CN101377902A - LED backlight module unit and temperature control method thereof - Google Patents

Abstract

The invention provides an LED backlight module and its temperature control method, which can control the temperature of the LED backlight module within a safe range. Specifically, the temperature control method of the LED backlight module of the present invention includes: obtaining the brightness BL of the LED backlight module; detecting the temperature of the LED backlight module; comparing the temperature of the LED backlight module with a preset temperature; If the temperature of the LED backlight module is greater than or equal to the preset temperature, calculate the target brightness BL' of the LED backlight module; adjust the brightness of the LED backlight module according to the target brightness BL'. The LED backlight module temperature control method of the present invention detects the temperature of the LED backlight module, and when the temperature of the LED backlight module reaches or exceeds a critical temperature, the present invention reduces the brightness of the LED backlight module to simulate the LED The further rise of the temperature of the backlight module protects the LED backlight module and prevents the lifespan of the LED backlight module from decreasing.

Description

LED backlight module and its temperature control method

technical field

The present invention relates to a temperature control method, in particular to a temperature control method of an LED backlight module.

Background technique

In recent years, the rapid development of the flat panel display (FPD) industry dominated by thin film transistor liquid crystal display technology (TFT-LCD) has brought unprecedented development opportunities to the upstream panel industry and optical material industry. Among them, the backlight is provided by CCFL, EEFL , LED, OLED, FFL and other light sources, the more mature one is CCFL. The full name of CCFL is Cold Cathode Fluorescent Lamp, that is, cold cathode lamp. CCFL seals an inert gas Ne+Ar mixed gas in a glass tube, which contains a small amount of mercury vapor (several mg), and coats the inner wall of the glass with phosphor. A high-voltage high-frequency electric field is applied between the two electrodes, and the mercury vapor is excited in this electric field to produce energy-releasing luminescence effect, emitting ultraviolet light with a wavelength of 253.7nm, and the phosphor atoms on the inner wall are excited by ultraviolet light to enhance their Energy level, when the atoms return to the original low energy level, visible light is emitted (the wavelength of this visible light is determined by the material characteristics of the phosphor). CCFL has many very good characteristics, such as excellent white light source, low cost, high efficiency (power goes in and light goes out), stable and predictable operation, brightness can be easily changed, light weight, etc., but CCFL has its own The problems of color, power consumption, and mercury content are difficult to solve.

LED refers to Light Emitting Diode, which is what we often call light-emitting diodes. This product and its application are not available now, and its application can be seen everywhere in our real life, such as roadside billboards and household appliances. LEDs are used as the light source for various indicator lights and backlighting on mobile phone keyboards. As far as its application in display products is concerned, it should also be regarded as an emerging technology product. From the perspective of the principle of light emission, since the LED is made of several layers of very thin doped semiconductor materials, one layer has excess electrons, and the other layer lacks electrons to form positively charged "holes". Through the combination of electrons and holes, the excess energy is released in the form of light radiation. LEDs are based on this principle to achieve electro-optic conversion. According to the different physical properties of semiconductor materials, LEDs can emit light from ultraviolet to infrared. Different colors of light under different spectrums, especially after the technical problem that LEDs cannot emit white light have been solved, have laid a fundamental foundation for the application of LEDs in the display field.

The main purpose of using LED as the backlight source of LCD TV is to improve the image quality, especially in terms of color saturation. The display screen with LED backlight technology can obtain a wide enough color gamut to make up for the defect of insufficient number of colors displayed by LCD devices. It can meet or even exceed the requirements of Adobe RGB and NTSC color standards, and can reach more than 100% of NTSC ratio. Some manufacturers have launched LCD TV panels with LED backlights, emphasizing the performance of bright red and dark green, which can display more color than the previous method. Realistic colors. At the same time, because of the flat light source characteristics of LED, the LED backlight can also realize the color and chromaticity adjustment function of sub-regions that cannot be compared with CCFL, so as to achieve more accurate color reproduction, so as to meet the needs of graphic publishing and graphic design. The dynamic adjustment can make the brightness and contrast can be dynamically corrected when displaying different pictures to achieve better picture quality.

