Abstract A control system for a horizontal type carrier, or ''''chain'''', printer wherein a recirculating shift register memory is employed to store the code representations of characters to be printed on the print line. A tracking or address counter is advanced in synchronism with the movement of data through the shift register and serves to identify each character stored therein with the particular print position in which it is to be printed. Generation of print command signals is accomplished by comparing, in sequence, each character stored in the memory with the output of a character generation counter which is advanced in synchronism with the movement of the type carrier to identify the order in which the types on the carrier move past the print positions. Actuation of the comparator and advancement of the character generation counter are controlled directly by the output of the tracking counter. Beginning-of-font sync pulses are generated by gating a primary index signal derived directly from the type carrier with a secondary index signal derived from a rotating code disc. A plurality of index marks are provided on the code disc in a manner to enable generation of properly timed beginning-of-font signals for any of a variety of different font length type carriers interchangeably employable in the printer.
Inventors
👤 Lynn W Marsh Jr
👤 Edward M Schneiderhan
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-08 05:29
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
204 words
In a system for generating sync signals in a printer having interchangeable type carriers, each of which employs a different length type font, combination comprising: a first transducer positioned adjacent the type carrier for sensing a beginning-of-font mark thereon; a bistable circuit connected to said first transducer and settable in response to detection of said beginning-of-font mark; a coincidence circuit having a first input connected to the set output of said bistable circuit; a timing disk rotatable in sync with the movement of said carrier and having character and index marks inscribed thereon, said character marks being spaced so as to pass a stationary reference point at the same repetition rate as the types on said carrier and said index marks being spaced so as to pass said reference point at (1/n)th said repetition rate, n being a submultiple of the number of characters in each different length type font usable with said printer; a second transducer for sensing said character marks and generating character sync signals in response thereto; and a third transducer for sensing said index marks and for transmitting to the second input of said coincidence circuit signals in response thereto, the outputs from said coincidence circuit being index sync pulses.
Claim 2
Dependent Claim
204 words
In a system for generating sync signals in a printer having interchangeable type carriers, each of which employs a different length type font, combination comprising: a first transducer positioned adjacent the type carrier for sensing a beginning-of-font mark thereon; a bistable circuit connected to said first transducer and settable in response to detection of said beginning-of-font mark; a coincidence circuit having a first input connected to the set output of said bistable circuit; a timing disk rotatable in sync with the movement of said carrier and having character and index marks inscribed thereon, said character marks being spaced so as to pass a stationary reference point at the same repetition rate as the types on said carrier and said index marks being spaced so as to pass said reference point at (1/n)th said repetition rate, n being a submultiple of the number of characters in each different length type font usable with said printer; a second transducer for sensing said character marks and generating character sync signals in response thereto; and a third transducer for sensing said index marks and for transmitting to the second input of said coincidence circuit signals in response thereto, the outputs from said coincidence circuit being index sync pulses.
Claim 3
Dependent Claim
36 words
The system set forth in claim 1 further comprising: a delay circuit for feeding each said index sync pulse to reset said bistable circuit at a time after said index mark has passed said third transducer.
Claim 4
Dependent Claim
32 words
The system set forth in claim 1 wherein said beginning-of-font mark is inscribed on said carrier adjacent a character type which is common to all different type fonts usable with said printer.