Ronald T Hansen

US Patent:

6369784, Apr 9, 2002

Filed:

Sep 23, 1999

Appl. No.:

09/405281

Inventors:

Igor L. Maslennikov - Sunnyvale CA
Dennis M. Urbon - San Jose CA
Christopher J. Spindt - Menlo Park CA
Ronald L. Hansen - San Jose CA
Christopher J. Curtin - Los Altos Hills CA

Assignee:

Candescent Intellectual Property Services, Inc. - San Jose CA

International Classification:

G09G 300

US Classification:

345 752, 345 741, 345204, 345208, 313339, 713321

Abstract:

A field emission display having an improved operational life. In one embodiment of the present invention, the field emission display comprises a plurality of row lines, a plurality of column lines, and a plurality of electron emissive elements disposed at intersections of the plurality of row lines and column lines, a column driver circuit, and a row driver circuit. The column driver circuit is coupled to drive column voltage signals over the plurality of column lines; and, the row driver circuit is coupled to activate and deactivate the plurality of row lines with row voltage signals. Significantly, according to the present invention, operational life of the field emission display is substantially extended when the electron emissive elements are intermittently reverse-biased by the column voltage signals and the row voltage signals. In another embodiment, the row driver circuit is responsive to a SLEEP signal. The row driver circuit, upon receiving the SLEEP signal, drives a sleep-mode voltage over the row lines to reverse-bias the electron emissive elements.

US Patent:

6429836, Aug 6, 2002

Filed:

Mar 30, 1999

Appl. No.:

09/281563

Inventors:

Ronald L. Hansen - San Jose CA

Assignee:

Candescent Intellectual Property Services, Inc. - San Jose CA

International Classification:

G09G 322

US Classification:

345 741, 345100

Abstract:

A circuit and method for displaying both interlaced and non-interlaced video information on a flat panel display. The flat panel display is a field emission display (FED) screen. Within the FED screen, a matrix of rows and columns is provided and emitters are situated within each row-column intersection. Rows are activated (e. g. , enabled) sequentially and separate gray scale information (voltages) is presented to the columns. When the proper voltage is applied across the cathode and anode of the emitters, they release electrons toward a phosphor spot, e. g. , red, green, blue, causing an illumination point. The present invention includes circuitry for enabling the rows in one of two different modes. In a first mode, the rows are enabled sequentially with each pulse width of the sufficient duration (âlong pulseâ) to perceptively energize the row for displaying image data thereon. In this mode, the rows are enabled for the display of non-interlaced video information.

US Patent:

6433473, Aug 13, 2002

Filed:

Feb 25, 1999

Appl. No.:

09/258021

Inventors:

Kishore K. Chakravorty - San Jose CA
Fariborz Nadi - Albany CA
Christopher J. Spindt - Menlo Park CA
Ronald L. Hansen - San Jose CA
Colin D. Stanners - San Jose CA

Assignee:

Candescent Intellectual Property Services, Inc. - San Jose CA

International Classification:

H01J 162

US Classification:

313495, 313309, 313336, 313351, 445 24, 445 50, 445 51

Abstract:

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.

US Patent:

6448949, Sep 10, 2002

Filed:

Jun 5, 2000

Appl. No.:

09/588267

Inventors:

Igor L. Maslennikov - Sunnyvale CA
Dennis M. Urbon - San Jose CA
Christopher J. Spindt - Menlo Park CA
Ronald L. Hansen - San Jose CA
Christopher J. Curtin - Los Altos Hills CA

Assignee:

Candescent Technologies Corporation - San Jose CA

International Classification:

G09G 300

US Classification:

345 74, 345 75, 345208, 3151691

Abstract:

A field emission display having an improved operational life. In one embodiment of the present invention, the field emission display comprises a plurality of row lines, a plurality of column lines, and a plurality of electron emissive elements disposed at intersections of the plurality of row lines and column lines, a column driver circuit, and a row driver circuit. The column driver circuit is coupled to drive column voltage signals over the plurality of column lines; and, the row driver circuit is coupled to activate and deactivate the plurality of row lines with row voltage signals. Significantly, according to the present invention, operational life of the field emission display is substantially extended when the electron emissive elements are intermittently reverse-biased by the column voltage signals and the row voltage signals. In another embodiment, the row driver circuit is responsive to a SLEEP signal. The row driver circuit, upon receiving the SLEEP signal, drives a sleep-mode voltage over the row lines to reverse-bias the electron emissive elements.

