Patents Represented by Attorney, Agent or Law Firm John C. Fox
  • Cathode ray tube with UV-reflective filter and UV-excitable phosphor
    Patent number: 5569977
    Abstract: Output and/or perceived persistence of visible light from a cathode ray tube is improved by incorporating a UV-excitable phosphor into the screen, and by placing a UV-reflective filter on the inside of the display panel prior to formation of the phosphor screen, so that UV light emitted from the screen upon excitation by the tube's electron beam(s) is reflected back onto the screen to excite the further emission of visible light.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: October 29, 1996
    Assignee: Philips Electronics North America Corporation
    Inventor: Robert L. Donofrio
  • Cathode ray tube with improved yoke clamp
    Patent number: 5568010
    Abstract: The deflection coil for a cathode ray tube is secured to the outside of the glass envelope of the tube via a yoke assembly including a yoke clamp having a band which encircles the assembly and is adjusted to securely hold the assembly in place. Dividing the band into sub bands separated by a space along substantially the entire length of the band significantly reduces the stress on the neck of the glass envelope of a cathode ray tube, thereby reducing the incidences of tube failures due to neck cracking.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: October 22, 1996
    Assignee: Philips Electronics North America Corporation
    Inventors: Chin Y. Cha, Shridhar V. Iyer
  • Holder for a rectangular cassette
    Patent number: 5560481
    Abstract: A holder for a rectangular cassette such as a magnetic-tape cassette comprises two parallel main walls and, three interconnecting transverse walls, and one short open side through which a cassette can be inserted into or removed from a cassette-receiving space defined by said walls. One of the main walls of the holder has a window which exposes a cassette main wall, provided with a label. The window of the holder is at least partly open, thereby enabling the cassette, when the holder is held in the palm of one hand, to be pushed out at least partly with a thumb, from which position the cassette can be loaded into a player/recorder by a loading mechanism.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: October 1, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Peter J. Doodson, Paul J. F. Van Weele
  • Reproducing device used with a record carrier containing two sides recorded in opposite directions that determines the selection of particular read back characteristics
    Patent number: 5559642
    Abstract: Digital information recorded in a track (T.sub.a.i) on a tape-like magnetic record carrier (20) can be read out again when the record carrier is transported in a specific direction. The transport direction of the record carrier when the information is recorded may be similar or opposite to the direction in which the information is reproduced. This implies that as a function thereof a first or second equalization filter (F.sub.1, F.sub.2) is to be used during reproduction so as to realise a first or second filtering of the information that is read out. For this purpose, markers (M.sub.1, M.sub.2) are introduced on the record carrier (20) or the cassette (61). From these markers there may be derived whether the side being read out at a specific moment has been recorded in a transport direction similar or opposite to the transport direction during reproduction.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: September 24, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Abraham Hoogendoorn, Gerardus C. P. Lokhoff
  • Liquid crystal display device with twist angle .phi. of 70.degree. to 90.degree.and alignment to polarization direction angle between .phi./2+30.degree.and .phi./2+60.degree.
    Patent number: 5555113
    Abstract: Picture inversion in display devices based on the twisted pneumatic effect is prevented by choosing a twist angle .phi.T such that 70.degree.<.phi.T<90.degree., and an angle .alpha. between the direction of polarization of one of the polarizers and the associated direction of orientation such that: 30.degree.+.phi.T/2<.alpha.<60.degree.+.phi.T/2.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: September 10, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Johannes C. H. Mulkens, Ingrid E. J. R. Heynderickx
  • One dimensional tension mask-frame assembly for CRT
    Patent number: 5554909
    Abstract: A one-dimensional tension mask-frame assembly for a color cathode ray tube includes a rectangular frame whose top and bottom members each have inwardly flexed upstanding portions with a spring constant, and a rectangular mask secured to the frame along the free edges of the upstanding frame portions, the frame portions maintaining the mask in a state of tension during thermal expansion of the mask. The assembly is useful in color display applications such as T.V.
    Type: Grant
    Filed: May 6, 1994
    Date of Patent: September 10, 1996
    Assignee: Philips Electronics North America Corporation
    Inventor: Matthew S. Brennesholtz
  • Cathode ray tube
    Patent number: 5536997
    Abstract: A cathode ray tube in which a glass-enamel layer having particles with a secondary electron emission coefficient smaller than 1, for example Cr.sub.2 O.sub.3 particles, is provided in the neck. The percentage of particles exceeds approximately 30% and the surface resistance or resistivity ranges between 10.sup.10 and 10.sup.14 .OMEGA./.quadrature.. The high-voltage behavior of such a layer is satisfactory. The convergence drift is relatively small. In addition, a description is given of a method of providing such a glass-enamel layer.
