| abstract |
AN AFOCAL TELESCOPE 20 INCLUDES IN PARTICULAR A LENS SYSTEM 21 AND A LENS SYSTEM 23 ALIGNED ON A COMMON OPTICAL AXIS 19. THE EYE SYSTEM IS FORMED BY A TRIPLET COMPRISING ELEMENTAL LENSES A, B, C, AMONG WHICH LENSES A AND B HAVE POSITIVE POWER AND THE LENS CA NEGATIVE POWER. THE EYEWEAR SYSTEM 23 HAS NO ASPHERIC SURFACE AND LENSES A, B, AND C CAN BE IN GERMANIUM FOR THE 8-14MM BAND OR IN SILICON FOR THE 3-5MM BAND. |