| 摘要 |
<p>1473478 Selective printing N-DIMENSIONS Inc 17 Feb 1975 [5 March 1974] 6689/75 Heading B6F [Also in Division G4] In a dot-matrix printer, a print head 18 is advanced along the print line using a lead screw 24, the head being pivotable between a position in which it engages the print medium and a follower on it engages the screw and a position in which these conditions do not hold. As disclosed, the printer is a portable, batteryoperated typewriter, actuation of any of its character keys 16 pulsing a motor 28 and a motor 52 (or solenoid), the latter rotating an arm 48 to release a chopper disc 40 for one revolution. Disc 40 is driven via gears 32, 34 from motor 28 which also drives the lead screw 24 so the lead screw is driven for one character width during the disc rotation. A bush 44 produces pulses from marks on disc 40 which drive a counter to read successive columns of the character matrix from a memory to drivers controlling heating current to a column of thinfilm resistors in the (thermal) print head 18. (There may be more than one column of resistors.) The memory is loaded from a decoder which responds to the character keys and can communicate in both directions, via FM radio, telephone line or direct line, with a computer. Another key pulses a motor 54 (or solenoid) to rotate head 18 about one (20) of its two guide rods shown so that it no longer engages the lead screw 24 whereupon a (constant tension) spring 60 returns it to the left. A paper-advance key pulses a motor 76 to advance the paper using a rod 78, disc 80, a one-way clutch, a (return) coil spring and another one-way clutch.</p> |
