# US 5,352,863 A · Flat bed thermophotographic film processor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,863 A - Document ID: US5352863A - Status: Granted - Kind: A - Application number: 07/862,830 - Filed: 1992-04-03 - Granted: 1994-10-04 - Earliest claimed: 1992-04-03 - Assignees: Minnesota Mining and Manufacturing Company - Inventors: John Svendsen - Web page: https://patentgrep.com/patent/US5352863A ## CPC - G03D 13/002: {Heat development apparatus, e.g. Kalvar} - G03D: APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS (apparatus specially adapted for photomechanical production of textured or patterned surfaces G03F); ACCESSORIES THEREFOR (photosensitive materials or processes for photographic purposes G03C; electrographic, electrophotographic, or magnetographic methods or apparatus G03G) ## Abstract A developer for sheets of dry silver media includes an oven having a film entrance and a film exit. A bed of spaced rollers of low thermal conductivity foam material is positioned within the oven between the entrance and exit. A roller drive mechanism rotates the rollers causing the film to be transported through the oven and developed without visible patterns. ## Claims ### Claim 1 A developer for sheets of thermophotographic film, including: an oven having a film entrance and a film exit: a generally flat and horizontally oriented bed of film support material within the oven along a film transport path between the film entrance and film exit, for engaging and supporting the film; wherein the bed of film support material includes at least three spaced rollers, each of said rollers comprising a cylindrical tube comprising polymeric foam having low density and low thermal conductivity, said tube surrounding a support rod, said rollers rotatably mounted within the oven along the film transport path; a drive mechanism for driving the bed of material to transport the film through the oven along the transport path, wherein the drive mechanism includes a roller drive mechanism for rotating the rollers and causing the rollers to transport the film through the oven along the transport path; and the film support material having a sufficiently low heat capacity to enable visible pattern-free development of the film as the film is transported through the oven. ### Claim 2 (depends on 1) The developer of claim 1 wherein said foam has a thermal conductivity less than about 3. ### Claim 3 (depends on 1) The developer of claim 1 wherein said foam has a thermal conductivity less than about 1. ### Claim 4 (depends on 1) The developer of claim 1 wherein said foam has a thermal conductivity less than about 0.25. ### Claim 5 (depends on 1) The developer of claim 1 wherein said foam has a density less than about 95 kg/m.sup.3. ### Claim 6 (depends on 1) The developer of claim 1 wherein said foam has a density less than about 48 kg/m.sup.3. ### Claim 7 (depends on 1) The developer of claim 1 wherein said foam has a density less than about 40 kg/m.sup.3. ### Claim 8 (depends on 1) The developer of claim 1 wherein the oven includes heat sources above and below the rollers. ### Claim 9 (depends on 8) The developer of claim 8 wherein each of the heat sources includes a plurality of independently controlled temperature zones. ### Claim 10 (depends on 1) The developer of claim 1 wherein the oven includes a plurality of independently controlled temperature zones. ### Claim 11 (depends on 1) The developer of claim 1 wherein the rollers are positioned in a generally parallel orientation with respect to one another about a linear transport path. ### Claim 12 (depends on 1) The developer of claim 1 wherein the rollers are mounted about a generally horizontal transport path. ### Claim 13 (depends on 1) The developer of claim 1 wherein the roller drive mechanism includes a mechanism for rotating all the rollers at about the same speed. ### Claim 14 A method for developing sheets of thermophotographic film having an emulsion on one side, including: supporting the film in a hot oven on a generally flat and horizontally oriented bed of material including at least three rollers, each of said rollers comprising a cylindrical tube comprising polymeric foam having low density and a low thermal conductivity, said tube surrounding a support rod, said foam having a sufficiently low heat capacity to enable visible pattern-free development of the film; and driving the bed of material by rotating the rollers to transport the film through the oven as the film is being developed. ### Claim 15 (depends on 14) The method of claim 14 and further including uniformly heating the oven. ### Claim 16 (depends on 14) The method of claim 14 and further including rotating all the rollers at about the same speed. ### Claim 17 (depends on 14) The method of claim 14 wherein supporting the film includes supporting the film on the rollers with the emulsion toward the rollers. ### Claim 18 (depends on 14) The method of claim 14 wherein said foam has a thermal conductivity less than about 3. ### Claim 19 (depends on 14) The method of claim 14 wherein said foam has a thermal conductivity less than about 1. ### Claim 20 (depends on 14) The method of claim 14 wherein said foam has a