Patents Represented by Attorney, Agent or Law Firm John C. Fox
  • Patent number: 6069603
    Abstract: A method of driving a matrix display device having an array of electro-optic display elements (12) each of which is connected in series with a two terminal non-linear device (15), such as a MIM, between associated row and column address conductors (16,17), in which the display elements are driven in a reset mode of operation by applying to the column address conductors data signals (D) and to the row address conductors selection signals (Vs) and reset signals (Va) to correct for non-uniformities in the characteristics of the non-linear devices, and in which in a row address period (T1) a data signal (D) applied to a column conductor is preceded by its inverse (D), a reset signal (Va) is applied during the application of the inverse data signal, and a selection signal (Vs+) is applied during the application of the data signal in the latter part of the row address period in order to minimize differences in ageing of the non linear devices.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: May 30, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Alan G. Knapp
  • Patent number: 6064091
    Abstract: A thin film transistor (10) in an electronic device such as an active matrix display panel having an intrinsic amorphous silicon semiconductor layer (22) providing a channel region (23) between source and drain electrodes (14, 16) includes directly adjacent to the side of the semiconductor layer (22) remote from the gate electrode (25) at the channel region (23) a layer (20) of amorphous semiconductor material which has a high defect density and low conductivity that serves to provide recombination centres for photogenerated carriers. Leakage problems due to the photoconductive properties of the intrinsic semiconductor material are then reduced. Conveniently, an hydrogenated silicon rich amorphous silicon alloy (e.g. nitride etc) can be used for the recombination centre layer (20).
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: May 16, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Steven C. Deane, John M. Shannon
  • Patent number: 6064424
    Abstract: An autostereoscopic display apparatus comprises means (10) for producing a display consisting of display pixels (12) in rows and columns, for example, an LC matrix display panel having a row and column array of display elements, and an array (15) of parallel lenticular elements (16) overlying the display, in which the lenticular elements are slanted with respect to the display pixel columns. The reduction in display resolution experienced in such apparatus, particularly in the case of a multi-view type display, is then shared between both horizontal and vertical resolution. Examples of full colour display apparatus using advantageous colour display pixel lay-out schemes are also described.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: May 16, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Cornelis van Berkel, John A. Clarke
  • Patent number: 6064581
    Abstract: A high voltage transformer (Tr) includes a primary winding (Lp), secondary windings (Ls1, Ls2, Ls3), and diodes (Di) coupled between successive secondary windings. The polarity of the diodes and the secondary windings is selected such that the flyback voltages across each of the secondary windings are summed via conductive diodes during at least a part of a flyback period (Tf) for generating a high voltage. A damp-circuit (1) comprises a rectifier element, a load (L), and a further winding (Ls4) of the high voltage transformer. These elements are arranged with respect to one of the secondary windings such that the further winding and the one of the secondary windings form a capacitance (Cd) across the load. The diode (D) is non-conductive during the flyback period. In this way, electrical oscillations of the high voltage transformer are damped.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: May 16, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Pieter J. Bax, Rudi Jonkman
  • Patent number: 6057895
    Abstract: A flat display device preferably of the PALC type in which the plasma channels are formed by depositing successive layers of electrically conductive and electrically insulating material on a substrate containing spaced walls of a resist material that are preferably structured with a negative slope to form in the space between the resist walls flanking channel walls comprising an electrode layer and rising above it a wall of insulating material with the electrode layer sides exposed to adjacent channels. Subsequently, the resist walls are removed by a lift-off process removing with it the layer deposits on the resist walls leaving behind the layer deposits between the resist walls. The remaining insulating walls are then covered with thin dielectric sheet-like member to form the plasma channels.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: May 2, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Henri R. J. R. Van Helleputte, Jacob Bruinink, Adrianus L. J. Burgmans, Petrus F. G. Bongaerts, Babar A. Khan, Karel E. Kuijk