US Patent:

6462484, Oct 8, 2002

Filed:

Feb 28, 2001

Appl. No.:

09/796868

Inventors:

James C. Dunphy - San Jose CA
Ronald L. Hansen - San Jose CA
Brian E. Lindberg - San Jose CA
Jerome M. Truppa - San Jose CA
Donald J. Elloway - Campbell CA
Duke K. Amaniampong - Campbell CA

Assignee:

Candescent Intellectual Property Services - San Jose CA

International Classification:

G09G 310

US Classification:

3151693, 3151691, 345 74, 345 76, 313497, 313495

Abstract:

A circuit and method for turning-on and turning-off elements of an field emission display (FED) device to protect against emitter electrode and gate electrode degradation. The circuit includes control logic having a sequencer which in one embodiment can be realized using a state machine. Upon power-on, the control logic sends an enable signal to a high voltage power supply that supplies voltage to the anode electrode. At this time a low voltage power supply and driving circuitry are disabled. Upon receiving a confirmation signal from the high voltage power supply, the control logic enables the low voltage power supply which supplies voltage to the driving circuitry. Upon receiving a confirmation signal from the low voltage power supply, or optionally after expiration of a predetermined time period, the control logic then enables the driving circuitry which drives the gate electrodes and the emitter electrodes which make up the rows and columns of the FED device. Upon power down, the control logic first disables the low voltage power supply, then the high voltage power supply. The above may occur upon each time the FED is powered-on and powered-off during the normal operational use of the display.

US Patent:

6541912, Apr 1, 2003

Filed:

Jul 26, 1999

Appl. No.:

09/361334

Inventors:

William C. Fritz - Menlo Park CA
Igor L. Maslennikov - Sunnyvale CA
Theodore S. Fahlen - San Jose CA
George B. Hopple - Palo Alto CA
Christopher J. Curtin - San Jose CA
Colin D. Stanners - San Jose CA
Petre H. Vatahov - San Jose CA
Christopher J. Spindt - Menlo Park CA
Ronald L. Hansen - San Jose CA

Assignee:

Candescent Technologies Corporation - San Jose CA

International Classification:

H01J 1724

US Classification:

313553, 313495, 313422, 417 48, 417 51

Abstract:

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.

US Patent:

6771027, Aug 3, 2004

Filed:

Nov 21, 2002

Appl. No.:

10/302063

Inventors:

Ronald L. Hansen - San Jose CA

Assignee:

Candescent Technologies Corporation - San Jose CA

International Classification:

G09G 310

US Classification:

3151691, 3151693, 345 752, 345 84, 345100, 345214

Abstract:

The present invention is a system and method for monitoring FED performance and compensating for adverse impacts associated with display emission generation. A present invention FED adjustment system and method is capable of providing real time emission characteristic monitoring during retrace periods. In one present emission compensation method a feedback type process is utilized that drives a constant level on dummy pixels not included in the active viewing area and compares the results (e. g. , the current that is associated with the emission) to an expected certain predetermined amount. If the current is too high then the voltage supply is reduced to the drive level or if the current is to low the voltage is increased. A driver voltage is supplied and an image is presented in an active pixel region during an active presentation time. Emissions are produced in a test pixel during a nonactive presentation and a determination is made if the emissions in the test area are accurate.

US Patent:

6822628, Nov 23, 2004

Filed:

Jun 28, 2001

Appl. No.:

09/895985

Inventors:

James C. Dunphy - San Jose CA
William Cummings - San Francisco CA
Christopher J. Spindt - Menlo Park CA
Ronald L. Hansen - San Jose CA
Jun (Gordon) Liu - Fremont CA
Lee Cressi - Morgan Hill CA
Colin Stanners - San Jose CA

Assignee:

Candescent Intellectual Property Services, Inc. - Los Gatos CA
Candescent Technologies Corporation - Los Gatos CA

International Classification:

G09G 322

US Classification:

345 752, 345207, 3151691

Abstract:

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.