Device for determining focused state of taking lens
US6822801B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 3, 2003 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Dec 3, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/959
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A beam splitter (24)for splitting light in a wavelength range of about 500 nm to about 600 nm is arranged in a relay optical system of a taking lens (12). A green light beam reflected from the beam splitter (24) is directed through a relay lens (R3) to a focusing state determination imaging unit (26). The imaging unit (26) comprises three imaging elements (A, B, C) for capturing the directed green light beam to determine the focusing state. Thus, a device for determining the focusing state of the taking lens is provided, in which the green light beam is separated as an object light for determining the focusing state from the object light entering the taking lens (12), so that the focusing state can be determined with high accuracy on the basis of the high-frequency components of the image signal generated by capturing the green light beam by means of the imaging elements (A, B, C) having different optical path lengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.