Plane wave focusing lens
US4844198A · kind A · utility
Inventor
Key dates
| Filing date | Apr 7, 1988 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Apr 7, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K11/28
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A lens incorporates two reflective shells. One shell's surface is generated when a parabola is rotated around a line which lies in the parabolic plane perpendicular to its axis of symmetry. The other shell's surface is generated when an ellipse is rotated about a line lying in the elliptic plane and passing through one focal point at a finite angle to its major axis. The parabolically-generated shell has a characteristic focal curve while the elliptically-generated shell has both a characteristic focal curve and a focal point. The lens incorporates these shells which are aligned so that they have coincident focal curves and axes of rotation. Plane wave radiation travelling parallel to the axis of rotation of the lens will be focused at the focal point of the elliptically-generated shell. Conversely, a transducer placed about this common focal point and can produce radiation which will be converted into a plane wave radiation. Additional transducers can be placed at the lens' focal curve to process the radiation for signal tracking and self-alignment. The lens operates as a transmitter or receiver of acoustic or electromagnetic radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.