Refractive/diffractive infrared imager and optics
US5973827A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 20, 1998 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Jan 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/4277
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This patent teaches a low cost imager. The imager has an refractive objective lens 10 having a surface with a color correcting diffractive pattern 16 and an infrared transmitting polymeric field lens 18 having a substantially flat surface with a first field-correcting diffractive pattern. In this imager, the first field-correcting diffractive pattern operates to reduce aberrations of an image. In some embodiments, the imager further has a second field-correcting diffractive pattern on the field lens, where the first and second field-correcting diffractive pattern cooperating to reduce aberrations of the image. Additionally, this patent teaches a refractive/diffractive achromatic lens group 30. This achromat 30 can be used in the disclosed imager or in other optical devices. The achromatic group 30 has a refractive lens 10 and a lens 28 having a substantially flat surface with a surface diffractive pattern 16, the surface diffractive pattern cooperating with the refractive lens to reduce chromatic aberrations. Preferably, the second lens is formed from a polymeric sheet. These optics of the present invention can be used in infrared or visible optical devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.