Magnetic recording on film of scene parameters and photofinishing process for use therewith

• US 5,025,283 A
• Filed: 08/23/1990
• Issued: 06/18/1991
• Est. Priority Date: 09/14/1989
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Robison, Gary L.
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Dang, Khanh
• Application Number:
  US07/571,008
• Time in Patent Office: 299 Days
• Field of Search: 355/40, 355/77, 355/41, 355/68, 355/69, 354/105, 354/106, 354/21
• US Class Current: 355/40
• 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: G03B 27/462 in enlargers, e.g. roll film printers
• CPC Class Codes: G03B 27/735 in dependence upon automatic analysis of the original

Abstract

A camera embodying the invention includes a magnetic recording head adjacent the film and a processor which senses the lens focal length, the aperture size and shutter speed, and the film ISO number or film speed. The processor causes the scene brightness value sensed at the time of exposure of each film frame to be recorded by the magnetic head in a magnetic track adjacent or in registration with the current film frame. The processor senses the aperture size and shutter exposure time acutally employed by the camera in exposing the current film frame to compute an actual exposure value. It then determines whether this actual exposure value deviates significantly from the ideal exposure value and if so by how much. The deviation thus computed, if any, is also recorded in the same magnetic track in the film or one next to it. The photofinishing apparatus searches a particular one of the magnetic tracks adjacent each film frame prior to its print exposure to determine the deviation between the ideal exposure value (computed from the recorded scene brightness value and film speed) and the actual exposure value (computed from the recorded aperture size and shutter speed actually employed by the camera in exposing the film frame). The photofinishing apparatus transmits this deviation to a print exposure controller, which changes the amount of light (exposure value) used to expose print paper to the current film frame so as to compensate for the deviation.

Claims

1. In photofinishing apparatus which processes a strip of developed film having a virtually transparent magnetic layer therein and a strip of photosensitive print paper, said photofinishing apparatus comprising a print exposure source for exposing individual frames on said film onto individual frames on said print paper and a print exposure value controller for controlling the amount of light with which said print exposure source exposes an individual frame of said film onto an individual frame on said print paper, the improvement comprising:

magnetic head means for sensing data previously recorded in magnetic tracks in said film magnetic layer; and

a processor, including means for;

a. sensing film speed value, scene brightness value and actual exposure value characterizing the exposure of an individual one of said film frames from said data,

b. computing from said scene brightness value and from said film speed value an ideal exposure value,

c. determining the difference between said actual exposure value and said ideal exposure value, and

d. commanding said print exposure value controller to employ a print exposure value corresponding to a nominal print exposure value modified by an amount corresponding to said difference, so as to compensate for said difference in exposing said print, whereby said print is characterized by a higher image quality than would otherwise be achieved using another print exposure value.

2. The improvement of claim 1 wherein said means for determining said actual exposure value comprise means for reading out through said magnetic head means the actual shutter exposure time and aperture size previously recorded in a magnetic track adjacent said film frame at the time of exposure of said frame, and computing therefrom said actual exposure value.

3. The improvement of claim 2 wherein said magnetic tracks comprise plural parallel tracks in registration with respective ones of said film frames, wherein for each one of said frames, said scene brightness value, said shutter exposure time and said aperture size is each recorded in a predetermined respective one of said tracks.

4. The improvement of claim 1 wherein said means for determining said actual exposure value comprise means for reading out through said magnetic head means an actual exposure value previously recorded on said film.

5. The improvement of claim 1 wherein said nominal print exposure value corresponds to a medium pixel density in said print paper, and wherein said print exposure value equals the sum of said nominal print exposure value and said difference.

6. In a photofinishing apparatus wherein previously developed film having a virtually transparent magnetic layer therein is exposed onto photosensitive print paper with a print exposure source, the improvement comprising:

magnetic head means for playing back data previously recorded in magnetic tracks on said film in registration with individual frames thereof;

print exposure value control means for varying the exposure value employed by said print exposure source in exposing a frame on said print paper to said frame on said film; and

a processor, including means for;

a. reading through said magnetic head means data previously recorded on said magnetic tracks representing a difference between an ideal exposure value and an actual exposure value characteristic of said film frame, and

b. transmitting said difference to said print exposure value controller, whereby said controller changes the exposure value employed by said print exposure source so as to compensate for said difference in making a print from said film frame.