Method and apparatus for printing by inking a latent thermal image

• US 5,067,404 A
• Filed: 08/21/1990
• Issued: 11/26/1991
• Est. Priority Date: 02/26/1988
• Status: Expired due to Term

• Current Assignee: Oce Printing Systems GmbH (Canon Inc.)
• Original Assignee: Siemens AG
• Inventors: Frunder, Henning, Wiedemer, Manfred
• Primary Examiner(s): Wiecking, David A.
• Assistant Examiner(s): Funk, Stephen R.
• Application Number:
  US07/555,406
• Time in Patent Office: 462 Days
• Field of Search: 101/488, 101/487, 101/467, 427/248.1, 427/256, 427/288, 427/53.1, 427/56.1
• US Class Current: 101/488
• CPC Class Codes: B41M 5/26 Thermography B41M5/20, B41M5/24 take precedence; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used B23K takes precedence; thermographic or photothermographic systems using noble metal compounds G03C1/494
• CPC Class Codes: G03G 15/06 for developing
• CPC Class Codes: G03G 17/00 Electrographic processes using patterns other than charge patterns, e.g. an electric conductivity pattern; Processes involving a migration, e.g. photoelectrophoresis, photoelectrosolography; Processes involving a selective transfer, e.g. electrophoto-adhesive processes; Apparatus essentially involving a single such process

Abstract

A printer comprising a temperature control (A) that sets a recording medium (10) conducted through the printer under motor drive approximately uniformly to a predetermined temperature, comprising a thermal writer (B) that generates a latent character image on the recording medium (10) by local heat application controlled character-dependent, and comprising a developer (C) in which the latent character image is developed by condensation of a color vapor or by color application.

Claims

1. A printing process, comprising the following method steps:

a) bringing a medium movably guided in a printer to a uniform temperature;

b) producing a latent thermal character image on the medium with a writing means that is controlled in character-dependent fashion to produce characters when desired; and

c) developing the latent thermal character image to form a developed character image in a development station by one of;

condensation of a colored vapor, and separate inking after condensation of a vapor, whereby condensation behavior of the vapor and temperature of the medium are selected such that the vapor precipitates on the medium to define a character to be printed in one of;

a positive and negative image; and

d) transferring the developed character image onto a recording medium in a transfer printing station.

2. A printing process according to claim 1, further comprising the following method step:

separately inking an intermediate image composed of vapor condensate with atomized colorant powder.

3. A printer apparatus, comprising:

a means for moving a medium through a printer;

a temperature control means for setting a temperature of the medium as the medium is moved through the printer to an approximately uniform, predetermined temperature;

a thermal writing means for generating a latent thermal character image by local application of heat onto the medium, said thermal writing means being controlled in character-dependent fashion;

a development means for developing the latent thermal character image to produce a developed character image by one of;

condensation of a colored vapor to define the developed character image, and separate inking after condensation of a vapor; and

a transfer printing station for transferring the developed character image onto a recording medium.

4. A printer apparatus according to claim 3, wherein said medium is composed of composite material that comprises a surface layer having a high thermal conductivity perpendicular to the surface and a low thermal conductivity in a surface direction and that comprises a heat-insulating carrier layer.

8. A printer apparatus according to claim 11, further comprising;

a vapor circulation system in communication with the development space and including a liquid vapor container, a heating means for evaporating a liquid and a temperature-controlled vapor buffer space, and

a return condensation unit that condenses the vapor conducted through the development space and supplies the condensed vapor to the liquid vapor container.

5. A printer apparatus according to claim 8, wherein said surface layer has a layer thickness of 30 through 300 μ

m and wherein said carrier layer has a layer thickness of 100 through 500 μ

m.

6. A printer apparatus according to claim 5, wherein said medium is one of:

an endless belt and a drum.

7. A printer apparatus according to claim 5, wherein said development means includes means defining a developmetn space that accepts the medium in a development region and is traversed by vapor.

9. A printer apparatus according to claim 11, further comprising;

a means for conducting the vapor through the development space opposite the moving direction of the medium.