KR100550866B1 - Flat fluorescent lamp - Google Patents

Abstract

The present invention relates to a flat fluorescent lamp for a backlight unit for irradiating light to a front surface of a panel of a flat panel display device, having a plurality of linear independent discharge channels, and having a small communication hole for mutual communication with the discharge channels in the horizontal direction of the discharge channel. A top plate which is bent to be formed in the upper surface of the discharge channel and the phosphor is coated on the inner surface of the discharge channel; And a lower plate on which a reflective film and a phosphor are printed on a front surface opposite to the top plate, and a bottom plate on which both sides of the rear side are formed to have an external electrode and an auxiliary electrode applied to the center so as to face the external electrode. The flat fluorescent lamp according to the present invention can realize a uniform luminance by connecting each of a plurality of independent linear discharge passages with fine communication holes to prevent electron drop phenomenon, and to be parallel to the external electrode and the external electrode on the rear of the lower plate. The use of the auxiliary electrode in the present invention not only improves the dark startup and lowers the starting voltage, but also increases the discharge efficiency by applying the second external electrode to both ends of the upper surface of the upper plate, which is useful in realizing the size of the flat panel display device. .

Flat fluorescent lamp, curved top plate, auxiliary electrode, communication hole

Description

Flat fluorescent lamp             

1 is a plan view of a top plate of a flat fluorescent lamp according to the present invention.

Fig. 2 is a bottom view of a bottom plate of a flat fluorescent lamp according to the present invention.

Fig. 3 is a partially enlarged cross-sectional view of the flat fluorescent lamp of Fig. 1A-B according to the present invention.

4 is a partially enlarged cross-sectional view of a flat fluorescent lamp of FIG. 1A'-B 'according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: top plate 11: discharge space

12, 12 ': second external electrode 13: fine communication hole

14: protective film 15: top fluorescent film

20: lower plate 21, 22: first external electrode

23: auxiliary electrode 24: reflecting film

25: lower fluorescent film 26: sealing material

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel fluorescent lamp for backlight unit (BLU) or general lighting for irradiating light to the front of a panel of a liquid crystal display (LCD), in particular having a plurality of linear independent discharge channels, the discharge A top plate formed with communication holes for channel communication; And a lower plate having a second electrode disposed at a center thereof so as to face the first external electrode and parallel to the first external electrode.

Typically, flat panel displays (FPDs) are classified into light emitting type and light receiving type. The light emitting type includes an electroluminescence device (EL), a plasma display panel (PDP), and the like, and the light receiving type includes a liquid crystal display. Since LCD itself cannot emit light and cannot form an image, a separate light source, a backlight unit (BLU), must be installed to observe the image, and the backlight unit can be mounted from a cold cathode fluorescent lamp (CCFL). Method of making irradiated light into a surface light source by using a diffusion plate or LGP, and by placing several external electrode fluorescent lamps (EEFL) in order to obtain uniform luminance on a large screen A method of making a light source and a surface light source method using a discharge having a discharge gas and a phosphor between two sheets of glass are applied. However, the production process of the display unit using the two electronic methods requires a lot of manpower and time for assembly, and the use of the light guide plate results in a large loss of light, low luminance, and difficulty in applying to a large flat panel display. Recently, in order to solve such a disadvantage, a flat fluorescent lamp, which is an electronic last method, which is composed of a single lamp and can simplify the manufacturing process, unlike a BLU using a conventional CCFL, has been developed as a next-generation BLU.

The basic luminescence principle of the flat fluorescent lamp is that electrons accelerated by an electric field flow in a discharge space containing an inert gas and a small amount of mercury and collide with mercury to emit 253.7 nm of ultraviolet light, The discharge space is interpreted to have the same meaning as the discharge channel by exciting the phosphor coated on the discharge space wall to emit visible light.

The flat fluorescent lamp may be classified into an internal electrode method and an external electrode method according to the electrode formation position, and the internal electrode method may be classified into a hot cathode start method and a cold cathode start method according to a start-up method. The hot cathode startup method is a method in which a preheating current flows through a filament to radiate an electron radiating material to sufficiently generate initial electrons, and then applies a starting voltage to turn on the primary cathode. The secondary battery is generated by applying an electric field of high voltage to the electrode to generate secondary electrons, and the secondary electrons flow back into the visible light through the phosphors. In the case of implementing the hot cathode startup method, a preheating device is required to emit the initial electrons, and the configuration is complicated. In the case of the internal electrode, the application is not easy due to the reduced life due to the loss of the electrode and the complexity of the configuration. The invention is described mainly with respect to an external electrode, but is not limited thereto and may be applied to an internal electrode method.

