US 6,003,994 A · Microfilm search method and device

Abstract

There is disclosed a microfilm search method and device in which the presence of frames is accurately determined from a density change in a running direction of a microfilm. The detected density change is binarized into white and black synchronously with a sampling signal outputted for each predetermined feeding amount of the microfilm. The number of white signals included in a group of a predetermined number of binarized signals consecutive immediately before each sampling signal is successively obtained in response to the sampling signal. For the negative film, the presense of frames is determined by judging white (out-frame) when the number of white signals equals/exceeds a set value and by judging black (in-frame) when the number of white signals is less than the set value. The set value for determining the inside or outside of the frame may be changed when going into the frame from the outside of the frame and vice versa. Thereby, detection precision can further be raised.

Claims10

Dependent claims

A method for searching a desired frame from a microfilm by detecting the presence of frames from a density change in the running direction of the microfilm, comprising the steps of:

a) successively detecting a film density of the microfilm along the running direction of the microfilm to obtain a series of density signals;
b) sampling a density signal from the density signals in synchronization with a sampling signal which is produced for each predetermined feeding amount of the microfilm, and binarizing the sampled density signal into binarized signal which is white or black signal, the white signal representing a film transparent portion and the black signal representing a film non-transparent portion;
c) successively obtaining the number of white or black signals included in a group of a predetermined number of the binarized signals consecutive immediately before each sampling signal in response to the sampling signal;
d) determining in-frame or out-frame when the number of the white or black signals in each group equals or exceeds a set value, while determining out-frame or in-frame when the number of the white or black signals is less than the set value;
e) discriminating one frame from a film position which is determined as in-frame to a film position which is successively determined as out-frame;
and
f) searching for the desired frame from a sequence of the discriminated frame.

4 more elements

A device for searching a desired frame from a microfilm by detecting the presence of frames from a density change in the running direction of the microfilm, comprising:

a) an encoder for outputting a sampling signal for each predetermined feeding amount of the microfilm;
b) a density sensor for successively detecting the film density of the microfilm along the running direction of the microfilm to output a series of density signals, the density sensor being provided within a frame travel width of the microfilm;
c) a binarizing section for sampling a density signal from the density signals in synchronization with said sampling signal, and for binarizing the sampled density signal into a binarized signal which is white or black signal, the white signal representing a film transparent portion and the black signal representing a film non-transparent portion;
d) a determination section for successively obtaining the number of white or black signals included in a group of a predetermined number of the binarized signals consecutive immediately before each sampling signal in response to the sampling signal, to determine in-frame or out-frame when the number of the white or black signals equals or exceeds a set value and to determine out-frame or in-frame when the number of white or black signals is less than the set value, and for descriminating one frame from a film position which is determined as in-frame to a film position which is successively determined as out-frame to output a determination signal indicative of the presence of the frame;
and
e) a searching section for searching for the desired frame based on said determination signal.

3 more elements

Dependencies are inferred from the claim text.

Microfilm search method and device

Life of this patent

Microfilm search method and device

Life of this patent

Abstract

Claims10