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: July 16, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Leonardus Th. M. Van Hout
  • Anti-implosion band in a cathode ray tube having improved structure for protecting suspension elements
    Patent number: 5536996
    Abstract: An anti-implosion band (4) for a cathode my tube comprises a suspension element (5) on its corners with the suspension element having a suspension aperture (8). The suspension element has a portion (7) in which the suspension aperture (8) is formed. This portion extends transversely to the clamping band. The suspension element further comprises projections (9) which extend on one side of the band (4), transversely to the edge of the band, and, when viewed in projection on the plane of the clamping band, the opposite side (10) of the band falls within the projections of the suspension elements. The projections do not influence the clamping function of the band. The bands can be stacked in a simple manner.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: July 16, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Frank C. Vijlbrief
  • Field emitter display device with two-pole circuits
    Patent number: 5537007
    Abstract: By incorporating two-pole circuits (13) as switching elements in a picture display device based on field emission, the emission (and hence the picture intensity) is substantially defined by the charge of a capacitance (15) associated with a part of a pixel (8). Charge-controlled drive leads to a more accurate adjustment than the voltage-controlled drive used until now and leads to lower drive voltages, less power consumption and a longer lifetime of the phosphors used in the display device.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: July 16, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Dirk W. Harberts, Karel E. Kuijk, Remko Horne, Gerardus N. A. Van Veen, Hans-Helmut Bechtel
  • Display device comprising a display screen provided with a light absorbing coating
    Patent number: 5534748
    Abstract: The display screen (3) of a cathode ray tube (1) is provided with a light-absorbing coating (8) comprising a hybrid inorganic-organic material consisting of an inorganic network of at least silicon oxide and a polymeric component. By means of a sol-gel process the coating can be provided in a relatively large thickness without causing crackles. Consequently, the layer can contain large quantities of dyestuff, so that said layer can very suitably be used as a chrominance or transmission coating to improve the picture contrast. Even if the display screen is not highly polished, the coating can be obtained with a high-polish and it complies with the customary mechanical, chemical and optical requirements.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: July 9, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Emmanuel W. J. L. Oomen
  • Single panel color projection video display
    Patent number: 5532763
    Abstract: A color projection video system utilizing only a single light valve. A white light source is separated into into red, green and blue bands. Scanning optics cause the RGB bands to be sequentially scanned across a light valve, such as a transmission LCD panel. Prior to each color passing over a given row of panels on the light valve, that row will be addressed, by the display electronics with the appropriate color content of that portion of the image which is being displayed. The image is projected by a projection lens onto a viewing surface, such as a screen. The sequence of light bands occurs so quickly as to give the viewer an appearance of simultaneous full color.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: July 2, 1996
    Assignee: North American Philips Corporation
    Inventors: Peter J. Janssen, Ralph H. Bradley, Joseph P. Bingham, William F. Guerinot, Detlev Otto
  • Method of manufacturing a thin-film magnetic head
    Patent number: 5531016
    Abstract: Method of manufacturing a thin-film magnetic head in which a main layer (5) of a non-magnetic material is formed on a support, which layer is recessed by removing material from a side remote from the support, said recess being subsequently filled up with a soft-magnetic material for forming a flux guide (17a, 17b), whereafter the main layer provided with the filled recess is mechanochemically polished for forming a main surface (19) at which subsequently a layer of a magnetoresistive material is provided for forming a magnetoresistive element (23).
