Imaging system
View Patent ↗There are disclosed imaging members wherein a chemical compound in a crystalline form is converted, at least partially, and preferably substantially completely or completely, to an amorphous form that has intrinsically a different color from the crystalline form. Also described are imaging methods utilizing the imaging members. The conversion of the compound from the crystalline form to an amorphous form can be effected by laser exposure.
1. A thermal imaging member comprising:
a substrate having first and second opposed surfaces, said first surface bearing at least a first color-forming layer, a first thermally-insulating interlayer, a second color-forming layer, a second thermally-insulating layer, and a third color-forming layer, wherein said first color-forming layer has a higher activation temperature than said second color-forming layer, and said second color-forming layer has a higher activation temperature than said third color-forming layer, said thermal imaging member further consisting of a radiation-absorbing material that is located either within said first color-forming layer or in a layer that is closer to said first color-forming layer than to any other color-forming layer;
wherein said second and third color-forming layers do not contain radiation-absorbing material;
wherein at least one of said color-forming layers comprises a chemical compound in a crystalline form, said crystalline form being capable of being converted to an amorphous form, said chemical compound having intrinsically a different color in said crystalline form than in said amorphous form.
2. The thermal imaging member of claim 1 wherein said radiation-absorbing material absorbs radiation having wavelengths in the range of 700-1200 nm.
3. The thermal imaging member of claim 2 wherein said radiation-absorbing material absorbs at least 5% of incident radiation at a wavelength that is in the range of 700-1200 nm.
4. The thermal imaging member of claim 1 wherein said second color-forming layer is not located between said first and third color-forming layers.
5. The thermal imaging member of claim 1 wherein said first color-forming layer is located at a greater distance from said first surface of said substrate than said second and said third color-forming layers.
6. The thermal imaging member of claim 1 wherein said first and second thermally-insulating layers differ in thickness by at least a factor of two.