DE1218881B - Electrophotographic process for the production of deformation images - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

G03g

German KL: 57 e - 1/02

Number: 1218 881

File number: G 29900 IX a / 57 e

Registration date: June 21, 1960

Opening day: June 8, 1966

The invention relates to an electrophotographic method for producing images in which a Charge image deforms a softened thermoplastic layer of a recording material.

It is known a photosensitive layer made of a thermoplastic material, a diazonium compound and optionally further additives with ultraviolet or short-wave blue light to expose imagewise and then to soften by heating and thereby that of the diazonium compound Allowing the split off nitrogen to expand and form vesicles. The vesicles scatter the incident light. Although this vesicular procedure without the use of chemicals and can be carried out under normal room lighting, exposure is ultraviolet light necessary.

It has been proposed for permanent recording of electrical signals, in particular Television signals, a charge image controlled by the signals onto a dielectric, thermoplastic Apply plastic layer, the plastic layer before, during or after application of the Charge image is softened by heating in such a way that it is deformed by the charge image. One The deformed plastic layer solidifies by cooling. At the same time it is proposed been to apply the plastic layer on a layer support in the form of a plate or a roller.

It has also been proposed that the layer support described be provided with an electrically conductive Layer to be provided between thermoplastic plastic layer and non-conductive layer support. Simultaneously it has been proposed that the plastic layer be reflective or the plastic layer transparent and the conductive layer is reflective or the plastic layer and the conductive layer are transparent and make the substrate reflective.

With all these methods a permanent visible image can be created in the plastic layer, which is clearly recognized by the human eye in transmitted or reflected light.

The object of the invention is, when producing deformation images, not only the surface, but also to utilize the inner structure of the thermoplastic plastic layer.

The subject matter of the invention is based on an electrophotographic process for the production of images, in which a charge image deforms a softened thermoplastic layer of a recording material, and is characterized by an electrophotographic process for
Production of deformation images

Applicant:

General Electric Company,

Schenectady, N. Y. (V. St. A.)

Representative:

Dr.-Ing. W. Reichel, patent attorney,

Frankfurt / M., Parkstr. 13th

Named as inventor:

George John Chafaris, East Syracuse, N. Y.

(V. St. A.)

Claimed priority:

V. St. ν. America from June 22nd, 1959 (822 097) - -

that a known recording material with a light-scattering, thermoplastic, optionally an electrically conductive layer and optionally a support is used.

A recording material with a light-scattering thermoplastic layer is preferably made Polystyrene in which gas bubbles, soot or glass particles are dispersed, is used.

The recording material thus contains a layer made of a transparent, thermoplastic Plastic in which tiny light-scattering particles are homogeneously distributed. To produce an image the recording material is provided with a charge image, heated and then cooled again.

Thicker image parts of the plastic layer contain a larger number of light-scattering particles than thinner ones. They therefore generate in the image generated by an optical projector when played back Photograph a lighter area. The projected © light that creates the desired light image is intensity-modulated by the light-scattering particles. This method of playback is different So it differs significantly from the earlier method, in which the projected light was passed through the various Increase in the elevations of the deformation image is scattered or flexed.

The invention will be explained in more detail with reference to the drawings.

F i g. 1 shows an enlarged cross section through the recording material;

609 578/309

2a, 2b and 2c explain in a schematic representation the physical principles that are used in the Thickness modulation of the recording material play a role.

The recording material 29 preferably consists of three layers. The first is the substrate 33, which is 0.25 to 0.1 mm thick and at a developing temperature is resistant between 100 and 150 ° C. Suitable materials are a polycarbonate resin a bivalent phenol (cf. CAEN, 1957, issue 14, p. 20) or a transparent cold-resistant one Polyester film of ethylene glycol and terephthalic acid (CAEN, 1954, p. 3718) or a Polyester-based photo film. The second is the very good electrically conductive layer 32, which is usually 1 μm thick and transparent and preferably consists of vapor-deposited chrome. Copper iodide can can also be used. The third layer 31 is 20 to 30 μπα thick and consists of a transparent one thermoplastic plastic, in which tiny light-scattering particles 30 that have a diameter Have from 1 to 5 μπι, embedded skid. Polystyrene, preferably pure polystyrene with a melting point between 100 ° and 150 ° C. is a suitable one Plastic. The light-scattering particles 30 can be transparent air bubbles or finely ground glass particles, whose refractive index differs from that of the plastic. They can also be uncertain Be soot particles.

During the imagewise exposure shown in Fig. 2a, light indicated by arrows falls on part A of an electrophotographic material 26 consisting of an electrically conductive layer 27 and a photoconductive layer 28, while no light falls on the adjacent part B. The charges of the initially uniformly charged plastic layer 31 flow to a much greater extent through the photoconductive layer 28 to the electrically conductive layer 27 than in B. After exposure and removal of the electrophotographic material 26 from the recording material 29, the plastic layer 31 obtain a charge image. An induced charge image forms on the opposite surface of the plastic layer, as shown in FIG. 2b. For development, the plastic layer 31 is liquefied so that the repulsive electrostatic forces between adjacent charges and the attractive forces between the two charge images can deform the plastic layer 31, as shown in FIG. 2c. If anything, part A has only deformed negligibly, while part B is considerably deformed. As FIG. 2c shows, the number of scattering particles per unit area in the deformed part B is considerably lower than in the undeformed part, since it is proportional to the thickness of the plastic layer and the concentration of the particles remains approximately constant during development. When reproducing the deformation image, the projection light is more strongly scattered in part ^ i than in part B, so that the image part of the light image which reproduces part B appears bright, while the part of the light image; which reproduces the Teil.i4 appears dark. That through

ao the compression of the area B of the displaced material forms small bumps at the edges of the individual deformations. These elevations do not interfere with the projection and, under certain circumstances, even increase the contrast of the light

image. ;

Claims (2)

Claims: y 1. Electrophotographic process for the production of images in which a charge image a softened thermoplastic layer of a recording material is deformed thereby characterized in that a known recording material with a light-scattering, thermoplastic, optionally an electrically conductive layer and - optionally one Layer support is used. 2. The method according to claim 1, characterized in that a recording material with a light-scattering thermoplastic layer made of polystyrene, in which gas bubbles, carbon black or Glass particles are dispersed is used. Considered publications:
U.S. Patent No. 2,703,756. 1 sheet of drawings 609 578/309 5.66. © Bundesdruckerei Berlin