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Projecting zoom lens system and projector apparatus

  • US 6,075,653 A
  • Filed: 05/29/1998
  • Issued: 06/13/2000
  • Est. Priority Date: 09/16/1997
  • Status: Expired due to Fees
First Claim
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1. A projecting zoom lens system having a telecentric incidence side comprising a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power and a fourth lens group having a positive refractive power, arranged in this order from a screen side, whereby zooming is carried out by fixing said first and fourth lens groups and moving said second and third lens groups, wherein said third lens group comprises a forward group disposed toward the screen side and a rearward group disposed toward the incidence side, and a distance between said forward and rearward groups is controlled during zooming.

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