In addition, the advantage of LED as a backlight is that it can replace the use of color filter. The three-color RGB LED adopts the color sequential method (color sequential) technology, and utilizes the characteristics of the persistence of human vision to achieve a full-color effect, so it can replace the color filter. However, the LED backlight module is not without disadvantages. The temperature control of the LED backlight module is still an important issue that the LED backlight module must overcome. Due to the high brightness requirements of the backlight module, the LED backlight module needs to use a large number of LED lamp tubes, which leads to the problem of temperature rise of the LED backlight module. Chinese patent application CN200410002701.5 provides an adjusting device for reducing the temperature of the LED light source by adding a fan, but due to space and noise control limitations, this method cannot be applied to LED backlight modules.

Chinese patent application CN200580032859.X provides an LED array with a temperature sensor. By detecting the temperature of the LED array, if the detected temperature is too high, the current input to the LED wick is reduced to reduce the temperature of the LED wick. . However, the patent application does not explain key issues such as how to reduce the current of the LED wick and how much the current is reduced. Because LED backlight modules are generally used in display devices, if the current of the LED tube is too low, the brightness of the LED backlight will be too low, which will affect the user's viewing. If the current of the LED tube is limited, the LED backlight module The effect of temperature control is limited, and it is possible that after reducing the current of the LED tube, the temperature of the LED backlight module will continue to rise. Therefore, there is a need in the art for a control method capable of precisely controlling the temperature of the LED backlight module.

Contents of the invention

In order to solve the above problems, the present invention provides an LED backlight module, including an LED backlight assembly, a controller and at least one temperature sensor, the temperature sensor detects the temperature of the LED backlight assembly, and transmits the detected temperature data to the controller, The controller receives the temperature data and compares the temperature data with a preset temperature, if the temperature data is greater than or equal to the preset temperature, the controller calculates the target of the LED backlight assembly brightness, and adjust the brightness of the LED backlight assembly to the target brightness.

The target brightness is BL': BL'=BL (1-coef),

Among them, BL is the brightness of the LED backlight module under normal conditions, and coef is the real-time coefficient of backlight adjustment:

coef=M·T/Cycle,

Among them, M is the adjustment range of the backlight unit, T is the temperature of the LED backlight module, and Cycle is the maximum value of the backlight adjustment accuracy.

The controller can adjust the brightness of the LED backlight assembly to the target brightness BL' in a stepwise manner.

If the LED backlight module includes at least two temperature sensors, the controller compares the received temperature data and takes the maximum value as the temperature data of the LED backlight module.

Further, the present invention also provides a temperature control method of an LED backlight module, comprising:

Obtain the brightness BL of the LED backlight module;

Detect the temperature of the LED backlight module;

Comparing the temperature of the LED backlight module with a preset temperature;

If the temperature of the LED backlight module is greater than or equal to the preset temperature comparison, calculate the target brightness BL' of the LED backlight module;

The brightness of the LED backlight module is adjusted according to the target brightness BL'.

The temperature control method of the LED backlight module may also include: adjusting the brightness of the image signal.

The above-mentioned target brightness is BL': BL'=BL·(1-coef),

Among them, coef is the real-time coefficient of backlight adjustment:

coef=M·T/Cycle,

Among them, M is the adjustment range of the backlight unit, T is the temperature of the LED backlight module, and Cycle is the maximum value of the backlight adjustment accuracy.

The temperature of the LED backlight module is a stable value obtained from multiple detections.

The LED backlight module temperature control method of the present invention detects the temperature of the LED backlight module, and when the temperature of the LED backlight module reaches or exceeds a critical temperature, the present invention reduces the brightness of the LED backlight module to simulate the LED The further rise of the temperature of the backlight module protects the LED backlight module and avoids the decrease of the service life of the LED backlight module. At the same time, the temperature control method of the LED backlight module of the present invention not only reduces the brightness of the LED backlight module, but also corrects the brightness of the image signal, making it difficult for the user to perceive the change of the brightness of the backlight, which is not beneficial to the normal viewing of the user. will have any effect.

Description of drawings

FIG. 1 is a schematic diagram of a common LED backlight assembly.

FIG. 2 is a schematic diagram of an embodiment of the LED backlight module of the present invention.

