| 摘要 |
1301203 Selective signalling DATACQ SYSTEMS CORP 12 March 1970 [14 March 1969] 11864/70 Heading G4H Key-actuated members carry coded patterns which are each sensed serially on actuation, by an optical-to-electric converter. When a typewriter key is actuated and the corresponding print arm moves to the print position, a coded pattern on the arm is sensed to provide coded electric signals identifying the character being printed which are supplied via a dial tone receiver connection, or direct wire connection, to a computer. The coded pattern is sensed photoelectrically (being of light reflecting bars, or light-transmitting marks or slots). Optical fibres or lenses may be used for conducting the light to and/or from the sensing position. Sensing is serial by bit. The coded pattern may be provided on/in a detachable inverted U-shaped member which is clipped over the print head on the end of the print arm. Two patterns may be provided on a given arm, corresponding to the upper and lower case characters carried by the arm, being at different heights so that only the appropriate one is sensed. The same pattern may be provided on both sides of the head, the two outputs from sensing the two sides being combined to compensate for lateral mispositioning of the head. The pattern may be sensed during both forward and reverse movement of the head for parity checking using a counter, or the code may incorporate parity information. Spacing of the typewriter carriage is indicated by optical sensing (via optical fibres) of a scale on the carriage, encoded signals being produced from a converter to indicate spacing. Line beginning is also indicated from the scale. Beginning of line and other format information can also be indicated by pressing respective auxiliary keys which move respective coded patterns past sensing means. Encoding of more than one key in the typewriter at a time may be prevented. Sensing may use infra-red or ultra-violet, and in the latter case the coded patterns may be of fluorescent ink or paint. Application to the keyboard of a desk calculator is mentioned. |
