JP2002083552A - Plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display device capable of enhancing practical luminous efficiency by effectively using light emitted from a plasma display panel. SOLUTION: In this plasma display device, discharge cells are formed by sectioning a discharge space between a front glass substrate and a back glass substrate, phosphor layers in the discharge cells emit light by a discharge generated in the discharge space, and the light is radiated through the front glass substrate. The front glass substrate 11 is formed of a glass material having a uniform refractive index distribution in the planar directions of the substrate and having a refractive index distribution in the thickness direction of the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having a plasma display panel.

[0002]

In recent years, a surface discharge type AC plasma display panel (hereinafter, referred to as PDP) has been attracting attention as a large and thin color screen display device, and its spread has been promoted. I have.

FIG. 2 is a perspective view showing the structure of a surface discharge type AC PDP in a state where the front glass substrate 1 and the rear glass substrate 4 are separated.

In FIG. 2, a plurality of row electrode pairs (X, Y) are arranged on the back side of a front glass substrate 1 and are covered with a transparent dielectric layer 2. On the back surface of the layer 2, a transparent protective layer 3 made of MgO is formed.

Each of the row electrodes X and Y has a wide I
It is composed of transparent electrodes Xa and Ya made of a transparent conductive film such as TO (Indium Tin Oxide) and bus electrodes Xb and Yb made of a narrow metal film to supplement the conductivity. They are alternately arranged in the column direction so as to face each other.

[0006] Each row electrode pair (X, Y) constitutes one display line (row) L of a matrix display.

A plurality of column electrodes D are arranged on the display surface side of the back glass substrate 4 so as to extend in a direction orthogonal to the row electrode pairs (X, Y), and extend in parallel between the column electrodes D. And a fluorescent material which is color-coded into three primary colors of red (R), green (G), and blue (B) so as to cover the side surfaces of the partition 5 and the column electrodes D, respectively. The layers 6R, 6G, and 6B are sequentially formed in the column direction.

The front glass substrate 1 and the rear glass substrate 4 configured as described above are opposed to each other in parallel via a discharge space, and a neon light is interposed between the front glass substrate 1 and the rear glass substrate 4. And a discharge gas in which xenon and the like are mixed.

As described above, in each display line L, the discharge space where the column electrode D intersects the row electrode pair (X, Y) is defined by the partition walls 5, so that the discharge forming the unit light emitting region is formed. Each pixel is formed, and three adjacent discharge cells on which the phosphor layers 6R, 6G, and 6B are formed respectively constitute one pixel.

The PDP is housed in a casing of a plasma display device (not shown).
On the front side of the front glass substrate 1 of the DP, a front filter 7 having a function such as an electromagnetic interference (EMI) shield is arranged so as to face the front glass substrate 1 in parallel.

An unnecessary radiation absorbing layer or an infrared absorbing layer for reducing unnecessary radiation or infrared rays generated by a discharge of the PDP, which will be described later, is formed on the front or back surface of the front filter 7. A prevention layer is formed.

Image formation in this plasma display device is performed as follows. That is, first, in each of the discharge cells on which the phosphor layers 6R, 6G, and 6B are formed, one of the row electrode pairs (X, Y) is selectively connected between the row electrode and the column electrode D by an address operation. Discharge (counter discharge) is performed on the light emitting cells (dielectric layer 2).
And the non-light-emitting cells (discharge cells in which no wall charge is formed in the dielectric layer 2) are distributed on the panel in accordance with the image to be displayed.

After this address operation, a sustaining pulse is applied to all the display lines L simultaneously and alternately to the row electrodes X and Y, and every time the sustaining pulse is applied, the dielectric layer 2 The surface discharge is performed in the light emitting cell in which the wall charges are formed.

Ultraviolet rays are generated by the surface discharge in each of the light emitting cells, and the phosphor layers 6R or 6G, 6B formed in each of the light emitting cells are respectively excited to emit light, so that light is emitted on the panel. An image is formed.

However, in the above-mentioned conventional plasma display device, the following problems occur.