FIG. 3 is a schematic diagram of an embodiment of a temperature control method for an LED backlight module of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the present invention, and to make the above-mentioned purpose, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG. 1 is a schematic diagram of a common LED backlight assembly. As shown in the figure, the LED backlight assembly 100 includes a reflective plate 110, a plurality of LEDs 120, a light guide plate 140 and a diffuser plate 150. Wherein, reflector 110 can be a kind of circuit board that is provided with reflective film on the surface; A light-conducting and heat-dissipating material is poured outside the LED 120 to form a light-conducting and heat-dissipating layer 130 . The light-guiding and heat-dissipating layer is generally connected with components that can dissipate heat, such as the shell of the backlight assembly 100 , so as to dissipate heat. The light guide plate 140 and the diffuser plate 150 are respectively placed on the upper end of the light guide and heat dissipation layer.

When working normally, the LED 120 is turned on and starts to work and emit light. Part of the light emitted by the LED 120 directly shines on the light guide plate 140, and the other part reaches the light guide plate 140 after being reflected by the reflector 110; The LED 120 is sealed, and the heat generated by the LED 120 is discharged through the structure such as the via hole on the reflector 110; the light guide plate 140 is placed between the light guide heat dissipation layer and the diffusion plate 150, and the received light generated by the LED 120 and the reflector The light reflected by 110 scatters to the diffuser plate 150, and the diffuser plate 150 is placed above the light guide plate 140 to diffuse and output the light generated by the LED 120.

Due to the large number of LED light tubes, and the LED light tubes themselves cannot completely convert into light energy, some heat energy will inevitably be generated, and the heat energy of many LED light tubes will accumulate, so that the backlight assembly 100 will accumulate a large amount of heat during the working process. , in addition, some light energy that cannot be reflected to the diffuser plate 150 will eventually be converted into heat energy, which further increases the temperature of the backlight assembly 100 .

FIG. 2 is a schematic diagram of an embodiment of the LED backlight module of the present invention. As shown in the figure, the LED backlight module 200 of this embodiment includes an LED backlight assembly 100 , a temperature sensor 210 and a controller 220 . The LED backlight module 200 adds a temperature sensor 210 and a controller 220 on the basis of the common LED backlight assembly 100 . The temperature sensor 210 is used to detect the temperature of the LED backlight assembly 100 and transmit the detected temperature data to the controller 220 . The controller 220 receives the temperature data sent by the temperature sensor 210, and compares the temperature data with a preset temperature (for example, 50° C.), if the current temperature detected by the temperature sensor 210 is lower than the preset temperature, The controller 220 continues to wait for new data; if the current temperature detected by the temperature sensor 210 is greater than the preset temperature, the controller 200 controls to reduce the brightness of the LED tubes of the LED backlight assembly 100 .

Specifically, the temperature sensor 210 can be a contact temperature sensor, which is attached to the LED backlight assembly 100 or arranged inside the LED backlight assembly 100 . Since the temperature measuring element of the contact temperature sensor has good thermal contact with the measured object, the heat balance is achieved through the principle of heat conduction and convection, and the indicated value is the temperature of the measured object. This temperature measurement method has relatively high accuracy and can measure the temperature distribution inside the object. The temperature sensor 210 can also be a non-contact temperature sensor, which can be arranged near or inside the LED backlight assembly 100 . Since the temperature measuring element of non-contact temperature measurement is not in contact with the measured object, the principle of radiative heat exchange is commonly used. The main feature of this temperature measurement method is that it can measure small targets in motion and objects with small heat capacity or rapid changes. The temperature distribution of the temperature field can also be measured, but it is greatly affected by the environment. Preferably, the temperature sensor 210 in this embodiment is a contact temperature sensor. In order not to affect the structure of the LED backlight assembly 100 , the temperature sensor 210 of this embodiment is disposed outside the LED backlight assembly 100 . Certainly, the position of the temperature sensor 210 is different, and the above preset temperature should also be different. If the temperature sensor 210 is arranged inside the LED backlight assembly 100, the preset temperature value can be relatively high; if the temperature sensor 210 is arranged outside the LED backlight assembly 100, the preset temperature value can be relatively low. In order to obtain a more comprehensive temperature of the LED backlight assembly, multiple temperature sensors in this embodiment can be provided and distributed around the LED backlight assembly 100, and the temperature of the LED backlight assembly can be obtained by calculating the average or maximum temperature of the multiple temperature sensors. 100 temp.

