Apparatus for thermic development of heat-sensitive paper

Claim 2

Apparatus for the thermic development of heat sensitive paper comprising an outer casing, a heat insulated compartment disposed in said casing, a drum rotatably mounted in said compartment, means for rotating said drum, means defining an elongated opening in one side of said compartment providing access to the periphery of said drum, said opening having opposite edges, a flexible curtain of heat conducting material having opposite ends, said curtain having one of said ends fixedly secured at a first edge of said opening and extending around the drum in the direction of its rotation to the second edge of said opening, means at the second edge of said opening for applying tension to the other end of said curtain to maintain said curtain taut around the drum, such paper to be developed being fed between said curtain and said drum at the first edge of said opening, carried around by the rotating drum and discharged at the second edge of said opening, means for applying heat to such paper comprising a thin heating sheet of resistive electrically conductive material conforming to the curvature of said curtain extending around the drum and in contact with said curtain throughout substantially its entire width and through a circumferential extent at least approximately equal to half the circumference of said drum, and means for controlling the temperature to which such paper is heated, said casing and compartment defining a passageway extending over said compartment and opening in front of and above said opening of said compartment, and suction means for drawing air through said passageway to draw off vapors from the discharged developed paper and to cool said casing.

Claim 3

Apparatus according to claim 1, in which said heating sheet is bonded to the outer face of said curtain.

Claim 4

Apparatus according to claim 1, in which said heating sheet is bonded to a relatively rigid intermediate sheet of heat conductive material which is applied to but not bonded to said curtain.

Claim 5

Apparatus according to claim 3, in which said intermediate sheet is aluminum.

Claim 6

Apparatus according to claim 1, in which said heating sheet comprises particles of electrically conductive resistance material bonded by a heat resistant synthetic material. Pg,14

Claim 7

Apparatus according to claim 1, in which said temperature control means comprises a heat sensing unit directly in contact with said flexible curtain downstream of said heating element, said sensing unit having a surface concavely curved to conform to the curvature of said curtain engaged by said sensing unit.

Claim 8

Apparatus according to claim 6, in which said heat sensing unit comprises a bulb containing a fluid having a high coefficient of expansion.

Claim 9

Apparatus according to claim 1, in which said drum has a diameter not less than 150 millimeters.

Claim 10

Apparatus according to claim 1, in which said curtain extends out over said second edge of said opening and in which said means for applying tension to said curtain comprises a plurality of tension springs acting between said other end of said curtain and a fixed support disposed above said opening.

Claim 11

Apparatus according to claim 1, in which said curtain comprises a fabric of heat resisting, heat conducting and electrically insulating material.

Claim 12

Apparatus for the thermic development of heat sensitive paper comprising a heat insulating compartment, a drum rotatably mounted in said compartment, means for rotating said drum, means defining an elongate opening in one side of said compartment providing access to the periphery of said drum, said opening having opposite edges, a flexible curtain of heat conducting material having opposite ends, said curtain having one of said ends fixedly secured at a first edge of said opening and extending around the drum in the direction of its rotation to the second edge of said opening, means at the second edge of said opening for applying tension to the other end of said curtain to maintain said curtain taut around the drum, such paper to be developed being fed between said curtain and said drum at the first edge of said opening carried around by the rotating drum and discharged at the second edge of said opening, means for applying heat to such paper comprising a thin heating sheet of resistive electrically conducting material conforming to the curvature of said curtain extending around the drum and in contact with said curtain throughout substantially its entire width and through a circumferential extent equal to half the circumference of said drum, means for controlling the temperature to which such paper is heated, guide means positioned in said opening to discharge developed paper from said drum, and guide means comprising a scraper having a portion essentially tangential to and grazing said drum to remove such paper therefrom and a plurality of spaced guide wires extending forwardly from said scraper and then upwardly, said guide wires having lower ends extending into spaced holes in said scraper and upper ends fixed to a cross bar positioned above said opening, means defining a passageway opening above said guide wires and suction means for drawing air through said passageway to draw off vapors from discharged developed paper while supported by said guide wires.

Claim 13

Apparatus for the thermic development of heat sensitive paper comprising a heat insulating compartment, a drum rotatably mounted in said compartment, means for rotating said drum, means defining an elongate opening in one side of said compartment providing access to the periphery of said drum, said opening having opposite edges, a flexible curtain of heat conducting material having opposite ends, said curtain having one of said ends fixedly secured at a first edge of said opening and extending around the drum in the direction of its rotation to the second edge of said opening, means at the second edge of said opening for applying tension to the other end of said curtain to maintain said curtain taut around the drum, such paper to be developed being fed between said curtain and said drum at the first edge of said opening carried around by the rotating drum and discharged at the second edge of said opening, means for applying heat to such paper comprising a thin heating sheet of resistive electrically conducting material conforming to the curvature of said curtain extending around the drum and in contact with said curtain throughout substantially its entire width and through a circumferential extent equal to half the circumference of said drum, means for controlling the temperature to which such paper is heated, guide means positioned in said opening to discharge developed paper from said drum, and guide means comprising a scraper having a portion essentially tangential to and grazing said drum to remove such paper therefrom and a plurality of spaced guide wires extending forwardly from said scraper and then upwardly, said guide wires having lower ends extending into spaced holes in said scraper and upper ends fixed to a cross bar positioned above said opening, means defining a passageway opening above said guide wires and suction means for drawing air through said passageway to draw off vapors from discharged developed paper while supported by said guide wires.