Patents by Inventor Harold G. Heller

Harold G. Heller 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).

  • Photochromic compounds
    Patent number: 4220708
    Abstract: Photochromic compounds are disclosed which are 3-furyl or 3-thienyl alkylidene succinic anhydrides or the corresponding succinimides. The compounds undergo reversible photocyclization on exposure to U.V. light in high yield and their cyclic forms are deeply colored making them suitable for a wide range of recording and display devices.
    Type: Grant
    Filed: October 27, 1977
    Date of Patent: September 2, 1980
    Inventor: Harold G. Heller
  • Photochromic compounds for hologram recording
    Patent number: 4186002
    Abstract: A holographic recording method and device is disclosed in which the recording medium is a photochromic material in which a holographic record is recorded by bleaching the photochromic material using a laser beam. The photochromic materials are a class of fulgides and fulgimides.
    Type: Grant
    Filed: October 27, 1978
    Date of Patent: January 29, 1980
    Inventors: Harold G. Heller, Peter Waterworth, Rodney J. Hurditch
  • Photochromic compounds
    Patent number: 4182629
    Abstract: Photochromic compounds and useful applications thereof having the general formula: ##STR1## in which X represents oxygen or NR.sub.6, R.sub.6 being hydrogen, alkyl, aryl or aralkyl, R.sub.1 represents hydrogen, alkyl, aryl, or aralkyl, Y and Y.sub.1 being the same or different represent hydrogen, alkyl, halogen, or alkoxy, Z represents hydrogen, halogen, alkyl, alkoxy, or aryloxy R.sub.5 represents hydrogen, alkyl, alkoxy, or aryloxy, R.sub.4 represents alkyl or aryl, and R.sub.2 and R.sub.3 represent the same or different alkyl, aralkyl or aryl groups or one of R.sub.2 and R.sub.3 represents hydrogen and the other is alkyl, aralkyl, or aryl, and with the proviso that when Z or Y is alkoxy or aryloxy, R.sub.1 is other than hydrogen.
    Type: Grant
    Filed: December 19, 1978
    Date of Patent: January 8, 1980
    Inventor: Harold G. Heller
  • Photochromic compounds
    Patent number: 4145536
    Abstract: Photochromic compounds of the general formula: ##STR1## in which X represents oxygen or NR.sub.6, R.sub.6 being hydrogen, alkyl, aryl or aralkyl, R.sub.1 represents hydrogen, alkyl, aryl, or aralkyl, Y and Y.sub.1 being the same or different represent hydrogen, alkyl, halogen, or alkoxy, Z represents hydrogen, halogen, alkyl, alkoxy, or aryloxy R.sub.5 represents hydrogen, alkyl, alkoxy, or aryloxy, R.sub.4 represents alkyl or aryl, and R.sub.2 and R.sub.3 represent the same or different alkyl, aralkyl or aryl groups or one of R.sub.2 and R.sub.3 represents hydrogen and the other is alkyl, aralkyl, or aryl, and with the proviso that when Z or Y is alkoxy or aryloxy, R.sub.1 is other than hydrogen.
    Type: Grant
    Filed: May 31, 1977
    Date of Patent: March 20, 1979
    Inventor: Harold G. Heller