6.
    发明专利
    未知

    公开(公告)号:DE2043334B2

    公开(公告)日:1975-06-05

    申请号:DE2043334

    申请日:1970-09-01

    Abstract: An improved process for diazo-type multicolor reproduction comprising A. exposing to light an assembly comprising I. AN ORIGINAL COMPRISING OPAQUE IMAGE AREAS AND COMPLEMENTARY NON-IMAGE AREAS WHICH TRANSMIT LIGHT, II. A PHOTOSENSITIVE LAYER CONTAINING AT LEAST ONE PHOTOSENSITIVE DIAZONIUM SALT (C), AN AZO COUPLER (B) AND A SUBSTANTIALLY NON-THERMOVOLATILE ACIDIC SUBSTANCE (D), THE ACIDIC SUBSTANCE (D) BEING PRESENT IN AN AMOUNT OF AT LEAST 5 MOLS PER MOL OF THE DIAZONIUM SALT (C), AND III. A LAYER OF A THERMOVOLATILE OR SUBLIMABLE COUPLER (A) DISPOSED BETWEEN THE ORIGINAL AND THE PHOTOSENSITIVE LAYER IN FACE-TO-FACE CONTACT WITH THE PHOTOSENSITIVE LAYER IN AREAS CORRESPONDING TO ONLY A SELECTED PORTION OF THE TOTAL IMAGE AREAS OF THE ORIGINAL, THE COUPLER (A) HAVING A HIGHER COUPLING RATE UNDER DEVELOPING CONDITIONS THAN THE COUPLER (B), AND A DYESTUFF FORMED FROM THE COUPLER (A) AND THE DIAZONIUM SALT (C), AND A DYESTUFF FORMED FROM THE COUPLER (B) AND THE DIAZONIUM SALT (C) HAVING HUES DIFFERENT FROM ONE ANOTHER, TO FORM LATENT IMAGE AREAS ON THE PHOTOSENSITIVE LAYER CORRESPONDING TO THE IMAGE AREAS OF THE ORIGINAL; B. heating the assembly to thereby transfer the coupler (a) onto the surface of the photosensitive layer, steps (A) and (B) being carried out coincidentally, or in the order of (A) to (B), or (B) to (A); and C. thereafter developing the exposed photosensitive layer whereby a multicolor reproduction is obtained in which image areas of one color correspond with areas where the coupler (a) has coupled with the diazonium salt (c), and in which image areas of another color correspond with the remaining image areas where the coupler (b) has coupled with the diazonium salt (c).

    8.
    发明专利
    未知

    公开(公告)号:DE2165360B2

    公开(公告)日:1975-04-03

    申请号:DE2165360

    申请日:1971-12-29

    Abstract: An electrophotographic process comprising the steps of (a) applying a first charge by means of direct current corona discharge to an overcoated photosensitive sheet consisting of a conductive base, a photoconductive layer and a surface insulating layer; (b) applying a second charge to the so charged sensitive sheet by means of a corona discharge current of asymmetrical wave form in which the discharge current of a polarity opposite that of the first charge is greater than that of the same polarity and the degree of asymmetry is sufficient to satisfy the specified requirements, and simultaneously exposing the sensitive sheet through or original having an image pattern of light and shadow: and (c) thereafter exposing the photosensitive sheet to an uniform illumination over the entire surface to form a latent electrostatic image of the light area and a latent electrostatic image of the dark area, which are of opposite polarity to each other.

    10.
    发明专利
    未知

    公开(公告)号:DE2165359B2

    公开(公告)日:1974-08-22

    申请号:DE2165359

    申请日:1971-12-29

    Abstract: 1357629 Electrostatic printing MITA INDUSTRIAL CO Ltd 29 Dec 1971 [29 Dec 1970] 60530/71 Heading G2H [Also in Division B6] Electrostatic printing is carried out by forming an electrostatic image on a surface 4, suitably by electro-photographic means, and developing it with a toner 6 whose particles have a charge of the same polarity as that of the latent image, then contacting the surface 4 with an imagereceiving member 7 with electrical properties so chosen as to be able to receive the toner image without dissipation or disturbance of the latent image, which can be redeveloped for making of a second toner image. A charged insulating surface 4 may be exposed to a light image, and simultaneously subjected to a corona discharge which either is A.C. or of the opposite polarity to the charge previously given to the surface at 13. Then the entire surface is exposed to light 16, and a latent image is formed.

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