Method and apparatus for determining line frequency and detectin

Optics: measuring and testing – Range or remote distance finding – With photodetection

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

356218, G03B 708

Patent

active

053942175

ABSTRACT:
A line frequency is determined by interleaved sampling of ambient light to obtain analog voltage samples at predetermined sampling rates associated with two or more line frequencies. Where there are two line frequencies, one method separates the first samples by a time period at least equal to an analog-to-digital conversion time, and less than the earliest time when a sample associated with one line frequency would coincide with a sample from the other. There are n samples per flicker frequency period and Q samples for each line frequency are taken. In a second method, a first common sample is taken for all line frequencies, and a condition characterized by simultaneous samples for different line frequency sample groups triggers a common sample for all line frequencies. For both methods, digital sample values one through Q-1 for each group are operated on to obtain a result, and then two through Q are similarly operated on to obtain a second result. The result for samples one through Q-1 for a given line frequency is compared to the result for samples two through Q. If the results for a given line frequency are within a predetermined limit, the presence of that line frequency is indicated. The known line frequency can be used to set the light sampling rate for exposure setting, as well as imprinting light source information onto photographic film.

REFERENCES:
patent: 3850530 (1974-11-01), Uno et al.
patent: 4041308 (1977-08-01), Fujita
patent: 4079388 (1978-03-01), Takahama et al.
patent: 4117502 (1978-09-01), Takeda et al.
patent: 4129366 (1978-12-01), Watanabe
patent: 4182560 (1980-01-01), Oguchi et al.
patent: 4220412 (1980-09-01), Shroyer et al.
patent: 4258993 (1981-03-01), Frank
patent: 4319133 (1982-03-01), Currie et al.
patent: 4340286 (1982-07-01), Carr
patent: 4464049 (1984-08-01), Schroeder
patent: 4511229 (1985-04-01), Schwartz et al.
patent: 4914738 (1990-04-01), Oda et al.
patent: 4989093 (1991-01-01), Kaneko
patent: 5016030 (1991-05-01), Dwyer et al.
patent: 5016039 (1991-05-01), Sosa et al.
patent: 5037198 (1991-08-01), Gaboury
patent: 5087936 (1992-02-01), Ogata et al.
patent: 5128708 (1992-07-01), Murayama et al.
patent: 5130745 (1992-07-01), Cloutier et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method and apparatus for determining line frequency and detectin does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for determining line frequency and detectin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for determining line frequency and detectin will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-851889

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.