Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

Keith O Mersereau

Wesley P Townsend

Casimir R Nijander

Avi Y Feldblum

An apparatus for creating an illusion of eye contact in a video telephony system includes a video camera and a display screen. The video camera is aligned with the display screen so the viewer's image is transmitted by the video camera with the illusion of eye contact. The display screen has an array of lenses defining part of a first optical path, for transmitting to a video camera a viewer's image. An array of regions interspersed among the array of lenses defines part of a second optical path, for directing to the viewer, displayed images. The array of lenses and the array of regions are each too small to be separately resolvable by the human eye, so that the lenses do not interfere with the perceived quality of the transmitted viewer's image, and the transparent regions do not deteriorate noticeably the video display images projected to the viewer.

Eye contact video telephony

Prior to the production of microlenses (29) by the reactive ion etch technique, a pattern of notches (25) is formed in a second surface of a substrate (11) opposite a first surface on which the microlenses (29) are to be formed. Reactive ion etching of the first surface to produce the microlenses is sufficiently deep to reach the pattern of notches, thereby to separate the substrate. The array of notches may define, for example, an array of first areas (26) on the second surface, each area being surrounded by a notch. Photoresist elements (28) are then each located on an area of the first surface corresponding to a first area of the second surface, so that the separation separates the substrate into a plurality of segments (26) each containing only one of the microlenses (29). The notches can be made such that each of the segments (26) is cylindrical so that each of the microlenses formed from the substrate has a circular outer periphery.

Method for making microstructures

During a reactive ion etching process (FIG. 5) for making lens elements (15, FIG. 4) in a silica substrate (12), the gas constituency in the reactive ion etch chamber is changed to adjust the curvature of lens elements formed in the silica substrate and to reduce the aberrations of such lens elements. For example, two gases, CHF.sub.3 and oxygen may be supplied to the reactive ion etch chamber and, during the reactive ion etch process, the proportion of oxygen is significantly reduced, which reduces the aberrations of the lens elements formed by the process.

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Northampton, PA, United States of America

Keith O Mersereau