  • Patent number: 6054725
    Abstract: An organic electroluminescent device (1) has an organic emitter layer (5) disposed between, on the one side, a common electrode (6) and, on the other side, a first and second electrode (3A, 3B) which are mutually interlaced and independently driveable. When driven by means of, respectively, the first and second electrode (3A, 3B), respectively, a first and second pattern-wise light-emitting surface emerges. Using different light-emitting patterns, optionally in combination with light-absorbing patterns, a group of icons differing in color and/or shape can be displayed selectively using the same part of a display area.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: April 25, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Coen T. H. F. Liedenbaum, Hermannus F. M. Schoo
  • Patent number: 6051925
    Abstract: A diode-addressed color display comprising an UV-diode and a phosphor of the general formula [Eu(diketonate).sub.a X.sub.b1 X'.sub.b2 ], wherein X=pyridine or a unidentate pyridine derivative and X'=2,2'-bipyridine or a 2,2'-bipyridyl derivative and 2a+b.sub.1 +2b.sub.2 =8, is characterized by a high quantum efficiency and a high extinction coefficient in the near-UV wavelength range and enables a color-sensitive image reproduction to be achieved.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: April 18, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Herbert Boerner, Thomas Justel, Hans Nikol, Cornelis Ronda
  • Patent number: 6052160
    Abstract: The display device is furnished with a channel plate (39) comprising channels (30, 30', 30") containing an ionizable gas (33), and the walls of the channels (30, 30', 30") being provided with electrodes (31, 32) for selectively generating a plasma discharge of the ionizable gas (33) during operation. The display device further comprises an electro-optical layer (35) of a material having an optical property which is governed by the discharge state of the plasma discharge. The display device is characterized in that at least one of the electrodes (31, 32) is furnished with a layer (37) comprising particles of a sputter-resistant material having an average diameter .ltoreq.2.5 .mu.m, preferably .ltoreq.1.5 .mu.m. The particles are preferably composed of rare-earth borides (for example LaB.sub.6) or ruthenium oxide.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: April 18, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Marcel R. Bohmer, Monica Scholten, Udo Van Slooten
  • Patent number: 6046479
    Abstract: A large-area electronic device, such as an AMLCD, has switching TFTs (T.sub.p) in a matrix and circuit TFTs (T.sub.s) in a peripheral drive circuit. Both the TFTs (T.sub.p, T.sub.s) comprise a field-relief region (130) which has a lower doping concentration (N-) than their drain region (113) and which is present between their channel region (111) and the drain region (113). This field-relief region (130), at least over most of its length, overlaps with the gate (121) in the circuit TFTs (T.sub.s) so as to reduce series resistance in the field-relief region (130) by conductivity modulation with the gate (121). However, the drain region (113) in the switching TFTs (T.sub.p) is offset from overlap with their gate (121) by at least most of the length of their field-relief region (130). This field-relief offset permits the switching TFTs (T.sub.p) to have a lower leakage current than the circuit TFTs (T.sub.s).
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: April 4, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Nigel D. Young, John R. A. Ayres, Martin J. Edwards
  • Patent number: 6046542
    Abstract: In a flat panel display or other type of electron device, a thin-film electron emitter (51) and/or emitter array (50) is formed in a semiconductor film (10) of, for example, hydrogenated amorphous and/or microcrystalline Si, SiC.sub.x, SiN.sub.y, SiO.sub.x N.sub.y or the like. An injector electrode (14) forms a potential barrier (.phi..sub.B) with the semiconductor film (10) at a back major surface (12) of the film (10). A front electrode (15) serves for biasing an emission area (11a) of the front major surface (11) at a sufficiently positive potential (V.sub.15) with respect to the injector electrode (14) as to inject electrons (e) over the barrier (.phi..sub.B) in the operation of the emitter (51) while controlling the magnitude of an electron accumulation layer (Ne) in the semiconductor film (10) at the emission area (11a).
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: April 4, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Sembukuttiarachilage R. P. Silva, John M. Shannon
  • Patent number: 6043596
    Abstract: A color CRT has a shadow mask formed from a bilayer composite of steel and invar. The thicknesses of steel and invar are chosen to take advantage of the lower thermal expansion coefficient of invar and the room temperature formability and higher modulus of elasticity of steel. Such composite masks exhibit reduced doming when compared to steel masks, and can be formed at room temperature.
