Candescent Technologies Corporation

Candescent Intellectual Property Services, Inc.

Other

Canon Kabushiki Kaisha

Sony Corporation

Gsi Group Corporation

Schneider (USA) Inc.

Ronald L Hansen

Christopher J Spindt

Christopher J Curtin

Colin D Stanners

Igor L Maslennikov

James C Dunphy

Theodore S Fahlen

Jay Friedman

Dennis M Urbon

William J Cummings

Robert M Duboc

George B Hopple

Petre Vatahov

William C Fritz

Jerome M Truppa

Lee Cressi

Jun (Gordon) Liu

James Montague Cleeves

Kishore K Chakravorty

John E Field

Yukinobu Iguchi

Donald John Elloway

William Edelman

Jun Liu

Dennis Constantinou

Gregory M Fink

Kenneth J Kramasz

Yuh L Jan

Miles Stefanovski

Paul Freiberg

Jerome Truppa

Lee Stoian

Amir Baghdadi

Fariborz Nadi

Duke K Amaniampong

Brian E Lindberg

Colin Stanners

Systems and methods for transforming and displaying a video signal on a display are provided with any number of features. In some embodiments, system is configured to receive a first set of input signals in a controller. The system can determine in the controller a first set of luminances and colors that would be produced on a first display with the first set of input signals. The system can then determine in the controller a second set of luminances that would produce the first set of colors on a second display. The system can then generate in the controller a second set of input signals that would produce the second set of luminances on the second display, and can output the second set of input signals to the second display.

Electronic color and luminance modification

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

A field emission display (FED) having a correction system with a correction coefficient derived from emission current is presented. Within one embodiment in accordance with the present invention, a field emission display has an anode at the faceplate and a focus structure. The anode potential is held at ground while the focus structure potential is held between, but is not limited to, 40 and 50 volts. The current flowing to the focus structure is measured and used as the basis for the correction coefficient for the field emission display.

System and method for recalibrating flat panel field emission displays

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

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. If the emissions are not accurate, adjustments to the pixels are made to provide a desired level.

System and method for adjusting field emission display illumination

Auxiliary chamber and display device with improved contaminant removal

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. By so doing, embodiments of the present invention reduce emitter electrode and gate electrode degradation by restricting electron emission from the emitter electrode directly to the gate electrode.

Procedures and apparatus for turning-on and turning-off elements within a field emission display device

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.

System and method for improving emitter life in flat panel field emission displays

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 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 (&ldquo;long pulse&rdquo;) 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. In the second mode, an interlaced mode, every other row driving pulse has a width that is insufficient (&ldquo;short pulse&rdquo;) to energize the row such that it does not perceptively display of information. By alternating pulse widths in this manner, an interlaced display mode is allowed wherein every other row is energized. Interlaced video can therefore be displayed using the same row enable and driver circuitry that is used for non-interlaced display. By providing n short pulses, per long pulse, every nth row can be energized for realizing alternate interlaced display modes.

Circuit and method for display of interlaced and non-interlaced video information on a flat panel display apparatus

A circuit and method for time multiplexing a voltage signal for controlling the color balance of a flat panel display. Within an FED screen, a matrix of rows and columns is provided and emitters are situated within each row-column intersection. Rows are sequentially activated during &ldquo;row on-time windows&rdquo; by row drivers and corresponding individual gray scale information (voltages) are driven over the columns by column drivers. When the proper voltage is applied across the cathode and anode of the emitters, electrons are released toward a phosphor spot, e.g., red, green, blue, causing illumination. Within each column driver, the present invention provides selection circuitry for driving a first voltage signal during a first part of the row on-time window and a second voltage during a second part of the row on-time window. The lengths of the first part and second part of the row on-time window can be adjusted for a given color, to adjust the color balance with respect to that color, e.g., red, green or blue. In one embodiment, a shift register is used to divide a digital representation of the first voltage value in half for application during the second part of the row on-time window. In a second embodiment, a multiplexer is used to divide the first voltage value in half for application during the second part. In a third embodiment, the first and second parts of the row on-time window are swapped such that two first parts occur consecutively and two second parts occur consecutively over a period of two row on-time windows. The third embodiment reduces the frequency of voltage change and thereby saves power.

Circuit and method for controlling the color balance of a field emission display

A field emission display of uniform brightness across the entire display screen. The field emission display according to the present invention includes row lines, column lines, and electron-emissive elements disposed at intersections of the row lines and column lines. The field emission display according to the present invention further includes row drivers coupled to selectively activate the row lines one row at a time and column drivers coupled to drive column voltages over the column lines. According to the present invention, the column voltages are derived from gray-scale data and a compensating voltage signal that represents a row position of the currently activated row line. In one embodiment of the present invention, the farther the currently activated row line is away from the driven ends of the column lines, the higher is the compensating voltage. Consequently, visual artifacts, specifically those caused by degradation of signals along the column lines attributed to transmission line effects, are significantly reduced or eliminated.

Field emission display of uniform brightness independent of column

A circuit and method for controlling the brightness of a display screen implemented using a flat panel 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 sequentially and separate gray scale information 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 brightness control circuitry positioned across the row drivers for altering row on-time of the applied voltage to the rows causing a uniform change in brightness cross the FED screen. The applied voltage is pulse width modulated to alter the brightness of the FED screen. Because the relative column voltages remain constant within the present invention, gray scale resolution or the gamma or the white point balance of the screen is not compromised as brightness is altered. Brightness is increased for an increase in the on-time window and decreased for a decrease in the on-time window.

Controlling the brightness of an FED device using PWM on the row side

Growing community of inventors

San Jose, CA, United States of America

Ronald L Hansen