| 1. | A flat type fluorescent lamp comprising: an ultraviolet ray generation part formed in a lamp body including a discharge electrode; and a light emission part installed on an outer surface of the lamp body to emit fluorescent light by the ultraviolet ray irradiated from the ultraviolet ray generation part. |
| 2. | The flat type fluorescent lamp of claim 1 , wherein the light emission part comprises a phosphor layer applied on an outer surface of the lamp body. |
| 3. | The flat type fluorescent lamp of claim 2, the light emission part further comprises a transparent protective layer formed on the phosphor layer. |
| 4. | The flat type fluorescent lamp of claim 1 , wherein the light emission part is formed of a separated single unit comprising a transparent substrate, a phosphor layer formed on the transparent substrate and a transparent protective layer formed on the phosphor layer. |
| 5. | The flat type fluorescent lamp of claim 1 , wherein the lamp body is formed of a plurality of cylindrical tubes or a single rectangular parallelepiped body. |
| 6. | A method of manufacturing a flat type fluorescent lamp, the method comprising the steps of: injecting discharge gas in the lamp body and embedding an discharge electrode; forming a phosphor layer by applying phosphors on an outer surface of the lamp body through a precipitation, printing or spraying process; and forming a transparent protective layer on the phosphor layer. |
| 7. | A method of manufacturing a flat type fluorescent lamp, the method comprising the steps of: injecting discharge gas in the lamp body and embedding an discharge electrode; preparing a separated light emission unit comprising a transparent substrate, a phosphor layer formed on the transparent substrate and a transparent protective layer formed on the phosphor layer; and assembling the separated light emission unit on the lamp body. |
FIELD OF THE INVENTION The present invention relates to a flat type fluorescent lamp and a manufacturing method thereof, and more particularly, to a flat type fluorescent lamp that enhances light emission efficiency and a uniform brightness by separating an ultraviolet ray generation part from a light emission part in which a phosphor layer is separately applied on an outer surface of a lamp body.
BACKGROUND OF THE INVENTION A flat type fluorescent lamp has been widely used as a backlight of a flat display device or lighting device, being increasingly applied to a variety of applications. A typical flat type fluorescent lamp includes two flat glass substrates, a sidewall coupling the glass substrates to each other, and a plurality of spacers disposed between the glass substrates to uniformly maintain a gap between them and define a discharge path. A phosphor layer is deposited on an inner surface of a lamp body and discharge electrodes are formed on both ends of the sidewalls. Inner air is exhausted through an exhaust tube formed on the sidewall of the lamp body, after which the exhaust tube is sealed. When voltage is applied to the discharge electrodes formed on the both ends of the fluorescent lamp, discharge is realized on the discharge path, thereby exciting the phosphor layer to function as a planar light source.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a flat type fluorescent lamp according to an embodiment of the present invention; FIG. 2 is a sectional view of a flat type fluorescent lamp according to an embodiment of the present invention; FIG. 3 is a sectional view of a flat type fluorescent lamp according to another embodiment of the present invention; FIG. 4 is a sectional view illustrating an example where an ultraviolet ray generation part is separated from a light emission part in a flat type fluorescent lamp according to the present invention; and FIG. 5 is a sectional view of a flat type fluorescent lamp according to another embodiment of the present invention.
TECHNICAL PROBLEMS A typical flat type fluorescent lamp can realize the planar light source by forming the ultraviolet ray generation part together with the light emission part in a lamp body. However, it has problems in that the uniform brightness cannot be realized throughout the overall surface and the service life is short. That is, the brightness and the uniformity of the light emission can be improved by uniformly forming the phosphor layer on the inner surface of the lamp body. However, since the inner structure of the lamp body including the spacers is too complicated to easily apply the phosphor layer, the phosphor layer cannot be uniformly formed. In addition, the spacers cause the non-emission region. Furthermore, in the typical flat type fluorescent lamp, mercury is infiltrated into the phosphor layer formed on the inner surface of the lamp body, thereby increasing the consumption amount of the mercury. Furthermore, during the sealing process of the lamp body at a high temperature, the phosphor layer may be deteriorated, thereby reducing the service life of the products.
