Abstract: A PALC display panel has a cathode including a conductive core, a protective coating of a material that is electrically conductive and is non-reactive with hydrogen, and an outer coating of refractory material, and an anode having a surface of a material that is electrically conductive and is non-reactive with hydrogen.
Abstract: A conductive refractory compound coating for electrodes is sputter resistant, very resistant to oxidation, and easy to apply by way of electrophoresis or screen printing. This structure is further enhanced by the presence of surface particles of electrically nonconductive ceramic material. When the cathode electrode is energized, electrically nonconductive material is penetrated by the electric field, which attracts secondary electrons out of the cathode electrode, thereby increasing the cathode's efficiency as an emitter of secondary electrons. More specifically, cathode electrodes are used in a plasma addressing structure. The coating is formed by approximately 5 nm particles, each comprised of a fused matrix of conductive and nonconductive particles co-deposited with frit particles by either electrophoresis or "silk" screening. The coating is subsequently baked to fuse the frit and bond the electrophoretically deposited particles to the electrodes.
Type:
Grant
Filed:
July 31, 1997
Date of Patent:
June 29, 1999
Assignee:
Tektronix, Inc.
Inventors:
John S. Moore, William W. Stein, Donald E. Kephart
Abstract: A channel substrate assembly for a plasma addressed liquid crystal display device is made from a channel substrate formed with channels in a first main surface thereof, by attaching a cover sheet to the channel substrate with a first main surface of the cover sheet in confronting relationship with the first main surface of the channel substrate. The cover sheet is then thinned from its second main surface.
Type:
Grant
Filed:
May 15, 1997
Date of Patent:
June 29, 1999
Assignee:
Tektronix, Inc.
Inventors:
Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
Abstract: A channel subassembly for a PALC display panel comprises a channel member defining an array of interconnected channels, a cover sheet extending over the channels and sealed to the channel member, whereby the channel member and the cover sheet define a sealed volume, a mixture of an ionizable gas and hydrogen in the sealed volume, and a quantity of an alloy composed of about 33 wt % Zr, about 33 wt % Fe and about 33 wt % V in communication with the sealed volume.
Type:
Grant
Filed:
September 8, 1997
Date of Patent:
June 29, 1999
Assignee:
Tektronix, Inc.
Inventors:
Mark W. Roberson, Michael D. Wagner, Wayne R. Kurowski
Abstract: In a plasma addressed liquid crystal display panel, a separating layer having a lower dielectric constant than the material of the upper substrate is interposed between the data drive electrodes and the upper substrate.
Type:
Grant
Filed:
May 16, 1997
Date of Patent:
June 1, 1999
Assignee:
Tektronix, Inc.
Inventors:
Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
Abstract: In a plasma addressed liquid crystal display panel comprising a channel substrate, a cover sheet, a layer of twisted nematic liquid crystal material, an upper substrate, and an array of electrodes on the lower surface of the upper substrate, ##EQU1## where V.sub.x is the voltage that will turn a simple TN liquid crystal cell from the off state to X% transmissive in a normally black mode, d.sub.TD is the thickness of the cover sheet, d.sub.LC is the thickness of the liquid crystal layer, .epsilon..sub.TD is the dielectric constant of the cover sheet, .epsilon..sub..perp. is the perpendicular dielectric constant of the liquid crystal material, and .epsilon..sub..parallel. is the parallel dielectric constant of the liquid crystal material, and d.sub.LC .DELTA.n.sub.LC is in the range from about 0.4 to 0.5, where .DELTA.n.sub.LC is the difference in refractive indices for the liquid crystal material.
Type:
Grant
Filed:
July 11, 1997
Date of Patent:
May 11, 1999
Assignee:
Tektronix, Inc.
Inventors:
Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
Abstract: A composite electrode in a channel substrate for a PALC display panel comprises a core that includes a metal and a surface layer of a resistive anodic oxide of the core metal.
Type:
Grant
Filed:
July 11, 1997
Date of Patent:
April 27, 1999
Assignee:
Tektronix, Inc.