The controller 220 can be an embedded processor, or an MCU (Micro Controller Unit), or a programmable device. The controller 220 receives the temperature data detected by the temperature sensor 210, and compares the temperature data with a preset temperature (for example, 50° C.), if the current temperature detected by the temperature sensor 210 is lower than the preset temperature, The controller 220 continues to wait for new data; if the current temperature detected by the temperature sensor 210 is greater than the preset temperature, the controller 200 controls to reduce the brightness of the LED tubes of the LED backlight assembly 100 . The preset temperature here is a critical value, which can be changed by the user's setting, and can also be set according to the performance index of the LED backlight module itself. For example, the optimal operating temperature of the LED backlight module should be less than 50°C, so the preset temperature here can be 50°C, or lower than 50°C, such as 45°C, 40°C and so on.

The brightness control of the LED backlight assembly 100 can be realized by sending a control command to the LED backlight assembly 100 . The drive signal can be a PWM (pulse width modulation) signal (that is, a pulse width modulation signal) with a certain duty cycle. The PWM drive signal is also the drive current, because the brightness is determined by the luminous flux of the RGB-LED (RGB light-emitting diode). Yes, and the LED luminous flux has a linear relationship with the current, so it can also be said that the brightness is determined by the driving current.

Since the LED backlight assembly 100 is generally used in a display device, if the brightness of the LED backlight assembly 100 changes too fast and decreases too much at one time, the LED backlight assembly 100 will suddenly become dark, which will definitely affect the user's viewing experience. And if the temperature detected by the temperature sensor 210 is greater than the above-mentioned preset temperature, since the LED backlight assembly 100 has been in the working state, its temperature will continue to rise. Change the state where the temperature continues to rise, so that if the temperature continues to rise, it may cause damage to the LED backlight assembly 100 itself. Therefore, after the temperature detected by the temperature sensor 210 is higher than the preset temperature, how to reduce the brightness of the LED backlight assembly 100 and how much the brightness is reduced becomes a key issue of the present invention.

In this embodiment, the brightness of the LED backlight assembly 100 is controlled in the following manner:

As mentioned above, if the brightness of the LED backlight assembly 100 decreases too little after the temperature detected by the temperature sensor 210 is higher than the preset temperature, the state of continuous temperature rise cannot be changed. Then, in order to prevent the temperature of the LED backlight assembly 100 from continuing to rise after the detected temperature is greater than the critical temperature, it is only necessary to make the heat generated by the LED backlight assembly 100 less than or equal to the heat emitted by the LED backlight assembly 100 .

Regardless of the gradual change process of the brightness of the LED backlight, it is assumed here that the brightness of the LED backlight decreases immediately after the controller 220 issues a control command. Since the LED backlight assembly is in use, there is a thermally conductive insulating sheet between the backplane of the display device, so it can be roughly considered that there is no gap between the LED backlight assembly and the backplane, and the contact thermal resistance between them is set to N, and the unit is ℃/ W. Therefore, the temperature generated by unit power is δT=N·δw(1).

Let the maximum value of the backlight adjustment accuracy be Cycle, and let the unit adjustment range M of the backlight have a linear relationship with the power δw consumed per unit, and set δw=k·M (2).

(稍大于1)，设 $\mathrm{\δ}{T}_{\mathrm{bl}}=\∂\·\mathrm{\δT}.$ To suppress the continuous rise of temperature, the temperature equivalent to the reduction of backlight brightness should be greater than or equal to the temperature generated by the LED backlight component itself, so δT _bl ≥ δT, the floating coefficient is introduced

(slightly greater than 1), set $\mathrm{\δ}{T}_{\mathrm{bl}}=\∂\&Center\; Dot;\mathrm{\δT}.$

Substitute into (1), (2) to get:

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; bl</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&delta;w</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; \&PartialD;</span><span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&delta;T</span>}<span\; class="notranslate">\; .</span>$

have to: $m=\frac{\&PartialD;\&Center\; Dot;\mathrm{\&delta;T}}{N\&Center\; Dot;k}.$

Real-time factor for backlight adjustment:

coef＝M·T/Cycle

Real-time temperature-controlled backlight adjustment:

BL'=BL·(1-coef)

Among them, BL is the brightness of the LED backlight under normal conditions.

