WO2008009177A1 - Tapered prism illumination device for lcd backlight - Google Patents

Abstract

A tapered prism illumination device for LCD backlight mounted in the rear of the LCD (1) includes a plurality of LEDs and a heat sink (3). Each of the LEDs includes a light emitting point (21) that is packaged externally with a transparent covering body (22) and, on a light emitting path of the LEDs, a tapered prism (23) is disposed. In the periphery of the LEDs a thermally conducting substrate (24) is disposed, while the heat sink (3) is mounted in the rear of the LED and has a reflective surface (31,32) in the periphery of the LEDs. When light is generated at the light emitting point (21), it can be projected onto the tapered prism, by which it is bent by 90°, and then projected on to the LCD (1) by the reflective surface (31,32). The heat generated by the high power LEDs is conducted by the thermally conducing substrate (24) to the heat sink (3) for removal.

Description

 Conical mirror type LCD backlight illumination device

 The invention relates to a conical prismatic LCD backlight illumination device, in particular to an LCD backlight illumination device which can be modularly assembled, easy to manufacture and repair, and can exhibit uniform and saturated brightness and color. Background technique

 The current LCD backlighting device is mainly based on white light CCFL (cold cathode fluorescent tube). The CCFL is placed behind the LCD, and then the light is projected onto the light guide plate, the diffusion sheet, the brightness enhancement sheet, and then projected on the LCD. The picture on the LCD is revealed. In the face of increasing LCD size, the required CCFL and its driver circuit must also increase. To achieve the backlighting function of large-size LCDs, most CCFLs must be serial/parallel. However, CCFLs have the following disadvantages -

1. CCFL brightness is uneven, even if the CCFL of the maximum number of serial/parallel is within the size range of the LCD, the brightness that can be obtained is still uneven, especially for large-size LCD;

 2. CCFL has a short life span, about 400 6,000 hours will start to reduce the brightness, and it is not easy to replace, resulting in a significant reduction in the life of the LCD;

 3. CCFL color saturation is insufficient, its color temperature is about 4800K, so it can only achieve the color gamut of NTS C specification of about 80%, especially for red light, it can not meet the high specification color requirements, such as The measurement of the instrument and the environment in which the specific color is expressed

Confirmation Underneath, it can be clearly found that its color is missing;

 4. CCFL is more power-hungry and contains harmful substances “mercury” during production. This is undoubtedly an injury to environmental protection. Therefore, the Kyoto reservations are scheduled to be banned from July 1, 2006. Therefore, the adoption of other backlight sources is an inevitable trend in the development of LCDs.

 At present, the technology commonly used in the industry is to use LED as a backlight source. LED has been used on small-sized LCD screens for a period of time, such as mobile phones and PDAs. In recent years, the brightness of LEDs has been greatly improved due to technological advancement. With its light weight, sturdiness, long life and fast start-up response, it has become the target of many large-size LCDs.

 Generally, LEDs are used as a source of LCD backlights. The number of LEDs on the LCD side or on both sides is different. When the power is turned on, the LED light source is projected on the LCD to make the image on the LCD appear. However, in general, the light of the LED is not uniformly scattered, but is concentrated in a small range, so that an area on the LCD that projects the light of the LED is particularly bright, but the brightness of the bright area can be seen around the bright area, and the color is not uniform. Presented.

 In addition, any of the foregoing LCD devices cannot be replaced individually when the components of the backlight unit are damaged, and must be replaced as a whole, which is costly. For large-size LCDs, only a single component loss must be eliminated, not only wasted, but also the LCD waste will increase the burden of environmental protection.

Therefore, a conical prismatic LCD for solving the above problems is provided The backlight illumination device is necessary. The cone-shaped LCD backlight device adopts the method of projecting light behind the LCD, and the LED light is refracted by the cone mirror to refract the 90-degree angle light source, so that the overall brightness and color of the LCD can be uniformly presented. . And the special heat dissipation mechanism removes the problems of high-power LED heating failure and brightness attenuation, and achieves simple maintenance with independent module design.

