Positive-negative microfilm film reader

Claim 2

In automatic microfilm reader apparatus having means for moving a film having positive and/or negative film type portions, each of such portions having at least one information image, an identifying code field disposed adjacent to each information image, and at least one code field position indicium disposed adjacent to each code field, the apparatus further including means for decoding a code field having predetermined information content which identifies a particular image, the combination comprising: a. means defining a reader station; b. means disposed at the reader station for detecting a moving code field position indicium for producing a signal having a first predetermined code pattern in response to A positive film type indicium and a second predetermined code pattern in response to a negative film position type indicium; c. storage means coupled to said signal producing means for storing said signal; d. polarity indicating means coupled to said storage means and respectively responsive to said signal for producing a control signal having a magnitude indicative of the polarity of the film type of the film portion at the reader station; e. means for detecting a recorded film code field and producing a first set of signals representative thereof; and f. means responsive to said control signal and said first set of signals for producing a second set of record signals representative of the film code field which have a predetermined phase irrespective of whether the polarity of the film portion at the reader station is positive or negative.

Claim 3

The invention as set forth in claim 1 wherein said code field position mark reponsive means includes first and second spaced photosensitive devices.

Claim 4

The invention as set forth in claim 2 wherein said storage means includes a shift register coupled to said first and second photosensitive devices and adapted to store said first and second predetermined code patterns.

Claim 5

For use in automatic film searching apparatus for identifying a particular document or information image from a film having positive and/or negative film type portions, with each such portion having a plurality of document images, and a predetermined identifying code field disposed adjacent to each document image, with each such predetermined code field having a plurality of column words and a column word position mark or indicium disposed adjacent to each column word, the combination comprising: a. means defining a reader station; b. spaced first and second photosensitive means disposed at the reader station, each said photosensitive means being adapted to produce signal code patterns in the presence or absence of column position marks respectively, said first and second photosensitive means being adapted to produce a first predetermined signal code pattern in response to a positive film column position mark, and a second predetermined signal code pattern in response to a negative film column position mark; c. storage means coupled to said first and second photosensitive means for storing said first and second code patterns; d. means coupled to said storage means and responsive respectively to said first and second predetermined code patterns for producing a polarity indicating signal indicating the film polarity of the type of the film portion at the reader station; and e. means responsive to said polarity indicating signal for decoding a code field having a predetermined information content irrespective of whether it is recorded on a positive or negative film portion at the reader station.

Claim 6

For use in automatic film searching apparatus for identifying a particular document or information image from a film having positive and/or negative film type portions, with each such portion having a plurality of document images, and a predetermined identifying code field disposed adjacent to each document image, with each such predetermined code field having a plurality of column words and a column word position mark or indicium disposed adjacent to each column word, the combination comprising: a. means defining a reader station; b. spaced first and second photosensitive means disposed at the reader station, each said photosensitive means being adapted to produce signal code patterns in the presence or absence of column position marks respectively, said first and second photosensitive means being adapted to produce a first predetermined signal code pattern in response to a positive film column position mark, and a second predetermined signal code pattern in response to a negative film column position mark; c. storage means coupled to said first and second photosensitive means for storing said first and second code patterns; d. means coupled to said storage means and responsive respectively to said first and second predetermined code patterns for producing a polarity indicating signal indicating the film polarity of the type of the film portion at the reader station; and e. means responsive to said polarity indicating signal for decoding a code field having a predetermined information content irrespective of whether it is recorded on a positive or negative film portion at the reader station.

Claim 7

The invention as set forth in claim 4 including transition detector means responsive to a change in the signal of one of said photosensitive means to cause said shift register to shift stored code pattern data.