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Title:
PROJECTION LENS SYSTEM WITH LITTLE SPHERICAL CHROMATIC ABERRATION
Document Type and Number:
Japanese Patent JPH0749450
Kind Code:
A
Abstract:

PURPOSE: To improve the spherical chromatic aberration of a projection lens system for projecting a video from a cathode ray tube in which spherical chromatic aberration is reduced to a screen.

CONSTITUTION: A highly dispersive lens element having a positive refractive power on an axis and at least one aspheric surface for changing the positive refractive power to a negative refractive power in the neighborhood of a peripheral part in a valid aperture is used as a first lens element L1 of a lens system. This first lens element L1 is preferably formed of styrene.


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Inventors:
JIEIKOBU MOSUKOBUITSUCHI
Application Number:
JP12735894A
Publication Date:
February 21, 1995
Filing Date:
June 09, 1994
Export Citation:
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Assignee:
US PRECISION LENS INC
International Classes:
G02B13/16; G02B13/18; G02B27/00; H04N9/31; (IPC1-7): G02B13/18; G02B13/16
Domestic Patent References:
JPH04121704A1992-04-22
JPS61213815A1986-09-22
JPH0395512A1991-04-19
JPH0367210A1991-03-22
JPH02190811A1990-07-26
JPH0339916A1991-02-20
JPH03131809A1991-06-05
JPS6111716A1986-01-20
JPS6111717A1986-01-20
JPS619613A1986-01-17
JPS60189722A1985-09-27
JPS6385515A1988-04-16
Attorney, Agent or Firm:
Seiji Yanagida (1 person outside)



 
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