Inventors:
Mark W. Roberson, Robert D. Hinchliffe, Kevin J. IIcisin, John S. Moore
Abstract: A method and an apparatus reduce cross talk effects in electro-optical addressing structures. In a preferred embodiment, a flat panel liquid crystal display system (10) includes a layer (28) of frequency-sensitive liquid crystal material having a dielectric anisotropy that approaches zero for signal frequencies greater than a characteristic threshold frequency f.sub.th. The frequency-sensitive liquid crystal material is nonresponsive to components of signals with frequencies greater than the threshold frequency f.sub.th. A data driver (32) delivers inverted data signals (62) and conventional, noninverted data signals (64) to each of the multiple display elements (16) during successive first and second time intervals, respectively. As a result, the data driver generates cross talk having frequency components greater than the characteristic threshold frequency f.sub.th of the liquid crystal material.
Abstract: A refractory compound coating (188) for electrodes is sputter resistant, has a low work function so that it is a good emitter of secondary electrons, is very resistant to oxidation, and is easy to apply by way of electrophoresis. More specifically, cathode electrodes (162) are used in a plasma addressing structure (10). The coating is preferably formed by electrophoretic deposition of particles (184) of at least one refractory compound along with a frit. The coating is subsequently baked to fuse the frit and bond the electrophoretically deposited particles to the electrodes.
Type:
Grant
Filed:
June 6, 1997
Date of Patent:
July 21, 1998
Assignee:
Tektronix, Inc.
Inventors:
John S. Moore, William W. Stein, Donald E. Kephart
Abstract: A switchable color filter (11) includes three polarizing filters (12, 14, and 16) and two zero to substantially half-wave optical retarders (36 and 38) and is incorporated in a field sequential display system (10) to provide output states of light of three different colors to form an image in full color. Each one of four preferred embodiments (11, 11a, 11b, and 11c) of the switchable color filter provides the output states of three colors. The third and fourth preferred embodiments (11b and 11c) provide a fourth additional output state of, respectively, white light and light of a color which is a combination of two of the other output state colors. The optical retarders comprise nematic liquid crystal cells (100) having fast relaxation times to operate the display system at video rates.
Abstract: A plasma addressed liquid crystal display panel comprises a channel substrate having plasma channels in its upper surface thereof and an upper substrate over the upper surface of the channel substrate. A first polarizer is disposed over the upper surface of the channel substrate and transmits only light that is polarized in a first state. An electro-optic layer extends over the first polarizer and has a first condition in which it transmits light that is polarized in the first state without changing the state of polarization and a second condition in which it converts light that is polarized in the first state to a second state of polarization that is orthogonal to the first state. A second polarizer is over the electro-optic layer and transmits only light that is polarized in the second state.
Type:
Grant
Filed:
February 21, 1997
Date of Patent:
December 2, 1997
Assignee:
Tektronix, Inc.
Inventors:
Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
Abstract: An addressing structure (10, 10') using an ionizable gaseous medium has plural nonintersecting channels (20, 20') extending in a first direction and filled with an ionizable gaseous medium. Each channel contains a reference electrode (30, 30') and a row electrode (62, 62'). An amplifier (100) provides a kicker pulse to one or both of the first and second electrodes in a channel at a time coincident with the application of a second electrical signal to the second electrode. The kicker pulse and the second electrical signal cooperate to promote ionization of the gaseous medium within a predetermined discharge initiation delay time tolerance. The ionization captures across a liquid crystal material (44) data signals placed on column electrodes (18); the data signals place display elements (16) associated with the electro-optic material in predetermined data storage or display element states.
Abstract: A photocurable polymer precursor added to a liquid crystal material polymerizes to form a mixture that significantly lowers the threshold and saturation voltages of a standard twisted nematic cell. The performance characteristics of the resulting display device resembles those of a device with a very high pretilt, thereby providing an economical method of fabricating liquid crystal cells of a type that require a high pretilt alignment. The presence of the polymer substantially reduces adverse ion-related effects such as optical droop and charge retention in the liquid crystal display device.
Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for determining a first area on the substrate where a colorant is to be deposited; determining a second area which is immediately adjacent to the first area; depositing an image-enhancing precoat over the first area and the second area; and depositing a colorant on the exposed surface of the image-enhancing precoat substantially so as to be over the first area, whereby a border of precoat material will be defined about the printed image on the substrate. A second aspect of the disclosure involves sealing a printed image on a substrate by applying an aftercoat.
Abstract: A display system (10) or display (12) has a supertwisted nematic liquid crystal cell (30) located between first and second polarizing filters (24, 54) that have respective first (26) and second (56) transmission axes that form respective polar angles (A, D) with a reference plane (28). The first polarizing filter passes a neutral polarized color along the first transmission axis and has another transmission axis (27) orthogonal to the first transmission axis and transmissive of a purple polarized color; the second polarizing filter is of a neutral density type. The cell has first and second electrode structures (32, 34) confining a liquid crystal composition, each having an inner surface with respective liquid crystal alignment directions (38, 40) of inner-surface-contacting directors of the liquid crystal composition forming respective polar angles (B, C) with the reference plane. The second polarizing filter may be associated with a translucent film (64) to reflect light toward the second polarizing filter.
Abstract: A color liquid crystal display (LCD) includes many ones of a color cell triad (150) of liquid crystal cells (80R, 80G, 80B) and a negative birefringence compensator plate (110). The color cell triads are positioned between a pair of linear polarizers (112, 114), and each color cell triad is in optical association with colored filters (152R, 152G, 152B). Each of the liquid crystal cells has a symmetrical director field (82, 82') that produces a symmetrical but nonuniform color viewing circle curve (100) from the liquid crystal cell. The negative birefringence plate restores the color viewing angle uniformity. When graphed on a polar plot, the measured light transmission percentage curves (120, 122, 124) characterizing the LCD are substantially concentric circles surrounding the optical axis (18) for all azimuthal angles (28) and viewing angles (24) up to 30 degrees. Thus, the color LCD provides a multi-color display having colors that are perceptibly uniform over a wide range of azimuthal and viewing angles.
Abstract: A liquid crystal cell (60) for an optical display system has a first transparent electrode structure (62) including plural separate display electrodes (72A-72E) spaced apart from and generally parallel to a second electrode structure (64) including a common electrode (106) opposing the display electrodes across a thin layer (76) of liquid crystal material captured between the two electrode structures. Each display electrode has left (92A-92E) and right (94A-94E) ends having respective electrical contact areas (96A-96E, 98A-98E). The left and right ends of each display electrode are electrically driven with a drive signal (V.sub.DRIVE (A-E)). The common electrode has top (116) and bottom (118) ends located adjacent respective top (108) and bottom (110) side margins of the second electrode structure and having top center (120) and bottom center (122) locations with respective top and bottom electrical contact areas (124, 126).
Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for determining a first area on the substrate where a colorant is to be deposited; determining a second area which is immediately adjacent to the first area; depositing an image-enhancing precoat over the first area and the second area; and depositing a colorant on the exposed surface of the image-enhancing precoat substantially so as to be over the first area, whereby a border of precoat material will be defined about the printed image on the substrate. A second aspect of the disclosure involves sealing a printed image on a substrate by applying an aftercoat.
Abstract: A CCD gate driver circuit provides an output drive signal in response to an input clock signal. The output drive signal is symmetrical, uses a minimum amount of power at high frequencies, and compensates for cross-coupling between CCD gates. An input circuit receives the input clock signal and converts it to current pulses on the transitions of the input clock signal. The current pulses are applied to a common input of a pair of complementary input transistors to switch conduction of the transistors. The control inputs of the input transistors are coupled to a reference voltage level. The outputs of the input transistors are coupled to respective current mirrors. The outputs of the current mirrors are in turn coupled to respective inputs of a pair of complementary output transistors that have a common output. A pair of voltage rails that define the voltage swing of the output drive signal are coupled to the respective control inputs of the output transistors.