 The main object of the present invention is to provide a conical prism type LCD backlight illumination device which can utilize a high power LED as a light source, and the light source is projected onto the conical prism to be refracted around the reflector at an appropriate angle. Reflected on the light guide plate to evenly reflect the light source onto the LCD, so that the LCD can display high brightness and high saturation color.

 Another object of the present invention is to provide a conical prismatic LCD backlight illumination device, which provides a special heat dissipation mechanism, which can mass produce a single specification backlight illumination module, thereby reducing the probability of failure due to heat, and can improve Production yield and brightness of large LCDs.

 A further object of the present invention is to provide a conical prismatic LCD backlight illumination device. Since the LED is composed of a small module, when a single component is damaged, the damaged portion of the module can be directly replaced, so that Maintenance of the size LCD becomes simple and feasible.

A conical prismatic LCD backlight illumination device is provided, including an LCD, a plurality of LEDs, and a heat sink base. The LED system is located behind the LCD and is used to generate light onto the LCD. The LED is a high-power LED that generates sufficient light. Each LED is packaged. The light-emitting point is externally packaged with a light-transmitting cover, and a tapered prism is disposed on the light-emitting path of the LED. A heat-conducting substrate is disposed around the LED, and the heat-dissipating base is disposed behind the LED. The heat-dissipating base is provided with a reflective surface around the LED, and the reflective surface is a slope. When the light-emitting point generates light, the light can be projected onto the tapered prism, and the light is bent at an appropriate angle through the tapered mirror, and then the light is projected onto the light guide sheet and the diffusion sheet to make the light The evenly distributed is presented on the LCD. The heat generated by the high-power LED is guided to the heat dissipation base via the heat-conducting substrate to maintain product stability.

 Compared with the prior art, the invention has the following advantages:

 Through the above structure, the operation of the invention is dispersed and uniformly projected onto the LCD after being bent for a plurality of times, thereby avoiding the lack of brightness unevenness of the light directly concentrated on the LCD-point, and prolonging the life of the product. . In addition, the present invention adopts a high-power LED, and through the area distribution of the heat-dissipating base itself, a material with high heat dissipation and low cost such as copper, aluminum, and tantalum is used, and the heat can be appropriately dispersed to increase the durability of the product. And the light of each LED can extend to the surrounding LED range, so that the light is further diffused and overlaps with the surrounding LED light to make the light on the LCD more uniform. Moreover, the modular design of the present invention makes the product easier to produce, and the present invention further provides positioning points on the heat dissipation base for facilitating the LED device. DRAWINGS

 1 is a perspective view of a conical prismatic LCD backlight illumination device of the present invention;

 2 is a cross-sectional view of the tapered prismatic LCD backlight illumination device;

FIG. 3 is a schematic diagram of the operation of the conical prismatic LCD backlight illumination device. detailed description

 Referring to FIG. 1 to FIG. 3, the present invention provides a conical prismatic LCD backlight illumination device, which is composed of an LCD 1, a plurality of LEDs 2, and a heat dissipation base 3. The LCD 1 is used to generate a picture, and a diffusion sheet 11 and a light guide sheet 12 are disposed behind the light guide sheet 11. The light guide sheet 11 is used to receive the light source and is evenly distributed to prevent the light from being concentrated. The diffusion sheet 12 further uniformizes the light. Dispersion, so that the entire LCD 1 picture can maintain consistent brightness and color saturation.

 The LED 2 system is located behind the LCD 1 and is used to generate light onto the LCD 1. The LED 2 is a high power LED that produces sufficient light. Each of the LEDs 2 includes a light-emitting point 21, and the light-emitting cover 21 is externally provided with a transparent cover 22, and a light-emitting path 23 is disposed on the light-emitting path of the LED 2, and when the light-emitting point 21 generates light, Light can be projected onto the tapered mirror 23, and the light is bent at an appropriate angle through the tapered mirror 23, and then projected onto the LCD 1 by the reflecting surfaces 31, 32 which will be described later. A heat conducting substrate 24 is disposed around the LED 2, and the heat conducting substrate 24 is a superconducting substrate of a nanometer process, and the heat generated by the high power LED 2 can be guided to the heat radiating base 3 to maintain product stability.

