Patent · US Expired

Projector lens system having three lens groups for image projector

US5357289A · kind A · utility

26Cited by
7References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 13, 1994
Grant dateOct 18, 1994
Priority date
Expiry dateJan 13, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N7/0122
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

This specification discloses an image projector for projecting a tri-color composite optical image on a screen as a magnified optical image. A reading light beam emitted from a light source is separated into three color beams, e.g., Red, Green and Blue color beams through a tri-color separation and composition optical system. The separated color beams are irradiated on image forming devices provided correspondingly with Red, Green and Blue color images to read out color images respectively therefrom. Each of the reflected light beams from the image forming device carrying color image information impinges again on the tri-color separation and composition optical system to compose a composite image beam. The composite image beam is projected on the screen through an optical lens system comprising a first lens group, a second lens group and a third lens group disposed along an optical axis in order. The first lens group forms a composite color image on the second lens group by focusing the composite image beam from the tri-color separation and composition optical system. The second lens group converges the composite image beam therefrom to the third lens group. The third lens group pr…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.