TW200933565A - Temperature control system of backlight module - Google Patents

Abstract

A temperature control system of a backlight module is applied in the backlight module in which the light-source quantities of the backlight units are directly increased to enhance the brightness of the liquid crystal display. The control circuit timely regulates down the light-emitting brightness of the light-emitting module through the detection of an electric resistance value of at least a thermo-sensitive resistance and matching of the pulse-width modulation, such that the temperature increase speed of the backlight unit is slowed down to avoid continuous accumulation of the heat energy generated by the light emitting module, which results in the disabling actions of the whole related electronic elements and the shortening of its use life-span.

Description

200933565 IX. Description of the invention: 'Technical field of the invention>> The present invention relates to a temperature control system for a backlight module, in particular to a resistance value detection through a thermistor, so that the control circuit adjusts the backlight module in a timely manner Temperature control system for illuminating brightness. [Prior Art] Liquid crystal is an organic compound between a solid and a liquid, and is a compound having a molecular arrangement of a specific molecular weight. When heated to a certain temperature, it becomes a transparent liquid and is cooled to a certain temperature. In the following, it will become a turbid solid state of crystal, so the characteristics are called liquid crystal. Due to the basic characteristics of liquid crystals, the basic principle of liquid crystal displays is to seal the liquid crystals in a glass box and then apply an electric field to change the orientation of the liquid crystal molecules. The change in orientation changes the optical properties, which can be changed by the polarizer. Translucent to achieve the effect of extinction. But 'the LCD monitor is in the environment where the sunlight or the external environment is very bright.' As a display kanban, it is often because the reflected light is too strong or the scattered light is too messy to make the display color faded even if the surface is not visible or visible.疋Because the degree of freedom of the display itself is insufficient to make the kneading image be reflected by the outside or the scattered light, at least the brightness of the liquid crystal display should be increased to 1000 cd/m2 or more to improve the problem that the kneading surface is covered by the ambient light source. To increase the brightness of the liquid crystal display, it is the most direct method to increase the number of light sources of the backlight unit. For example, when a high-performance reflective sheet, a brightening sheet, and a liquid crystal panel with a high aperture ratio can be simultaneously combined, the utilization of light can be increased, thereby achieving High brightness effect. However, when the light is emitted, the light source itself generates heat. The more the number of light sources, the higher the total heat generation. As the lighting time of the backlight unit increases, the temperature of the entire liquid crystal display module will become higher and higher, resulting in higher and higher temperatures. The product is hot, the display contrast is degraded, and even the electronic components are unable to work due to overheating, which in turn causes problems in the crash. It should be noted that 'the existing liquid crystal display is a factor that cannot be handled due to high temperature'. Therefore, the brightness of liquid crystal display products on the market is mostly about 300 cd/m2, with a semi-reflective design, or without using a backlight unit. Reflecting the way of liquid crystal display to overcome the problem of external light source reflection. However, these methods also cause the screen of the semi-reflective liquid crystal display ❹ the number of colors is reduced, the color purity is not high, which affects the picture quality, and the total reflection product cannot be displayed in a place where the light is insufficient. SUMMARY OF THE INVENTION Therefore, in order to solve the above-mentioned defects and avoid the existence of a defect, the main purpose of the present invention is to increase the illumination brightness of the illumination source by increasing the number of illumination sources to greatly improve the illumination of the backlight module. The continuous accumulation of heat from the light source avoids related materials and electronic components, does not reduce performance or shorten the life due to excessive temperature, and increases the service life of the liquid crystal module. ❿ Based on the above purpose, the present invention provides a backlight module for directly increasing the number of light sources of the backlight unit to increase the brightness of the liquid crystal display, and at least includes: a backlight for providing brightness of the backlight module a light-emitting module; at least one thermistor for sensing the temperature of the backlight module, and a control circuit for receiving a change signal of the resistance value of the thermistor for controlling the brightness output of the light-emitting module, thereby adjusting the backlight The temperature of the module produces 'slows the rate of temperature increase' and gradually decreases. The light emitting module is composed of a plurality of light emitting diodes (Light

Emitting Diode ; LED) or cold cathode fluorescent tube (c〇ld Cathode 200933565

The Fluorescent Lamp (CCFL) is composed of a control circuit that controls the brightness of the illumination module by Pulse Width Modulation (PWM). When the control circuit receives the resistance value of the thermistor lower than the reference value, the brightness of the light emitting module is lowered; when the control circuit receives the resistance value of the thermistor is higher than the reference value, the The brightness of the light-emitting module is supplied to the light-emitting module to maintain the brightness of the light-emitting module. The effect of the present invention is to increase the number of light sources of the backlight unit.

The backlight module structure of the brightness of the liquid crystal display is improved by the detection of the resistance value of the thermistor and the pulse width modulation of the control circuit, so as to timely reduce the brightness of the illumination module and make the backlight single degree. Increase = slow 1 = drop. The heat generated by the light-emitting module can be avoided. Secondly, the temperature of the liquid crystal display module (LCD) rises, and the related materials and the mines cannot be avoided _ from the ^ n U Or the life test 70 pieces will be reduced by (4) high temperature [Implementation]

For the purpose of step-by-step description of the chain A of the present invention, but the compartment: the inner valley and the technical description, now the number of sources of the embodiment is the most direct brightness of the 2$ module' to increase the light source of the backlight unit, Raise ^ so the total amount of heat generated in the backlight unit is higher, the brightness of the display module (LCM), but the backlight unit lighting time % like the heat generated by the illuminating source, will follow The temperature of the entire LCD module is also higher and higher. 200933565 will become higher and higher, causing the product to become hot, the display contrast to drop, and even the electronic components can not work due to overheating, which leads to the problem of crashing.

