Self-clocking encoding/decoding film information exchange system using dedicated magnetic tracks on film

• US 4,977,419 A
• Filed: 10/07/1988
• Issued: 12/11/1990
• Est. Priority Date: 10/07/1988
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Whitfield, Arthur A., Wash, Michael L.
• Primary Examiner(s): MATHEWS, ALAN A
• Application Number:
  US07/254,987
• Time in Patent Office: 795 Days
• Field of Search: 354/75, 354/76, 354/105, 354/106, 354/109, 355/40, 352/37, 352/92, 352/236, 360/3, 360/1, 430/496, 430/140, 358/345, 358/346
• US Class Current: 396/311
• CPC Class Codes: G03B 17/24 with means for separately producing marks on the film, e.g. title, time of exposure
• CPC Class Codes: G03B 2206/004 using markings on the photographic material, e.g. to indicate pseudo-panoramic exposure
• CPC Class Codes: G03B 2217/244 Magnetic devices
• CPC Class Codes: G03B 2217/246 Details of the markings
• CPC Class Codes: G03D 15/003 Marking, e.g. for re-printing

Abstract

A virtually transparent magnetic layer is included as an additional layer in a color negative film. Information exchange between various users of the film--such as (for example) the film manufacturer, the camera user, the dealer and photofinisher--is carried via plural longitudinal magnetic tracks on the film that begin and end in individual frames. Each track is dedicated to the writing and reading of a predetermined set of parameters related to the corresponding frame. The photofinisher-dedicated tracts fill the exposed image area of each frame. The camera-dedicated tracks lie along the edges of the film between the film perforations, the perforations being widely spaced for this purpose. All data is recorded on the film using a novel self-clocking code which is completely self-clocking, in order to provide automatic data synchronization between the various users without requiring that any of them to transport the film at the same speed or even at a uniform speed when reading and writing. A start sentinel character and stop sentinel character, each having a predetermined self-clocking encoded binary bit sequence, are placed at the beginning and end of each track respectively, and facilitate automatic detection of film transport direction.

Claims

1. In an elongate photographic film strip susceptible of exposure of successive frames thereof in a camera having a magnetic reading or writing system and adapted for printing by a photofinishing device having a magnetic reading or writing system, the improvement comprising:

a virtually transparent magnetic layer; and

longitudinal parallel tracks magnetically recorded in said magnetic layer, said tracks comprising self-clocking three-part encoded data, each of said tracks beginning and ending within a particular frame, and each of said tracks further comprising first and second three-part encoded binary characters uniquely representing start and stop sentinels respectively, whereby said film strip may be transported at different velocities with respect to the magnetic reading or writing means in said camera and in said photofinishing device and whereby the direction of film strip transport can be automatically detected through said start and stop sentinels.

2. In a stage of a film processing system which processes an elongate photographic film strip having successive frames, the improvement comprising:

means for writing or reading self-clocking encoded data in a virtually transparent magnetic layer on said film strip, said data being relegated to longitudinal parallel tracks in each of said frames, and said encoded data including a start sentinel character and a stop sentinel character placed at the beginning and end of each said track respectively, said characters each having a predetermined self-clocking encoded binary bit sequence.

3. The improvement of claim 2 further comprising means for sensing whenever the complement of either of said binary bit sequences is read from any of said tracks so as to sense if said film strip is being transported in a longitudinal direction opposite to that in which said tracks were previously recorded.

4. The improvement of claim 3 wherein the stage of the film processing system comprises one of:

a camera, a dealer order entry system, a photofinisher order entry system, a classifier, a printer, an inspection or re-classifier station, and an envelope-sorter station.

5. In a photofinishing system in which an elongate photographic film strip having a virtually transparent magnetic layer and successive frames is developed and printed after exposure by a camera, the improvement comprising:

means for sensing whether self-clocking data has previously been recorded in said magnetic layer as longitudinal parallel camera-dedicated tracks; and

means for recording self-clocking encoded data in said magnetic layer so as to create longitudinal parallel photofinisher-dedicated tracks in each of said frames, and for placing a start sentinel character and stop sentinel character at the beginning and end of each said track respectively, said characters each having a predetermined self-clocking encoded binary bit sequence.

6. The improvement of claim 5 further comprising means for sensing whenever the complement of either of said binary bit sequences is read from any of said tracks so as to sense if said film strip is being transported in said photofinishing system in a longitudinal direction opposite to that in which said tracks were previously recorded.