Method and apparatus for depositing processing fluid on cassette contained film strips

The method of depositing a coating of processing fluid on the emulsion side of a photographic film strip in a cassette following exposure of the film strip, comprising the steps of:

• trailing a run of said film strip across an opening through which a layer of said processing fluid is deposited onto the emulsion side of said film strip;
• moving said film strip run longitudinally across said opening;
• spacing a doctoring member from said emulsion side of said film strip and doctoring said layer of processing fluid against the emulsion side of said film strip to develop in said layer of processing fluid a hydrodynamic force component of predetermined minimum and maximum magnitude in a direction tending to displace said film strip away from said doctoring member;
• and
• supporting the other side of said film strip opposite said doctoring member with a force opposite to and at least substantially equal to said predetermined minimum and substantially equal to or less than said predetermined maximum magnitude of said hydrodynamic force component to approximately balance said hydrodynamic force and thereby permit deflection of said film strip away from said doctoring member responsive to particles carried by the film strip or the fluid engaging said doctoring member in a manner tending to provide increased force between said doctoring member and said emulsion surface so as to thereby permit such particles to pass said doctoring member.

In a cassette configured for retaining a photographic film strip having a light-sensitive emulsion on one surface thereof, said cassette containing a processor operative to deposit processing fluid on a moving run of the film strip after exposure of the film emulsion;

• said processor having a nozzle opening through which the processing fluid is passed into contact with the film emulsion, a doctoring surface following said nozzle opening in the direction of moving run travel, said doctoring surface being spaced from the film emulsion and configured during moving run travel to produce a hydrodynamic force component within the processing fluid and directed toward the film strip, the trailing edge of said doctoring surface defining a gap with the emulsion surface of the film strip, said gap ranging between 0.0006 to 0.0009 inches, and a pressure pad for engaging the other side of the film strip opposite from the emulsion and said doctoring surface, the improvement comprising:
• means for biasing said pressure pad and thus the film strip toward said doctoring surface with a force of approximately the same magnitude as and opposite to said hydrodynamic force component developed within the processing fluid between said doctoring surface and the moving run of the film strip during processing, said means for biasing said pressure pad and film strip comprising a spring stressed to exert a force on said pressure pad in the range of approximately 14 to 23 grams.

The method of depositing a processing fluid on the emulsion side of a photographic film strip in a cassette following exposure of said film strip, said method comprising the steps of:

• trailing a run of said film strip across an opening through which processing fluid is passed onto the emulsion side of said film strip;
• moving said film strip run longitudinally across said opening at a speed varying between 30 and 90 inches per second;
• spacing a doctoring member from said emulsion side of said film strip to provide a gap therewith in the range of 0.0006 to 0.0009 inches and doctoring said processing fluid against the emulsion side of said film strip to develop a hydrodynamic force component in a direction tending to displace said film strip away from said doctoring member;
• and
• supporting said film strip with a force opposite to and of approximately the same magnitude as said hydrodynamic force component and in the range of from 14 grams to approximately 23 grams so as to approximately balance said hydrodynamic force and thereby permit deflection of said film strip away from said doctoring member responsive to irregularities carried by the film strip or the fluid engaging said doctoring member.