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1.发明授权Digital image scanning device having an automatic background compensation circuit 失效具有自动背景补偿电路的数字图像扫描装置
公开(公告)号：US4970605A
公开(公告)日：1990-11-13
申请号：US309086
申请日：1989-02-06
CPC分类号： H04N1/403
摘要： The background compensation circuit defines a background threshold signal in dependence on an average value between the positive-peak and negative-peak signals previously received from the elements for scanning the pixels of the image, and in dependence on the analog signal (AS) of the pixel added to a reference signal. The circuit comprises two detectors (21, 22) for respectively detecting a positive peak and a negative peak and which each have a short charge time constant and a long discharge time constant. A summing circuit (25) generates a threshold signal (V.sub.s) as a linear combination of the signals (V.sub.max, V.sub.min) of the detectors (21, 22) the analog signal (AS) of the pixel and a reference signal (V.sub.r). Finally the threshold signal is compared (26) to the analog signal (AS) of the pixel to produce a binary reading signal which is at "one" level when the threshold signal is greater than the analog signal and is at "zero" level when the threshold signal is less than the analog signal.
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2.发明授权
公开(公告)号：US4571634A
公开(公告)日：1986-02-18
申请号：US473966
申请日：1983-03-10
申请人： Mario Caneschi , Giorgio Tadini
发明人： Mario Caneschi , Giorgio Tadini
CPC分类号： H03M7/42 , H04N1/2166 , H04N1/4105 , H04N1/4175
摘要： One-dimensional compression is effected by addressing a first ROM (62) with information in respect of the length and the type of run. One-dimensional decompression is effected by addressing with the compressed code, a second ROM, bearing the information in respect of the runs and the length of the code. That is provided by a shift register controlled by a logic unit capable of recognising a group of least significant bits, to permit additional shifting of the register, and addressing of the second ROM with a bit number less than the maximum length of the codes. For two-dimensional compression or decompression, there is provided a pair of RAMs for temporarily storing a reference line which, together with the current line, actuates a logic means (38), for controlling coding and decoding of the latter. For compression of the medium tones, besides the runs of the two colors, coding is effect in respect of the runs of the alternations of the two colors defined on the basis of the color of the initial pixel, and the type of the successive run is defined. Besides the coding and decoding for two-color images, the two ROMs also carry the coding and decoding for images with the half tone. Finally, the apparatus comprises an archive memory which can be connected to the compression module for archival storage of the images with the maximum degree of compression. By instead connecting the decompression module between the archive memory and the compression module, the image can be transmitted with a type of compression compatible with the receiving station.
摘要翻译： 通过用关于运行的长度和类型的信息寻址第一ROM（62）来实现一维压缩。 通过用压缩代码寻址来实现一维解压缩，第二ROM支持关于代码的运行和长度的信息。 这由由能够识别一组最低有效位的逻辑单元控制的移位寄存器提供，以允许寄存器的附加移位，以及以小于代码的最大长度的位数寻址第二ROM。 对于二维压缩或解压缩，提供了一对用于临时存储参考线的RAM，该参考线与当前行一起致动逻辑装置（38），用于控制后者的编码和解码。 对于中等音调的压缩，除了两种颜色的运行之外，编码对于基于初始像素的颜色定义的两种颜色的变化的运行而言是有效的，并且连续运行的类型是 定义 除了双色图像的编码和解码之外，两个ROM还对具有半色调的图像进行编码和解码。 最后，该装置包括可以连接到压缩模块的存档存储器，用于以最大程度的压缩存档图像。 通过替代地将压缩模块连接在归档存储器和压缩模块之间，可以使用与接收站兼容的压缩类型来传输图像。
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公开(公告)号：US4954888A
公开(公告)日：1990-09-04
申请号：US309085
申请日：1989-02-06
摘要： The apparatus for reading and digital processing of color images comprises groups of CCD sensing elements for reading the individual pixels forming the image. Each group of the sensing elements is associated with one primary color, for generating corresponding reading signals, which control a color indication circuit generating a color indicatory signal for indicating the presence of any color in the image. The colour indicator signal is derived from a table of zones of colours which is recorded in a ROM and can be addressed by the reading signals of the various colours, input from corresponding reading elements via compensation circuits. The colour signal is capable of controlling second selective scanning of document for recording the reading signals for all the primary colours of the image. The ROM is also capable of providing an indication of the mixture of colours of each pixel, which is compared to a predetermined mask for the purposes of suppressing a particular mixture of colours from the recording.
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公开(公告)号：US4485386A
公开(公告)日：1984-11-27
申请号：US397770
申请日：1982-07-13
摘要： The ink jet dot printer comprises a head mounted on a carriage movable along a platen supporting the paper and is formed by a plurality of tubes and piezoelectric transducer for ejecting the ink, which are supported by two parallel plates spaced from one another, between which a polymerizable resin is cast to form a single block. The tubes are aligned in a single row F--F' in a direction inclined with respect to the printing line, in such manner that the distance between the extreme tubes measured perpendicularly to the printing line is equal to the maximum height of the characters. On the outside of the front plate supporting the tubes there is fixed a thin plate bearing a row of nozzles, each of which is aligned with the corresponding ejector tube. The expulsion of the drops of ink is obtained by means of the compression exerted on the tubes by the piezoelectric transducers activated in parallel by electric pulses generated by an energizing circuit under the control of a driving logic circuit by means of which it is possible to vary the slope of the printed characters and obtain bidirectional printing at high speed.
摘要翻译： 喷墨点打印机包括安装在可支撑纸张的台板上移动的托架的头部，并且由用于喷射油墨的多个管和压电换能器形成，所述压力换能器由彼此间隔开的两个平行板支撑， 可聚合树脂被浇铸以形成单个块。 以相对于印刷线倾斜的方向将管排列成单列F-F'，使得垂直于印刷线测量的最终管之间的距离等于字符的最大高度。 在支撑管的前板的外侧，固定有一排带有一排喷嘴的薄板，每个喷嘴与相应的喷射管对准。 通过在驱动逻辑电路的控制下通过由激励电路产生的电脉冲并联激活的压电换能器来实现油墨滴的排出，这些压电换能器通过驱动逻辑电路的控制而施加在管上的压缩获得，借助于该驱动逻辑电路可以改变 打印字符的斜率，并获得高速双向打印。
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