• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    1535426 Half-tone electro-photography XEROX CORP 6 April 1976 [10 April 19751 13903/76 Heading G2X An electro-photographic machine having a photoconductive member and half-tone screen positionable relative to the member and means for adjusting the spring between the member and the screen to regulate the contrast, the machine being operative either (i) to produce a screen pattern on the member or (ii) not to produce a screen pattern. As shown, Fig. 2, light is reflected from the document 22 via mirrors 70 and 72 and through screen 28 to form a screened image on photoconductor 12 whilst light from lamp 82 also lights screen 28 and flattens the contrast. The contrast may be adjusted by moving screen 28 vertically to change the spacing between screen and photoconductor. Alternatively, drive system 74 can move screen 28 out of the optical path and an unscreened image produced on photoconductor 12. In a further embodiment (not shown), the photoconductor can be exposed to the screen pattern before or after imagewise exposure by moving the lamp 82 and screen 28.
    公开号:SU822771A3
    申请号:SU762342407
    申请日:1976-04-06
    公开日:1981-04-15
    发明作者:Натан Горен Роберт
    申请人:Ксерокс Корпорейшн (Фирма)；
    IPC主号:
    专利说明:

    W), an additional source 17 for attaching the raster screen 8, the medium 18 for changing the distance between the raster screen and the photoelectric illumination carrier. In FIG. 3 shows a variant of the exposure system, where the raster crane 8 is located behind the projection zone of the multi-color original 3 onto the semiconductor carrier 9, the additional source 17 of the lighting JQ of the raster screen 8 is powered by the current source 19.
    The electrophotographic apparatus for multicolor Copy works as follows.
    The exposure lamp 1 is peremet-5 across the originator 2 with a multi-color original 3 located on it. The light rays from the surface of the original reflect mirror-frame 4, pass through the lens 5-20 and the corresponding replaceable filter of the system 6 light filters. The resulting monochromatic uniform light projection of the original is reflected by mirror 7 to the raster screen 8, which forms the modulated projection of the original on the photo-semiconductor image carrier 9, pre-charged by the charging unit 10. The latent raster image, p, appears in one of the bins 11, 12 or 13 with color readers, depending on the copy color obtained, is transferred onto a sheet of paper by the image transfer means 14 and is thermally fixed in the means 15..
    To copy the next color of the original, the image is projected through another filter, and the raster screen is shifted by the device 16 in the screen plane 1/3 the distance between its adjacent lines. The cycle of exposure is repeated, and the development takes place in another color corresponding to the copy color 45 bunker with a color manufacturer. The additional source 17 of illumination of the raster screen 8 makes it possible to reduce the necessary luminance of the sources of exposure and even out the contrast of the image. Adjusting the image contrast is made by changing the distance between the photo-semiconductor carrier and the raster screen using a device with 18. The radius of curvature of the raster screen is larger than the radius of curvature of the photo-semiconductor carrier, and the centers of their curvature coincide, while the difference between the values of their radii of curvature is controlled by device 18. 60 operation of the device in the production mode of stroke copies, the device 18 removes the raster screen from the zone of passage of light rays, thereby excluding the process of rasters ani 65
    images. Simultaneously device
    18 moves the raster screen to the position corresponding to its optimum distance from the photo semiconductor surface to obtain high-contrast copies. .
    Thus, the ability of the apparatus to work in the manufacture of stroke or halftone copies is determined by the position of the raster screen. When copying halftone originals, a raster screen is entered in the fresh stream of projection of the original, and when copying a stroke screen, it is displayed.
    FIG. 4 shows a variant of the exposure device, where the raster screen 8 is located behind the exalted area, and the rasterization occurs already after the formation of a latent image on the photo semiconductor surface. -. .
    The rasterization of the photosemiconductor surface can be accomplished even before the original is projected onto its surface. In both cases, the resulting composite rasterized latent electrostatic image is formed. In the case of operation of the device in the mode of obtaining line copies, the source
    The power of the lamp 17 is not turned on, and the photo-semiconductor surface is not rasterized. Raster screen 8 (Fig. 4). contains many uniform opaque lines. When the machine is operating in half-tone copy mode, the raster screen is shifted by a distance of 1/3 the distance between adjacent lines when projecting each color of the original. This screen shift prevents the formation of moire and improves color, saturation. The inclusion of the bias mechanism 16 is carried out using the software logic of the apparatus. ..
