Claims
- 1. A control device for selectively controlling the mechanical printing elements of a matrix printer, which elements are arranged in a printing head moving along a print line to generate the characters to be printed by means of print dots, which dots are arranged in at least one predetermined printing raster, said control device comprising:
- a control unit which generates a print signal for each printing element individually when said printing element reaches a position which lies a certain printing path before an envisaged printing location on an information carrier, characterized in that at least those printing elements whose arrangement in the printing head corresponds to a column of the printing raster are connected to a delay device which is controlled by the print signal to start a control signal for the direct mechanical triggering of the associated printing element after a delay time which is dependent on the speed of the printing head, wherein the delay device comprises a shift register and the print signal writes a first binary value into a stage of the shift register and which is derived from a correction value dependent on the printing head speed, the contents of the shift register are then shifted further by means of shift pulses and the arrival of the first binary value at a given stage in the shift register starts the control signal, and wherein the shift pulses are derived from position pulses generated during the movement of the printing head and the delay time is independent of which printing element is selected.
- 2. A control device as claimed in claim 1, further comprising a correction device for generating the correction value, which correction device comprises, a first counter with parallel set inputs which receives at its count input a pulse signal of constant frequency and at its set inputs a value related to the pulse signal and determined by the printing delay time between triggering of the printing element and its impact on the information carrier, and a second counter with parallel set inputs which receives at its count input the position pulses and at its set inputs a value depending on the determined printing path at maximum speed of the printing element, wherein the two counters receive a same set control signal, and wherein a carry signal of the first counter is operative as a control signal so that a correction value, derived from the position then reached by the second counter, is supplied to the delay device.
- 3. A control device as claimed in claim 2, further comprising means for generating an error signal upon the appearance of a carry signal of the second counter before the appearance of the carry signal of the first counter.
- 4. A control device as claimed in claim 3, wherein said error generating means derives the error signal if the carry signal of the first counter appears with a delay of at least one period of the pulse signal after the appearance of the carry signal of the second counter.
- 5. A control device for selectively controlling the mechanical printing elements of a matrix printer, which elements are arranged in a printing head moving along a print line to generate the characters to be printed by means of print dots, which dots are arranged in at least one predetermined printing raster, said control device comprising:
- a control unit which generates a print signal for each printing element individually when said printing element reaches a position which lies a certain printing path before an envisaged printing location on an information carrier, characterized in that at least those printing elements whose arrangement in the printing head corresponds to a column of the printing raster are connected to a delay device which is controlled by the print signal to start a control signal for the direct mechanical triggering of the associated printing element after a delay time which is dependent on the speed of the printing head, and wherein the delay device comprises a counter and the print signal sets the counter to a correction value which depends on the printing head speed and the counter then counts to a first end value by means of count pulses of a first frequency provided via a count pulse input, whereby the control signal is started when said first end value is reached.
- 6. A control device as claimed in claim 5, further comprising switching means controlled by the counter so that the counter, after reaching the first end value, controls the switching means to switch the count pulse input to count pulses of a constant, second frequency corresponding to the energizing time of a printing element, wherein the switching means ends the control signal when the counter end value is reached a second time and also switches over the count pulse input to count pulses having a third frequency chosen so that the counter reaches the end value for a third time for a maximum printing head speed after at least a programmed printing element cycle time has elapsed since the print signal, further print signals being blocked up to that moment.
- 7. A control device as claimed in claim 6, wherein the switching means further comprises a converter connected to the count pulse input of the counter, which converter supplies the count pulse input successively with a rest signal and count pulses of the three frequencies, wherein the counter generates a carry signal in its end position and starts counting again from an initial position with the next count pulse, and the carry signal switches a further counting device having four positions, which device controls the converter, generates a load signal for the first counter when a print signal is received, moves into the first operational state, and generates the output signal during the second operational state.
- 8. A control device as claimed in claim 5, wherein the count pulses are derived from position pulses generated in response to movement of the printing head.
