Color image reproduction sheet employed in photoelectrophoretic imaging

• US 3,870,517 A
• Filed: 06/05/1972
• Issued: 03/11/1975
• Est. Priority Date: 10/18/1969
• Status: Expired due to Term

• Current Assignee: Isao Ota, Tetsuro Otsuka
• Original Assignee: Isao Ota, Tetsuro Otsuka
• Inventors: Ota, Isao, Otsuka, Tetsuro
• Primary Examiner(s): Torchin, Norman G.
• Assistant Examiner(s): Miller, John R.
• Application Number:
  US05/259,817
• Time in Patent Office: 1,009 Days
• Field of Search: 96/1.5,1PE,1.2 204/181PE
• US Class Current: 430/38
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1685 Operation of cells; Circuit arrangements affecting the entire cell
• CPC Class Codes: G03G 17/04 using photoelectrophoresis

Abstract

A color image reproduction sheet for use in an electrophoretic color image reproducing apparatus. The sheet has a suspension layer having a white colored suspending medium and at least three differently colored photosenstive electrophoretic materials in the form of finely divided powder suspended in the white colored suspending medium, the three differently colored photosensitive electrophoretic material consisting essentially of cyan colored material which is principally photosensitive to red light, magenta colored material which is principally photosensitive to green light, and yellow colored material which is principally photosensitive to blue light. The suspension layer is supported on a base, so that when the sheet is passed between a substantially transparent first electrode and a second electrode which are spaced from and opposed to each other with the electrodes against the two opposite major surfaces of the suspension layer, respectively, with the transparent electrode against the free surface of the suspension layer, and a D. C. electric field is applied across the suspension layer between the electrodes, and the suspension layer is exposed to a color image through the transparent electrode, the D. C. electric field changes electrophoretically, in cooperation with the color image, the spatial distribution of the three differently colored photosensitive electrophoretic materials so that the optical reflective property of the suspension layer changes in accordance with the color image.

Claims

1. A COLOR IMAGE REPRODUCTION SHEET FOR REPRODUCING A DIRECTLY VISIBLE COLOR IMAGE THEREON, THE SHEET CONSISTING ESSENTIALLY OF AN ELECTROPHORETIC SUSPENSION LAYER HAVING A WHITE COLORED OPAQUE ELECTRICALLY INSULATING SUSPENDING MEDIUM AND AT LEAST THREE DIFFERENTLY COLORED PHOTOSENSITIVE ELECTROPHORETIC MATERIALS IN THE FORM OF FINELY DIVIDED POWDER SUSPENDED IN SAID WHITE COLORED OPAQUE SUSPENDING MEDIUM, SAID WHITE COLORED OPAQUE ELECTRICALLY INSULATING SUSPENDING MEDIUM BEING NON-FRACTURABLE DURING THE IMAGE REPRODUCTION AND SAID AT LEAST THREE DIFFERENTLY COLORED PHOTOSENSITIVE ELECTROPHORETIC MATERIALS CONSISTING ESSENTIALLY OF CYAN COLORED MATERIAL WHICH IS PRINCIPALLY PHOTOSENSITIVE TO RED LIGHT, MAGENTA COLORED MATERIAL WHICH IS PRINCIPALLY PHOTOSENSITIVE TO GREEN LIGHT, AND YELLOW COLORED MATERIAL WHICH IS PRINCIPALLY PHOTOSENSITIVE TO BLUE LIGHT, AND A BASE ON WHICH SAID SUSPENSION LAYERS IS SUPPORTED, WHEREBY WHEN SAID SHEET IS PASSED BETWEEN A SUBSTANTIALLY TRANSPARENT FIRST ELECTRODE AND A SECOND ELECTRODE WHICH ARE SPACED FROM AND OPPOSED TO EACH OTHER WITH THE ELECTRODES AGAINST THE TWO OPPOSITE MAJOR SURFACES OF SAID SUSPENSION LAYER, RESPECTIVELY, WITH THE TRANSPARENT ELECTRODE AGAINST THE FREE SURFACE OF THE SUSPENSION LAYER AND A D.C. ELECTRIC FIELD IS APPLIED ACROSS THE SUSPENSION LAYER BETWEEN SAID ELECTRODES, AND SAID SUSPENSION LAYER IS EXPOSED TO A COLOR IMAGE THROUGH SAID TRANSPARENT ELECTRODE, THE D.C. ELECTRIC FIELD CHANGES ELECTROPHORETICALLY, IN COOPERATION WITH THE COLOR IMAGE, THE SPATIAL DISTRIBUTION OF SAID AT LEAST THREE DIFFERENTLY COLORED PHOTOSENSITIVE ELECTROPHORETIC MATERIALS SO THAT THE OPTICAL REFLECTIVE PROPERTY OF THE SUSPENSION LAYER CHANGES IN ACCORDANCE WITH SAID COLOR IMAGE, A DIRECTLY VISIBLE COLOR IMAGE BEING THUS REPRODUCED ON SAID SHEET WIHOUT FRACTURING SAID ELECTROPHORETIC SUSPENSION LAYER.

2. A sheet as claimed in claim 1 wherein said white colored opaque suspending medium is selected from the group consisting of a white solution colored with a dye, a colloidal liquid having a white colored material in the form of a finely divided powder suspended therein, and a liquid having a white colored porous layer inserted therein.

3. A sheet as claimed in claim 1 wherein said at least three differently colored photosensitive electrophoretic materials have a charge polarity which can be changed by application of the D. C. electric field in cooperation with exposure to said color image.

4. A sheet as claimed in claim 1 wherein said at least three differently colored photosensitive electrophoretic materials have an electrophoretic mobility which can be changed by application of the D. C. electric field in cooperation with exposure to said color image.

5. A sheet as claimed in claim 1 wherein said suspension layer further contains at least one control agent for said photosensitive electrophoretic materials selected from the group consisting of a charge control agent, a dispersion agent, a sensitizing agent and a fixing agent.

6. A sheet as claimed in claim 1 wherein said white colored suspending medium is a hardenable material.

7. A sheet as claimed in claim 1 where said white colored suspending medium is heat hardenable.

8. A sheet as claimed in claim 1 where said white colored suspending medium is heat softenable.

9. A sheet as claimed in claim 1 wherein said white colored suspending medium is solvent softenable.