KR100560640B1 - Flat panel type fluorescent lamp - Google Patents

Abstract

The present invention relates to an electrode configuration of a flat fluorescent lamp.

Two glass substrates, an anode and a cathode formed on the inner surface of the lower glass substrate of the glass substrate, an insulator protective film formed on the anode and the cathode, a phosphor film formed on the inner surface of the upper glass substrate. In the flat type fluorescent discharge lamp comprising a discharge gas filled in the space between the two glass substrates, characterized in that the protective film surrounding the anode and the cathode is formed differently from other portions at the plate specific portion.

Therefore, since the discharge can be induced in a specific area of the flat lamp, the brightness of the flat fluorescent lamp can be evenly spread over the entire surface, and the reproducibility of the brightness pattern can be obtained.

Flat Panel, Fluorescent Discharge, Lamp, Backlight, Protective Film

Description

Flat panel fluorescent lamp

1 is a schematic side sectional view showing the basic configuration of a surface discharge method among flat fluorescent lamps.

Fig. 2 is a plan view showing the lower panel constituting the flat fluorescent lamp.

3 to 5 are side cross-sectional views showing an electrode structure in one embodiment of the present invention.

※ Explanation of symbols for main parts of drawing

11,21: lower glass substrate 13,23: anode

14,24: cathode 15,25,25 ', 35,45: protective film

16: protrusion 17: upper glass substrate

18: spacer 19: phosphor film

The present invention relates to a flat type fluorescent discharge lamp, and more particularly, to an electrode configuration of a flat type fluorescent discharge lamp configured to enable stable light emission.

In the development of the information society, the screen display device is an important foundation element. With the development of the information society, the demand for display devices is increasing in various forms. LCDs are evolving as a substitute for CRTs for mobile image display devices due to their light weight, thinness, and low power consumption. In particular, the development of TFT (Thin Film Transistor) LCD field is a breakthrough and can meet the demands of modern high-definition image display devices, and is being developed in various ways such as TV monitors in addition to mobile applications such as monitors of notebook computers.

In order for LCDs to serve as screen display devices in these fields, development of high quality images such as high definition, high brightness, and various color displays while maintaining the characteristics of light weight, thinness, and low power consumption as much as possible is at stake. .

In connection with the high quality of the screen, a light source for displaying the screen becomes a problem. Display light sources are particularly problematic in LCDs because LCDs themselves do not have luminous capabilities. In early LCDs such as TN and STN, there are many reflective types using external light sources, information display functions are limited, and the screen is small. Therefore, even in the presence of light sources, a small lamp is added to the front or side of the reflective LCD. This was used a lot.

However, as the screen has become larger and the demand for high quality has increased, the backlight method is used to install a light source behind the screen and display an image as light passes through the liquid crystal panel rather than a light source installed in front or side. As the light source of the backlight LCD, EL (Electro luminascence), LED (Light Emitting Diode), CCFL (Cold Cathode Flourscent Lamp), HCFL (Hot Cathode Flourscent Lamp) are used. The thin CCFL method is widely used in large color TFT LCDs.

However, in the case of the CCFL type backlight mainly used in large color TFT LCDs, since the main component of the gas encapsulated in the discharge tube is mercury, it is easy to form amalgam by combining with a metal, so it is easy to reduce the life of the lamp. The change is severe, and in particular, with the recent increase in environmental concerns, the disposal of wastes caused by the use of mercury, a toxic heavy metal, has become a problem.

In addition, CCFL-type fluorescent discharge tubes may be directly installed on the lower side of the liquid crystal panel to directly illuminate the screen, but large screens are mainly installed on the lower side side of the liquid crystal panel, so that the edges are illuminated by the light guide plate and the reflector. In the case of the edge type, the luminance is low.

This low luminance is closely related to the fact that 40% to 50% of the amount of light is lost in the process of converting the linear fluorescent discharge tube into a surface light source using a light guide acrylic plate or the like. Therefore, there has been a demand for the development of a new panel type backlight that can improve these problems.

According to the request, one of the newly developed flat plate fluorescent lamps using xenon (Xe) is introduced in European Patent WO 98/11596.

