Claims
- 1. In a printing arrangement operative in a first mode for printing on only one side of a sheet and operative in a second mode for printing on both sides of a sheet, of type comprised of drive means for effecting transport of a sheet to be printed along a predetermined path through the printing arrangement, further comprised of a plurality of printing devices cooperating to effect printing of a sheet passing along said path, and further comprised of means operative for effecting a changeover from one to the other of said modes in a manner altering a portion of and changing the length of said path, a control system for the printing arrangement, comprising, in combination, a shift register having a plurality of shift register stages and having a shifting pulse input for receipt of shifting pulses and having an information signal input for receipt of information signals; means for applying to said information signal input a predetermined signal in response to the arrival of a sheet at a predetermined location along said path; shifting pulse generating means synchronized with said drive means and operative for applying to said shifting pulse input a train of synchronizing shifting pulses causing said predetermined signal to be registered by successive ones of said shift register stages in synchronism with the travel of the sheet along said path; a plurality of actuating means each associated with and controlling the operation of a respective one of said printing devices and each connected to a respective one of said shift register stages and each operative for actuating the respective printing device in response to the arrival of said predetermined signal at the respective shift register stage so as to control the operation of the respective printing device in a manner correlated with the arrival of the sheet to be printed at the portion of said path associated with the respective shift register stage; and compensating means operative upon a change of operating mode for at least partially offsetting changes in the correlation between shift register stages of said shift register and the associated portions of said path.
- 2. The arrangement defined in claim 1, wherein said compensating means comprises means for introducing into said shift register a number of intermediate additional shift register stages to compensate for the increase in the length of said path resulting from a change of operating mode.
- 3. The arrangement defined in claim 1, wherein said shifting pulse generating means comprises means for generating a train of synchronizing shifting pulses separated from each other by time intervals corresponding to the time interval required for a sheet to travel a predetermined distance along said path, and wherein said compensating means comprises means for introducing into said shift register a number of intermediate additional shift register stages equal to the distance by which said path is increased upon a changeover of operating mode, divided by the distance a sheet is transported along said path by said drive means during the time interval between two successive shifting pulses, minus any non-integral remainder in such quotient.
- 4. The arrangement defined in claim 1, wherein said synchronizing means comprises means for generating a train of synchronizing shifting pulses separated from each other by time intervals corresponding to the time interval required for a sheet to travel a predetermined distance along said path, and wherein said compensating means comprises means for separating said shift register into a first section comprised of respective first and last shift register stages and a second section comprised of respective first and last shift register stages, the last shift register stage of said first section having an information signal output and a shifting pulse output, and the first shift register stage of said second section having an information signal input and a shifting pulse input, an additional shift register comprised of respective first and last shift register stages, the first shift register stage of said additional shift register having an information signal input and a shifting pulse input and the last shift register stage of said additional shift register having an information signal output and a shifting pulse output, and means operative upon a change of mode of the printing arrangement for effectively inserting the shift register stages of said additional shift register intermediate the shift register stages of said first and second sections by so connecting said additional register to said first and second sections that the information signal input of the first shift register stage of said additional register is connected to the information signal output of the last stage of said first section, the information signal output of the last shift register stage of said additional register connected to the information signal input of the first shift register stage of said second section, and the shifting pulse output of said additional register connected to the shifting pulse input of the first shift register stage of said second section, whereby the compensation for the increase in the length of the path of travel of sheets through the printing arrangement associated with a change of operating mode is effected by causing said predetermined signal after it passes through the stages of said first section to pass through the stages of said additional register before arriving at the stages of said second section.
- 5. The arrangement defined in claim 4, wherein said shifting pulse generating means comprises means for applying to the shifting pulse input of the first stage of said additional register the same shifting pulses as are applied by said shifting pulse generating means to the shifting pulse input of the first stage of said first section.
- 6. The arrangement defined in claim 5, wherein the number of shift register stages in said additional shift register is equal to the change in length of said path associated with a change of operating mode, divided by the distance travelled by a sheet along said path during the time interval between two successive shifting pulses, minus any non-integral remainder in such quotient.
- 7. The arrangement defined in claim 6, wherein at least one of said actuating means is provided with enabling gate means having an enabling signal input for preventing such actuating means from controlling the associated printing device despite the arrival of said predetermined signal at the shift register stage to which such actuating means is connected until and unless an enabling signal is applied to said enabling signal input, further including means for applying to said enabling signal input a train of enabling signals having the signal repetition frequency of the train of shifting pulses generated by said shifting pulse generating means but time-delayed with respect to the latter by a time interval equal to said non-integral remainder multiplied by the time interval between successive shifting pulses.