    Type: Grant
    Filed: December 4, 1997
    Date of Patent: March 28, 2000
    Assignee: Philips Electronics North America Corporation
    Inventor: Venugopal Lakshmanan
  • Patent number: 6036564
    Abstract: An assembly of electrodes for an electron is inspected. The relative positions of a number of apertures (at least three but preferably four) is determined by means of two optical systems, one for determining the positions of two apertures of electrodes, e.g. the G1 and the G2 electrode, the other for determining the position of the other aperture or apertures.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: March 14, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Pieter Scholten, Hector H. Velasco
  • Patent number: 6033279
    Abstract: A method in which a (display) device having a part (41) comprising a first wall (43) and a second wall (44) is manufactured, which part (41) is warmed up during the temperature treatment by unilateral irradiation with heat by means of heat radiators (35). The method is characterized in that the temperature treatment further comprises measures which cause a fluid (53) to be fed past the outer surface of the first wall (43) to remove heat from said outer surface and/or measures which cause a fluid to be fed past the inner surface of the second wall (44) to supply heat to said second surface. In an embodiment, the inner surface of the second wall (44) is provided with a heat-absorbing coating (48). Preferably, the heat radiators (35) emit electromagnetic radiation having a wavelength below 3 .mu.m.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: March 7, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Leendert Van der Tempel, Hans Galenkamp, Richard B. J. Droste
  • Patent number: 6028749
    Abstract: Magnetic head having a multilayer structure which comprises at least one magnetoresistive layer (9) and a transducing gap terminating in a head face. The magnetoresistive layer has an active central portion located between two end portions, which central portion is provided with equipotential strips (13). Layers (15) of a hard-magnetic material with an axis of magnetization extending in the longitudinal direction of the magnetoresistive layer are provided opoosite to, and spaced apart from the end portions, a non-magnetic spacer layer (17) of electrically insulating material being present between the end portions and said layers of hard-magnetic material.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: February 22, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Lambertus Postma
  • Patent number: 6018222
    Abstract: The invention relates to a dynamic focusing circuit with an output (1) for supplying a dynamic focusing voltage (Vf) to a focus electrode of a cathode ray tube (CRT). The dynamic focusing voltage (Vf) has, in succession, a falling edge, an almost flat part and a rising edge. A first transistor (T1) has a main current path (c1, e1) coupled between a supply voltage (V+) and the output (1). An arrangement of a secondary winding (Ls) of a transformer (T) and a current determining circuit (12) is coupled between the control input (b1) of the first transistor (T1) and the output (1). The current determining circuit (12) supplies a bias current (Ib). A second transistor (T2) has a control electrode (b2) for receiving an input voltage (Vi) related to a parabolically shaped input waveform (Vin), and a main terminal (c2) coupled to the control input (b1) of the first transistor to withdraw current (Id) from the control input (b1).
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: January 25, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Franky M. M. E. Vaneerdewegh, Robert C. C. Van Der Sanden
  • Patent number: 6013975
    Abstract: A colour display tube 1 has a shadow mask 12 in a supporting frame 20. The supporting frame comprises at least two sides 22 which bend when the temperature increases. This causes the distance between the shadow mask and the display screen to change. An improvement of "overall doming" is possible.
    Type: Grant
    Filed: September 28, 1993
    Date of Patent: January 11, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Johannes H. N. Gijrath
  • Patent number: 6014197
    Abstract: Switchable electro-optic medium (2) between two substrates (3, 4) at least one of which carries a grating structure (7, 8) at the side of the electro-optic medium, which grating structure has refractive indices which are substantially identical to those of the medium in the non-isotropic state. In the isotropic state diffraction occurs at the grating structure due to a difference in refractive index so that the central beam (11) decreases in intensity. Based on this principle, light shutters for, for example projection display but also beam splitters, colour selectors and beam deflectors may be realized.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: January 11, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Rifat A. M. Hikmet
  • Patent number: 6008571
    Abstract: A color cathode ray tube has a shadow mask. The shadow mask is provided with a layer of a material having an average Z number below 20 on the side facing the phosphor screen. The layer is preferable deposited by means of electrodeposition.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: December 28, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Jacques J. Van Oekel, Michael J. M. J. Severens, Gerarda M. H. Timmermans, Maria C. Van Uden, Marcel Brouha
  • Patent number: 6007399
    Abstract: To improve performance, reliability and lifetime of a plasma-containing electro-optic display device, at least the cathode electrodes have hollows or wells within which plasma discharge occurs. This reduces the tendency of the electrode material to be sputter deposited on the walls of the device. In addition, cathode emission is improved by incorporating emitter materials into the electrodes, either by alloying or by surface coatings.
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: December 28, 1999
    Assignee: Philips Electronics North America Corporation
    Inventors: Vivek Mehrotra, Babar A. Khan
  • Patent number: 6005260
    Abstract: For contacting a non-linear switching element (10), for example for use in a display device (1), a metallic layer (14) is provided on a layer of non-linear resistive material by means of a low-energetic deposition technique. This layer may function as a contact but also as a protective layer when a contact metallization (15) is provided at a later stage.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: December 21, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Alfred J. Van Roosmalen, Jan H. W. Kuntzel