PHOTOGRAPHIC FILM ASSEMBLAGE AND METHOD FOR RELEASE OF GAS IN DIFFUSION TRANSFER SYSTEM

• US 3,615,540 A
• Filed: 03/31/1967
• Issued: 10/26/1971
• Est. Priority Date: 03/31/1967
• Status: Expired due to Term

• Current Assignee: Albert J. Bachelder, Edwin H. Land
• Original Assignee: Albert J. Bachelder, Edwin H. Land
• Inventors: Land, Edwin H., Bachelder, Albert J.
• Primary Examiner(s): Torchin, Norman G.
• Assistant Examiner(s): Goodrow, John J.
• Application Number:
  US04/627,538
• Time in Patent Office: 1,670 Days
• Field of Search: 56/76
• US Class Current: 430/208
• CPC Class Codes: G03C 8/46 characterised by the trapping means or gas releasing means

Abstract

A photographic film unit comprising all of the materials required to produce a photographic print including a pair of sheets secured at their margins in face-to-face relation and a liquid processing agent; and a method of rapidly spreading a viscous liquid processing agent in a continuous uniform layer between the superposed sheets. A film unit is disclosed comprising a photosensitive sheet and a second sheet secured in face-to-face relation at the edges of the sheets by essentially fluidtight binding means adopted to release gas from between the sheets during spreading of the liquid carried in a collapsible container secured at one edge of the sheets so as to discharge its contents between the sheets when compressive pressure is applied to the container. A method is disclosed in which gas is discharged from between the sheets during spreading of the processing liquid therebetween and liquid is prevented from escaping by way of the means for releasing the gas.

Claims

2. A method of rapidly spreading a viscous photographic liquid in a continuous uniform layer within a photographic film unit comprising a pair of sheets secured in face-to-face relation at their lateral edges and at their trailing end by a binding element of an essentially fluid impermeable sheet material adhered around and to the lateral and trailing end margins of said sheets, and said method comprising:

injecting a mass of viscous liquid processing composition between the leading end portions of said sheets;

progressively applying compressive pressure to a transverse region of said sheets extending substantially from side-to-side thereof and located behind said mass of liquid to advance said mass between said sheets toward the trailing ends thereof to spread said liquid in a layer between said sheets and force gas between said sheets ahead of said mass toward said trailing ends;

discharging said gas from between said sheets at said trailing ends thereof while directing said gas between said trailing end margin of one of said sheets and said binding element adhered thereto at regions of said binding element in which the latter is not adhered to said one sheet;

anD as said mass of liquid approaches said trailing edges of said sheets compressing said binding element against said one sheet to prevent escape of said liquid from between said one sheet and said binding element.

3. The method defined in claim 2 wherein compressive pressure is progressively applied to said sheets in a transverse region ahead of said mass of liquid to expel gas from between said sheets ahead of said mass of liquid.