Patents by Inventor Ling K. Hung

Ling K. Hung has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Water-based photoresists using stilbene compounds as crosslinking agents
    Patent number: 4299910
    Abstract: Improved aqueous photoresist compositions comprising a water-soluble polymeric material and a photosensitive cross-linking agent, therefore, having the formula: ##STR1## wherein, A and B are independently amino or nitro and M is an alkali metal or ammonium ion, and process of exposing and developing same.
    Type: Grant
    Filed: November 24, 1980
    Date of Patent: November 10, 1981
    Assignee: RCA Corporation
    Inventors: Ling K. Hung, Allen Bloom
  • Novel liquid crystal dyestuffs and electro-optic devices incorporating same
    Patent number: 4184750
    Abstract: Novel liquid crystal dyestuffs of the formula ##STR1## wherein Y and Z are different and can be nitro or cyano and --N(R).sub.2 wherein R is alkyl or alkylene, preferably of 1 to 4 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro, can be added to known liquid crystal compositions to impart color to the mixtures and improve contrast in a liquid crystal electro-optic device containing such mixtures.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: January 22, 1980
    Assignee: RCA Corporation
    Inventors: Allen Bloom, Ling K. Hung
  • Liquid crystal dyestuffs and electro-optic devices incorporating same
    Patent number: 4153343
    Abstract: Novel dyes of the formula ##STR1## wherein X is --NH, --NCH.sub.3, --S or --O; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently at each occurrence can be hydrogen, fluoro, chloro, bromo, alkoxy, cyano, nitro, --N(R).sub.2 wherein R is alkyl or two of R.sub.1 to R.sub.4 together can be part of an aromatic ring; R.sub.5 and R.sub.6 are hydrogen, fluoro, chloro, bromo or lower alkyl; and R.sub.7 is hydrogen, fluoro, chloro, bromo, alkoxy, cyano, nitro, --N(R.sub.2), ##STR2## HYDROGEN, FLUORO, CHLORO, BROMO, ALKOXY, CYANO, NITRO, DI-ALKYLAMINO, ##STR3## can be added to known liquid crystal compositions to impart color to the mixtures and to improve contrast of a liquid crystal electro-optic device containing such mixtures.
    Type: Grant
    Filed: June 9, 1977
    Date of Patent: May 8, 1979
    Assignee: RCA Corporation
    Inventors: Allen Bloom, Ling K. Hung
  • Cholesteryl carbonates and carbamates of azo dyes
    Patent number: 4134888
    Abstract: Novel liquid crystal dyes of the formula ##STR1## wherein (CHOL--) is a cholesteryl radical, X can be 0 or NH, R.sub.1 can be H, --OH, methyl, fluoro or chloro; R.sub.2 can be --NO.sub.2, --CN, N-(alkyl).sub.2, --OCOOR, --OCOR, alkyl or alkoxy and R.sub.3 can be H, methyl, fluoro or chloro, can be added to known liquid crystal compositions to impart color to the mixtures and improved contrast to a liquid crystal electro-optic device containing such mixtures.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: January 16, 1979
    Assignee: RCA Corporation
    Inventors: Allen Bloom, Ling K. Hung
  • Liquid crystalline 4"-cyano- or 4"-nitrobenzylidene-4'-(N,N-dialkylamino)-1-aminoazabenzene dyes
    Patent number: 4105654
    Abstract: Compounds of the formula ##STR1## wherein Y and Z are different and one is nitro or cyano and the other is --N(R).sub.2 wherein R is alkyl or alkylene, preferably of 1 to 4 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro, are dyes having liquid crystal properties.
    Type: Grant
    Filed: November 12, 1976
    Date of Patent: August 8, 1978
    Assignee: RCA Corporation
    Inventors: Allen Bloom, Ling K. Hung