 The heat dissipation base 3 is disposed behind the LED 2 for mounting the LED 2 and an associated circuit unit (not shown). The heat dissipation base 3 is provided with reflective surfaces 31 and 32 around the LED 2, and the reflective surface 31 is disposed. 32 is a sloped surface, and receives light from the tapered prism 23, and bends and projects onto the LCD 1.

 Since each LED 2 is modular in design, the present invention is quite convenient in terms of manufacturing and maintenance, and the defective LED 2 can be replaced separately without replacing the entire backlight.

Through the above structure, the present invention is operated by the light-emitting point 21 to emit light first. The light is projected onto the conical mirror 23 via the path, and is bent at an appropriate angle through the conical mirror 23, and then projected onto the reflecting surfaces 31, 32, which bend the light. Projected onto the LCD 1, since the light has been dispersed and uniformly projected onto the LCD 1 after being bent for a plurality of times, it is possible to prevent the light from being directly concentrated on the LCD-point, and the life of the product is prolonged. In addition, the present invention uses a high-power LED 2, the heat of which can be conducted to the heat dissipation base 3 via the heat-conducting substrate 24, and the heat distribution of the heat-dissipating base 3 itself is increased by using copper, aluminum, germanium, etc. The material can disperse the heat properly and increase the durability of the product.

 The height of the reflective surface 31 on the inner side of the LCD 1 is slightly lower than the reflective surface 32 around the LCD, so that the light of each LED 2 can extend to the range of the surrounding LED 2, so that the light is further diffused, and the surrounding LED 2 rays Overlap, making the light on the LCD 1 more uniform.

 Moreover, the modular design of the present invention makes the product easier to produce, and the present invention further provides an positioning point 33 on the heat dissipation base 3 for facilitating the device of the LED 2. This embodiment is provided on the heat conductive substrate 24 The slot 25 allows the LED 2 and the thermally conductive substrate 24 to be quickly positioned on the heat sink base 3 through the notch 25 for rapid production.

 The above description is only a specific description of the specific embodiments of the present invention, and it is understood by those skilled in the art that any non-substantial changes or modifications are included in the scope of the present invention.

Claims

Claim 1 . A conical prismatic LCD backlight illumination device, characterized in that it comprises - LCD;  a plurality of LEDs, the device is disposed behind the LCD, the LED includes a light-emitting point, and the light-emitting point is externally packaged with a light-transmitting cover body, and a light-emitting mirror is disposed on the light-emitting path of the LED, and the base of the LED is disposed around the base Thermally conductive substrate;  a heat sink base disposed behind the LED for mounting the LED and the associated circuit unit, and the heat sink base is provided with a reflective surface around the LED;  The light emitted by the aforementioned LED light-emitting point is bent through the tapered mirror and projected onto the surrounding reflective surface.  2. The conical prismatic LCD backlight illumination device of claim 1 wherein the LED is a high power LED <  3. The conical prismatic LCD backlight display device according to claim 1, wherein the angle of the conical prism is such that the light of the light-emitting point is bent at an appropriate degree.  4. The conical mirror type LCD backlight illumination device according to claim 1, wherein the reflective surface is a sloped surface.  5. The conical prismatic LCD backlight illumination device of claim 1 wherein the height of the reflective surface on the inside of the LCD is slightly lower The reflective surface around the LCD allows the light of each LED to be improved Diffusion.  6. The conical prismatic LCD backlight illumination device of claim 1, wherein the heat dissipation base is provided with a positioning point to facilitate locking of the LED device. 7. The conical prismatic LCD backlight device of claim 1, wherein the back side of the LCD is provided with a diffusion sheet and a light guide sheet, so that the light projected by the LED can pass through the light guide sheet and the diffusion sheet. , and then evenly projected onto the LCD.