    Thus, the multi-color copying machine operates in the mode of obtaining bar-shaped and gray-scale multi-color copies by setting the operator nporpeiMmy from the program from the control panel.
    权利要求:
    Claims (2)
    [1]
    1. Electrophotographic apparatus for multi-color copying, containing a photo-semiconductor image carrier, a charging unit, an exposure means comprising a raster screen, and a system of light filters, a display unit with hoppers for color manufacturers, a device for rotating the multi-color image, and also sources of exposure in the form of exposure lamps, distinguished by
    that, in order to expand technological capabilities, it has a means of 1dl moving a raster screen in the plane of the lines by a distance equal to 1/3 of the distance between adjacent lines.
    [2]
    2. The apparatus according to claim 1, of which it contains: in addition to
    P
    1b
    a light source mounted above the screen and means for varying the distance between the raster screen and the photo-semiconductor carrier.
    Sources of information taken into account in the examination
    1. US patent I 3854443, cl. 6 03 G 15/00, 1974.
    phage L
    Fm.1
    figm
    类似技术:
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    US4066353A|1978-01-03|Half tone imaging system
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    US5065199A|1991-11-12|Obtaining color balance for optical copiers by setting the exposure and primary voltage for each color
    US5010366A|1991-04-23|Slide transparency projector apparatus for use with an electrophotographic reproduction machine
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    同族专利:
    公开号 | 公开日
    NL7603869A|1976-10-12|
    DE2606310A1|1976-10-21|
    GB1535426A|1978-12-13|
    US4007981A|1977-02-15|
    CA1090867A|1980-12-02|
    FR2307296A1|1976-11-05|
    JPS51126837A|1976-11-05|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR1333280A|1961-08-30|1963-07-26|Rank Xerox Ltd|Xerographic apparatus for reproducing a graphic original|
    US3120790A|1961-08-30|1964-02-11|Xerox Corp|Xerographic exposure apparatus|
    US3313623A|1961-09-05|1967-04-11|Xerox Corp|Line sequential color xerography|
    DE1161474B|1962-12-11|1964-01-16|Elbe Kamera Gmbh|Copy device for producing electro-photographic halftone images|
    US3517596A|1967-12-27|1970-06-30|Rca Corp|Screening unit for half-tone color reproduction|
    US3580671A|1968-10-24|1971-05-25|Xerox Corp|Exposure apparatus|
    US3775006A|1969-06-04|1973-11-27|Xerox Corp|Apparatus for optical color separation imaging|US4068940A|1976-09-13|1978-01-17|Xerox Corporation|Variable contrast optical screening system|
    US4066353A|1976-09-13|1978-01-03|Xerox Corporation|Half tone imaging system|
    US4227795A|1977-01-12|1980-10-14|Xerox Corporation|Half-tone imaging system|
    JPH0372978B2|1977-04-28|1991-11-20|Canon Kk|
    US4338018A|1980-04-11|1982-07-06|Coulter Systems Corporation|Light scanning assembly for electrophotographic printing plate making apparatus|
    US6163382A|1989-07-20|2000-12-19|Netz; Yoel|Devices and methods for offset and similar printing systems|
    US5252415A|1989-12-11|1993-10-12|Konica Corporation|Dot-image forming method and the photoreceptor therefor|
    US5134439A|1990-05-25|1992-07-28|Colorocs Corporation|Exposure compensation system for a dual mode electrophotographic print engine|
    US5150158A|1990-10-29|1992-09-22|Colorocs Corporation|Flat screen for an electrophotographic printing device|
    US5289235A|1990-12-27|1994-02-22|Fuji Xerox Co., Ltd.|Image producing apparatus|
    US5245387A|1991-02-01|1993-09-14|Sharp Kabushiki Kaisha|Electrophotographic apparatus with reduced contamination from toner scattering|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    US05/566,873|US4007981A|1975-04-10|1975-04-10|Dual mode electrostatographic printing machine|
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