Optical Coating Laboratory, Inc.

Flex Products, Inc.

Vernon C Spellman

Roger Winston Phillips

Marc A Kamerling

Wayne L Gossett

Paul G Coombs

David W Todd

Steven A Silver

Hans J Riedel

Tamper evident optical device comprising a substrate and a multi-layer taper evident splittable coating carried by the substrate. The coating has a release region formed therein. An adhesive is secured to the tamper evident coating.

Tamper evident optical device and article utilizing the same

Tamper evident optical device having at least first and second layers with a spacer layer therebetween and providing a desired optical property. A release layer is disposed between the first and second layers which permits the first and second layers to be separated from each other and to destroy the desired optical property.

Tamper evident optically variable device comprising an optically variable device having at least first and second layers with a spacer layer therebetween providing a color shift with change in viewing angle. A release layer is disposed between the first and second layers to permit the first and second layers to be separated from each other and to thereby destroy the optical shifting properties of the optically variable device.

Tamper evident optically variable device and article utilizing the same

Level control apparatus for cyrogenic liquids having a cryogenic liquid. Means is provided for introducing cryogenic liquid into the chamber and outlet means is provided to permit removal of the cryogenic liquid from the chamber. Level sensing means is mounted on the flask and has a probe extending into the chamber so that it will come in contact with the cryogenic liquid when the cryogenic liquid reaches a predetermined level within the chamber. The probe includes a thermocouple with a resistor secured to the thermocouple for heating the thermocouple. When the resistor is in contact with the cryogenic liquid, the thermocouple remains cold and provides a signal of one type. When the resistor is uncovered by the cryogenic liquid and the thermocouple becomes hot, a signal of a different type is provided. The signals from the thermocouples are utilized for controlling the entrance of the cryogenic liquid into the chamber and to maintain the liquid level at a predetermined level within the chamber. Two thermocouples and two resistors are utilized for the probe means to greatly reduce the cycling required for operating the filling means for the chamber.

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Santa Rosa, CA, United States of America

Vernon C Spellman