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: July 2, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Lambertus Postma, Henricus G. R. Maas, Jan Haisma, Jacobus J. M. Ruigrok, Gerardus H. J. Somers
  • Single panel color projection video display having improved scanning
    Patent number: 5528318
    Abstract: A color projection video system utilizing only a single light valve. A white light source is separated into red, green and blue bands. Scanning optics in the form of three prisms coaxially mounted for rotation cause the RGB bands to be sequentially scanned across a light valve, such as a transmission LCD panel. Prior to each color passing over a given row of panels on the light valve, that row will be addressed, by the display electronics with the appropriate color content of that portion of the image which is being displayed. The image is projected by a projection lens onto a viewing surface, such as a screen. The sequence of light bands occurs so quickly as to give the viewer an appearance of simultaneous full color.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: June 18, 1996
    Assignee: North American Philips Corporation
    Inventor: Peter J. Janssen
  • Magneto-resistance device, and magnetic head comprising such a device
    Patent number: 5527626
    Abstract: A magneto-resistance device comprises a stacked structure, which stacked structure has a non-conducting substrate having a surface on which a multilayer structure is provided. The surface is furnished with a plurality of grooves which are substantially mutually parallel, each groove comprising a first and a second face. All first faces are substantially planar and mutually parallel. The constituent layers of the multilayer structure are provided in a stack upon each first face in such a manner as to be parallel thereto, the thickness of the stacks being such that each stack makes physical contact with each immediately neighbouring stack.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: June 18, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Martinus A. M. Gijs, Jacobus B. Giesbers
  • Dispenser cathode and method of manufacturing a dispenser cathode
    Patent number: 5518520
    Abstract: Method of manufacturing a dispenser cathode, in which method tungsten and a scandium-containing material are mechanically alloyed and the product thus formed is pressed into a cathode body. The cathode body is further provided with a barium-containing component. In the mechanical alloying process the tungsten is highly deformed and the scandium-containing material is mixed with the tungsten so as to be very finely distributed therein, so that an improved dispensation of scandium and hence an improved recovery after ion bombardment of the final cathode is attained.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: May 21, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Jan Hasker, Robert H. Kane, Paul D. Goodell, Jacobus A. J. M. Deckers
  • Magnetic head with wear resistant layer having alignment mark, and magnetic head unit incorporating same
    Patent number: 5513057
    Abstract: Magnetic head unit comprising a magnetic head secured in a housing and having a magnetic head structure provided with a head face and at least one transducing gap terminating in the head face. A wear- resistant layer (31 ) having at least one alignment mark (35, 36, 37) occupying a defined position with respect to the transducing gap is provided on the head face.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: April 30, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Victor Zieren, Jacobus J. M. Ruigrok, Mathijs De Jongh, Arnold Broese Van Groenou
  • Shield-anode coating contactor and CRT incorporating same
    Patent number: 5510669
    Abstract: An improved IMS-anode coating spring contactor for a cathode ray tube (CRT) has a base with a semi-dart clip configuration and a tail extending from the base, which base and tail are interlocked in a set of two adjacent apertures in the IMS of the CRT. When assembled into a CRT, the body of the contactor is flexed, urging the head against the anode coating, and urging the base and tail against the edges of the apertures, thereby to achieve good electrical contact between the IMS and the anode coating.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: April 23, 1996
    Assignee: Philips Electronics North America Corporation
    Inventor: Gerald E. Van Buren
  • Single panel color porjection video display having control circuitry for synchronizing the color illumination system with reading/writing of the light
    Patent number: 5508738
    Abstract: A color projection video system utilizing only a single light valve. A white light source is separated into into red, green and blue bands. Scanning optics cause the RGB bands to be sequentially scanned across a light valve, such as a transmission LCD panel. Prior to each color passing over a given row of panels on the light valve, that row will be addressed, by the display electronics with the appropriate color content of that portion of the image which is being displayed. The image is projected by a projection lens onto a viewing surface, such as a screen. The device includes circuitry to synchronize the illumination of the light valve with the video signal and to minimize video breakup when changing video sources.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: April 16, 1996
    Assignee: North American Philips Corporation
    Inventors: Peter Janssen, William Guerinot
  • Active matrix display devices having bidirectional non-linear devices connected between adjacent pixels and respective address conductor
    Patent number: 5490002
    Abstract: An active matrix display device comprises an array of display elements (12), e.g. liquid crystal display elements, connected between sets of row and column address conductors (22,24). A display element electrode (20) is connected to an associated address conductor (22) of one set via two, parallel, switch means each of which comprises at least two, two-terminal, bi-directional, non-linear devices (30), for example, MIM type thin film diode devices, connected in series. A bidirectional, non-linear device (e.g. 30b) of each switch means (e.g. 30a, 30b) is shared by, and comprises a part of, a switch means (e.g. 30b, 30e) associated with a respective adjacent display element, there being in each switch means at least one non-linear device (e.g. 30a) between the shared device (30b) and the display element electrode (20).
    Type: Grant
    Filed: July 26, 1994
    Date of Patent: February 6, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Keith H. Nicholas
  • Reflecting image projection screen and image projection system comprising such a screen
    Patent number: 5486884
    Abstract: A reflecting image projection screen (1) is described, as well as an image projection system (17) in which such a projection screen (1) is used. Viewed from the front side (3) of the projection screen (1), the image projection screen comprises, in this order, a linear polarizer (9), a .lambda./4 plate (11), a reflecting polarizer (13) in the form of a cholesteric filter and a reflecting layer (15) which is also active as a depolarizing diffuser layer. By combining a cholesteric filter (13) with a depolarizing reflecting layer (15), an image projection screen is obtained which is highly reflective to the direction of polarization supplied by the image projector (19) and substantially absorbs the other direction of polarization.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: January 23, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Adrianus J. S. M. De Vaan