TW556449B - Illumination device - Google Patents

Abstract

An illumination device includes a fluorescent tube arranged in a shell. The shell has a metal base and the fluorescent tube is arranged above the bottom of the metal base. An expansion board is arranged above the fluorescent tube, and a reflective board is arranged between the bottom of the metal base and the fluorescent tube. The illumination device is characterized in that the bottom of the metal base has at least one slot arranged opposite to the position of the fluorescent tube, thereby increasing the gap between the fluorescent tube and metal base.

Description

556449 V. Description of the Invention (1), [Field of the Invention] The present invention relates to a lighting device, and more particularly to a backlight device for a liquid crystal display. [Prior Art] Generally, a liquid crystal display includes a liquid crystal panel (which has two substrates and a liquid crystal layer sandwiched therebetween) and a lighting device, such as a backlight device, disposed behind the liquid crystal panel. The backlight device is configured to uniformly distribute a light from a light source on a surface of the liquid crystal panel. There are currently several types of backlight devices, such as a direct type and an edge type. FIG. 1 is a diagram for explaining a conventional direct type backlight device. The backlight device 100 includes a plurality of lamp tubes 110 and is disposed in a housing 120. More specifically, the lamp tube 110 is disposed in the housing 120. Above the bottom 124 of the metal base 122, the backlight device 100 also includes a diffuser 1 2 1 located above the lamp tube 1 1 0 and a reflective plate 1 2 3 located at the bottom 1 of the metal base 1 2 2 Between 2 4 and the lamp 1 1 0. In the conventional technology, the bottom of the metal base of the direct type backlight device is a flat surface, so the lamp tube is very close to the bottom of the metal base. When the lamp tube is lit, a capacitive effect occurs between the lamp tube and the bottom surface of the metal base. The closer the distance between the lamp tube and the bottom surface of the metal base is, the larger the capacitance is, and it is easy to generate a leakage current, which in turn makes the backlight device as a whole. The brightness uniformity and efficiency are worsened. [Summary of the Invention] Therefore, the object of the present invention is to provide a lighting device, which is characterized by providing a metal base with a novel structure, so that the distance between the lamp tube and the bottom surface of the metal base is increased to overcome or at least reduce the above-mentioned Prior art

ibi 00584.ptd Page 4 556449 V. The explanation of the problems encountered in (2) *. According to the lighting device of the present invention, it mainly includes an inner portion, the outer casing includes a metal base, and the metal has a substantially flat surface, and the lamp tube is disposed above the light tube. The lighting device is characterized in that a groove (preferably an arc groove) on the metal bottom is provided directly opposite to the bottom of the light tube and the metal base, so that if the light tube and the bottom of the metal base are Approximately a first vertical distance, the light tube and the metal bottom have a distance greater than the first best, and the second vertical distance is 5 · 0 times. In addition, the lighting device also includes a reflecting plate provided on the metal base tube. The lighting device of the present invention is suitable for reducing the capacitance effect due to the distance between the bottom surface of the metal base and the bottom surface of the metal base. Avoid adding lighting device (backlight device) [Explanation of the invention] Figure 2a shows that according to the present invention, it mainly contains three U-shaped lamp tubes 2 1 0 220 including a metal base 224 with a vertical spacing for the first vertical A diffuser plate is disposed above the lamp tube and between the bottom surface and the lamp tube, and reflects from the lamp to the diffuser plate. / For the backlight device of the liquid crystal display The novel groove design makes its lamp tube and conventional backlight device larger, so it can have or improve the leakage current problem, thereby increasing the brightness uniformity and efficiency. The lighting device 2000 of an embodiment is provided in a housing 220, wherein the housing and a housing 22, the three U-shaped tubes, a tube base and a metal base are mounted on the bottom. The space between the lamps is flat on the bottom surface of the table seat and the second vertical space is located at the position of at least a tube at the bottom of a housing containing a bottom seat. More detailed vertical spacing of the grooves between the faces. From about 1.5 to about

00584.ptd Page 5 556449 V. Description of the invention (3) The factory 2 1 0 is not above the metal base 2 2 4 and the lighting device 2000 has a reflector 240 provided on the lamp tube 21 and Between the metal bases 224 and a diffuser plate 250 is sealed at the top of the casing 2 2 2 of the casing 2 2 0. The side metal base 2 2 4 has a bottom 2 2 6, and the lamp tube 2 10 is arranged above the bottom 22 6 in parallel. The lighting device 20 0 is characterized in that the bottom 226 of the metal base 224 has a substantially flat surface 228 and two grooves 2 3 〇 and grooves 2 3 of the same shape as the lamp tube 2 10. 〇 is located directly opposite the lamp tube 210, thereby increasing the distance between the lamp tube 21 and the bottom 2 2 6 of the metal base 224. Fig. 3a is a sectional view of the lighting device 200 shown in Fig. 2a after the assembly is completed, and Fig. 3b is a partial enlarged view of the lighting device 200 shown in Fig. 3a. Referring to Fig. 3b, in this embodiment, the vertical distance d 'between the lamp tube 21o and the bottom of the groove 23o is greater than the vertical distance d between the lamp tube 21o and the flat surface 228. Preferably, d is about 1-5 times to about 5.0 times d.

