Imaging optical system and endoscope provided with imaging optical system
US7317180B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2006 |
| Grant date | Jan 8, 2008 |
| Priority date | — |
| Expiry date | Jun 6, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/555
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An imaging optical system includes a spherical or nearly spherical viewing port, an objective lens that includes an aspheric surface and is formed as a single lens element, and a solid-state image sensor that receives an image formed by the imaging optical system. Specified conditions are satisfied by the imaging optical system and the objective lens so that an in-focus image having low distortion, sufficient contrast, and formed by light rays of restricted angles of incidence is formed even for an object in contact with the viewing port. The specified conditions relate to features of the imaging optical system such as focal length and f-number of the imaging optical system, astigmatism and distortion of the imaging optical system, and pixel pitch of the solid-state image sensor. An endoscope that includes the imaging optical system is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.