Thermal recording medium and method

Claim 1

A thermally sensitive image recording medium of the transparency type comprising: a transparent support layer; a transparent thermally sensitive recording layer carried on one side of said support layer and being responsive to selective application of thermal energy for producing a visible recorded image; and a background layer strippably coupled to one of said support and recording layers in overlying relation to said recording layer for providing a contrasting backgound against which at least one component of an image may be viewed by reflected light while image recording of said at least one component is in progress and thereafter, being strippably removable so that said recorded image may be viewed by transmitted light.

Claim 15

A method of thermally recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type including a transparent support layer and a transparent thermally sensitive recording layer carried on said support layer, said recording layer being of the type wherein dot size increases with increased amounts of thermal energy applied to form a dot, said recording method comprising the steps of: providing a background layer strippably adhered to one of said support and recording layers in overlying relation to said recording layer for providing a contrasting background against which recorded dots are visible by reflected light; providing image information indicative of a desired density for each pixel area of the desired image; applying thermal energy to selected pixel areas of the recording layer in accordance with said image information to form a dot in each having an initial size smaller than necessary to achieve its said desired density; while applying said thermal energy, monitoring the density of each selected pixel area by optically sensing its dot with light reflected by said contrasting background layer; comparing the monitored density of each selected pixel area to its said desired density; based on said comparison, applying additional thermal energy to said selected pixel areas to progressively increase dot size in each until a predetermined value of denstiy comparison is achieved and thereupon terminating application of thermal energy; and after said image is recorded, stripping said background layer from said one of said transparent support and recording layers so that said recorded image may be viewed by transmitted light.

Claim 16

A method of thermally recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type including a transparent support layer and a transparent thermally sensitive recording layer carried on said support layer, said recording layer being of the type wherein dot size increases with increased amounts of thermal energy applied to form a dot, said recording method comprising the steps of: providing a background layer strippably adhered to one of said support and recording layers in overlying relation to said recording layer for providing a contrasting background against which recorded dots are visible by reflected light; providing image information indicative of a desired density for each pixel area of the desired image; applying thermal energy to selected pixel areas of the recording layer in accordance with said image information to form a dot in each having an initial size smaller than necessary to achieve its said desired density; while applying said thermal energy, monitoring the density of each selected pixel area by optically sensing its dot with light reflected by said contrasting background layer; comparing the monitored density of each selected pixel area to its said desired density; based on said comparison, applying additional thermal energy to said selected pixel areas to progressively increase dot size in each until a predetermined value of denstiy comparison is achieved and thereupon terminating application of thermal energy; and after said image is recorded, stripping said background layer from said one of said transparent support and recording layers so that said recorded image may be viewed by transmitted light.