04789222 is referenced by 27 patents and cites 5 patents.

This specification discloses an illuminating optical system in which the optical position of a multi-beam generating optical element along the direction of the optical axis is variable, whereby a desired printing wavelength selected from a wide wavelength range from the UV area to the Deep UV area can be used in the same illuminating optical system and illumination irregularity can be kept very slight.

Title
Illuminating optical system
Application Number
585245
Publication Number
4789222
Application Date
June 2, 1987
Publication Date
December 6, 1988
Inventor
Takashi Omata
Yokosuka
JP
Masakatu Ota
Tokyo
JP
Agent
Fitzpatrick Cella Harper & Scinto
Assignee
Canon Kabushiki Kaisha
JP
IPC
G02B 27/44
G02B 27/00
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