SUMMARY OF THE INVENTION Therefore, the present invention has been made in an effort to solve the above-described problems. It is an objective of the present invention to provide a flat type fluorescent lamp that eliminates the non-emission region, and prevents the consumption of the mercury to prevent the phosphor layer from being damaged by separating an ultraviolet ray generation part from a light emission part by separately applying a phosphor layer on an outer surface of a lamp body, To achieve the above objective, the present invention provides a flat type fluorescent lamp comprising an ultraviolet ray generation part formed in a lamp body including a discharge electrode; and a light emission part installed on an outer surface of the lamp body to emit fluorescent light by the ultraviolet ray irradiated from the ultraviolet ray generation part. The light emission part may include a phosphor layer applied on an outer surface of the lamp body. The light emission part may further include a transparent protective layer formed on the phosphor layer. Alternatively, the light emission part may be formed of a separated single unit comprising a transparent substrate, a phosphor layer formed on the transparent substrate and a transparent protective layer formed on the phosphor layer. The lamp body may be formed of a plurality of cylindrical tubes or a single rectangular parallelepiped tube. According to another aspect of the present invention, there is provided a method of manufacturing a flat type fluorescent lamp, the method comprising the steps of injecting discharge gas in the lamp body and embedding an discharge electrode; forming a phosphor layer by applying phosphors on an outer surface of the lamp body through a precipitation, printing or spraying process; and forming a transparent protective layer on the phosphor layer. According to still another aspect of the present invention, there is provided a method of manufacturing a flat type fluorescent lamp, the method comprising the steps of injecting discharge gas in the lamp body and embedding an discharge electrode; preparing a separated light emission unit comprising a transparent substrate, a phosphor layer formed on an outer surface of the transparent substrate and a transparent protective layer formed on the phosphor layer; and assembling the separated light emission unit on the lamp body.
INDUSTRIAL APPLICABILITY According to the present invention, since the phosphor layer is formed on the outer surface of the ultraviolet ray generation part, the light emission part can be separately formed or prepared, thereby improving the uniformity of the phosphor layer and easing the manufacturing process. In addition, the quality and life service of the product can be improved. Furthermore, the productivity can be improved and the required number of the diffusing plates and optical sheets can be reduced, thereby saving the manufacturing costs. In addition, by applying the light emission part between the transparent substrate and the transparent protective layer, the damage of the phosphor layer can be prevented.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in more detail hereinafter in conjunction with the accompanying drawings. FIGS. 1 and 2 show a flat type fluorescent lamp according to a first embodiment of the present invention. As shown in the drawings, the inventive flat type fluorescent lamp is for realizing a planar light source such as a backlight of a flat display device or lighting device, having a rectangular parallelepiped lamp body 1. The lamp body 1 includes transparent front and rear substrates 3 and 5 and a side seal member 7 attaching the front and rear substrates 3 and 5 to each other. Spacers 9 are disposed between the front and rear substrates 3 and 5 to uniformly maintain a gap between the front and rear substrates 3 and 5 and define a discharge path in the lamp body 1. The spacers 17 may be formed of a tube shape as shown in the drawings or a rectangular bar. On opposite ends of the discharge path defined by the spacers 9, discharge electrodes 11 are installed. The discharge electrodes 11 are formed of a cold cathode or a thermal cathode and integrally supported on the side seal member 7. The above-described lamp body 1 is sealed by molten bonding and discharge gas is injected in the lamp body 1 to form an ultraviolet ray generation part 13. The ultraviolet ray generation part 13 of the present invention is formed without forming the phosphor layer on the inner surface of the lamp body 1. Therefore, a light emission part 15 including a phosphor layer formed on an outer