level L ₂₂, and concern S ₂₀Another part S ₂₂(t) make the brightness of light maintain the second level L ₂₂(shown in Fig. 3 f-Fig. 3 i).In the present embodiment, one the 3rd level L ₂₃With second o'clock apart from t _I2A part of t _I21Product deduct at second o'clock apart from t _I2A part of t _I21(second o'clock apart from t for the brightness summation of middle light _I2A part of t _I21With concern S ₂₀A part of S ₂₁(t) area that is surrounded) equal in fact at second o'clock apart from t _I2Another part t _I22(second o'clock apart from t in the brightness of middle light _I2Another part t _I22With concern S ₂₀Another part S ₂₂(t) area that is surrounded) summation deducts the 3rd level L ₂₃With second o'clock apart from t _I2Another part t _I22Product, shown in following formula:

$t_{i2}\&times;{\mathrm{<figure-callout\; id="23"\; label="L"\; filenames="H071D8212620070807E000043.png,H071D8212620070807E000061.png"\; state="\{\{state\}\}">L</figure-callout>}}_{23}={\&Integral;}_0^{t_{i21}}{S}_{21}\left(t\right)\mathrm{Dt}+{\&Integral;}_{t_{i21}}^{t_{i22}}{S}_{22}\left(t\right)\mathrm{Dt}$ Formula

Certainly, also can under different time, present the different S that concern ₂₀(has part S ₂₁(t) and part S ₂₂(t)), do not give unnecessary details in this appearance.

Hold, more please with reference to shown in Figure 2, because of according to liquid crystal indicator 2 of the present invention at second o'clock apart from t _I2In, light B ₂₀Brightness by the first level L ₂₁Gradual is the second level L ₂₂, so that at second o'clock apart from t _I2In, the light transmittance T of pel array 211 ₂₀With light B ₂₀The product of brightness be minimum, reduce the generation of extra brightness.Thus, not only can guarantee quality of display pictures, and can avoid backlight module 22 to make reduce serviceable life because improving the driving signal.

In addition, please with reference to shown in Figure 4, light B ₂₀Brightness be to concern S with a liquid crystal reaction relation is inversely proportional to approximately ₂₀By the first level L ₂₁Gradual is the second level L ₂₂, so that at second o'clock apart from t _I2In, the light transmittance T of pel array 211 ₂₀With light B ₂₀The product of brightness be minimum, reduce the generation of extra brightness.And the liquid crystal reaction relation is the light transmittance T of definition reaction time and pel array 211 ₂₀Between relation, and liquid crystal reaction relation and environment temperature, liquid crystal material, the driving liquid crystal front and back of rotating show that GTG value etc. is relevant.

Wherein, liquid crystal indicator 2 more can comprise a frame load module 23, a frame buffer module 24, an analysis module 25, an over-drive value generation module 26 and a frame output module 27.Frame buffer module 24 electrically connects with frame load module 23, to export a plurality of pixel P ₂₀A plurality of demonstration GTG value G ₂₁To analysis module 25.And the said pixel P of frame load module 23 outputs ₂₀GTG value G a plurality of to be shown ₂₂To analysis module 25.Analysis module 25 is according to said demonstration GTG value G ₂₁One of them and said GTG value G to be shown at least ₂₂At least one of them, with real-time operation or deck watch than reciprocity mode and must concern S with the liquid crystal reaction relation is inversely proportional to approximately ₂₀ Control module 222 is according to concerning S ₂₀And duty cycle D ₂₀With control luminescence unit 221 output light B ₂₀

Over-drive value generation module 26 electrically connects with frame load module 23 and frame buffer module 24 respectively, with the said demonstration GTG value G of foundation ₂₁One of them and said GTG value G to be shown at least ₂₂At least one of them, obtain an over-drive value V with real-time operation or deck watch than reciprocity mode ₂₀ Frame output module 27 output over-drive value V ₂₀To driver element 212 with driving pixels array 211.

Hold; Because of according to liquid crystal indicator of the present invention be second o'clock apart from; The brightness of light is gradual by first level to be second level; And second o'clock product apart from interior brightness and light transmittance can compensate at first o'clock product apart from interior brightness and light transmittance, so that human eye can be experienced correct video data.In brief; The level of the brightness of the interior light of distance changes to reduce the generation of extra brightness liquid crystal indicator of the present invention through being controlled at not simultaneously; And need not reduce the duty cycle of light, not only can guarantee quality of display pictures, and can avoid reduce the serviceable life of backlight module.

[control method of the liquid crystal indicator of preferred embodiment]

Please with reference to shown in Figure 5; The control method of the liquid crystal indicator of preferred embodiment; Wherein, liquid crystal indicator has a display panels and a backlight module, and backlight module has a control module and luminescence unit; Control module is exported a light to display panels with duty cycle control luminescence unit, and control method comprises step S100 to step S110.

Step S100 be one first o'clock apart from, be one first level by the brightness of control module control light that luminescence unit is exported.

Step S110 be one second o'clock apart from, gradual by first level by the brightness of control module control light that luminescence unit is exported is one second level, wherein, duty cycle is defined as second o'clock distance and first o'clock distance and the second o'clock ratio apart from sum.

