Lens testing system
US6195159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1998 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Dec 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0228
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system which determines one or more properties of a lens includes a light source and a target pattern illuminated by the light source illuminates and substantially positioned at a first conjugate position of the lens. A detector, including an active surface, is positioned at a second conjugate position of the lens such that an image of the target pattern is formed on the active surface. The detector generates an analog electrical signal based on the image and the a generator converts the electrical signal to a representative digital signal for processing. In the system, the detector is movable relative to the lens to test the lens at plural focus positions, and plural detector output signals correspond to a feature of the target pattern at plural focus positions. A memory stores computer-executable process steps, and a processor executes the process steps stored in the memory so as to obtain a modulation transfer function value of the lens based on a position of the detector with respect to the lens, a rotational orientation of the lens about its optical axis, a color of the light and the lens distortion measured at a plurality of field positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.