thermal conductivity less than about 0.25. ### Claim 21 A developer for sheets of thermophotographic film, including: an oven having a film entrance and a film exit: a generally flat and horizontally oriented bed of film support material within the oven along a film transport path between the film entrance and film exit, for engaging and supporting the film; wherein the bed of film support material includes at least three spaced rollers, each of said rollers comprising a cylindrical tube having low density and thermal conductivity below about 0.25, said tube surrounding a support rod, said rollers rotatably mounted within the oven along the film transport path; a drive mechanism for driving the bed of material to transport the film through the oven along the transport path, wherein the drive mechanism includes a roller drive mechanism for rotating the rollers and causing the rollers to transport the film through the oven along the transport path; and the film support material having a sufficiently low heat capacity to enable visible pattern-free development of the film as the film is transported through the oven. ### Claim 22 (depends on 21) The developer of claim 21 wherein said tube has a density less than about 95 kg/m.sup.3. ### Claim 23 (depends on 21) The developer of claim 21 wherein said tube has a density less than about 48 kg/m.sup.3. ### Claim 24 A method for developing sheets of thermophotographic film having an emulsion on one side, including: supporting the film in a hot oven on a generally flat and horizontally oriented bed of material including at least three rollers, each of said rollers comprising a cylindrical tube having low density and thermal conductivity below about 0.25, said tube surrounding a support rod, said tube having a sufficiently low heat capacity to enable visible pattern-free development of the film; and driving the bed of material by rotating the rollers to transport the film through the oven as the film is being developed. ### Claim 25 (depends on 24) The method of claim 24 and further including uniformly heating the oven. ### Claim 26 (depends on 24) The method of claim 24 and further including rotating all the rollers at about the same speed. ### Claim 27 (depends on 24) The method of claim 24 wherein supporting the film includes supporting the film on the rollers with the emulsion toward the rollers. ### Claim 28 A developer for sheets of thermophotographic film, including: an oven having a film entrance and a film exit: a generally flat and horizontally oriented bed of film support material within the oven along a film transport path between the film entrance and film exit, for engaging and supporting the film; wherein the bed of film support material includes at least three spaced rollers, each of said rollers comprising a cylindrical tube having a density below 48 kg/cm.sup.2 and low thermal conductivity, said tube surrounding a support rod, said rollers rotatably mounted within the oven along the film transport path; a drive mechanism for driving the bed of material to transport the film through the oven along the transport path, wherein the drive mechanism includes a roller drive mechanism for rotating the rollers and causing the rollers to transport the film through the oven along the transport path; and the film support material having a sufficiently low heat capacity to enable visible pattern-free development of the film as the film is transported through the oven. ### Claim 29 (depends on 28) The developer of claim 28 wherein said tube has a thermal conductivity less than about 3. ### Claim 30 (depends on 28) The developer of claim 28 wherein said tube has a thermal conductivity less than about 1. ### Claim 31 (depends on 28) The developer of claim 28 wherein said tube has a thermal conductivity less than about 0.25. ### Claim 32 A method for developing sheets of thermophotographic film having an emulsion on one side, including: supporting the film in a hot oven on a generally flat and horizontally oriented bed of material including at least three rollers, each of said rollers comprising a cylindrical tube having density below 48 kg/m.sup.3 and low thermal conductivity, said tube surrounding a support rod, said tube having a sufficiently low heat capacity to enable visible pattern-free development of the film; and driving the bed of material by rotating the rollers to transport the film through the oven as the film is being developed. ### Claim 33 (depends on 32) The method of claim 32 and further including uniformly heating the oven. ### Claim 34 (depends on 32) The method of claim 32 and further including rotating all the rollers at about the same speed. ### Claim 35 (depends on 32) The method of claim 32 wherein supporting the film includes supporting the film on the rollers with the emulsion toward the rollers. ### Claim 36 (depends on 32) The method of claim 32 wherein said tube has a thermal conductivity less than about 3. ### Claim 37 (depends on 32) The method of claim 32 herein said tube has a thermal conductivity less than about 1. ### Claim 38 (depends on 32) The method of claim 32 wherein supporting the film includes said tube has a thermal conductivity less than about 0.25.