This application claims the benefit of Korean Patent Application No. 10-2005-0112239, filed on Nov. 23, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present embodiments relate to a plasma display apparatus, and more particularly, to a plasma display apparatus having an improved structure so as to increase luminescence efficiency and uniformity and a method of manufacturing the plasma display apparatus.
2. Description of the Related Art
Plasma display panels (PDPs) form images using electrical discharge, have good brightness characteristics and a wide viewing angle, etc., leading to an increase in the use of PDPs recently. PDPs display images using visible light emitted through a process of exciting a phosphor material with ultraviolet rays generated from a discharge of a discharge gas between electrodes when a direct current (DC) voltage or an alternating current (AC) voltage is applied to the electrodes. PDPs are classified into DC type panels and AC type panels according to the discharge process (the discharge method). Also, PDPs are classified into facing discharge type panels and surface discharge type panels according to the arrangement of electrodes.
Referring to
The conventional PDP illustrated in
However, the density of electron emission contributing to the discharge is not constant in the unit discharge cells, thus reducing luminescence uniformity of the conventional PDP illustrated in
The present embodiments provide a plasma display apparatus having an improved structure so as to increase luminescence efficiency and uniformity and a method of manufacturing the plasma display apparatus.
According to an aspect of the present embodiments, there is provided a plasma display apparatus, comprising: a front substrate and a rear substrate facing each other; a plurality of first and second sustain electrodes formed on the front substrate and spaced apart from each other; and first and second electron emitting layers formed on the first and second sustain electrodes, respectively, emitting electrons received from the first and second sustain electrodes, and having a structure in which their thickness decreases as the first and second electron emitting layers approach a gap between the first and second sustain electrodes.
The first and second electron emitting layers may be formed of an oxidized porous polysilicon (OPPS) or an oxidized porous amorphous silicon (OPAS). The first and second sustain electrodes may be formed of one selected from a group consisting of indium tin oxide (ITO), Al, and Ag. The density of electrons emitted from the first and second electron emitting layers may be relatively varied according to the width of the first and second electron emitting layers. The closer the first and second electron emitting layers are to the gap between the first and second sustain electrodes, the lower the density of electrons emitted from the first and second electron emitting layers is. The further the first and second electron emitting layers are from the gap between the first and second sustain electrodes, the higher the density of electrons emitted from the first and second electron emitting layers is. The first emitter electrode may be interposed between the first sustain electrode and the first electron emitting layer, and the second emitter electrode may be interposed between the second sustain electrode and the second electron emitting layer, wherein the first and second emitter electrodes may be formed of a conductive material.
According to another aspect of the present embodiments, there is provided a plasma display apparatus, comprising: a front substrate and a rear substrate facing each other; a plurality of first and second sustain electrodes formed on the front substrate and spaced apart from each other; first and second electron emitting layers formed on the first and second sustain electrodes, respectively, emitting electrons received from the first and second sustain electrodes; and a dielectric layer covering the first and second electron emitting layers, having a window exposing an upper face of the first and second electron emitting layers, and having a structure in which the closer the first and second electron emitting layers are to a gap between the first and second sustain electrodes, the thinner the window becomes.
The first and second electron emitting layers may be formed of an OPPS or an OPAS. The first and second sustain electrode are formed of one selected from a group consisting of ITO, Al, and Ag. A density of electrons emitted from the first and second electron emitting layers may be relatively varied according to the width of the window. The closer the first and second electron emitting layers are to the gap between the first and second sustain electrodes, the lower the density of electrons emitted from the first and second electron emitting layers is. The farther the first and second electron emitting layers are from the gap between the first and second sustain electrodes, the higher the density of electrons emitted from the first and second electron emitting layers is.
According to another aspect of the present embodiments, there is provided a method of manufacturing a plasma display apparatus, the method comprising: preparing a front substrate and a rear substrate facing each other; forming a plurality of first and second sustain electrodes on the front substrate to be spaced apart from each other; forming first and second silicon layers on the first and second sustain electrodes, respectively; anodizing the first and second silicon layers and forming first and second electron emitting layers formed of an oxidized porous silicon; and selectively etching and removing a specific area of the first and second electron emitting layers so that the thinner the first and second electron emitting layers are, the closer the first and second electron emitting layers approach a gap between the first and second sustain electrodes.
