Patents by Inventor Craig W. Walker

Craig W. Walker 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).

  • Laser assisted demolding of ophthalmic lenses
    Patent number: 5294379
    Abstract: An apparatus and method for removing a molded ophthalmic lens from between the mold portions in which it is produced. A source of intense electromagnetic radiation, preferably a carbon dioxide (CO.sub.2) laser of about 80 Watts at a wavelength of 10.6 .mu.m, is applied to at least one of the mold portions. The exposure of the mold portion to the laser is between one half and one second. Differential expansion of the heated mold polymer relative to the cooler polymer shifts one surface with respect to the other, and the shear force breaks the polymerized lens polymer mold adhesion and assists in the separation of mold portions. The greater the temperature gradient between the surfaces of the mold portions, the greater the shearing force and the easier the mold portions separate. The heated back mold portion is promptly removed so that very little energy is transferred to the polymer lens, avoiding the possibility of thermal decomposition of the lens.
    Type: Grant
    Filed: September 18, 1992
    Date of Patent: March 15, 1994
    Assignee: Johnson & Johnson Vision Products, Inc.
    Inventors: Denwood F. Ross, Craig W. Walker, Olin W. Calvin, Thomas G. Davis