Patents Assigned to Lockley Services Pty. Ltd.
  • Sheet printed with invisible inks, developers and erasure compounds _for invisible inks
    Patent number: 4477593
    Abstract: The invention relates to a developable surface comprising a carrier layer having thereon at least two deposits of one or more invisible inks in adjacent or overlapping relationship, said deposits in the developed state being unresolvable.
    Type: Grant
    Filed: March 2, 1982
    Date of Patent: October 16, 1984
    Assignees: Lockley Services Pty. Ltd., Graham Charles Barry, Norman John Field
    Inventor: Roderick P. J. Tomlinson
  • Sheet printed with invisible inks
    Patent number: 4322466
    Abstract: The invention relates to a developable surface comprising a carrier layer having thereon at least two deposits of one or more invisible inks in adjacent or overlapping relationship, said deposits in the developed state being unresolvable.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: March 30, 1982
    Assignees: Lockley Services Pty. Ltd., Graham Charles Barry, Norman John Field
    Inventor: Roderick P. J. Tomlinson