The control method of the liquid crystal indicator of present embodiment has detailed (like Fig. 2, Fig. 3 a to Fig. 3 i and shown in Figure 4) in above-mentioned liquid crystal indicator 2, do not give unnecessary details in this appearance.

[backlight module of preferred embodiment]

Please with reference to shown in Figure 6, the backlight module 22 of preferred embodiment comprises luminescence unit 221 and control module 222, and control module 222 is with duty cycle D ₂₀ Control luminescence unit 221 output light B ₂₀, duty cycle D ₂₀Be defined as at second o'clock apart from t _I2With first o'clock apart from t _I1Reach at second o'clock apart from t _I2The ratio of sum.At one first o'clock apart from t _I1In, the brightness of light is one first level L ₂₁, and at one second o'clock apart from t _I2In, the brightness of light concerns S according to one ₂₀By the first level L ₂₁Gradual is one second level L ₂₂

The backlight module 22 of present embodiment has detailed (like Fig. 2, Fig. 3 a to Fig. 3 i and shown in Figure 4) in the backlight module 22 in above-mentioned liquid crystal indicator 2, do not give unnecessary details in this appearance.

[control method of the backlight module of preferred embodiment]

Please with reference to shown in Figure 7, the control method of the backlight module of preferred embodiment, wherein, backlight module has a control module and luminescence unit, and control module is exported a light with duty cycle control luminescence unit, and control method comprises step S200 to step S210.

Step S200 be one first o'clock apart from, be one first level by the brightness of control module control light that luminescence unit is exported.

Step S210 be one second o'clock apart from, gradual by first level by the brightness of control module control light that luminescence unit is exported is one second level, wherein, duty cycle is defined as second o'clock distance and first o'clock distance and the second o'clock ratio apart from sum.

The control method of the backlight module of present embodiment has detailed (like Fig. 2, Fig. 3 a to Fig. 3 i and shown in Figure 4) in above-mentioned liquid crystal indicator 2, do not give unnecessary details in this appearance.

In sum; Because of according to backlight module of the present invention, liquid crystal indicator and control method thereof be second o'clock apart from; The brightness of light is gradual by first level to be second level; In other words, the control method of the control method of backlight module of the present invention, backlight module, liquid crystal indicator and liquid crystal indicator is to change reducing the generation of extra brightness through being controlled at not simultaneously apart from the level of the brightness of interior light, and need not change the duty cycle of light; Not only can guarantee quality of display pictures, and can avoid reduce the serviceable life of backlight module.

The above is merely illustrative, but not is restricted person.Anyly do not break away from spirit of the present invention and category, and, all should be included in the claim of the present invention its equivalent modifications of carrying out or change.

Claims (6)

1. liquid crystal indicator comprises:

One display panels; And

One backlight module has a luminescence unit and a control module, and this control module is exported a light to this display panels with this luminescence unit of duty cycle control, wherein,

One first o'clock apart from, the brightness of this light is one first level,

One second o'clock apart from, the brightness of this light is gradual by this first level to be one second level, wherein, this duty cycle be defined as this second o'clock distance with this first o'clock apart from and this second o'clock ratio apart from sum, wherein

This brightness of this light is to be this second level with the relation that is inversely proportional to approximately with a liquid crystal reaction relation by this first level is gradual.

2. liquid crystal indicator as claimed in claim 1; Wherein, The product of the part of one the 3rd level and this second o'clock distance deducts the brightness summation of this light in this part of this second o'clock distance; The brightness summation that equals this light in another part of this second o'clock distance in fact deducts the product of this another part of the 3rd level and this second o'clock distance, and this part and this another part sum equal second o'clock distance

In the part of second o'clock distance, the brightness of light is gradual by first level to be second level; In another part of second o'clock distance, the brightness of light maintains second level.

3. liquid crystal indicator as claimed in claim 1, wherein, the brightness of light according to stepped gradual by first level be second level.

4. the control method of a liquid crystal indicator; This liquid crystal indicator has a display panels and a backlight module; This backlight module has a control module and luminescence unit; This control module is exported a light to this display panels with this luminescence unit of duty cycle control, and control method comprises:

One first o'clock apart from, the brightness of this light is one first level; And

One second o'clock apart from, the brightness of this light is gradual by this first level to be one second level, wherein, this duty cycle be defined as this second o'clock distance with this first o'clock apart from and this second o'clock ratio apart from sum,

Wherein, this brightness of this light is to be this second level with the relation that is inversely proportional to approximately with a liquid crystal reaction relation by this first level is gradual.

5. the control method of liquid crystal indicator as claimed in claim 4; Wherein, The product of the part of one the 3rd level and this second o'clock distance deducts the brightness summation of this light in this part of this second o'clock distance; The brightness summation that equals this light in another part of this second o'clock distance in fact deducts the product of this another part of the 3rd level and this second o'clock distance, and this part and this another part sum equal second o'clock distance

In the part of second o'clock distance, the brightness of light is gradual by first level to be second level; In another part of second o'clock distance, the brightness of light maintains second level.

6. the control method of liquid crystal indicator as claimed in claim 4, wherein, the brightness of light according to stepped gradual by first level be second level.

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