Ghost image prevention element for imaging optical system
US6783246B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 2002 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Sep 18, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0018
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging optical system includes at least one ghost image prevention element. Ghost images are prevented even when the imaging optical system includes an optical element that has at least one planar surface that is generally orthogonal to an optical axis of the imaging optical system, and is located in a light flux area with at least a central portion of the light flux area being generally parallel to the optical axis. The ghost image prevention element is especially useful in video cameras and digital cameras that use an image sensor having a planar surface that exhibits a high coefficient of reflection. The ghost image prevention element includes one planar surface, that is “tightly bound” to the planar surface of the optical element, and another surface that is curved so as to satisfy a given condition. The curved surface diffuses light that would otherwise contribute to a ghost image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.