| 摘要 |
1,215,608. Selective printing; photographic type-composing; re-usable writing surfaces. ING. C. OLIVETTI & C. S.p.A. 13 March, 1968 [25 May, 1967], No. 12109/68. Headings B6F, B6P and B6W. A device permitting temporary inscription of matter such as computer output comprises a temporary inscription carrier 1 having a dark coloured surface at least partly covered by a thin layer of light-coloured paste unaffected by air, an impression member 8 carrying a raised character 10 which when pressed against the carrier 1 displaces paste to reveal an area of the dark-coloured surface in the shape of the selected character, and erasing means such as rollers 12, 6 for evening out the layer of paste. The carrier 1 may be in the form of an endless band or a drum. Temporary image carriers; repeatedly usable writing surfaces.-The carrier 1 may comprise a synthetic rubber or darkened stainless steel band covered with a thin layer of white paste formed of equal proportions by weight of a silicone oil and a pigment which may be titanium dioxide, talc, zinc oxide, or titanium hydroxide. A permanent record of the matter inscribed may be obtained by photographing an image in the region L on microfilm. The image is erased in two stages, partly by a smoothing roller 12 fitted with a foam rubber sleeve 13 having a smooth, non-porous outer surface, and finally by a roller 6 bearing a felt annulus (21), Fig. 3 (not shown), covered by a nylon fabric sleeve (22), and incorporating an annular paste reservoir (23) from which paste can be squeezed through the felt annulus by an annular piston (27) under the action of a screw (26) to replenish the layer of paste on the carrier 1. The paste is applied only to the central region of the carrier 1, and is prevented from spreading to the edges by a scraper 11 comprising a block (34), Fig. 4 (not shown), of polytetrafluorethylene, formed with a groove receiving the carrier 1, and fitted with lugs (30, 31) carrying flexible strips (28, 29) disposed at an angle to the direction of motion of the carrier 1 so as to displace the paste layer towards the centre of the carrier. Letter spacing; line spacing; tensioning and winding arrangements.-The carrier 1 may carry a single line of characters, the letter spacing being effected by a drive roller 2 driven stepwise by a motor 35. Alternatively, lines of characters may be printed transversely of the carrier 1 by a ball-shaped type head (not shown) traversing the carrier, the roller 2 effecting line spacing. A pivotally mounted roller 3, urged counterclockwise by a spring 7, tensions the carrier 1. The carrier may be removed by releasing the tension by pivoting the roller 3 clockwise and swinging the erasing roller 6 out of contact with the carrier. Types.-The raised character 10 on the impression member 8 is formed with a curved impression surface (17), Fig. 2 (not shown), for effective displacement of the paste.
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