KR20040098158A - Plasma Display Panel comprising means to increase visible light - Google Patents

Abstract

PURPOSE: A plasma display panel is provided to achieve improved luminance by decreasing ultraviolet ray emitted through a front panel and increasing visible light. CONSTITUTION: A plasma display panel comprises a front panel(FP) and a back panel(BP); a filter set(80) arranged on the front panel such that the filter set passes a selected visible light; and a unit which is transparent to visible light and reflects ultraviolet ray longer than a wavelength of 330nm to the back panel. The unit is arranged on or in the front panel, or on the filter set.

Description

Plasma display panel comprising means for increase visible light

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display, and more particularly, to a plasma display panel having a visible light increasing means (hereinafter referred to as a plasma display panel).

PDP puts a gas such as Ne + Xe between the front glass and the back glass and the glass enclosed by the partition therebetween and applies a voltage to the anode and the cathode so that the ultraviolet light emitted from Xe is converted into visible light by exciting the phosphor. One of the flat panel type video display devices used as display light.

PDP has many advantages that are suitable for large-sized display among various flat panel displays such as liquid crystal display (LCD), field emission display (FED), and electro-luminescence display (ELD), which are being actively studied.

The high brightness and high luminous efficiency of the PDP can be achieved through the plasma generation by the efficient electrode structure and the driving circuit and the improvement of the UV radiation efficiency and the visible light conversion efficiency of the phosphor.

1 shows a perspective view of an AC PDP according to the prior art having such characteristics.

Referring to FIG. 1, a PDP according to the related art is provided with a front glass substrate 10 and a rear glass substrate 12 facing in parallel with the front glass substrate 10, and a filter set in front of the front glass substrate 10. 30 is provided. The filter set 30 blocks infrared rays (IR), EMI, and the like emitted from the PDP. The filter set 30 is composed of a black stripe region 32 and a filtering region 32b. The filtering area 32b is an area in which filtering elements such as infrared rays or EMI generated in the discharge cells are incident and filtered. The black stripe region 32 corresponds one-to-one with the partition wall 26 to be described below, and is for preventing the filtering elements generated in one discharge cell from entering the neighboring discharge cells. First and second discharging holding electrodes 14a and 14b are arranged in parallel on a surface of the front glass substrate 10 facing the rear glass substrate 12. The first and second discharge sustain electrodes are transparent. A gap d exists between the first and second discharge sustain electrodes 14a and 14b as shown in FIG. 2. A first bus electrode 16a is formed on the first discharge sustain electrode 14a, and a second bus electrode 16b is formed on the second discharge sustain electrode 14b, respectively. The first and second bus electrodes 16a and 16b are for preventing voltage drop due to resistance during discharge. The first and second discharge sustain electrodes 14a and 14b and the first and second bus electrodes 16a and 16b are covered with a first dielectric layer 18, and the first dielectric layer 18 is covered with a protective film 20. have. The passivation layer 20 protects the first dielectric layer 18 having low durability from discharge, thereby allowing the PDP to operate stably for a long time, and at the same time, discharge a large amount of secondary electrons during discharge to lower the discharge voltage. As the protective film 20, a magnesium oxide film (MgO) is widely used.

On the rear glass substrate 12, an address electrode 22 for pixel addressing is provided. One address electrode 22 is provided in the discharge cell, and three address electrodes 22 are provided in one pixel. At this time, the address electrodes 22 are all arranged in parallel, but are arranged perpendicularly to the first and second discharge sustain electrodes 14a and 14b. The second dielectric layer 24 covering the address electrode 22 is formed on the rear glass substrate 12, and a plurality of barrier ribs 26 are provided on the second dielectric layer 24. The second dielectric layer 24 is provided for light reflection. The partitions 26 are spaced apart by a given interval. The partition 26 is located on the second dielectric layer 24 between the address electrodes 22. Thus, when viewed on the second dielectric layer 24, the address electrodes 22 and the partition walls 26 are alternately arranged. The partition 26 is in close contact with the passivation layer 20 provided on the rear surface of the front glass substrate 10 in the process of bonding the front and rear glass substrates 10 and 12. Fluorescent layers 28a, 28b, and 28c are applied to the surfaces of the second dielectric layer 24 and the surfaces of the partition walls 26 between the partition walls 26. The first fluorescent layer 28a is excited by ultraviolet light to emit red (R) light, the second fluorescent layer 28b to green (G) light, and the third fluorescent layer 28c to blue (B) light, respectively. To emit.