Please refer to FIG. 1 , so the present invention proposes a temperature control system for a backlight module that is applied to a backlight module that directly increases the number of light sources to improve the liquid crystal display. The at least one includes: - a control circuit 1G, the control circuit: 10 series A light-emitting module 12 is controlled by a pulse width modulation (PWM) method, wherein the light-emitting module 12 is composed of a plurality of light-emitting diodes or cold cathode fluorescent lamps to provide brightness of the backlight module. And the at least one thermistor 11 is configured to sense the temperature of the backlight module, and the thermistor transmits the change signal of the resistance value to the control circuit 10, so that the control 4 channel 10 is used for controlling Adjusting the brightness output of the light-emitting module, thereby adjusting the temperature change of the light-emitting module, so that the temperature increase speed is slowed down and gradually decreases. The surface brightness of the backlight module increases or decreases as the number of illumination sources on the illumination module 12 increases or decreases. For example, when the backlight module includes 64 light-emitting diodes (LED) light-emitting chips as the light-emitting source, the surface of the backlight module is brightly produced to be 3078 〇Cd/m2', and the brightness can be passed through the liquid B-day panel. The surface brightness of IXM is as high as 3388 ed/m2'. Such high brightness can be used as a display kanban to improve the display screen being covered by the ambient light source in an environment where the sunlight or the external environment is very bright. Referring to FIG. 2, as the lighting time of the illumination module 12 increases, the heat generated by the illumination module 12 will continue to accumulate, causing the temperature of the optical module to gradually rise, and the liquid crystal display module ( The temperature of Lcm) also rises. At this time, the resistance value is transmitted to the control circuit through the detection of the resistance value of the thermistor u. When the resistance value of the thermistor U is lower than a predetermined reference value, it indicates that the temperature of the backlight module has passed. When the height is high, the control circuit 10 adjusts the pulse width to reduce the brightness of the illumination module 200933565 12, so that the heat of the illumination module 12 is lowered, so that the temperature increase rate of the backlight unit 1 is slowed down, and gradually decline. Therefore, it is possible to prevent the heat generated by the light-emitting module 12 from accumulating, causing the temperature of the entire liquid crystal module (LCM) to rise continuously, and the normal operation cannot be performed, and the material and the electronic component can be avoided. Excessive temperature reduces performance or shortens life. However, when the control circuit 10 receives the resistance value signal of the thermistor u higher than a predetermined reference value, 'the backlight cylinder is not too high or has been reduced to a reasonable range, then the control circuit 10 The pulse width of the 10D diode is supplied to the power output of the LED module 12, and the illumination degree of the LED module 12 is maintained, and the illumination brightness of the LED module 12 is not adjusted. For the device for directly increasing the number of illumination sources of the backlight unit to increase the surface brightness of the liquid crystal display module (LCM), the higher the number of light sources, the higher the total heat generation, the detection of the resistance value of the thermistor by the present invention In combination with the pulse width modulation of the control circuit, the brightness of the illumination module can be lowered in a timely manner, so that the temperature increase of the backlight unit can be slowed down and gradually decreased, thereby avoiding the accumulation of heat generated by the illumination module, resulting in The entire LCD module can not operate normally, increasing the service life of the liquid crystal module, and also avoiding related materials and electronic components, without reducing the performance or shortening the life due to excessive temperature. The above is only the preferred embodiment of the invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the present invention are covered by the scope of the invention. 9 200933565 ; [Simplified illustration of the drawings] Fig. 1 is a schematic diagram of the temperature control system of the embodiment of the present invention. 2 is a flow chart for determining the resistance value of the control circuit of the embodiment of the present invention. [Main component symbol description] I 〇 : Control circuit II : Thermistor 12 : Light-emitting module

Claims (1)

200933565 'X. Patent application scope: ' 1. A temperature control system for a backlight module, comprising at least: a light emitting module for providing brightness of the backlight module; at least one thermistor for sensing the backlight mode a temperature change of the group; and a control circuit that receives the change signal of the resistance value of the thermistor to control the brightness output of the light-emitting module, thereby adjusting the temperature of the backlight module. 2. The temperature control system of claim 1, wherein the illuminating module is composed of a plurality of illuminating diodes. 3. The temperature control system of claim 1, wherein the illumination module is comprised of a plurality of cold cathode fluorescent tubes. 4. The temperature control system of claim 1, wherein the control circuit controls the brightness of the illumination module by a pulse width modulation. 5. The temperature control system of claim 1, wherein when the control circuit receives the resistance value of the thermistor lower than a reference value, the illumination brightness of the illumination module is lowered; when the control circuit receives If the resistance value of the thermistor is higher than the reference value, the luminance of the illumination module is not adjusted. 11