Patent Application
20070075622
The present invention relates to anode structures for field emission displays, and more particularly, to a field emission display with high vacuum degree.
Field emission displays (FEDs) are a new, rapidly developing area of flat panel display technology. Compared to conventional technologies, e.g. cathode-ray tube (CRT) and liquid crystal display (LCD) technologies, FEDs are superior in having a wider viewing angle, low energy consumption, a smaller size and a higher quality display.
FEDs are based on emission of electrons in a vacuum from microscopically-sized tip in a strong electric field, which are then accelerated, and collide with a fluorescent material which is thus excited to emit light. FEDs must be maintained in a high vacuum state so that electrons are moved without energy loss.
One problem with FEDs is that internal components continuously outgas, which causes the performance of FEDs to degrade over time. The effects of outgassing are minimized by using a gas-absorbing material (commonly called getter) within the sealed vacuum chamber of FEDs.
Referring to
An exhausting path 40 for exhausting an internal gas is formed at one side of the rear plate 20, and a sealing cap 40a for sealing the outlet of the exhausting path 40 is formed at the outlet of the exhausting path 40. A gas path 42 through which the internal gas is flowed into, is positioned at another side of the rear plate 20. A getter container 46 including a getter 44 for absorbing gases is connected to the end of the gas path 42.
In the conventional FED, the getter container 46 protrudes outwardly from the rear plate 20, so that it increases the total thickness of the FED including the getter container 46. Further, since the absorption of the gas is made through the gas path 42 having a narrow section area with very large gas flow resistance, the effective absorption of the gas is difficult. Accordingly, the internal gas cannot be effectively removed, and as a result there is a limited internal vacuum level.
What is needed, therefore, is a field emission display with high internal vacuum degree.
An anode structure for a field emission display according to one preferred embodiment includes a front substrate, an anode electrode formed on the front substrate, a phosphor layer formed on the anode electrode and a getter material. The phosphor layer has a plurality of separated phosphor strips each configured for emitting light of a respective single color. The getter material is arranged between two adjacent phosphor strips thereof.
A field emission display according to another preferred embodiment includes a cathode structure having a cathode electrode and an anode structure positioned opposite to the cathode structure. The anode structure includes a front substrate, an anode electrode formed on the front substrate, a phosphor layer formed on the anode electrode and getter material. The phosphor layer has a plurality of separated phosphor strips each configured for emitting light of a respective single color. The getter material is arranged between two adjacent phosphor strips thereof.
The present anode structure for the field emission display uses the getter material arranged between two adjacent phosphor strips thereof, so that the internal gas in the field emission display can be effectively removed and the field emission display is maintained in a high vacuum degree.
Other advantages and novel features will become more apparent from the following detailed description of the present anode structure, when taken in conjunction with the accompanying drawings.
Many aspects of the present anode structure for the field emission display can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present anode structure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference will now be made to the drawings to describe a preferred embodiment of the present field emission display with high internal vacuum state in detail.
Referring to
The anode structure 110 includes a front substrate 111, an anode electrode 112 formed on the front substrate 111, a phosphor layer 113 formed on the anode electrode 112 and a getter material 114. The phosphor layer 113 has a plurality of separated phosphor strips 1131, 1132, 1133 etc. The getter material 114 is arranged between the adjacent phosphor strips thereof.
The front substrate 111 is a flat plate made of an insulating transparent material, such as glass. The anode electrode 112 is made of a transparent conductive material, such as indium tin oxide (ITO). The phosphor layer 113 is formed on the anode electrode 112, and the phosphor layer is composed of a plurality of separated phosphor strips 1131, 1132, 1133 etc. Each separated phosphor strip is configured for emitting light of a respective single color. The separated phosphor strips are arranged in series. A pixel of the field emission display 100 includes three separated phosphor strips 1131, 1132, 1133, which can emit red light, green light and blue light, respectively.
The anode structure 110 further includes a black matrix 114. The black matrix 114 defines a plurality of openings with the phosphor strips 1131, 1132, 1133 arranged at the openings. In this preferred embodiment, the black matrix 114 is made of black non-evaporable getter material. That is, the getter material is incorporated into the black matrix 114 so that the black matrix 114 can be used as a getter material for removing the internal gas produced in the field emission display and can be also used as a black matrix for improving contrast and color purity. The getter material 114 can be made of a black non-evaporable getter material selected from a group consisted of titanium (Ti), zirconium (Zr), hafnium (Hf), thorium (Th), thulium (Tm) and their alloys.
The cathode structure 120 includes a rear substrate 121, a plurality of cathode electrodes 122 formed on the rear substrate 121, a plurality of electron emission source 123, an insulating layer 124 and a plurality of gate electrode 125. The plurality of electron emission source 123 are formed on the corresponding cathode electrode 122, respectively. A plurality of gate electrodes 125 are formed on the insulating layer 124.
In operation, the electron emission source 123 emits electrons, and then the electrons are accelerated by a electric field between the cathode electrode 122 and the gate electrode 125. The electrons are further accelerated by an electric field between the gate electrode 125 and the anode electrode 112 and collide with the phosphor layer 113, which is thus exited to emit light.
Compared with conventional field emission display, the present field emission display 100 has following advantages. The present field emission display 100 uses a getter material 114 incorporated into the black matrix for removing internal gas produced in the field emission display 100. That is, the getter material 114 is arranged in each pixel of the field emission display 100, so that the internal gas in the field emission display 100 can be effectively removed and the field emission display 100 is maintained in a high vacuum state. Furthermore, the getter material 114 is incorporated into the black matrix, so that the present field emission display has a simply structure without any requiring any additional manufacturing in the assembly of the field emission display.
Referring to
Referring to
It is to be understood that the above-described embodiment is intended to illustrate rather than limit the invention. Variations may be made to the embodiment without departing from the spirit of the invention as claimed. The above-described embodiments are intended to illustrate the scope of the invention and not restrict the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200510036895.5 | Aug 2005 | CN | national |