3 is a cross-sectional view of the unit discharge cell of the PDP, and a cross section cut in a direction perpendicular to the address electrode 22 is shown.

In Fig. 3, reference numeral A1 denotes ultraviolet rays (hereinafter referred to as first ultraviolet rays) having wavelengths of 147 nm and 173 nm emitted from the plasma formation region 32 in the discharge cell toward the fluorescent layers 28a, 28b, and 28c. Denotes visible light emitted while the fluorescent layers 28a, 28b, and 28c excited by the first ultraviolet light are stabilized. Reference numeral A3 denotes ultraviolet rays (hereinafter referred to as second ultraviolet rays) having wavelengths 147 nm and 173 nm emitted in the opposite direction to the first ultraviolet ray A1.

As shown in FIG. 3, in the case of the PDP according to the related art, a part of ultraviolet rays emitted from the plasma forming region 32 in the cell, that is, the second ultraviolet ray A3, is absorbed by the front panel. In other words, in the PDP according to the prior art, the fluorescent layers 28a, 28b, and 28c are excited by only part of the ultraviolet light emitted from the plasma forming region 32, not by all of them. In other words, only the first ultraviolet light is used to excite the fluorescent layers 28a, 28b and 28c in the PDP according to the prior art.

The visible light emitted from the fluorescent layers 28a, 28b, and 28c is increased in proportion to the amount of ultraviolet rays irradiated to the fluorescent layers 28a, 28b, and 28c, and the conventional PDP is as described above. , The amount of visible light emitted from the fluorescent layers 28a, 28b, 28c is also limited because the amount of ultraviolet rays irradiated to the 28c. As a result, the brightness and efficiency of the PDP according to the prior art are lowered.

Therefore, the technical problem to be achieved by the present invention is to improve the above-described problems of the prior art, to provide a PDP that can improve the brightness by increasing the amount of visible light as the amount of ultraviolet light emitted through the front panel is reduced and the amount of ultraviolet light is reduced. Is in.

1 is an exploded perspective view of a PDP according to the prior art.

FIG. 2 is a perspective view separately showing only the discharge sustaining electrode and the bus electrode shown in FIG. 1.

3 is a cross-sectional view of the PDP shown in FIG. 1 in a direction perpendicular to the bus electrode.

4 is an exploded perspective view of a PDP equipped with a visible light increasing means according to an embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of FIG. 4 taken in a direction perpendicular to the address electrode.

FIG. 6 is a graph illustrating a second positive band spectrum of nitrogen gas used as a source gas for plasma formation in the PDP shown in FIG. 4.

FIG. 7 is a graph showing light transmittances of the front panel and the front glass substrate of the PDP shown in FIG. 4.

FIG. 8 is a graph showing preferable optical characteristics of the visible light increasing means shown in FIG. 4.

9 and 10 are cross-sectional views illustrating a case in which the visible light increasing means is provided in the front panel in the PDP according to the embodiments of the present invention shown in FIGS. 4 and 5.

11 is a cross-sectional view illustrating a case in which the visible light increasing means is provided toward the filter set in the PDP according to the embodiments of the present invention shown in FIGS. 4 and 5.

12 is an enlarged cross-sectional view of a part of the visible light increasing means included in the PDP according to the embodiment of the present invention.

* Description of Signs of Major Parts of Drawings *

40: front glass substrate 42, 44: first and second discharge holding electrodes

46 and 48: first and second bus electrodes 50 and 64: first and second dielectric films

52: protective film 60: back glass substrate

62: address electrode 66: partition wall

68a, 68b, 68c: first to third fluorescent layers

70: visible light increasing means 70a, 70b, 70c: first to third transmission reflectors

70d, 80d: first and second black stripes

80: filter set 80a, 80b, 80c: first to third filters

C: discharge cell PA: plasma forming region

In order to achieve the above technical problem, the present invention is a plasma display panel having a front panel and a rear panel, provided with a filter set in front of the front panel and the plasma is formed between the two panels, transparent to visible light, It provides a plasma display panel, characterized in that a means for reflecting the ultraviolet rays of a predetermined wavelength or more to the back panel is provided.

The means is provided on the front panel, in the front panel or in the filter set.

The means is provided between the dielectric film and the protective film of the front panel or between the dielectric film and the electrode.