- 8. The arrangement defined in claim 4, wherein the number of shift register stages in said additional shift register is equal to the change in length of said path associated with a change of operating mode, divided by the distance travelled by a sheet along said path during the time interval between two successive shifting pulses, minus any non-integral remainder in such quotient, and further including means for applying to the shifting pulse input of the first shift register stage of said additional shift register shifting pulses having the same pulse repetition frequency as the shifting pulses applied to the shifting pulse input of the first shift register stage of said first section but delayed with respect to the latter by a time interval equal to said non-integral remainder multiplied by the time interval between successive shifting pulses.
- 9. The arrangement defined in claim 1, wherein at least one of said actuating means is provided with enabling gate means having an enabling signal input for preventing such actuating means from controlling the associated printing device despite the arrival of said predetermined signal at the shift register stage to which such actuating means is connected until and unless an enabling signal is applied to said enabling signal input, and wherein said compensating means comprises means for applying to said enabling signal input a train of enabling signals having the pulse-repetition frequency of said train of synchronizing shifting pulses generated by said shifting pulse generating means but time delayed with respect to the latter in order to at least partially offset any change of correlation between shift register stages of said shift register and predetermined locations of said path resulting upon a change of operating mode.
- 10. The arrangement defined in claim 1, wherein said compensating means comprises means operative upon a change of operating mode for disconnecting at least one of said actuating means from the shift register stage to which it is connected and connecting such disconnected actuating means to a different shift register stage, in order to at least partially offset any change in the correlation between such actuating means and the associated portion of said path resulting from a change of operating mode of the printing arrangement.
- 11. The arrangement defined in claim 1, wherein said compensating means comprises means operative upon a change of operating mode of the printing arrangement for disconnecting at least one of said actuating means from the shift register stage to which it is connected and connecting such disconnected actuating means to a different shift register stage of said shift register, the two shift register stages to which such actuating means is alternatively connected being separated by n intermediate shift register stages, where n is equal to (q - 2), q being equal to the change in the length of said path associated with a change of operating mode, divided by the distance travelled by a sheet along said path during the time interval between two successive shifting pulses, minus any non-integral remainder in such quotient.
- 12. The arrangement defined in claim 11, wherein said at least one actuating means is provided with enabling gate means having an enabling signal input for preventing such actuating means from controlling the associated printing device despite the arrival of said predetermined signal at the shift register stage to which such actuating means is connected until and unless an enabling signal is applied to said enabling signal input, and further including means for applying to said enabling signal input a train of enabling signals having the signal repetition frequency of the train of shifting pulses generated by said shifting pulse generating means but time-delayed with respect to the latter by a time interval equal to said non-integral remainder multiplied by the time interval between successive shifting pulses.
- 13. The arrangement defined in claim 1, wherein said compensating means comprises means for separating said shift register into a first section comprised of respective first and last shift register stages and a second section comprised of respective first and last shift register stages, the last shift register stage of said first section having an information signal output and a shifting pulse output and the first shift register stage of said second section having an information signal input and a shifting pulse input, the information signal output of the last shift register stage of said first section being connected to the information signal input of the first shift register stage of said second section, and means operable when the printing arrangement is in one mode for connecting the shifting pulse input of the first shift register stage of said second section to the shifting pulse output of the last shift register stage of said first section and operable when the printing arrangement is in the other mode for disconnecting the shifting pulse input of the first shift register stage of said second section from the shifting pulse output of the last shift register stage of said first section, and means for applying to said shifting pulse input of said first shift register stage of said second section a train of shifting pulses having the same pulse repetition frequency as the train of shifting pulses generated by said shifting pulse generating means but delayed in time with respect to the latter by a time period equal to the time required for a sheet travelling along said path to move a distance equal to the change in the length of said path associated with a change of operating mode of the printing arrangement.
- 14. The arrangement defined in claim 1, wherein at least one of said actuating means comprises auxiliary sheet detector means operative for determining whether a sheet is present at the portion of said path associated with the shift register stage to which such actuating means is connected, and overriding means operative for preventing the actuating means from controlling the respective printing device, even if said predetermined signal is registered in the respective shift register stage, if said auxiliary detector means determines the absence of a sheet at the location corresponding to the respective shift register stage.
- 15. The arrangement defined in claim 14, wherein said actuating means is comprised of a bistable interrogating stage having a first input and an associated first output and having a second input and an associated second output, said overriding means comprising an AND-gate having an output connected to said first input, an inverter having an input connected to said second output and having an output connected to one input of said AND-gate, said AND-gate having a second input connected to said auxiliary sheet detector means, said first input of said interrogating stage being connected to the respective shift register stage for receipt of said predetermined signal, and said first output of said interrogating stage being connected to the respective printing device for controlling the operation thereof.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of the commonly owned copending application Ser. No. 258,078, filed May 30, 1972, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3264916 |
Owen |
Aug 1966 |
|
3343672 |
Vries et al. |
Sep 1967 |
|
3654861 |
Rudolph et al. |
Apr 1972 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
258078 |
May 1972 |
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