- 9. A control device as claimed in claim 8, further comprising a correction device for generating the correction value, said correction device comprising; a first counter with a set of parallel inputs and a count input which receives a pulse signal of constant frequency, said set of inputs receiving a value related to the pulse signal and determined by the printing delay time between triggering of the printing element and its impact on the information carrier, and a second counter with a set of parallel inputs which receives at its count input the position pulses and at its set of parallel inputs a value depending on the determined printing path at maximum speed of the printing element, wherein the two counters receive a same set control signal, and wherein a carry signal of the first counter operates as a control signal so that a correction value, derived from the position then reached by the second counter, is supplied to the delay device.
- 10. A control device as claimed in claim 9, further comprising means for generating an error signal upon the appearance of a carry signal of the second counter before the appearance of the carry signal of the first counter.
- 11. A control device as claimed in claim 10, wherein said error generating means derives the error signal if the carry signal of the first counter appears with a delay of at least one period of the pulse signal after the appearance of the carry signal of the second counter.
- 12. A control device for controlling operation of the mechanical printing elements arranged in a printing head of a matrix printer, said control device comprising:
- a first input for receiving signal pulses indicative of the speed of the printing head and generated in response to movement of the printing head,
- means responsive at least to said signal pulses for deriving a print signal at a predetermined distance before the printing elements reach a desired printing spot on an information carrier,
- a correction device responsive to said signal pulses and to a pulse signal of constant frequency to derive at its output a correction signal determined by the speed of the printing head, and
- a delay device responsive to said print signal and to said correction signal for deriving at its output a control signal for triggering the printing elements after a delay time determined by the correction signal and thus by the speed of the printing head.
- 13. A control device as claimed in claim 12 wherein the delay device comprises;
- a counter having first input means for receiving said correction signal and which, under control of the print signal, sets the counter to a correction count determined by the speed of the printing head, said counter having a count pulse input and an output, and
- means for applying count pulses of a first frequency to said count pulse input whereby the counter counts to a first end count position at which it delivers a signal at its output whereby said control signal is started.
- 14. A control device as claimed in claim 13 wherein the delay device further comprises;
- a logic circuit controlled by the signal at the counter output, and
- said count pulse applying means comprises a switching device having input means coupled to terminals for supplying count pulses of said first frequency and of a second frequency corresponding to the energizing time of a printing element and of a third frequency related to the cycle time of the control device, and
- means coupling output means of the logic circuit to a control input of the switching device whereby, when the counter reaches said first end count position, the switching device in response to the logic circuit supplies count pulses of the second frequency to the counter count input whereby the counter counts to the end count position a second time to trigger the switching device via the logic circuit to supply the counter count pulse input with count pulses of the third frequency.
- 15. A control device as claimed in claim 12 wherein the correction device comprises;
- a first counter having a count input for receiving a constant frequency pulse signal and input means for receiving a signal related to the pulse signal and determined by the printing delay time, said first counter also having a further input and a carry signal output,
- a second counter having a count input which receives the signal pulses and having input means for receiving a signal dependent on a determined printing path for maximum speed of the printing elements, said second counter also having a further input and an output for developing the correction signal, and
- a delay device coupling the carry signal output of the first counter to said further inputs of the first and second counters.
- 16. A control device as claimed in claim 15 wherein the correction device further comprises;
- a logic circuit controlled by said carry signal output, by a carry signal output of the second counter, and by said constant frequency pulse signal thereby to derive an error signal if the second counter produces a carry signal before the first counter produces its carry signal.
- 17. A control device as claimed in claim 12 wherein the delay device comprises;
- a shift register having input means for receiving said correction signal and further input means for the print signal whereby a first binary value is written into a stage of the shift register which is determined by said correction signal, the contents of the shift register being shifted by shift pulses so that when said first binary value reaches a given stage of the shift register the shift register develops a signal to start the control signal.
- 18. A control device as claimed in claim 17 wherein said shift pulses are derived from the signal pulses.
Priority Claims (2)
Number |
Date |
Country |
Kind |
3922616 |
Jul 1989 |
DEX |
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4007537 |
Mar 1990 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 07/549,344, filed Jul. 6, 1990 now abandoned.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
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Parent |
549344 |
Jul 1990 |
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