A solution of hydrogen fluoride (HF) and ethanol may be used for the anodizing process. The first and second sustain electrodes may be formed of one selected from a group consisting of ITO, Al, and Ag. A gap between the first and second electron emitting layers may be adjusted to control a discharge start voltage.
According to another aspect of the present embodiments, there is provided a method of manufacturing a plasma display apparatus, the method comprising: preparing a front substrate and a rear substrate facing each other; forming a plurality of first and second sustain electrodes on the front substrate to be spaced apart from each other; forming first and second silicon layers on the first and second sustain electrodes, respectively; anodizing the first and second silicon layers and forming first and second electron emitting layers formed of an oxidized porous silicon, using an anodizing process; forming a dielectric layer covering the first and second electron emitting layers; and selectively etching and removing a specific area of the dielectric layer, having a window exposing an upper face of the first and second electron emitting layers, and having a structure in which the thinner the window is, the closer the first and second electron emitting layers are to a gap between the first and second sustain electrodes.
A solution of HF and ethanol may be used for the anodizing process. The first and second sustain electrodes may be formed of one selected from a group consisting of ITO, Al, and Ag. A gap between the first and second electron emitting layers may be adjusted to control a discharge start voltage.
The above and other features and advantages of the present embodiments will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
The present embodiments will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown. In the drawings, the thickness of layers and regions are exaggerated for clarity.
Referring to
The rear substrate 110 includes address electrodes 111 and a first dielectric layer 112 that covers the address electrodes 111. The first dielectric layer 112 is coated with phosphor layers 114 including red R, green G, and blue B phosphor layers. The front substrate 120 includes first and second sustain electrodes 121a and 121b which are spaced apart from each other. A second dielectric layer 123 covers the first and second sustain electrodes 121a and 121b. First and second emitter electrodes 124a and 124b formed of conductive materials such as indium tin oxide (ITO), Al, Ag, etc. are formed on the second dielectric layer 123, and correspond to the first and second sustain electrodes 121a and 121b, respectively. First and second electron emitting layers 128a and 128b formed of an oxidized porous silicon (OPS) material are formed on the first and second emitter electrodes 124a and 124b, respectively. The OPS material is an oxidized porous polysilicon (OPPS) or an oxidized porous amorphous silicon (OPAS).
If a specific alternating current (AC) voltage is applied to the first and second sustain electrodes 121a and 121b, an electric field having a specific magnitude is formed between the first and second sustain electrodes 121a and 121b so that the first and second emitter electrodes 124a and 124b supply electrons to the first and second electron emitting layers 128a and 128b, respectively. The electrons are accelerated through the first and second emitting layers 128a and 128b and emitted to the discharge spaces 115. More specifically, silicon nano-crystallization particles forming the first and second electron emitting layers 128a and 128b have a diameter of about 5 nm. The diameter of the silicon nano-crystallization particles is much smaller than a means free path of about 50 nm of the electrons. Therefore, the electrons are not likely to collide with each other in the silicon nano-crystallization particles, and most of the electrons reach the interface of the silicon nano-crystallization particles through the silicon nano-crystallization particles. A very thin oxidization film is formed between the silicon nano-crystallization particles forming an electric field area in the first and second electron emitting layers 128a and 128b when a specific voltage is applied to the first and second sustain electrodes 121a and 121b. The electrons tunnel through the oxidization film, are accelerated in the electric field area formed in the first and second electron emitting layers 128a and 128b, and are emitted to the discharge spaces 115. Therefore, the first and second electron emitting layers 128a and 128b of the plasma display apparatus according to the current embodiment can improve discharge and brightness characteristics of the plasma display apparatus.