1 is a schematic side sectional view showing the basic configuration of a surface discharge method among flat fluorescent lamps. According to the configuration, the anode 13 and the cathode 14 are formed together on the lower glass substrate 11 to adopt a surface discharge method, and the insulator protective film 15 is formed in a semicircular shape on the electrode, and the upper glass substrate ( On the inner surface of 17), a phosphor film 19 is laminated. The spacing between the substrates is kept constant through the spacers 18. In principle, a glow discharge is used in the same way as a mercury fluorescent discharge tube. When a discharge voltage is applied, a low-pressure gas substance such as encapsulated xenon is excited to form a plasma phase, and ultraviolet rays emitted from the gas substance excite the phosphor on the surface of the discharge tube. To give out visible light.

Fig. 2 is a plan view showing the lower panel constituting the flat fluorescent lamp.

In the lower glass substrate 11 of the flat fluorescent lamp, two electrodes are formed in parallel and a protrusion 16 is formed to protrude slightly toward the anode 13 at regular intervals of the long cathode 14, when a voltage is applied. Make it easy to discharge. Therefore, in this part, the luminance becomes significantly higher than the surroundings.

However, artificially installed projections on the cathode to facilitate the discharge in many places on the screen because of the characteristics of the fluorescent lamp, if the discharge occurs only in any part of the wide panel surface, plasma is first formed at a high density only in this area and the luminance This is to eliminate the phenomenon in which the difference in luminance with other parts is remarkably increased.

For example, when a plurality of cathodes and anodes are arranged side by side at the same interval on all planes, the distance between the cathodes and anodes is the same, so the discharge may be concentrated only at a certain portion due to minute differences, which may result in a difference in luminance. The only difference is that the difference is so small that the next time the fluorescent lamp is turned on, a bright spot can be formed in a completely different place, and there may be a difference in brightness with other parts. In order to prevent such a problem, it is preferable to form an electrode so that an electric discharge easily occurs in a large number of places on the panel surface, and evenly arrange the discharge generation sites of the plurality of places on the panel surface. In addition, it is more preferable to form and use a pattern of a certain type to reduce the amount of light in the corresponding portion of the surface of the opposing glass substrate so that the individual discharge generation sites are dispersed in the surroundings.

The present invention is configured such that the discharge between the electrodes in a flat fluorescent lamp as described above so that the discharge between the electrodes in a certain portion is easier than the other portion, and evenly arranges this configuration in a large number of plate surface and also distributes the light to the peripheral part An object of the present invention is to provide a flat type fluorescent discharge lamp having an improved electrode structure so as to prepare a tool that can be used in advance.

The flat type fluorescent discharge lamp of the present invention for achieving the above object is two glass substrates, an anode and a cathode formed on the inner surface of the lower glass substrate of the glass substrate, an insulator protective film formed on the anode and the cathode, the inner surface of the upper glass substrate Formed phosphor film. In the flat type fluorescent discharge lamp comprising a discharge gas filled in the space between the two glass substrates, characterized in that the protective film surrounding the positive electrode and the negative electrode is formed differently from the other portions.

In the present invention, the method of differentiating the protective film from other parts in the specific part may vary the thickness or change the position at the specific part of the protective film to make the distance between the positive and negative protective films closer, or connect the positive and negative protective films. For example, such a method may be mentioned.

In addition, the material of the protective film at a specific portion may be formed differently from other parts.

The main problem in the present invention is that when the discharge occurs between the electrodes of the two polarities formed in the flat fluorescent lamp, that is, the anode and the cathode, when the plasma is formed, the conditions between the anode and the cathode are equally given, If several cathodes and anodes are installed at the same interval in parallel in one direction, the discharge will not be performed well, and even if the discharge occurs, the plasma density will be increased around the specific point where the discharge began, and the luminance will be uneven. Since the luminance pattern is not reproducible, the electrode structure is artificially installed so that discharge occurs easily at a specific part of the cathode and the anode installed on the front of the panel, and the specific part is made as many as possible and the distribution is uniform throughout the panel. .

