Abstract: An optical instrument for use in conducting optometric examinations which generates an alphanumeric type display simulating the optical features of displays provided by video display terminals. The instrument comprises a light source and a multi-layered screen through which light from the source may be transmitted. The screen employs light from the source in forming characters which are comprised of pixel-like light elements similar to those making up VDT generated characters. Further, the screen is operative for degrading the image quality of the characters by transforming the light elements into Gaussian type spatial profiles typical of the pixels generated by VDTs.
Type:
Grant
Filed:
March 7, 1991
Date of Patent:
March 2, 1993
Assignee:
Applied Vision Concepts, Inc.
Inventors:
Cosmo Salibello, Jonathan G. Torrey, Steven G. Coffman, Gerald M. Murch
Abstract: An optical instrument for use in conducting optometric examinations which generates an alphanumeric type display simulating the optical features of displays provided by video display terminals. The instrument comprises a light source and a multi-layered screen through which light from the source may be transmitted. The screen employs light from the source in forming characters which are comprised of pixel-like light elements similar to those making up VDT generated characters. Further, the screen is operative for degrading the image quality of the characters by transforming the light elements into Gaussian type spatial profiles typical of the pixels generated by VDTs.
Type:
Grant
Filed:
December 12, 1988
Date of Patent:
March 12, 1991
Assignee:
Applied Vision Concepts, Inc.
Inventors:
Cosmo Salibello, Jonathan G. Torrey, Steven G. Coffman, Gerald M. Murch