Patent GB-1222113-A (GB)
Title: Facsimile transceiver
Inventor: BROUWER FRANS
IPC: H04N1/36
Filed: 1968-02-02
Abstract: 1,222,113. Facsimile transceiver. STEWARTWARNER CORP. 2 Feb., 1968 [2 Feb., 1967], No. 6463/68. Heading H4F. A facsimile transceiver comprises three scanner carriages mounted on an endless timing belt which passes round a drive pulley and an idler pulley, each scanner carriage including a photo-electric pick-up device for scanning copy material moved past a slit on a rotating drum, and an electrolytic printing contact element which engages with a printer bar between which recording paper is moved when the transceiver is in its receiving mode. The timing belt comprises two flexible tapes joined by parallel spaced pins which engage cylindrical surfaces and recesses in the pulleys, spring biased guides for the tapes between the pulleys being provided. Each photo-electric pick-up device is mounted on two adjacent pins and comprises an elongate lens holder 192, Fig. 14, a double convex lens 194 being mounted in the forward end thereof, which end faces outwardly of the timing belt assembly and has side wing portions 200 carrying lamp bulbs 202 for illuminating the copy material. In front of the photo-cell 212 is disposed a diaphragm comprising leaves 218 and 220, Fig. 15, having slots 222 and 224 respectively, the position of which may be pre-set by screws 226 and 288 to move the position of the square aperture, formed where the slots cross, relative to the centre-line of the lens holder so that the photo-cell may receive the projected image of a preselected object area. The electrolytic printing contact element 255, Fig. 12, is carried at the end of a contact strip 242 mounted on a carriage block 174 supported vertically above the pick-up device 172. In operation received facsimile signals are fed to element 255 against which is pressed moist electrolytic recording paper by means of an elongated printer bar, metal from the bar being deposited on the paper and reacting therewith to produce an image which is fixed (dried) by means of a rotating heated roller. This heated roller in combination with a pressure roller also draws the recording paper web past the printer bar. The received facsimile signals, the outputs of the photo-cells (when the transceiver is operating in the receiving mode) and the supply for the light bulbs, are applied and transmitted from the individual scanner carriages by means of a flexible ribbon carrying conducting strips, which engage with contacts on the carriage at the side of the printer block, and a rotor assembly. The drive and heated roller 326, Fig. 22, for the electrolytic recording paper is driven by a single-speed reversible motor 366 via an arrangement of gears and clutches so that it may be driven at high speed for rapidly clearing the print-out area of dry paper, and at low (normal) speed while data is being reproduced. In detail a drive pinion 370, on the output shaft of the motor engages with gears 376 and 386 which are connected via overrunning clutches with gears 380 and 390. Depending on the direction of rotation of pinion 380 either gear 380 or 390 is driven and thus the gear 364 on roller 326 is driven at one of two speeds. Further details.-Synchronization between two associated transceivers is effected by means of a disc having slots mounted for rotation on the drive pulley and associated with a plurality of light sources and photo-cells. The driven circumference of the timing belt is equal to a whole number multiple, e.g. 3, of the effective drive circumference of the drive pulley. As described, one revolution of the drive pulley is equivalent to one scan length. The recording paper roll is provided with a run-out detector (426, Figs. 4 and 24, not shown). To equalize wear along the lower edge of the print-out bar, means are provided for cyclically shifting the whole printer bar unit (466, Fig. 24, not shown) lengthwise as the combined drive and heat roller rotates in the receiving mode.