The groove 2 3 0 can have various shapes, such as a ladder shape, a triangular shape, or an arc shape. Figure 2b shows a lighting device 3 00 according to another embodiment of the present invention. The structure of the lighting device 3 00 is substantially the same as that of the lighting device 2 00. Therefore, parts of the same structure are marked with the same as the lighting device 2 2 Label. The difference between the lighting device 3 00 and the lighting device 2 0 is that it uses a linear lamp tube 3 丨 〇 as a light source ', so the corresponding groove 3 丨 4 of its metal base 2 2 4 is also designed to be linear. The lamp tube of the present invention may be a cold cathode fluorescent lamp (CCFL). Although the lamp tube shown in the present invention is U-shaped (tube 2 1 0) or linear (tube 3 丨 0), the present invention

556449 V. Description of the invention (4) ’’ The lamp may also have other shapes, such as V, W, double V, triple U, etc. In the embodiment of the present invention, the lamp tubes 2 10 and 3 1 0 have two end portions 2 1 2 and 3 1 2 for electrically connecting to a power source. The two ends 2 1 2 and 312 of the lamp tube 2 1 0 and 3 1 0 are fixed to the base 224 of the casing 22 0. The reflecting plate 240 is disposed between the lamp tube 2 10 or 3 10 and the bottom 2 2 6 of the base 224. Therefore, when the lamp tube 2 10 or 3 1 0 is lit, the light directly entering the diffusion plate 2 50 will be mixed with the light reflected by the reflection plate 2 40 and entering the diffusion plate 2 50 to form the diffusion plate 25. 0 surface luminescence (surface luminance). In order to achieve high uniformity and consistency of the surface light emission of the lighting device, the surface of the reflecting plate 240 is substantially flat, has no grooves, and is non-conductive. The lighting device according to the present invention can be designed as a backlight device for a liquid crystal display. The backlight device according to the present invention is characterized in that a groove corresponding to the lamp tube is designed at the bottom of the metal base. Compared with the conventional backlight device of liquid crystal display, the design of the present invention can effectively increase the distance between the lamp tube and the metal bottom, thus greatly reducing or preventing the capacitive effect between the two, ^ improving the problem of leakage current and obtaining higher brightness Uniformity and low power consumption. Although the present invention has been disclosed in the foregoing embodiments, it is not intended to limit the present invention. 'Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention is protected. The scope shall be determined by the scope of the attached patent application.

00584.ptd Page 7 556449 Schematic description-[Illustration] In order to make the above and other objects, features, and advantages of the present invention more apparent, the following description will be described in detail with the accompanying drawings. Fig. 1: is a sectional view of a direct-type backlight device of a conventional liquid crystal display; Fig. 2a is an exploded perspective view of a lighting device according to an embodiment of the present invention; Fig. 2b is a diagram according to the present invention An exploded perspective view of a lighting device according to another embodiment of the invention; FIG. 3a: a sectional view of the lighting device shown in FIG. 2a; and FIG. 3b: a partially enlarged view of the lighting device shown in FIG. 3a. [Illustration of drawing number]

1 2 1 diffuser 123 reflector (non-metal) 2 1 2 end 222 housing 2 2 6 bottom 23 0 groove 1 0 0 backlight 1 1 0 tube 1 2 0 housing 122 metal base 1 2 4 bottom 2 0 0 Lighting 2 1 0 Tube 2 2 0 Housing 224 Metal base 2 2 8 Flat surface 24 0 Reflective plate (non-metal)

00584.ptd Page 8 556449 Brief description of the drawing, 2 5 G diffuser 3 0 0 lighting device 3 1 0 lamp 3 1 2 end 314 groove

00584.ptd Page 9

Claims (1)

556449 6. Scope of patent application 1. A lighting device comprising: a housing including a metal base, wherein the metal base includes a bottom having a substantially flat surface; at least one lamp tube is provided above the bottom of the metal base A diffuser plate is disposed above the light tube; a reflective plate is disposed between the bottom of the metal base and the at least one light tube, wherein the bottom of the metal base has at least one groove provided directly opposite the light tube; s position. 2. The lighting device according to item 1 of the scope of patent application, wherein the groove at the bottom of the metal base is an arc groove. 3. The lighting device according to item 1 of the scope of the patent application, wherein the lamp has a first vertical distance from a substantially flat surface at the bottom of the metal base, and the lamp has a distance from the bottom of the groove on the bottom of the metal base. A second vertical pitch that is greater than the f vertical pitch. 4. The lighting device according to item 3 of the scope of patent application, wherein the second vertical distance is about 1.5 to about 5.0 times the first vertical distance. 5. The lighting device according to item 1 of the scope of patent application, wherein the lighting device is a backlight device for a liquid crystal display. 00584.ptd Page 10