Photocopying – Projection printing and copying cameras – Illumination systems or details
Reexamination Certificate
2002-03-20
2004-11-09
Nguyen, Henry Hung (Department: 2851)
Photocopying
Projection printing and copying cameras
Illumination systems or details
C359S683000
Reexamination Certificate
active
06816236
ABSTRACT:
BACKGROUND OF THE INVENTION
Conventionally, projection optical systems and projection and light exposure apparatus are known for use in projecting the pattern of an original onto a surface in the production of a print board. Among these, an isometric magnification projection lens is disclosed in Japanese Patent No. 3026648 in which lens groups are symmetrically positioned in relation to a stop and light flux is nearly telecentric on both the object side and image side.
A lens system that is totally symmetric in relation to a stop forms an isometric image. However, in general, a totally symmetric lens system is difficult to obtain because of production errors in the components which make up the lens system. Image magnification is slightly deviated, and the deviation should be corrected in each lens system. When plural patterns are exposed on a board, the images should precisely overlap. Since the board expands or contracts with changes in temperature, minute adjustment of magnification is required in the course of exposure. In general, the entire lens system is moved along the optical axis to change the image magnification of the lens system. Because the projection lens system described above is telecentric on the object and image sides, moving the entire lens system along the optical axis does not result in a change in magnification.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a projection optical system and a projection and light exposure apparatus, especially one used to produce a print board. A first object of the present invention is to provide a projection optical system and a projection and light exposure apparatus that are telecentric on both the object side of a stop and the image side of the stop so as to allow for excellent correction of image magnification deviations caused by production errors in making the components. A second object of the invention is to provide a projection optical system and a projection and light exposure apparatus that will enable the adjustment of image magnification so as to compensate for the expansion or contraction of the print board due to changes in temperature in an easy manner while favorably correcting image aberrations.
REFERENCES:
patent: 4997265 (1991-03-01), Nishina
patent: 5313330 (1994-05-01), Betensky
patent: 5606459 (1997-02-01), Nakatsuji
patent: 6215599 (2001-04-01), Ohtake
patent: 6366412 (2002-04-01), Noda et al.
patent: 6433938 (2002-08-01), Kawamura
patent: 6459534 (2002-10-01), Kato et al.
patent: 3026648 (2000-01-01), None
Arnold Bruce Y.
Arnold International
Fuji Photo Optical Co., Ltd.
Nguyen Henry Hung
LandOfFree
Projection optical system and projection and light exposure... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Projection optical system and projection and light exposure..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Projection optical system and projection and light exposure... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3333719