That is, the light α 'emitted from the phosphor layer 6R or 6G, 6B by the surface discharge as described above is:
The light reaches the viewer's eyes through the front glass substrate 1 and the front filter 7, and the viewer's viewing characteristics at this time are almost the same as the emission viewing characteristics from the phosphor layers 6 R, 6 G, and 6 B. Since the light emitted from the layers 6R, 6G, 6B is fully diffused light, as shown in FIG.
The light α ′ emitted from the phosphor layers 6R, 6G, 6B at an angle equal to or greater than a predetermined angle with respect to a direction x perpendicular to the front glass substrate 1 and the front filter 7 when passing through the front glass substrate 1 and the front filter 7 The light is diffused out of the practical viewing angle due to the refraction of light and is not effectively used, so that practical luminous efficiency cannot be improved.

The present invention has been made to solve the above-mentioned problems in the conventional plasma display device. That is, an object of the present invention is to provide a plasma display device capable of improving practical luminous efficiency by effectively utilizing light emitted from a plasma display panel.

[0018]

According to a first aspect of the present invention, there is provided a plasma display apparatus comprising: a unit light emitting area formed by dividing a discharge space between a front substrate and a rear substrate; In a plasma display device in which a phosphor layer emits light by discharge generated in a discharge space and the light is emitted through a front substrate, the front substrate has a uniform refractive index distribution in a plane direction of the substrate. And a glass material having a refractive index distribution in the thickness direction of the substrate.

In the plasma display device according to the first aspect of the present invention, when the light which is the completely diffused light emitted from the phosphor layer by the discharge in each unit light emitting region passes through the front substrate, the front substrate is formed. Due to the lens action due to the characteristics of the glass material, the light is refracted in a direction in which the light is condensed in a direction perpendicular to the glass surface of the front substrate, thereby reducing the angle of light emitted from the front surface of the front substrate.

Therefore, according to the first aspect, the angle with respect to the direction perpendicular to the plate surface of the front substrate when emitted from the phosphor layer is large, and in the conventional plasma display device, it spreads out of the practical viewing angle. The ineffective light, which has been used, is also directed within the practical viewing angle, so that the practical luminous efficiency can be improved.

Since the above-described light focusing is not performed by the microlens array, it is not necessary to adjust the alignment of the optical axis and the like.

According to a second aspect of the present invention, in order to achieve the above object, in addition to the configuration of the first aspect, the front substrate is a gradient index glass plate. Accordingly, light passing through the front substrate is condensed in a direction perpendicular to the front substrate, and effective light directed to within a practical viewing angle is increased, so that practical luminous efficiency is improved.

According to a third aspect of the present invention, there is provided a plasma display device, wherein a phosphor layer in a unit light emitting region formed by dividing a discharge space between a front substrate and a rear substrate is formed in the discharge space. In a plasma display device in which light is emitted by a discharge generated inside and the light passes through the front substrate, the front substrate has a uniform refractive index distribution in a plane direction and a refraction in a thickness direction on the front side of the front substrate. A protective substrate formed of a glass material having a rate distribution is provided.

In the plasma display device according to the third aspect of the present invention, when the light which is the completely diffused light emitted from the phosphor layer by the discharge in each unit light emitting region passes through the protection substrate disposed on the front surface of the front substrate. In addition, due to the lens action due to the properties of the glass material forming the protective substrate, the light is refracted in a direction condensed in a direction perpendicular to the glass surface of the protective substrate, thereby causing The angle becomes smaller.

Therefore, according to the third aspect, the angle with respect to the direction perpendicular to the plate surface of the protective substrate when emitted from the phosphor layer is large, and in the conventional plasma display device, it spreads out of the practical viewing angle. The ineffective light, which has been used, is also directed within the practical viewing angle, so that the practical luminous efficiency can be improved.

Since the above-described light condensing is not performed by the microlens array, it is not necessary to adjust the alignment of the optical axis or the like.

A plasma display device according to a fourth aspect of the present invention is characterized in that, in order to achieve the above object, in addition to the configuration of the third aspect, the protective substrate is a gradient index glass plate. As a result, light passing through the protection substrate is condensed in a direction perpendicular to the protection substrate, and effective light directed to a practical viewing angle is increased, so that practical luminous efficiency is improved.