In particular, the closer the first and second electron emitting layers 128a and 128b are to a gap between the first and second emitter electrodes 124a and 124b, the thinner the first and second electron emitting layers 128a and 128b are. The first and second emitter electrodes 124a and 124b may have the same structure as the first and second electron emitting layers 128a and 128b. In this case, the density of the electrons emitted from the first and second electron emitting layers 128a and 128b is changed according to the width of the first and second electron emitting layers 128a and 128b. For example, the closer the first and second electron emitting layers 128a and 128b are to the gap between the first and second emitter electrodes 124a and 124b, the lower the density of the electrons emitted from the first and second electron emitting layers 128a and 128b is, and vice versa. Since the density of the electrons is changed according to the width of the first and second electron emitting layers 128a and 128b, the width of the first and second electron emitting layers 128a and 128b is controlled according to the location thereof so that the electric field can be uniformly distributed in the unit discharge cells.
In comparison with the structure in which the width of the first and second electron emitting layers 128a and 128b is gradually changed and the structure in which the electron emitting layers 128a and 128b has a uniform width in the unit discharge cells, the density of the electrons contributing to the discharge is more uniform than the discharge spaces 115. The plasma display apparatus of the current embodiment can provide an improved distribution of the electric field in the unit discharge cells compared to the conventional PDP. The conventional PDP has a strong luminescence since the current density is high inside the first and second sustain electrodes 21a and 21b, and has a weak luminescence since the current density is low outside the first and second sustain electrodes 21a and 21b. However, the plasma display apparatus of the current embodiment has a weak current density by relatively decreasing the width of the first and second electron emitting layers 128a and 128b inside the first and second sustain electrodes 121a and 121b, and has a strong current density by relatively increasing the width of the first and second electron emitting layers 128a and 128b outside the first and second sustain electrodes 121a and 121b. Therefore, the unit discharge cells have a uniformly distributed electric field, thereby increasing luminescence efficiency and uniformity in the unit discharge cells and improving the voltage and brightness characteristics of the plasma display apparatus.
Like reference numerals in
Referring to
The rear substrate 110 includes address electrodes 111 and a first dielectric layer 112 that covers the address electrodes 111. The first dielectric layer 112 is coated with phosphor layers 114 including red R, green G, and blue B phosphor layers. The front substrate 220 includes first and second sustain electrodes 221a and 221b which are spaced apart from each other. First and second electron emitting layers 228a and 228b formed of an OPS material are formed on the first and second sustain electrodes 221a and 221b, respectively. A second dielectric layer 229 covers the first and second electron emitting layers 228a and 228b. The second dielectric layer 229 includes a window that exposes upper faces of the first and second electron emitting layers 228a and 228b to the discharge spaces 115. The closer the first and second electron emitting layers 228a and 228b are to a gap between the first and second sustain electrodes 221a and 221b, the thinner the window becomes. In this case, a density of electrons emitted from the first and second electron emitting layers 228a and 228b is changed according to the thickness of the window. For example, the closer the first and second electron emitting layers 228a and 228b are to the gap between the first and second sustain electrodes 221a and 221b, the lower the density of the electrons emitted from the first and second electron emitting layers 228a and 228b is, and vice versa. As described in
Referring to
Referring to
The first and second silicon layers 125a and 125b are anodized to form first and second electron emitting layers 128a and 128b, which are formed of an OPS material. Any anodizing process is known in the art can be used. In the current embodiment, a solution of hydrogen fluoride (HF) and ethanol is used for the anodizing process, thereby obtaining an OPS layer.
Referring to
A gap between the first and second electron emitting layers 128a and 128b can influence a discharge start voltage of the plasma display apparatus. Therefore, the gap between the first and second electron emitting layers 128a and 128b may be controlled in order to minimize the discharge start voltage. For example, the gap between the first and second electron emitting layers 128a and 128b can be increased or decreased during the etching process.
Referring to
Referring to
Referring to
As described with reference to
According to an embodiment, a plasma display apparatus, e.g., a PDP, having improved luminescence efficiency and uniformity in discharge cells can be obtained. In detail, the thickness of electron emitting layers is changed according to their position relative to unit discharge cells so that the density of emitted electrons contributed to a discharge can be uniformly distributed, thereby optimizing discharge efficiency. The unit discharge cells can be controlled to have a uniform distribution of electric field so that the plasma display apparatus has high discharge efficiency at a low voltage, thereby improving brightness and voltage characteristics of the plasma display apparatus.
While the present embodiments have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present embodiments as defined by the following claims.
Number | Date | Country | Kind |
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10-2005-0112239 | Nov 2005 | KR | national |