Film registration device

• US 4,034,393 A
• Filed: 02/24/1976
• Issued: 07/05/1977
• Est. Priority Date: 02/24/1976
• Status: Expired due to Term

• Current Assignee: Howard K. Goldmacher
• Original Assignee: Howard K. Goldmacher
• Inventors: Goldmacher, Howard K.
• Primary Examiner(s): Gonzales, John
• Application Number:
  US05/660,842
• Time in Patent Office: 497 Days
• Field of Search: 116/114 J, 242/57, 242/71.6, 354/207, 354/214, 354/215, 354/217, 354/218, 354/275, 354/289, 354/354
• US Class Current: 396/285
• CPC Class Codes: G03B 1/60 Measuring or indicating length of the used or unused film; Counting number of exposures

Abstract

A device for providing means enabling a user to rewind a partially-exposed film strip packaged in a film cassette, to then remove the cassette from the camera, and thereafter to reinsert the film into the camera with the assurance of correct registration of the previously-exposed frames with the shutter opening and with the camera frame counter. This invention also pertains to the method of modifying the film strip to form the device. One embodiment of the device is a small, rectangular laminated tab having a body of flexible plastic material formed into a compressible hook at one end, which tab is installed near the tongue end of the film either by the user or by the film manufacturer. The bottom lamination of the tab is of self-adhesive material for adhering the tab to the tongue end of a film strip and the top lamination is a decalcomania having film index marks and a set of numerals at least equal to the number of exposure frames of the film printed thereon, the numerals being of a rub-off nature. When the tab is properly installed on the film tongue end, installed in a camera, and the index marks aligned with the camera drive sprocket teeth, a desired number of exposures is then made. The film can then be rewound into the cassette with the tab hook preventing rewinding of the tongue into the cassette, the cassette removed from the camera, and the last exposed frame number recorded by rubbing off the corresponding numeral from the decalcomania. Subsequently, the cassette can be reinstalled in the camera, the index marks realigned with the drive sprocket teeth, and the film accurately advanced to the next unexposed frame.

Claims

1. A device to enable a film strip packaged in a cassette to be installed in a camera, less than the total number of frames to be exposed, the film strip to be rewound into the cassette without rewinding the tongue end of the film into the cassette, the cassette to be removed from the camera, the cassette to be subsequently reinstalled into the camera, and the film strip to be advanced to the first remaining unexposed frame with correct registration with respect to the camera exposure counter and the exposed frame, comprising:

a projection disposed near the tongue end of the film strip forming a mechanical stop and arranged to contact the light trap of the film cassette during a rewind operation, thus alerting the user to cease rewinding thereby preventing rewinding of the film end into the cassette, said projection having associated index means alignable with selected teeth of the camera film drive sprocket.

2. The device as defined in claim 1 in which said projection is an essentially rectangular tab, said tab being constructed of a thin, flexible material whereby said tab does not interfere with winding of the film strip on the camera film takeup spool, said tab having a self-adhesive for attaching said tab to the film strip, and said tab having a hook formed on one end whereby said hook contacts the light trap.

3. The device as defined in claim 2 in which said tab further comprises a plurality of printed numerals deposited thereon, individual ones of said numerals capable of being easily removed, whereby selected frames of the film strip can be identified by removal of the corresponding numeral.

4. The device as defined in claim 1 in which said projection is a flap cut into the film strip and bent outward from the film strip, and said index means is formed by a side of said flap immediately adjacent to two film strip sprocket holes.

5. In a film strip packaged in a cassette for use in a camera, the cassette having a light trap, and the film strip having a tongue end projecting from the light trap, sprocket drive holes along a longitudinal edge of the film strip, an emulsion side, and a base side, the improvement comprising:

a compressible projection disposed near the tongue end of the film strip and projecting outward from the base side of the film strip; and

indexing means formed by disposing said projection adjacent to at least one sprocket hole of the film strip;

whereby said projection will be at least partially compressed when the film strip is wound on a takeup spool in a camera without interfering with such winding, will reopen outward during rewinding of the film strip into the cassette in such camera, and will contact the cassette light trap as rewindng is continued thereby preventing the tongue end of the film strip from being completely rewound into the cassette, and whereby said indexing means provides a reference for installing the film strip in a camera to allow the film strip to have less than its total number of frames exposed, to be rewound into its cassette, the cassette removed from the camera, and the cassette to be subsequently reinstalled into the camera with the previously-exposed frames in correct registration with the shutter opening and the frame numbers of such frames correctly synchronized with the frame counter of the camera.

6. The improvement defined in claim 5 in which said compressible projection is a flap having a free end and an attached end, said flap formed from the film strip by cutting the film strip so as to orient said free end in a direction toward the cassette light trap and said attached end in a direction toward the film tongue end, said flap being folded outward from the base side of the film strip at an angle slightly less than ninety degrees.

7. The improvement defined in claim 5 further comprising:

a set of numerals from one to a number at least equal to the number of frames of the film strip, said set disposed on an external surface of the cassette, said numerals arranged to be easily removable on an individual basis;

whereby a numeral is removable to indicate a desired frame number.

8. The method of modifying a film strip packaged in a cassette to allow exposure of less than the total number of frames, to then allow rewinding of the film strip into the cassette without winding the end of the film strip completely into the cassette, to allow removal of the cassette from the camera, to allow subsequent reinstallation of the cassette into the camera, and to allow reregistration of the exposed frames with the camera shutter opening and the camera frame counter, consisting of the steps of:

forming a compressible projection on the base side of the film near the end of the film strip with the projection acting as a mechanical stop; and

simultaneously locating said projection so as to define an indexing means for accomplishing such reregistration.

9. The method as defined in claim 8 in which the step of forming a projection includes the steps of:

cutting a flap near the end of the film strip with the free end of the flap toward the cassette; and

folding the flap outward from the base side of the film; and

in which the step of locating the projection includes the step of;

locating an edge of the flap immediately adjacent to at least one film drive sprocket hole, thereby designating such hole as an index mark.