A plasma source gas emitting ultraviolet rays having a wavelength longer than 330 nm exists in the plasma forming region, and a surface of the back panel exposed to the ultraviolet rays is covered with a fluorescent film that is excited by the ultraviolet rays and emits visible light.

The means is a transmissive reflector that reflects ultraviolet light longer than 330 nm.

The transmissive reflector is a monolith or a monolith divided into first to third transmissive reflectors. In the latter case, a black matrix is provided between the first to third transmission reflectors.

The first through third transmission reflectors are transmission reflection plates each composed of a plurality of optical material layers. In this case, the plurality of optical material layers are two material layers having different refractive indices, one of which is a metal oxide having a refractive index of about 1.7 to 2.5, and a titanium oxide film (TiO ₂ ), Ta ₂ O ₅ , ZrO ₂ , CeO ₂ , MgO And the other is a silicon oxide film (SiO ₂ ), NaF, Na ₃ AlF ₆ , MgF ₂ , CaF ₂ , BaF ₂ , LiF having a refractive index of about 1.3 to 1.46.

With this invention, a means for reflecting the ultraviolet rays directed toward the front panel at the same time as the occurrence of the ultraviolet rays initially generated from the plasma forming region in the discharge cell to the rear panel, but transmitting visible light is provided. Therefore, the visible light emitted from the fluorescent film covered on the back panel is the sum of the excitation by the ultraviolet rays reflected by the means and the excitation of the first generated ultraviolet rays toward the back panel. Thus, the amount of visible light emitted from the front panel is much higher than in the prior art, and as a result, the PDP luminance of the present invention is much brighter than in the prior art.

Hereinafter, a PDP equipped with a visible light increasing means according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

4 is an exploded perspective view of a PDP according to an embodiment of the present invention.

In FIG. 4, reference numeral FP denotes a front panel, and BP denotes a back panel facing the front panel FP.

Referring to FIG. 4, a visible light increasing means 70 is provided on the front panel FP, and a filter set 80 that passes only selected visible light above the visible light increasing means 70 is provided. The front panel FP includes a front glass substrate 40, first and second discharge sustain electrodes 42 and 44, first and second bus electrodes 46 and 48, a first dielectric layer 50, and a passivation layer. It consists of 52. The front glass substrate 40 has a first surface facing the user and a second surface facing the rear panel BP. The first and second discharge sustain electrodes 42 and 44 are provided on the second surface of the front glass substrate 40, but are provided in parallel with each other at predetermined intervals. The first and second bus electrodes 46 and 48 are provided on the first and second discharge sustain electrodes 42 and 44, respectively. The first and second bus electrodes 46 and 48 are parallel to the first and second discharge sustain electrodes 42 and 44, respectively. The first dielectric film 50 covers the first and second bus electrodes 46 and 48 and the first and second discharge sustain electrodes 42 and 44 on the second surface of the front glass substrate 40. Formed. The surface of the first dielectric film 50 is flat. The protective film 52 is formed on the surface of the first dielectric film 50. The rear panel BP includes a rear glass substrate 60, an address electrode 62, a second dielectric layer 64, a barrier rib 66, and first to third fluorescent layers 68a, 68b, and 68c. It is provided. The rear glass substrate 60 is a glass plate having a uniform thickness having a third surface facing the front panel FP and a fourth surface facing the opposite side. The address electrodes 62 are formed on the third surface of the rear glass substrate 60 in parallel with each other at a predetermined distance. The second dielectric film 64 is formed on the third surface of the back glass substrate 60, and its surface is flat. The address electrode 62 is covered with this second dielectric film 64. The partition 66 is formed on the second dielectric layer 64 between the address electrodes 62 to be parallel to the address electrode 62 and have a stripe shape. The partition 66 is formed at a predetermined height. The height of the partition 66 is an important factor that determines the discharge cell area of the PDP along with the gap of the partition 66. Two partitions 66 define a discharge cell. Since the address electrodes 62 are provided one by one in the second dielectric film 64 between the partitions 66, the number of address electrodes 62 and discharge cells provided in the PDP are the same. The first, second, and third fluorescent layers 68a, 68b, and 68c are provided in three discharge cells constituting unit pixels, respectively. Specifically, the first to third fluorescent layers 68a, 68b, and 68c are applied to the surface of the second dielectric film 64 and the partition 66 between the partitions 66. The first to third fluorescent layers 68a, 68b, and 68c are excited by the ultraviolet light to be irradiated. Red (R), green (G), and blue (B) from the first to third fluorescent layers 68a, 68b, and 68c during stabilization of the excited first to third fluorescent layers 68a, 68b, and 68c. Visible light is emitted.

