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Patent Searching and Data


Title:
DARK FIELD ILLUMINATION DEVICE
Document Type and Number:
Japanese Patent JPS5950417
Kind Code:
A
Abstract:

PURPOSE: To improve the use rate of a light source, by arranging an elliptic mirror between the light source and a collimator lens so that the light emitted from the light source is condensed at the front-side focus of the collimator lens.

CONSTITUTION: One focus of an elliptic mirror 9 exists on a light source 1, and the other is a point (a), and a conjugate point a' of a plane mirror 10 is the front-side focus of a collimator lens 3. The light from the light source 1 is condensed to the point a' and becomes a parallel light by the collimator lens 3 and is condensed onto a sample 7 through a light shielding plate 5, a reflective mirror 4, and a condensing mirror 6. Consequently, all of the light striking the elliptic mirror 9 can be used to enhance the intensity of illumination; and since the light of the light source 1 does not strike the upper part of the elliptic mirror 9, the light emitted from the collimator lens 3 has the shape of a ring and the luminous flux intercepted by the light shielding plate 5 is slight, and the use rate of the luminous flux is improved in this respect.


Inventors:
FUSHIMI SATOSHI
AKIYAMA NOBUYUKI
HARA YASUHIKO
OOSHIMA YOSHIMASA
Application Number:
JP16096382A
Publication Date:
March 23, 1984
Filing Date:
September 17, 1982
Export Citation:
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Assignee:
HITACHI LTD
International Classes:
G02B21/10; (IPC1-7): G02B21/10
Attorney, Agent or Firm:
Toshiyuki Usuda