The flat fluorescent lamp has a discharge path by using meandering curved glass as a top plate and sealing the panel glass with a bottom plate, and secures a discharge path by inserting a rod-shaped spacer between two panel glasses. Can be distinguished in a manner. The meander-shaped upper plate forming glass method is a method of forming a rectangular shape by continuously bending a long tube in an S-shape to form electrodes generally at both ends of the discharge space. The above method requires high starting and discharging voltages due to the long discharge length, and thus has high heat generation, high pipe wall resistance, low efficiency, and low luminance uniformity. In particular, due to the large size of the liquid crystal display device, there is a problem that the circuit implementation for the required discharge voltage is not practical.

On the other hand, in the case of the upper and lower panel glass method, the luminance uniformity is improved than the upper plated glass method, but since the discharge space (discharge path) is formed of a plurality of long spacers, the manufacturing process is complicated, and the discharge path is rectangular or Because of the rhombus shape, plasma formation for discharge is more disadvantageous than cylindrical shape, and crack generation due to thermal shock is increased during manufacturing, and light emission is weakened at the edges of the multi-facets.

In addition, both the meander-shaped upper plate glass and the spacer interposing method have been pointed out as a problem of poor luminance uniformity due to interference between neighboring channels and electron dropping into a channel that is easy to discharge.

In order to solve the problems caused by the expansion of the conventional meander discharge space formed on the upper plate, the inventors have a linear independent discharge channel with a reduced discharge space, and includes a top plate formed with a communication hole for mutual communication with the discharge channels. It is to propose a flat fluorescent lamp. The flat fluorescent lamp according to the present invention utilizes the characteristics of the plasma discharge, which is formed in a round shape around the center of the discharge passage by providing an independent discharge passage in the form of a semicircle or a semi-ellipse in cross section. It is proposed to solve the problem caused by the discharge passage of the square or rhombus formed by the spacer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flat fluorescent lamp for improving interference between discharge channels.

Another object of the present invention is to provide a flat fluorescent lamp for improving the luminance uniformity defect due to the electron pulling phenomenon to the easy discharge channel.

It is still another object of the present invention to provide a flat fluorescent lamp having a low starting voltage by introducing a zero potential auxiliary electrode in the center of the lower plate so that the plasma discharge region can be formed relatively wide.

A flat fluorescent lamp for achieving the above object is a flat fluorescent lamp for a backlight unit for irradiating light to the front of the panel of the flat panel display device, and has a plurality of linear independent discharge channels, fine for the mutual communication of the discharge channels A communication plate is formed and an upper plate coated with a phosphor on an inner surface of the discharge channel; And a lower plate on which a reflective film and a phosphor are printed on the front surface opposite to the upper plate, and an external electrode is formed on the rear surface. In particular, the fine communication hole for the communication between the discharge channel is characterized in that formed in the central portion in the horizontal direction of the linear independent discharge channel. In addition, the flat fluorescent lamp according to the present invention is characterized in that the auxiliary electrode is formed so as to face in parallel to the external electrode in the longitudinal direction at the rear center of the lower plate.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. 1 is a plan view of a top plate having a plurality of linear independent discharge channels, and a communication hole for mutual communication between the discharge channels is formed in a center portion in the transverse direction of the discharge channel; FIG. FIG. 3 is a bottom enlarged view of the lower plate of FIG. 3 and FIG. 4 is a partial enlarged view of the A'-B 'cross section of the lower plate.

The flat fluorescent lamp according to the present invention is a glass top plate (10) bent so that the discharge passage (11) to which the phosphor material is applied is independently formed in a plurality of transverse directions; The lower plate 20 is sealed to the upper plate 10 and has a first external electrode 21 and 22 on the rear surface to which a high voltage is applied, and discharge gas is injected into the discharge passage and vacuum discharge is performed. And an exhaust port (not shown). A communication hole 13 for mutual communication between the discharge passages 11 is formed in the horizontal center portion of each discharge passage 11 of the upper plate, and the lower plate is disposed so as to face the first external electrodes 21 and 22 in parallel. (20) The auxiliary electrode 23 is applied to the rear center portion. Second external electrodes 12 and 12 ′ may be applied to both side ends of the upper surface of the top plate 10.

The glass plate 10 is bent in a circular or oval cross section so that a plurality of independent discharge passages are formed in the transverse direction, and each communication passage has a minute communication hole 13 for mutual communication between discharge passages in the horizontal direction of the discharge passage. ) Is formed. The communication hole is not only a function for preventing electrons from being easily discharged into the discharge channel, but also a function of facilitating the injection and discharge of discharge gas into a plurality of discharge passages, and a small amount during the baking process. It is a microchannel for smooth diffusion of mercury.

