Abstract A resistive ribbon thermal transfer printing apparatus has an improved ribbon configuration. The ribbon contains a two-ply resistive element positioned on a conductive layer. The resistive element contains a top layer having a low resistance, for example 3x10-5 OMEGA for making contact with the writing head and a bottom layer having a higher resistance, for example 1x10-3 OMEGA in contact with the conductive layer for generating heat. The ratio of the resistance of the high resistance layer to the resistance of the low resistance layer, RH/RL, is 1.1 to 1000. An example of such a ribbon contains a top resistive layer of polyimide containing 35% conductive carbon, a bottom resistive layer of a SiO/Cr cermet (60%/40%), a stainless steel conductive layer and a Versamid ink layer.
A resistive ribbon for thermal transfer printing comprising a two layered resistive layer having a first layer and a second layer wherein the ratio of the resistance of the second layer to the resistance of the first layer, R second /R first , is 1.1 to 1000, a conducting layer positioned on said second resistive layer, and an ink transfer layer positioned on said conductive layer.
Claim 2
Dependent Claim
66 words
A resistive ribbon for thermal transfer printing comprising a two layered resistive layer having a first layer and a second layer wherein the ratio of the resistance of the second layer to the resistance of the first layer, R second /R first , is 1.1 to 1000, a conducting layer positioned on said second resistive layer, and an ink transfer layer positioned on said conductive layer.
Claim 3
Dependent Claim
22 words
A resistive ribbon as described in claim 1 wherein said first resistive layer contains a polymer and a conductive material dispersed therethrough.
Claim 4
Dependent Claim
16 words
A resistive ribbon as described in claim 1 wherein said second resistive layer is a cermet.
Claim 5
Dependent Claim
17 words
A resistive ribbon as described in claim 1 wherein said second resistive layer is a SiO/Cr cermet.
Claim 6
Dependent Claim
16 words
A resistive ribbon as described in claim 1 wherein said second resistive layer is silicon carbide.
Claim 7
Dependent Claim
15 words
A resistive ribbon as described in claim 1 wherein said conductive layer is stainless steel.
Claim 8
Dependent Claim
14 words
A resistive ribbon as described in claim 1 wherein said conductive layer is aluminum.
Claim 9
Dependent Claim
16 words
A resistive ribbon as described in claim 1 wherein said second resistive layer is aluminum oxide.
Claim 10
Dependent Claim
20 words
A resistive ribbon as described in claim 1 wherein said first resistive layer is in contact with a printing head.