Candescent Technologies Corporation

Other

Candescent Intellectual Property Services, Inc.

Canon Kabushiki Kaisha

Colin D Stanners

Christopher J Spindt

Theodore S Fahlen

Ronald L Hansen

William J Cummings

James C Dunphy

Lawrence S Pan

George B Hopple

George R Brandes

Xueping Xu

Robert M Duboc

John M Macaulay

Christopher J Curtin

Shiyou Pei

Igor L Maslennikov

Petre Vatahov

William C Fritz

Jun (Gordon) Liu

Lee Cressi

N Johan Knall

John D Porter

Kishore K Chakravorty

Victoria A Bascom

Frederick K Byers

Fariborz Nadi

Methods for compensating for brightness variations in a field emission device. In one embodiment, a method and system are described for measuring the relative brightness of rows of a field emission display (FED) device, storing information representing the measured brightness into a correction table and using the correction table to provide uniform row brightness in the display by adjusting row voltages and/or row on-time periods. A special measurement process is described for providing accurate current measurements on the rows. This embodiment compensates for brightness variations of the rows, e.g., for rows near the spacer walls. In another embodiment, a periodic signal, e.g., a high frequency noise signal, is added to the row on-time pulse in order to camouflage brightness variations in the rows near the spacer walls. In another embodiment, the area under the row on-time pulse is adjusted to provide row-by-row brightness compensation based on correction values stored in a memory resident correction table. In another embodiment, the brightness of each row is measured and compiled into a data profile for the FED. The data profile is used to control cathode burn-in processes so that brightness variations are corrected by physically altering the characteristics of the emitters of the rows.

Methods and systems for compensating row-to-row brightness variations of a field emission display

Inert gas provided at a suitable level inside a hermetically sealed cathode-ray tube display, typically of the flat-panel type, enables the display's electron-emitting device () to be automatically cleaned during display operation subsequent to final display sealing. Upon being struck by electrons emitted by the electron-emitting device, atoms () of the inert gas ionize to produce positively charged ions () which travel backward to the electron-emitting device and dislodge overlying contaminant material (and). A getter () collects dislodged contaminant. A reservoir () provides inert gas to replace inert gas lost during the cleaning process.

Cleaning of cathode-ray tube display

An apparatus for removing contaminants from a display device is disclosed. In one embodiment, an auxiliary chamber is adapted to be coupled to a surface of a display device such that contaminants within the display device can travel from the display device into the auxiliary chamber. A getter is disposed in the auxiliary chamber. The getter is adapted to capture the contaminants once the contaminants travel from the display device into the auxiliary chamber. In other embodiments, the getter is disposed in the border region surrounding the active area of the display.

Apparatus for removing contaminants from a display device

A light-emitting device ( , or ) suitable for a flat-panel CRT display contains a plate ( ), a light-emissive region ( ), a light-blocking region ( ), and a light-reflective layer ( or ). The light-emitting device achieves one or more of the following characteristics by suitably implementing the light-reflective layer or/and providing one or more layers ( , and ) along the light-reflective layer: (a) reduced electron energy loss as electrons pass through the light-reflective layer, (b) gettering along the light-reflective layer, (c) reduced secondary electron emission along the light-reflective layer, (d) reduced electron backscattering along the light-reflective layer, and (e) reduced chemical reactivity along the light-reflective layer.

Light-emitting device having light-reflective layer formed with, or/and adjacent to, material that enhances device performance

Auxiliary chamber and display device with improved contaminant removal

Methods for performing cathode burn-in with respect to an FED display that avoid display non-uniformities near and around the spacer wall structures. In a first method, the anode is floated or receives a negative voltage with respect to the electron emitter. A positive voltage is then applied to the focus waffle structure with respect to the electron emitter. The cathode is then energized thereby preventing emitted electrons from escaping the focus well. Under these conditions, cathode burn-in conditioning can occur but electrons are energetically forbidden from hitting the anode or the spacer walls except for a small region near the focus waffle. Under the second method, the anode is grounded or allowed to float. A negative bias is applied to the focus waffle. This causes electrons to be collected at the M layer of the gate. Electrons are energetically forbidden from hitting any portion of the tube except the M layer. Under either method, no electrons hit the spacer walls and therefore display non-uniformities near and around the spacer wall structures are avoided.