A protective film 14 / phosphor 15 or a phosphor may be coated on the inner surface of each discharge passage 11, and a reflective film for front reflection of light on the inner surface of the lower plate 20 opposite to the upper plate 10. 24 and phosphor 25 can be printed. The protective film and the phosphor is preferably applied by a printing method using a screen printing machine, but may be by a deeping, spraying, dispensing method. The protective film and the phosphor component may have a known structure, for example, magnesium oxide, alumina, or the like may be applied as the protective film, and the phosphor may be red (Y, Gd) BO ₃ : Eu or Y ₂ O ₃ : Eu; Zn ₂ SiO ₄ : Mn or BaAl ₁₂ O ₁₉ : Mn to emit green; BaMgAl ₁₄ O ₂₃ : Eu and the like that emit blue, but are not limited thereto. A portion 26 where the upper plate 10 and the lower plate 20 are in contact with each other may be provided with a seal 26 to which a glass encapsulant such as frit glass is printed in a stripe form to prevent separation. Preferably, the encapsulant has a similar thermal expansion coefficient value to the upper and lower plates, and is made of a material having high transparency.

The first external electrodes 21 and 22 according to the present invention are formed in the longitudinal direction at both ends of the lower plate through printing on the rear surface of the lower plate, and the auxiliary electrode 23 is applied to the center of the rear surface of the lower plate so as to face the first external electrode. . Screen printing or etching may be used for electrode printing, but is not limited thereto. The method of the external electrode is configured to prevent light non-uniformity due to the electrode, and to prevent localized darkening phenomenon compared to the internal electrode method, the auxiliary electrode applied to the central portion is the first external electrode on both ends of the lower plate rear As the position is increased, the electrode input voltage is increased to generate a discharge, and the proposed structure is made to compensate for the fact that the discharge efficiency is lower than the input voltage. The auxiliary electrode is connected to the first external electrode by a separate conductor so that the zero potential can be applied. The auxiliary electrode is generally used as a band-shaped electrode, but is not limited thereto, and electrodes of various modifications for extending the surface, for example, a circular hole having a constant diameter or a date are perpendicular to the band-shaped electrode. Various types of electrodes are possible, such as a shape. The rear externally formed first external electrodes 21 and 22 and the auxiliary electrode 23 are coated with a conductive material such as silver or copper, and are preferably printed with silver paste having high reflectivity. Apart from the first external electrodes 21 and 22, the second external electrodes 12 and 12 ′ may be applied to both ends of the upper surface of the upper plate. The second external electrodes 12 and 12 'induce an enlargement of the electrode area to decrease the cathode drop voltage, thereby lowering the starting voltage and the discharge voltage, and the electric field is formed on the upper and lower portions of the electrode to facilitate the formation of wall charges of electrons. It can serve to increase the discharge efficiency.

On the other hand, when the sealing operation of the upper and lower plates is finished, the exhaust is performed. The flat fluorescent lamp is filled with a small amount of mercury and an inert gas such as Ar, Ne, Kr, etc. At this time, it is preferable to inject gas and mercury in a sufficient vacuum (10 ^-5 torr or more), and in the flat fluorescent lamp The optimum gas pressure may be adjusted to an optimal value according to the discharge efficiency and the lamp life, and the amount of mercury may depend on the discharge space volume of the fluorescent lamp.

Although the flat fluorescent lamp according to the present invention has been described with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed herein, and may be applied within the scope of the technical idea. .

Flat fluorescent lamp according to the present invention can implement the luminance uniformity by preventing each electron directing phenomenon by connecting each independent linear discharge passage with a fine communication hole, parallel to the first external electrode and the first external electrode on the back of the lower plate By using the auxiliary electrode in the center, it is possible not only to improve the dark startup and to lower the starting voltage, but also to increase the discharge efficiency by applying the second external electrode to both ends of the upper surface of the upper plate, thereby efficiently increasing the size of the flat panel display device. Useful for

Claims (4)

In a flat fluorescent lamp for a backlight unit for irradiating light to the front of the panel of the flat panel display device, a flat fluorescent lamp having a plurality of linear independent discharge channels, so that a micro communication hole for mutual communication of the discharge channel is formed in the center of the discharge channel transverse A top plate that is bent and molded and a phosphor is coated on an inner surface of the discharge channel; And a reflecting film and a phosphor printed on the front surface facing the upper plate, and a lower plate on which the auxiliary electrode is longitudinally applied at the center portion so as to face the first external electrode and the first external electrode in parallel opposite sides at both rear ends thereof. Flat fluorescent lamps. The flat fluorescent lamp of claim 1, wherein the curved cross section of the upper plate is semicircular or elliptical. The flat fluorescent lamp of claim 1, wherein second external electrodes are further coated on both ends of the upper surface of the upper plate. The flat fluorescent lamp of claim 1, wherein a zero potential is applied to the auxiliary electrode applied to the lower surface of the lower plate.

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