Such first to third fluorescent layers 68a, 68b, 68c are preferably excited by ultraviolet (UV) light having a wavelength greater than at least 330 nm, for example, 337 nm, 358 nm or 381 nm. Therefore, it is preferable that the first fluorescent layer 68a is a fluorescent layer that emits red light with respect to ultraviolet rays having the above-described wavelengths, such as a Y ₂ O ₂ S: Eu layer. The second fluorescent layer 68b is preferably a fluorescent layer that emits green light, such as a BAM (BaAl ₁₂ O ₁₉ : Mn) layer. In addition, the third fluorescent layer 68c is preferably a fluorescent layer emitting blue light, for example, a BAM (BaMgAl ₁₀ O ₁₇ : Eu) layer.

When ultraviolet rays having a wavelength of at least 330 nm or more are used for the excitation of the first to third fluorescent layers 68a, 68b, and 68c, the stokes efficiency of the phosphor is 2 compared with using ultraviolet rays having a conventional wavelength of 147 nm. It is about double and the transmittance | permeability with respect to the front panel FP also becomes high.

Meanwhile, some of the ultraviolet rays generated in the discharge region of the PDP are directed toward the rear panel BP and some are directed to the front panel FP. As described above, the ultraviolet rays directed to the rear panel BP are excited by the first to third fluorescent layers 68a, 68b and 68c to emit visible light from the first to third fluorescent layers 68a, 68b and 68c.

After passing through the front panel FP, the ultraviolet rays emitted toward the front panel FP are reflected downward by the visible light increasing means 70. The ultraviolet rays reflected downward by the visible light increasing means 70 toward the rear panel BP excite the first to third fluorescent layers 68a, 68b, and 68c, and thus the first to third fluorescent layers 68a, 68b, Visible light from 68c).

As such, since the visible light increasing means 70 is provided on the front panel FP, the amount of visible light emitted through the front panel FP is a front panel of the conventional PDP in which the visible light increasing means 70 is not provided. Much more than the amount of visible light emitted.

As such, the visible light increasing means 70 reflects the ultraviolet light passing through the front panel FP to the first to third fluorescent layers 68a, 68b, and 68c, and as a result, the first to third fluorescent layers 68a, 68b, For increasing the amount of visible light emitted from 68c), for example, the first through third transmission reflectors 70a, 70b, 70c are included. For convenience, the visible light increasing means 70 is divided into first to third transmission reflectors 70a, 70b, and 70c to correspond to each discharge cell, but the first to third transmission reflectors 70a, 70b, and 70c are single. It is preferable that it is a transmission reflector. In other words, the first to third transmission reflectors 70a, 70b, 70c are all the same transmission reflector.

Meanwhile, the first black stripe 70d may be provided between the first to third transmission reflectors 70a, 70b, and 70c as shown in the drawing. In this case, it is preferable that the first black stripe 70d is provided at a position corresponding to the partition wall 66. The first black stripe 70d prevents electromagnetic interference between neighboring discharge cells, for example, ultraviolet rays or visible light generated in one discharge cell, from entering another neighboring cell.

Since the first to third transmission reflectors 70a, 70b, and 70c reflect ultraviolet rays emitted from the discharge region toward the inside of the discharge cell, that is, toward the first to third fluorescent layers 68a, 68b, and 68c, the first to third transmission reflectors 70a, 70b, and 70c reflect the ultraviolet rays emitted from the discharge region. As shown in FIG. 8, the transmissive reflectors 70a, 70b, 70c have a high reflectance for the excitation light emitted from the discharge region, that is, the excitation light having a wavelength longer than 300 nm and shorter than 450 nm, and the wavelength of the visible light region longer than this. It is preferable to have an optical characteristic with low reflectance.

It is preferable that all of the first to third transmission reflectors 70a, 70b, and 70d having such optical characteristics have a predetermined predetermined optical thickness, and are preferably composed of predetermined optical material layers having different refractive indices. This will be described later.

4, the filter set 80 provided at the front spaced apart from the visible light increasing means 70 by a predetermined distance to block infrared rays (IR), electromagnetic waves, etc. emitted from the elements formed thereunder. For the purpose, the first to third filters 80a, 80b, 80c and the second black stripe 80d are integrated. The first to third filters 80a, 80b, and 80c are positioned at positions corresponding to the first to third transmission reflectors 70a, 70b, and 70c, and the second black stripe 80d is disposed on the first black stripes 70d. Each is provided at a corresponding position.

