摘要:
The ink jet dot printer comprises a head mounted on a carriage 10 movable along a platen supporting the paper and is formed by a plurality of tubes 24 and piezoelectric transducers 36 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 24 there is fixed a thin plate S1 bearing a row of nozzles U o- U 19 , each of which is aligned with the corresponding ejector tube 24. The expulsion of the drops of ink is obtained by means of the compression exerted on the tubes 24 by the piezoelectric transducers 36 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:
The head comprises a tube (24) for ejecting ink through a nozzle (54), when a transducer (36) is operated. The tube (24) is connected to an ink reservoir (31) by a flexible tube (30), which is longer than the distance between the tube (24) and the reservoir (31). The tube (30) is wound on a drum (130) in an arrangement which optimises the utilisation of space by the tube (30). When the head comprises more than one ink ejecting tube (24), each having a respective, ink conducting tube (30), each tube may be wound around the drum (1301 for one and a half turns between diametrically opposite positions on the circumference of the drum, so that each half turn of the drum left free by one tube (30) is occupied by the first half turn of an adjacent tube (30). This arrangement minimises the axial length of the drum occupied by the tubes (30).
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 colours, coding is effect in respect of the runs of the alternations of the two colours defined on the basis of the colour of the initial pixel, and the type of the successive run is defined. Besides the coding and decoding for two- colour images, the two ROMs also carry the coding and decoding for images with the half-tones. Finally, the apparatus comprises an archive memory which can be connected to the compression module for achival 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:
The device comprises a colour indicator (47) for recording a signal (44) in association with a reading signal for a predetermined colour (G). 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 (14G,14R,14B). 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 (51) to a predetermined mask (M) for the purposes of suppressing a particular mixture of colours from the recording.
摘要:
The head comprises a tube (24) for ejecting ink through a nozzle (54), when a transducer (36) is operated. The tube (24) is connected to an ink reservoir (31) by a flexible tube (30), which is longer than the distance between the tube (24) and the reservoir (31). The tube (30) is wound on a drum (130) in an arrangement which optimises the utilisation of space by the tube (30). When the head comprises more than one ink ejecting tube (24), each having a respective, ink conducting tube (30), each tube may be wound around the drum (1301 for one and a half turns between diametrically opposite positions on the circumference of the drum, so that each half turn of the drum left free by one tube (30) is occupied by the first half turn of an adjacent tube (30). This arrangement minimises the axial length of the drum occupied by the tubes (30).
摘要:
The circuit defines the digitization threshold (V s ) in dependenced on 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. 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 the threshold signal (V s ) as a linear combination of the signals (V max , V min ) of the detectors (21, 22), the analog signal (AS) of the pixel and a reference signal (V r ). Finally the threshold signal is compared (26) to the analog signal (AS) of the pixel to produce a binary reading signal.
摘要:
The circuit defines the digitization threshold (V s ) in dependenced on 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. 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 the threshold signal (V s ) as a linear combination of the signals (V max , V min ) of the detectors (21, 22), the analog signal (AS) of the pixel and a reference signal (V r ). Finally the threshold signal is compared (26) to the analog signal (AS) of the pixel to produce a binary reading signal.