Optical: systems and elements – Lens – With variable magnification
Patent
1997-08-25
1999-10-12
Epps, Georgia
Optical: systems and elements
Lens
With variable magnification
359694, G02B 1514
Patent
active
059662492
ABSTRACT:
A zoom lens barrel includes a front lens holder frame with a male helicoid and a rear lens holder frame including a cam follower pin. A linear movement guide mechanism guides the front and rear lens holder frames to move in the optical axis direction. A rotatable drive ring, with a female helicoid, engages with the male helicoid of the front lens holder frame and with a cam groove in which the cam follower pin of the rear lens holder frame is fitted. The cam groove is provided with a plurality of spaced back focal distance adjusting sections parallel with the lead of the helicoids and with a plurality of zoom sections that connect the adjacent ones of the spaced back focal distance adjusting sections and that are not parallel with the lead of the helicoids. The drive ring is always stopped when the cam follower pin is located in any one of the back focal distance adjusting sections.
REFERENCES:
patent: 4974949 (1990-12-01), Tanaka
patent: 5245476 (1993-09-01), Shono
patent: 5349475 (1994-09-01), Nomura et al.
patent: 5485315 (1996-01-01), Nomura et al.
patent: 5537262 (1996-07-01), Aoki et al.
patent: 5579173 (1996-11-01), Hamasaki et al.
patent: 5589987 (1996-12-01), Tanaka
Asahi Kogaku Kogyo Kabushiki Kaisha
Epps Georgia
Letendre Suzanne
LandOfFree
Zoom lens barrel and method for adjusting back focal distance th does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Zoom lens barrel and method for adjusting back focal distance th, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zoom lens barrel and method for adjusting back focal distance th will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-657990