Cathode burn-in procedures for a field emission display that avoid display non-uniformities

A structure and method for forming an column electrode for a field emission display device wherein the column electrode is disposed beneath the field emitters and the row electrode. In one embodiment, the present invention comprises depositing a resistor layer over portions of a column electrode. Next, an inter-metal dielectric layer is deposited over the column electrode. In the present embodiment, the inter-metal dielectric layer is deposited over portions of the resistor layer and over pad areas of the column electrode. After the deposition of the inter-metal dielectric layer, the column electrode is subjected to an anodization process such that exposed regions of the column electrode are anodized. In so doing, the present invention provides a column electrode structure which is resistant to column to row electrode shorts and which is protected from subsequent processing steps.

Row electrode anodization

A flat panel display that has internal components that are cleaned using a dry cleaning treatment. The cleaned internal components include a matrix structure, a focus structure and a support structure. The dry cleaning treatment removes contaminants from the surfaces of the internal components. By cleaning the internal components, contaminants are removed that can deleteriously affect the performance of the display. The cleaned support structure has uniform resistance and does not produce spatially nonuniform resistivity over time. This prevents regions of the visible display that are not properly illuminated and minimizes the possibility of arcing.

Tailored spacer structure coating

A cathode structure suitable for a flat panel display is provided with coated emitters. The emitters are formed with material, typically nickel, capable of growing to a high aspect ratio. These emitters are then coated with carbon containing material for improving the chemical robustness and reducing the work function. One coating process is a DC plasma deposition process in which acetylene is pumped through a DC plasma reactor to create a DC plasma for coating the cathode structure. An alternative coating process is to electrically deposit raw carbon-based material onto the surface of the emitters, and subsequently reduce the raw carbon-based material to the carbon containing material. Work function of coated emitters is typically reduced by about 0.8 to 1.0 eV.

Fabrication of electron emitters coated with material such as carbon

A cathode structure suitable for a flat-panel display contains an emitter layer ( ) divided into emitter lines, a plurality of electron emitters ( , or ) situated over the emitter lines, and a gate layer ( A) having an upper surface spaced largely above the electron emitters. The gate layer has a plurality of gate holes ( B) each corresponding to one of the electron emitters. The cathode structure further includes a carbon-containing layer ( , or ) coated over the electron emitters and directly on at least part of the upper surface of the gate layer such that at least part of the carbon-containing layer extending along and above the gate layer is exposed.

Electron emitters coated with carbon containing layer

A flat panel display that has internal components that are cleaned using a dry cleaning treatment. The cleaned internal. components include a matrix structure, a focus structure and a support structure. The dry cleaning treatment removes contaminants from the surfaces of the internal components. By cleaning the internal components, contaminants are removed that can deleteriously affect the performance of the display. The cleaned support structure has uniform resistance and does not produce spatially nonuniform resistivity over time. This prevents regions of the visible display that are not properly illuminated and minimizes the possibility of arcing.

Cleaning of components of flat panel display

Multiple procedures are presented for removing contaminant material (12) from electron-emissive elements (10) of an electron-emitting device (30). One procedure involves converting the contaminant material into gaseous products (14), typically by operating the electron-emissive elements, that move away from the electron-emissive elements. Another procedure entails converting the contaminant material into further material (16) and removing the further material. An additional procedure involves forming surface coatings (18 or 20) over the electron-emissive elements. The contaminant material is then removed directly from the surface coatings or by removing at least part of each surface coating.

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San Jose, CA, United States of America

Colin D Stanners