surface of the lamp body 1. The light emission part 15 is excited by the ultraviolet ray irradiated from the ultraviolet ray generation part 13. That is, the light emission part 15 of the present invention is formed by applying the phosphor layer 17 on the outer surface of the front substrate 3 of the lamp body 1. A transparent protective layer 19 is applied on the phosphor layer 17. Here, the phosphor layer 17 is formed on the outer surface of the front substrate 3 after the lamp body 1 is sealed through the molten bonding. Therefore, it becomes possible to form a uniform layer thickness, thereby preventing the phosphor layer from being damaged. In this embodiment, the front substrate 3 constituting the lamp body 1 is preferably formed of ultraviolet ray-transmitting material such as quartz so that the ultraviolet ray irradiated from the ultraviolet ray generation part 13 can be effectively transmitted. The lamp body 1 of the present invention may be formed of a plurality of cylindrical tubes as well as a single rectangular parallelepiped body. The cylindrical tube type lamp body 1 is illustrated in FIG. 3. The lamp body 1 is formed by adjacently arranging and bonding a plurality of cylindrical tubes 1 a. The ultraviolet ray generation part 13 is formed in each cylindrical tube 1a. The light emission part 15 is formed on an outer surface of each cylindrical tube 1a. A method for forming the inventive fluorescent lamp of the present invention will be described hereinafter. The lamp body 1 may be formed of a plurality of cylindrical tubes or the single rectangular parallelepiped body. The discharge gas is injected in the lamp body 1 and the discharge electrodes 1 1 are buried, thereby forming the ultraviolet ray generation part 13 without the phosphor layer. Therefore, during the molten bonding process of the lamp body 1 , the phosphor layer is not damaged. After the above, phosphors are applied on the outer surface of the front substrate 3 of the lamp body 1 , thereby forming the phosphor layer 17. The application of the phosphors is performed by a precipitation, printing or spraying process. Next, the transparent protective layer 19 is applied on the phosphor layer 17, thereby completing the manufacture of the flat type fluorescent lamp. FIGS. 4 and 5 show a flat type fluorescent lamp according to a second embodiment of the present invention. As shown in the drawings, the lamp body 1 is identical to that of the first embodiment except for the structure of the light emission part. The light emission part of this embodiment is formed in a single unit separated from the lamp body 1 and is then assembled with the lamp body 1. To this end, the light emission part 15 includes a phosphor layer 17 formed by applying phosphors on a transparent substrate 21 and a transparent protective layer 19 installed on the phosphor layer 17. Since the phosphor layer 17 is formed on a separated transparent substrate 21 , the phosphor layer can be uniformly formed. In addition, since the light emission part 15 is separated from the lamp body, there is no need to go through the high temperature process, thereby preventing the phosphor layer from being damaged. In addition, the transparent protective layer 19 functions to protect the phosphor layer 17. Preferably, the lamp body 1 may be formed of a plurality of cylindrical tubes or a single rectangular parallelepiped body. The cylindrical tube type lamp body 1 is illustrated in FIG. 5. The lamp body 1 is formed by adjacently arranging and bonding a plurality of cylindrical tubes 1 a. The ultraviolet ray generation part 13 is formed in each cylindrical tube 1a. The light emission part 15 that is separately prepared is assembled with the lamp body 1 . A method for forming the inventive fluorescent lamp of the present invention will be described hereinafter. The lamp body 1 may be formed of a plurality of cylindrical tubes or the single rectangular parallelepiped body. The discharge gas is injected in the lamp body 1 and the discharge electrodes 1 1 are buried, thereby forming the ultraviolet ray generation part 13 without the phosphor layer. After the above, the phosphor layer 17 is formed by applying phosphors on the outer surface of the transparent substrate 21 that is separately prepared from the lamp body 1. The application of the phosphors is performed by a precipitation, printing or spraying process. Next, the transparent protective layer 19 is applied on the phosphor layer 17. Then, the light emission part 15 is assembled on the lamp body 1 , thereby completing the manufacture of the flat type fluorescent lamp.