Process of producing double-sided holographic replicas

Claim 1

A METHOD OF FORMING AN INFORMATION STORAGE REPLICA IN THE FORM OF A CONTINUOUS SHEET OF TRANSPARENT, THERMOPLASTIC MATERIAL HAVING INFORMATION ON BOTH SIDES OF SAID SHEET, SAID INFORMATION BEING IN THE FORM OF A SURFACE RELIEF PATTERN COMPRISING A TILTED OFF-AXIS RECORDED TRANSMISSION HOLOGRAM FORMED BY OBJECT AND REFERENCE BEAMS WHICH DEFINE A PLANE OBLIQUE TO THE LONGITUDINAL AXIS OF THE HOLOGRAM COMPRISING THE STEPS OF: PASSING SAID SHEET AND A FIRST MASTER CONTAINING A FIRST RELIEF PATTERN BETWEEN A FIRST PAIR OF CALENDER ROLLERS WHILE HEATING SAID FIRST MASTER TO A TEMPERATURE SO THAT SAID SHEET IS HEATED TO A TEMPERATURE BELOW ITS FLOW TEMPERATURE, BUT ONE WHICH CAUSES SAID SHEET TO ADHERE FIRMLY TO SAID FIRST MASTER, TO IMPRESS SAID FIRST PATTERN INTO ONE SIDE OF SAID SHEET, PASSING SAID SHEET ADHERED TO SAID FIRST MASTER AND A SECOND MASTER CONTAINING A SECOND RELIEF PATTERN BETWEEN A SECOND PAIR OF CALENDER ROLLERS WHILE HEATING SAID SECOND MASTER TO A TEMPERATURE BELOW THE FLOW TEMPERATURE OF SAID SHEET TO PRESS SAID SECOND PATTERN INTO SAID SHEET ON THE OPPOSITE SIDE FROM SAID FIRST PATTERN, COOLING SAID FIRST AND SECOND MASTERS BELOW A TEMPERATURE AT WHICH SAID SHEET ADHERES TO SAID MASTERS, AND SEPARATING SAID SHEET FROM SAID FIRST AND SECOND MASTERS,

Claim 2

A METHOD OF FORMING AN INFORMATION STORAGE REPLICA IN THE FORM OF A CONTINUOUS SHEET OF TRANSPARENT, THERMOPLASTIC MATERIAL HAVING INFORMATION ON BOTH SIDES OF SAID SHEET, SAID INFORMATION BEING IN THE FORM OF A SURFACE RELIEF PATTERN COMPRISING A TILTED OFF-AXIS RECORDED TRANSMISSION HOLOGRAM FORMED BY OBJECT AND REFERENCE BEAMS WHICH DEFINE A PLANE OBLIQUE TO THE LONGITUDINAL AXIS OF THE HOLOGRAM COMPRISING THE STEPS OF: PASSING SAID SHEET AND A FIRST MASTER CONTAINING A FIRST RELIEF PATTERN BETWEEN A FIRST PAIR OF CALENDER ROLLERS WHILE HEATING SAID FIRST MASTER TO A TEMPERATURE SO THAT SAID SHEET IS HEATED TO A TEMPERATURE BELOW ITS FLOW TEMPERATURE, BUT ONE WHICH CAUSES SAID SHEET TO ADHERE FIRMLY TO SAID FIRST MASTER, TO IMPRESS SAID FIRST PATTERN INTO ONE SIDE OF SAID SHEET, PASSING SAID SHEET ADHERED TO SAID FIRST MASTER AND A SECOND MASTER CONTAINING A SECOND RELIEF PATTERN BETWEEN A SECOND PAIR OF CALENDER ROLLERS WHILE HEATING SAID SECOND MASTER TO A TEMPERATURE BELOW THE FLOW TEMPERATURE OF SAID SHEET TO PRESS SAID SECOND PATTERN INTO SAID SHEET ON THE OPPOSITE SIDE FROM SAID FIRST PATTERN, COOLING SAID FIRST AND SECOND MASTERS BELOW A TEMPERATURE AT WHICH SAID SHEET ADHERES TO SAID MASTERS, AND SEPARATING SAID SHEET FROM SAID FIRST AND SECOND MASTERS,

Claim 5

A method of pressing a separate series of off-axis, phase-modulated transmission holographic replicas in the form of relief patterns from first and second metal holographic masters onto opposite surfaces, respectively, of a flexible, transparent thermoplastic web of sheet material, said method comprising the steps of: a. passing said web and said first master between a first pair of calender rollers while indirectly heating said web to a temperature from about 0.3 to 0.85 times the flow temperature of said web as it passes through said calender rollers by heating said first master in contact with said web and causing said web to adhere temporarily to said first master, thereby pressing said first pattern onto one surface of said web, b. passing said web and said second master, while said first master is still adhered to said one surface of said web, between a second pair of calender rollers while indirectly heating said web to a temperature in the range from about 0.3 to 0.85 times the flow temperature of said web as it passes between said second pair of calender rollers by heating said second master, thereby pressing said second pattern onto the opposite surface of said web, c. cooling said web to about 30*C, and d. separating said web from said first and said second masters.

Claim 6

A method of pressing a separate series of off-axis, phase-modulated transmission holographic replicas in the form of relief patterns from first and second metal holographic masters onto opposite surfaces, respectively, of a flexible, transparent thermoplastic web of sheet material, said method comprising the steps of: a. passing said web and said first master between a first pair of calender rollers while indirectly heating said web to a temperature from about 0.3 to 0.85 times the flow temperature of said web as it passes through said calender rollers by heating said first master in contact with said web and causing said web to adhere temporarily to said first master, thereby pressing said first pattern onto one surface of said web, b. passing said web and said second master, while said first master is still adhered to said one surface of said web, between a second pair of calender rollers while indirectly heating said web to a temperature in the range from about 0.3 to 0.85 times the flow temperature of said web as it passes between said second pair of calender rollers by heating said second master, thereby pressing said second pattern onto the opposite surface of said web, c. cooling said web to about 30*C, and d. separating said web from said first and said second masters.