FIG. 5 is a partial cross-sectional view of FIG. 4 taken in a direction perpendicular to the address electrode 62, and a cross-sectional view of a discharge cell C having a second phosphor 68b as a representative example. In FIG. 5, reference numeral PA denotes a region where plasma is formed. The plasma formation area PA is shown by the inventors for convenience. Therefore, it is not preferable to interpret that the plasma formation region PA is spatially limited as shown in FIG.

A modification of the PDP according to the embodiment of the present invention described below is described with reference to FIG. 5, and this description can be applied to the discharge cells provided with the first and third phosphors 68a and 68c.

Although not shown in FIG. 5, the source gas for plasma formation is filled in the discharge cell C. The source gas is preferably a gas capable of emitting excitation light longer than 330 nm, for example, longer than 330 nm and shorter than 450 nm in the plasma formation process. For example, the source gas may be nitrogen gas (N ₂ ), fluorine xenon gas (XeF ^* ), but preferably the nitrogen gas. When the source gas is nitrogen gas, a predetermined buffer gas may be added to the nitrogen gas. The buffer gas is, for example, helium gas (He), neon gas (Ne), argon gas (Ar), krypton gas (Kr), or xenon gas (Xe).

6 shows a second positive band spectrum of the nitrogen gas used as the source gas, and it can be seen that peaks appear at 337 nm, 358 nm, and 381 nm. That is, when the source gas is nitrogen gas, it can be seen that three ultraviolet rays longer than 330 nm are emitted during the plasma formation process.

FIG. 7 is a graph showing light transmittances of the front panel FP and the front glass substrate 40. The first graph G1 shows the light transmittance of the front glass substrate 40 having a thickness of 2.8 mm. (G2) shows the light transmittance with respect to the front panel (FP).

Referring to the first and second graphs G1 and G2 and Table 1 below, it can be seen that the transmittance of the 337 nm ultraviolet ray (hereinafter referred to as the first ultraviolet ray) for the front panel FP is 31%. have. The transmittance of the 358 nm ultraviolet ray (hereinafter referred to as the second ultraviolet ray) with respect to the front panel FP is 66%. Moreover, it turns out that the transmittance | permeability with respect to the front panel FP of 381 nm ultraviolet-ray (hereinafter, 3rd ultraviolet-ray) is about 73%.

This shows that when the source gas is nitrogen gas, at least 31% of the ultraviolet rays emitted from the plasma forming region PA of the discharge cell C to the front panel FP pass through the front panel FP. .

Wavelength (nm) Transmittance (%) 337 31 358 66 381 73

As such, ultraviolet rays passing through the front panel FP are reflected into the cell by the first to third transmission reflectors 70a, 70b, and 70c, and are used to excite the first to third phosphors 68a, 68b, and 68c. Therefore, the amount of visible light emitted from the first to third phosphors 68a, 68b, and 68c is greater than when the first and second transmission reflectors 70a, 70b, and 70c are not provided, and thus, the front panel FP. The amount of visible light emitted through) increases more than before.

As a result, the total amount of light reaching the user from the PDP is much higher than before. In other words, the brightness of the PDP according to the present invention is much increased compared with the conventional.

Next, a modification of the PDP according to the embodiment of the present invention shown in FIG. 4 will be described with reference to FIG. 5. In this case, the second transmission reflector 70b in FIG. 5 is considered to represent the visible light increasing means 70.

In FIG. 5, the second transmission reflector 70b provided on the front panel FP may be provided between the elements constituting the front panel FP. 9 and 10 show an example of this.

Specifically, as shown in FIG. 9, the second transmission reflector 70b may be provided between the first dielectric layer 50 and the passivation layer 52. In addition, the second transmission reflector 70b may be provided between the first dielectric layer 50 and the bus electrodes 46 and 48 as shown in FIG. 10.

Meanwhile, the second transmission reflector 70b may be provided at a position spaced apart from the front panel FP. For example, as illustrated in FIG. 11, the second transmission reflector 70b may be provided to contact the bottom surface of the filter set 80b. In addition, although not shown in the drawings, the second transmission reflector 70b may be provided on the filter set 80b or may be provided between the front panel FP and the filter set 80b.

On the other hand, although not shown in the drawings, the bottom of the filter set 80 may be provided with a coating film that can play an equivalent role as the second transmission reflector 70b.