In addition, a good discharge means that the voltage required for the discharge at a specific site is low, and the required discharge voltage is a distance between the anode and the cathode, the density or pressure of the discharge gas, the type of the discharge gas, and the insulating film forming the protective film. It depends on the dielectric constant and the placement of the protective film between the anode and cathode.

In addition, since it is difficult to partially control the pressure and type of gas in the surface light source for backlight having no partition structure among the factors influencing the discharge voltage, an example of partially varying the distance between the electrodes has been published. However, it is possible to make certain parts discharge well by using elements that have not been recognized until now, that is, other factors that facilitate discharge.

 Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Fig. 3 is a side sectional view showing an electrode structure in one embodiment of the present invention. In this example, as in the conventional example, a plurality of anodes 23 and cathodes 24 are formed long side by side on the lower glass substrate 21 surface, and the protective layer 25 surrounding the two electrodes has a predetermined interval at a double (25 ') length. Reference). When the protective film is formed in duplicate, the protective film may be applied to only one of the two electrodes, or the protective film may be formed on both electrodes at a specific position.

In this example, when the space filled with the discharge gas assumes the dielectric constant of 1, when the permittivity of the passivation layer is greater than 1, when the passivation layer is thick, a low voltage is applied to the space between the thickening passivation layers, it is difficult to cause discharge and relatively double layer is formed. Discharge is easy where it is not.

4 is a side sectional view showing an electrode structure in another embodiment of the present invention.

Unlike the case in which the protective film 35 is doubled to increase the thickness as shown in FIG. 3, the shape of the protective film is extended to the other electrode in this example. Even in this case, the pattern of discharge varies depending on the dielectric constant of the protective film. If the dielectric constant is larger than that of the gas space, the discharge is easily diverted to the outer side in the space between the two electrodes.

FIG. 5 is a side cross-sectional view illustrating a state in which the embodiment of FIG. 4 is further deepened and a state in which two electrodes are connected by a partial passivation layer 45. In this example, the same discussion as in FIG. 4 is possible. That is, when the dielectric constant of the protective film is greater than the dielectric constant of the gas space, where the protective film is connected between the electrodes, the voltage is small between the spaces and thus the voltage for discharge is not easily reached, so the discharge is likely to be bypassed from the outer side.

On the contrary, when a thin film of a specific portion is formed in the anode and the cathode formed side by side, the probability of discharge between the electrodes in the portion increases. However, if the discharge is severe, there is a risk that the thin protective film will be damaged and fail to protect the electrode. Therefore, the thickness or shape of the protective film should be determined in consideration of this point.

In addition, when the dielectric constant of the protective film is smaller than the gas space, the protective film plays a role similar to a kind of conductor, so that the thickness of the protective film may be increased or the protective film may be biased between the electrodes to easily discharge at the site.

According to the present invention, since an electrode structure capable of inducing a discharge in a specific portion of the flat fluorescent lamp can be formed, the brightness of the flat fluorescent lamp can be uniformly spread over the entire surface, and the luminance pattern can be reproduced. Therefore, it becomes easy to provide a tool which can evenly adjust the luminance according to the regular variation of the luminance.

Claims (5)

Two glass substrates, an anode and a cathode formed on the inner surface of the lower glass substrate of the glass substrate, an insulator protective film formed on the anode and the cathode, a phosphor film formed on the inner surface of the upper glass substrate. In the flat type fluorescent discharge lamp comprising a discharge gas filled in the space between the two glass substrate, At least one of the anode and the insulator protective layer surrounding the cathode may have a space between the insulator protective layer surrounding the anode and the insulator protective layer surrounding the cathode and a voltage smaller than that of other spaces, so that discharge is relatively difficult. Flat type fluorescent discharge lamp. The method of claim 1, The anode and the cathode are flat fluorescent lamps, characterized in that formed side by side alternately long over the entire surface of the lower glass substrate. The method of claim 1 And at least one of the insulator protective film surrounding the anode and the cathode is a double layer. The method of claim 1 And at least one of the anode and the insulator protective layer surrounding the cathode extends toward the other electrode. The method of claim 1, And at least one of the insulator protective layer surrounding the cathode and the cathode is connected to an insulator protective layer of the other electrode.

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