The above is the calculation method of the adjusted brightness of the LED backlight when the brightness of the LED backlight is adjusted at one time. However, as mentioned above, if the brightness of the one-time adjustment is too large, it may cause discomfort to the user. Therefore, this embodiment The LED backlight module can adjust the brightness of the LED backlight in a gradual manner.

If it is adjusted by gradient, the real-time coefficient of backlight adjustment:

coef'=coef+δcoef,

coef' is the backlight adjustment coefficient controlled by the fading period; δcoef is the unit change of the backlight adjustment coefficient, and the positive or negative is determined by the difference between the real-time coefficient of the backlight adjustment controlled by the fading period and the previous backlight adjustment coefficient.

It can be seen that the LED backlight module of this embodiment reduces the brightness of the LED backlight to suppress the continuous rise of the temperature of the LED backlight module, thereby protecting the optical performance of the LED lamp tube and avoiding the reduction of the life of the LED. At the same time, the LED backlight module of this embodiment only adds peripheral devices such as temperature sensors on the basis of general-purpose LED backlight components, which is low in cost and strong in versatility.

FIG. 3 is a schematic diagram of an embodiment of a temperature control method for an LED backlight module of the present invention. As shown in the figure, the LED backlight module temperature control method of the present embodiment includes:

Step 310: Obtain the brightness BL of the LED backlight module;

Step 320: detect the temperature of the LED backlight module;

Step 330: comparing the temperature of the LED backlight module with a preset temperature;

Step 340: If the temperature of the LED backlight module is greater than or equal to the preset temperature comparison, calculate the target brightness BL' of the LED backlight module;

Step 350: adjust the brightness of the LED backlight module according to the target brightness BL';

Step 360: Adjust the brightness of the image signal.

Specifically, for general LED backlight modules, the brightness BL of the LED backlight module can be obtained by reading data such as user settings; and for some LED backlight modules that can automatically adjust the brightness of the backlight according to the image signal , the brightness BL of the LED backlight module can be obtained by analyzing the received image signal, for example, calculating the average brightness of the image signal and so on.

The temperature of the LED backlight module is generally detected by a temperature sensor. In order to avoid the impact of instantaneous temperature changes on the display of the LED backlight module, this embodiment determines the current temperature of the LED backlight module through the stable value obtained by multiple detections of the temperature sensor, for example, by calculating the temperature of the LED backlight module within 1 second. The average temperature of the temperature is used to obtain the current temperature of the LED backlight module, etc. In this embodiment, the temperature of the LED backlight module can also be obtained by reading data from multiple temperature sensors.

After obtaining the temperature of the LED backlight module, this embodiment compares the temperature of the LED backlight module with a preset temperature. The preset temperature here is a critical value, which can be changed by the user's setting, and can also be set according to the performance index of the LED backlight module itself. For example, the optimal operating temperature of the LED backlight module should be less than 50°C, so the preset temperature here can be 50°C, or lower than 50°C, such as 45°C, 40°C and so on.

If the temperature of the LED backlight module is lower than the preset temperature, it means that the LED backlight module is currently working normally and there is no need to control the temperature. And if the temperature of the LED backlight module is greater than or equal to the preset temperature, the temperature of the LED backlight module needs to be controlled. In this embodiment, at first the target brightness BL' of the LED backlight module is calculated according to the brightness BL of the LED backlight module:

BL'=BL·(1-coef)

Among them, coef is the real-time coefficient of backlight adjustment:

coef＝M·T/Cycle

Among them, M is the adjustment range of the backlight unit, T is the temperature of the LED backlight module, and Cycle is the maximum value of the backlight adjustment accuracy. Since M, T, and Cycle are all positive numbers, the real-time coefficient coef for backlight adjustment is also positive. It can be seen that the target brightness BL' must be smaller than the brightness BL of the LED backlight module under normal conditions.

After obtaining the target brightness BL' of the LED backlight module, the method for controlling the temperature of the LED backlight module in this embodiment starts to adjust the brightness of the LED backlight module. There are many adjustment methods here, and the simplest method is to directly set the brightness of the LED backlight module to the target brightness BL'. However, if the gap between the target brightness BL' and BL is too large or BL' changes frequently, the brightness of the LED backlight module will suddenly dim or flicker, which may affect the user's viewing experience. In order to avoid this situation, this embodiment can adjust the brightness of the LED backlight module step by step, for example, adjust once a second, adjust the brightness level of 1 each time, until the target brightness BL' is reached, etc. etc., the present invention is not limited thereto.