Referring to FIG. 12, which shows an enlarged cross-sectional view of a portion of the second transparent reflector 70b, the second through reflector 70b may include the first to nth optical material layers L1, L2,..., Ln sequentially. It is composed of stacked. In this case, n is 5 or more, preferably 5, 7 or 9. Each optical material layer is composed of optical material layers having different refractive indices. For example, each of the optical material layers includes a first material layer 70b 'having a relatively high refractive index and a second material layer 70b''having a lower refractive index. The first material layer 70b 'is formed on the second material layer 70b ". The first material layer 70b' is a metal oxide having a refractive index of about 1.7 to 2.5, for example, a titanium oxide film (TiO _2). ), Ta ₂ O ₅ , ZrO ₂ , CeO ₂ , MgO, and the second material layer 70b ″ is a material film having a refractive index of about 1.3 to 1.46, for example, silicon oxide film (SiO ₂ ), NaF, Preference is given to Na ₃ AlF ₆ , MgF ₂ , CaF ₂ , BaF ₂ , LiF.

When the optical thickness D is nd / 4λ (λ is the incident ultraviolet wavelength, n is the refractive index of the material layer to which the ultraviolet light is incident, and d is the physical thickness of the material layer), the first material layer 70 'having a high refractive index is used. ), The thickness is preferably 0.5D.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, a person of ordinary skill in the art may not simply attach the visible light increasing means 70 to the front panel FP or the filter set 80, but rather to the front panel FP or the filter set 80. ) And unitary. In addition, the visible light increasing means 70 may be provided at a position other than the above-described position, or may be made of a different material. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the PDP according to the present invention includes visible light increasing means for reflecting the ultraviolet rays emitted from the discharge cells into the cells to increase the visible light. Therefore, the visible light emitted from the fluorescent film covered on the rear panel is much higher than that of the conventional non-visible light increasing means, so that the amount of visible light emitted from the front panel is much higher than the conventional. As a result, the PDP luminance of the present invention is much brighter than before.

Claims (14)

A plasma display panel comprising a front panel and a rear panel, a filter set in front of the front panel, and a plasma formed between the two panels. And a means for reflecting the ultraviolet light having a predetermined wavelength and being transparent to visible light to the rear panel. The plasma display panel of claim 1, wherein the means is attached to an upper surface of the front panel. The plasma display panel of claim 1, wherein the means is provided in the front panel. The plasma display panel of claim 1, wherein the means is attached to the filter set. The plasma display panel of claim 1, wherein the means is provided between the front panel and the filter set. 4. The front panel of claim 3, wherein a front glass substrate, a dielectric film, and a protective film are sequentially stacked, and a discharge sustaining electrode and a bus electrode are provided between the front glass substrate and the dielectric film. And between the passivation layer or between the dielectric layer and the two electrodes. The plasma source gas of claim 1, wherein a plasma source gas emitting ultraviolet rays having a wavelength longer than 330 nm is present between the front panel and the rear panel, and is excited by the ultraviolet rays on the surface of the rear panel to emit visible light. Plasma display panel characterized in that the fluorescent film is covered. 7. A plasma display panel according to any one of claims 1 to 6, wherein said means is a transmissive reflector which reflects ultraviolet rays longer than 330 nm. The plasma display panel of claim 8, wherein the transmissive reflector comprises first to third transmissive reflectors. 10. The plasma display panel of claim 9, wherein a black matrix is provided between the first through third transmission reflectors. 10. The plasma display panel of claim 9, wherein each of the first through third transmission reflectors is a transmission reflection plate composed of a plurality of optical material layers. 12. The plasma display panel of claim 11, wherein each of the plurality of optical material layers comprises two material layers having different refractive indices. The method of claim 12, wherein one of the two material layers having different refractive indices is a metal oxide having a refractive index of about 1.7 to 2.5, and is a titanium oxide layer (TiO ₂ ), Ta ₂ O ₅ , ZrO ₂ , CeO ₂ , MgO, and the other is A plasma display panel comprising a silicon oxide film (SiO ₂ ), NaF, Na ₃ AlF ₆ , MgF ₂ , CaF ₂ , BaF ₂ , LiF having a refractive index of about 1.3 to 1.46. 8. The plasma display panel of claim 7, wherein the fluorescent film is a Y ₂ O ₂ S: Eu film emitting red light, a BAM film emitting green light, or a BAM film emitting blue light.