Title:
【発明の名称】オーバヘッドプロジェクタの固定焦点型トリプレット映写レンズ
Document Type and Number:
Japanese Patent JPH11508700
Kind Code:
A
Abstract:
A Cooke triplet projection lens for use in overhead projectors comprises two outer positive elements of an ophthalmic crown glass and one inner negative element of a light flint glass. The crown glass has a refractive index of roughly 1.523 and an Abbe value of 58.5. The flint has an index of less than 1.573 and an Abbe value of between 43 and 53. One of the positive elements is biconvex; the other is meniscus.
More Like This:
JP2553508 | [Title of Invention] Objective Lens |
JPS60177313 | TRIPLET LENS |
WO/2004/038478 | IMAGING LENS |
Inventors:
Echult, Stephen Kay
Application Number:
JP50439396A
Publication Date:
July 27, 1999
Filing Date:
May 09, 1996
Export Citation:
Assignee:
Minnesota Mining and Manufacturing Company
International Classes:
G02B9/16; G02B13/00; G02B13/16; G03B21/00; (IPC1-7): G02B13/16; G02B9/16
Attorney, Agent or Firm:
Aoyama Ryo (2 outside people)