Asynchronous serial printer

Claim 2

In a serial on-the-fly printer for serially printing characters at a plurality of printing positions to form a print line, wherein a type-carrying member is maintained in continuous motion to present in sequence different characters at a printing position with the direction of motion of said characters proximate to the printing position being substantially parallel to the print line, and wherein said type-carrying member is mounted on a printing carriage which is moved between adjacent printing positions with a movement independent of the motion of said type-carrying member, the improvement comprising: detecting means for detecting the position of said type-carrying member relative to said detecting means and for delivering coded signals representing said position of the type-carrying member, comparing means for comparing said coded signals with a code representing a character required to be printed to generate signals representing the results of said comparison, and means for timing at a variable rate responsive to the movement of said carriage and coupled to said comparing means, said timing means being effective for controlling printing at suitable moments in said printing positions, independently of the actual position of said printing carriage.

Claim 3

The printer of claim 1, wherein said variable rate timing means includes a timing pulse generator and a pulse counter, means for starting said pulse generator and said counter at the beginning of every printing carriage movement operation from one printing position to the next, and circuit means responsive to signals generated by said comparing means for varying the counting frequency of said counter.

Claim 4

In a printer wherein a carriage moves parallel to a print line comprising spaced apart character image receiving locations, wherein a character member mounted on saiD carriage comprises a moveable type-carrying member which presents characters sequentially and cyclically proximate to said print line and moving substantially parallel to said print line independent of the motion of said carriage, and wherein a printing member mounted on said carriage responds to a control signal to cooperate with one of said characters to form an image of said character on said print line, the improvement comprising: character position indicating means for delivering a first signal when one of said characters reaches a predetermined position relative to said carriage, offset correction representing means responsive to at least one second signal and controlled by a third signal representing information relating to said carriage movement for generating a representation of the offset correction relative to one of a plurality of predetermined carriage positions spaced apart along the path of travel of said carriage, delay providing means responsive to said first signal and controlled by said representation for generating said second signal, and means responsive to said first signal and to said representation for generating said control signal after the expiration of a delay interval initiated by said first signal, the duration of said delay interval being controlled by said representation to provide for the formation of a character image by said printing member in one of said image receiving locations.

Claim 5

In a printer wherein a carriage moves parallel to a print line comprising spaced apart character image receiving locations, wherein a character member mounted on saiD carriage comprises a moveable type-carrying member which presents characters sequentially and cyclically proximate to said print line and moving substantially parallel to said print line independent of the motion of said carriage, and wherein a printing member mounted on said carriage responds to a control signal to cooperate with one of said characters to form an image of said character on said print line, the improvement comprising: character position indicating means for delivering a first signal when one of said characters reaches a predetermined position relative to said carriage, offset correction representing means responsive to at least one second signal and controlled by a third signal representing information relating to said carriage movement for generating a representation of the offset correction relative to one of a plurality of predetermined carriage positions spaced apart along the path of travel of said carriage, delay providing means responsive to said first signal and controlled by said representation for generating said second signal, and means responsive to said first signal and to said representation for generating said control signal after the expiration of a delay interval initiated by said first signal, the duration of said delay interval being controlled by said representation to provide for the formation of a character image by said printing member in one of said image receiving locations.

Claim 6

The printer of claim 3 wherein said offset correction representing means comprises a counter.

Claim 7

The printer of claim 4 wherein said delay providing means comprises a pulse generator, wherein the pulses provided by said pulse generator are coupled to said counter to stop said counter following the occurrence of said first signal, and wherein said control signal is generated when said counter reaches a predetermined value.

Claim 8

In a serial on-the-fly printer for serially printing characters at a plurality of printing positions to form a print line, wherein a type-carrying member is maintained in continuous motion to present in sequence different characters at a printing position with the direction of motion of said characters proximate to the printing position being substantially parallel to the print line, and wherein said type-carrying member is mounted on a printing carriage which is moved between adjacent printing positions with a movement independent of the motion of said type-carrying member, the improvement comprising: detecting means for detecting the position of said type-carrying member relative to said detecting means and for delivering coded signals representing said position of the type-carrying member, comparing means for comparing said coded signals with a code representing a character required to be printed to generate comparison signals representing the result of said comparison, clocking means for indicating with a clock signal when said carriage leaves a printing position and initiates its travel toward a next printing position, and means for timing at a variable rate responsive to said clocking means and to said comparing means for controlling printing at suitable moments in said printing position with a delay in respect to said comparison signals representing the result of the comparison, which depends on the interval between said clock signal and said comparison signals.

Claim 9

In a serial on-the-fly printer for serially printing characters at a plurality of printing positions to form a print line, wherein a type-carrying member is maintained in continuous motion to present in sequence different characters at a printing position with the direction of motion of said characters proximate to the printing position being substantially parallel to the print line, and wherein said type-carrying member is mounted on a printing carriage which is moved between adjacent printing positions with a movement independent of the motion of said type-carrying member, the improvement comprising: detecting means for detecting the position of said type-carrying member relative to said detecting means and for delivering coded signals representing said position of the type-carrying member, comparing means for comparing said coded signals with a code representing a character required to be printed to generate comparison signals representing the result of said comparison, clocking means for indicating with a clock signal when said carriage leaves a printing position and initiates its travel toward a next printing position, and means for timing at a variable rate responsive to said clocking means and to said comparing means for controlling printing at suitable moments in said printing position with a delay in respect to said comparison signals representing the result of the comparison, which depends on the interval between said clock signal and said comparison signals.

Claim 10

A serial on-the-fly printer as claimed in claim 6 further comprising: auxiliary clocking means for indicating with auxiliary clock signals when said carriage passes through preestablished positions intermediate to said printing positions, said means for timing at a variable rate, also being responsive to said auxiliary clock signals.