After adjusting the brightness of the LED backlight module, in order not to affect the user's viewing, this embodiment can also adjust the brightness of the image signal. Taking directly setting the brightness of the LED backlight module as the target brightness BL' as an example, since BL'=BL·(1-coef), the adjusted backlight brightness becomes (1-coef) times under normal conditions. Since the brightness of the image viewed by the user is the result of the joint effect of the brightness of the backlight and the brightness of the image signal, as long as the brightness of the image signal is adjusted to the original 1/(1-coef), it is difficult for the user to notice the change. Of course, this may disable some signal of the image signal itself, but overall it is beneficial to the user.

It can be seen that the LED backlight module temperature control method of the present invention detects the temperature of the LED backlight module. When the temperature of the LED backlight module reaches or exceeds a critical temperature, the present invention reduces the brightness of the LED backlight module. The further rise of the temperature of the LED backlight module is simulated, thereby protecting the LED backlight module and avoiding the decline of the service life of the LED backlight module. At the same time, the temperature control method of the LED backlight module of the present invention not only reduces the brightness of the LED backlight module, but also corrects the brightness of the image signal, making it difficult for the user to perceive the change of the brightness of the backlight, which is not beneficial to the normal viewing of the user. will have any effect.

Of course, the above descriptions are not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention shall also belong to protection scope of the present invention.

Claims (10)

1, a kind of LED-backlit module, comprise the LED-backlit assembly, it is characterized in that, described LED-backlit module also comprises controller and at least one temperature sensor, temperature sensor detects the temperature of LED-backlit assembly, and detected temperature data is transferred to controller, controller receives described temperature data and described temperature data is compared with a predefined temperature, if described temperature data is more than or equal to this predefined temperature, controller calculates the object brightness of described LED-backlit assembly, and the brightness of adjustment LED-backlit assembly is to object brightness.

2, LED-backlit module according to claim 1 is characterized in that: described object brightness is BL ':

BL′＝BL·(1-coef)，

Wherein, BL is the brightness of the LED-backlit module under the normal condition, and coef is the real-time coefficient of adjustment backlight:

coef＝M·T/Cycle，

Wherein, M is the amplitude that unit backlight adjusts, and T is the temperature of LED-backlit module, and Cycle is the maximal value of adjustment precision backlight.

3, LED-backlit module according to claim 2 is characterized in that: described controller is adjusted the brightness of described LED-backlit assembly to object brightness BL ' in the mode of stepping.

4, according to the arbitrary described LED-backlit module of claim 1-3, it is characterized in that: described LED-backlit module comprises at least two temperature sensors, described controller is made comparisons the temperature data that receives, with wherein the maximal value temperature data as the LED-backlit module.

5, a kind of temperature-controlled process of LED-backlit module comprises:

Obtain the brightness BL of LED-backlit module;

Detect the temperature of LED-backlit module;

The temperature of LED-backlit module is compared with a predefined temperature;

If the temperature of LED-backlit module is compared more than or equal to this predefined temperature, calculate the object brightness BL ' of LED-backlit module;

According to object brightness BL ' brightness of LED-backlit module is adjusted.

6, the temperature-controlled process of LED-backlit module according to claim 5 is characterized in that: the temperature-controlled process of described LED-backlit module also comprises: the brightness to picture signal is adjusted.

7, according to the temperature-controlled process of claim 5 or 6 described LED-backlit modules, it is characterized in that: described object brightness is BL ':

BL′＝BL·(1-coef)，

Wherein, coef is the real-time coefficient of adjustment backlight:

coef＝M·T/Cycle，

Wherein, M is the amplitude that unit backlight adjusts, and T is the temperature of LED-backlit module, and Cycle is the maximal value of adjustment precision backlight.

8, the temperature-controlled process of LED-backlit module according to claim 7 is characterized in that: the brightness of described picture signal is adjusted into 1/ original (1-coef) doubly.

9, the temperature-controlled process of LED-backlit module according to claim 7 is characterized in that: the mode by stepping is adjusted to object brightness BL ' with the brightness of LED-backlit module.

10, the temperature-controlled process of LED-backlit module according to claim 7 is characterized in that: the temperature of described LED-backlit module is the stationary value that repeated detection obtains.

Images