According to a fifth aspect of the present invention, in addition to the configuration of the third aspect of the invention, the front substrate has a uniform refractive index distribution in a plane direction of the substrate. Is formed of a glass material having a refractive index distribution in the thickness direction.

According to the plasma display device of the fifth aspect, when the light emitted from the phosphor layer passes through the front substrate and the protection substrate, the light is condensed by the lens action due to the characteristics of the respective glass materials. Therefore, the effective light directed within the practical viewing angle is further increased, and the practical luminous efficiency can be further improved.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a plasma display panel (hereinafter referred to as a PDP) of a plasma display device according to the present invention.
10 and a side cross-sectional view of a front filter 20 arranged on the front of the PDP 10.

In FIG. 1, the components other than the front glass substrate 11 and the front filter 20 of the PDP 10 are the same as those of the conventional plasma display device of FIGS. .

In this example, the front glass substrate 11 of the PDP 10 is formed of a gradient index glass (GRIN glass).

The gradient index glass refers to a glass plate formed of a glass material having a uniform refractive index in the plane direction of the glass surface and a refractive index distribution in the thickness direction.

In the above-described plasma display device, the front glass substrate 11 is formed when the light α which is the completely diffused light emitted from the phosphor layer 6 by the surface discharge in each discharge cell passes through the front glass substrate 11. Due to the lens function of the gradient index glass, the light is refracted in a direction in which light is condensed in a direction perpendicular to the glass surface of the front glass substrate 11.

As a result, the angle θ2 when this light is emitted from the front surface of the front filter 20 becomes smaller than the angle θ1 in the conventional plasma display device in FIG.

Therefore, the angle with respect to the direction perpendicular to the glass surface of the front glass substrate 11 when emitted from the phosphor layer 6 is large, and the ineffective light that has spread out of the practical viewing angle in the conventional plasma display device is also reduced. Since the light is directed within the practical viewing angle, practical luminous efficiency is improved.

In this plasma display device, since the above-described light focusing is not performed by the microlens array, it is not necessary to adjust the alignment of the optical axis and the like.

Here, in the above description, an example is shown in which the front glass substrate 11 is formed of a gradient index glass, but the front filter 20 may be formed of a gradient index glass. Good.

In this case, the same effect as described above can be obtained. Furthermore, both the front glass substrate 11 and the front filter 20 may be formed of a gradient index glass, and in this case, the practical luminous efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view schematically illustrating an example of an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a conventional plasma display device.

FIG. 3 is a side sectional view showing a state of diffusion of light emission in a conventional plasma display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Front glass substrate (front substrate) 2 ... Dielectric layer 3 ... Protective layer 4 ... Rear glass substrate (rear substrate) 5 ... Partition wall 6 ... Phosphor layer 7 ... Front filter 10 ... PDP 11 ... Front glass substrate (front substrate) 20) Front filter (protective substrate) X ... Row electrode Y ... Row electrode Xa ... Transparent electrode Ya ... Transparent electrode Xb ... Bus electrode Yb ... Bus electrode α ... Light

Claims (5)

[Claims] 1. A phosphor layer in a unit light emitting region formed by partitioning a discharge space between a front substrate and a rear substrate, emits light by a discharge generated in the discharge space, and the light passes through the front substrate. In the plasma display device emitted by passing through, the front substrate is formed of a glass material having a uniform refractive index distribution in a plane direction of the substrate and having a refractive index distribution in a thickness direction of the substrate. Plasma display device. 2. The plasma display device according to claim 1, wherein the front substrate is a gradient index glass plate. 3. A phosphor layer in a unit light emitting region formed by partitioning a discharge space between the front substrate and the rear substrate, emits light by discharge generated in the discharge space, and the light is emitted from the front substrate. In the plasma display device that is radiated through, a protective substrate formed of a glass material having a uniform refractive index distribution in a planar direction and a refractive index distribution in a thickness direction is disposed on a front side of the front substrate. A plasma display device. 4. The plasma display device according to claim 3, wherein the protective substrate is a gradient index glass plate. 5. The plasma display device according to claim 3, wherein the front substrate is formed of a glass material having a uniform refractive index distribution in a plane direction of the substrate and a refractive index distribution in a thickness direction of the substrate.