BACKGROUND

Film reel scanners are used to scan and digitize reels of film (e.g., reels containing images of documents) for imaging and archiving purposes. Film to be scanned is stored on reels, which are connected to the scanner. The scanner is configured to control the movement of the film through the scanner in order to accurately scan the film.

SUMMARY

The present disclosure presents new and innovative systems and methods for controlling a film transport apparatus. In one embodiment, a system is provided comprising a line scanning camera configured to capture images of film located in a scanning area, a supply reel motor that rotates a supply reel to supply film from the supply reel for scanning by the line scanning camera, a take-up reel motor that rotates a take-up reel to collect film on the take-up reel after scanning by the line scanning camera, and a plurality of capstan motors that rotate a plurality of capstans to direct the film from the supply reel, across the scanning area, and to the take-up reel. The system may also include a control system configured to receive position information from the supply reel motor, the take-up reel motor, and at least a subset of the plurality of capstan motors, dynamically adjust the position information by adding or subtracting adjustment information to the position information, provide the dynamically adjusted position information to a plurality of controllers, and generate control signals for the supply reel motor, the take-up reel motor, and the at least a subset of the plurality of capstan motors with the controllers.

In another embodiment, the control system is further configured to dynamically adjust the position information received from the subset of the plurality of capstan motors according to offset information.

In a further embodiment, the control system is configured to scan a target film with the line scanning camera, receive, from each of the subset of the plurality of capstan motors, a plurality of rotational position measurements at a plurality of times during the scan of the target film, and detect an inconsistency in the scan of the target film. The control system may also be configured to calculate an offset factor for an associated rotational position of at least one of the subset of the plurality of capstan motors based on (i) a measurement of the inconsistency and (ii) rotational position measurements associated with a time at which the inconsistency was scanned by the line scanning camera and add the offset factor to the offset information.

In yet another embodiment, the target film includes markings of a fixed thickness and/or a fixed distance apart and the inconsistency is a difference in thickness or distance apart for one or more of the markings.

In a still further embodiment, the control system is further configured to dynamically adjust position information from the supply reel motor based on a supply radius of the supply reel and dynamically adjust position information from the take-up reel motor based on a take-up radius of the take-up reel.

In another embodiment, the control system is further configured to receive (i) a supply rotation rate of the supply reel and (ii) a supply film speed across a first capstan of the plurality of capstans located closest to the supply reel, calculate the supply radius based on the supply rotation rate and the supply film speed, receive (i) a take-up rotation rate of the take-up reel and (ii) a take-up film speed across a second capstan of the plurality of capstans located closest to the take-up reel, and calculate the take-up radius based on the take-up rotation rate and the take-up film speed.

In a further embodiment, the control system is further configured to calculate the supply radius by dividing the supply film speed by the supply rotation rate and calculate the take-up radius by dividing the take-up film speed by the take-up rotation rate.

In yet another embodiment, the system further comprises a capstan motor profile generator used by at least one controller to generate control signals for a plurality of capstan motors.

In a still further embodiment, the control system is further configured to receive position information from each of the plurality of capstan motors.

In another embodiment, the control system is further configured to generate control signals for each of the plurality of capstan motors.

In a further embodiment, the position information includes one or more of: rotational speed measurements, rotational position measurements, and film speed measurements.

In yet another embodiment, (i) the position information from the supply reel motor and take-up reel motor include rotational speed measurements and (ii) the position information from the subset of the plurality of capstan motors include film speed measurements of the film across the subset of the plurality of capstan motors.

In a still further embodiment, the system further comprises a time of flight sensor configured to measure a height of a film loop in the system. The control system may also be further configured to dynamically adjust the position information from a capstan motor adjacent to the film loop based on the height of the film loop.

In another embodiment, a method is provided comprising receiving position information from a supply reel motor, a take-up reel motor, and at least a subset of a plurality of capstan motors, dynamically adjusting the position information by adding or subtracting adjustment information to the position information, providing the dynamically adjusted position information to a plurality of controllers, and generating control signals for the supply reel motor, the take-up reel motor, and the at least a subset of the plurality of capstan motors with the controllers.

In a further embodiment, the method further comprises scanning a target film with a line scanning camera, receiving, from each of a subset of the plurality of capstan motors, a plurality of rotational position measurements at a plurality of times during the scan of the target film, and detecting an inconsistency in the scan of the target film. The method may also comprise calculating an offset factor for an associated rotational position of at least one of the subset of the plurality of capstan motors based on (i) a measurement of the inconsistency and (ii) rotational position measurements associated with a time at which the inconsistency was scanned by the line scanning camera and adding the offset factor to offset information.

In yet another embodiment, the method further comprises dynamically adjusting position information from the supply reel motor based on a supply radius of the supply reel and dynamically adjusting position information from the take-up reel motor based on a take-up radius of the take-up reel.

In a still further embodiment, the method further comprises receiving (i) a supply rotation rate of the supply reel and (ii) a supply film speed across a first capstan of the plurality of capstans located closest to the supply reel, calculating the supply radius based on the supply rotation rate and the supply film speed, receiving (i) a take-up rotation rate of the take-up reel and (ii) a take-up film speed across a second capstan of the plurality of capstans located closest to the take-up reel, and calculating the take-up radius based on the take-up rotation rate and the take-up film speed.

In another embodiment, at least one of the controllers is configured to generate control signals for a plurality of capstan motors based on a single capstan motor profile generator.

In a further embodiment, the method further comprises receiving, from a time of flight sensor, a height measurement of a film loop and dynamically adjusting the operations sensor readings from a capstan motor adjacent to the film loop based on the height measurement.

The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.

