JP2007062324A - Continuous sheet printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit the positional deviation of a driving mechanism or paper of a continuous sheet printing device by reinforcing the self-retention force of a motor by short-circuiting the winding of the motor at the time of power supply interception or when an energy star does not turn on. <P>SOLUTION: In the continuous sheet printing device, a short-circuiting means for short-circuiting the windings 7, 8 of the motor 1 when the motor 1 is not energized at the time of power supply interception or when the energy star does not turn on to fix so that a paper conveyance mechanism is fixed, is provided. Thereby, the self-retention force of the motor is reinforced, and the position shift of the driving mechanism or the continuous paper printing device and the paper is inhibited. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a continuous paper printing apparatus.

  Printing apparatuses that use continuous paper are often used for forms such as preprinted paper that require printing position accuracy. However, in the continuous paper printing apparatus, since the sheets are connected, unfixed toner remains in the apparatus even when printing is stopped, and reprinting starts from the unfixed toner remaining in the apparatus when printing is started. The continuous paper has a perforation for separating the normal paper, and if the position of the perforation is shifted during the stop, the paper after the occurrence of the perforation is not printed on the intended portion. In order to improve positional accuracy, not only the accuracy of conveyance control during printing, but also the conveyance mechanism and paper must be fixed so that the paper position does not shift due to external forces such as pulling the paper when printing is stopped. It was.

  Conventionally, a continuous paper printing apparatus has energized a motor related to paper conveyance so that the paper position does not shift while printing is stopped, and holds the paper position so that it does not shift even when an external force is applied during stoppage. In recent years, some printing apparatuses are compatible with an energy star that shuts off a power source for power saving when a printing stop time continues for a certain time for power saving. In the continuous paper printing apparatus, the power supply is cut off in the energy star state, and thus the excitation of the motor related to the paper conveyance is cut off. For this reason, the paper holding force is weak and the paper position is shifted when the paper is pulled. In addition, since it is not possible to detect that the perforation of the paper has shifted while the power is turned off, there is a problem that when printing is started after returning from the energy star, printing is performed while the position from the perforation is shifted. It was.

JP 2003-48650 A

JP 2004-307163 A

  The problem to be solved by the present invention is that the position of the sheet perforation is shifted due to an external force such as pulling the sheet remaining in the apparatus when the power is shut off or in the power saving mode. This is to prevent the printing position from deviating from the position to be originally printed.

  The present invention is characterized in that in a continuous paper printing apparatus provided with a conveying means for conveying paper using a motor, a short-circuit means for short-circuiting the winding of the motor when the power is cut off is provided.

  The conveyance drive circuit of the continuous paper printing apparatus of the present invention shorts the excitation winding of the motor when the motor is not energized when the power is shut off and at the time of energy star, so that the positional deviation can be achieved even when no current is supplied from the power source. There is an advantage that a holding force is exerted against an external force to be generated, a paper transport mechanism and a paper are prevented from being displaced, and a printing positional deviation at the time of restarting can be prevented.

  Further, since no external energy such as applying a voltage to the motor is required to maintain the stopped state, a special mechanism is not required, and the conveyance drive circuit can be simplified.

  A function to short-circuit the motor's excitation winding when the motor's excitation power supply is cut off has been achieved with the minimum number of parts and without sacrificing the operation during printing.

  An outline of the continuous paper printing apparatus is shown in FIG. The paper 29 is a long continuous paper, and feed holes are formed at regular intervals along the paper transport direction at both edges. The paper 29 is loaded by automatic paper loading, in which a predetermined amount is conveyed by the folding length by the tractor 28 mainly used for paper conveyance, and is in a print standby state.

  When a print start signal is transmitted from a host device (not shown), the photosensitive drum 30 rotating in the paper transport direction is charged to a predetermined potential by the charger 31 and is exposed to the photosensitive drum 30 by the irradiation beam of the exposure device. An electrostatic latent image is formed on top. The electrostatic latent image on the photosensitive drum 30 is reversely developed by the developing device 32. The toner image on the rotating photosensitive drum 30 is transferred by the transfer device 33. The paper 30 to which the toner image has been transferred is conveyed by the tractor 28, and the toner image is fixed on the paper 29 by the fixing device 34 and is carried out to the stacker 35.

  Here, when the motor 26 rotates during printing, the timing belt 27 rotates and transmits power to the tractor 28. The tractor 28 is rotated by the timing belt 27 and conveys the paper 29. At the time of stopping, if the position of the paper 29 is shifted before the start of the next printing, a printing position shift occurs in the next printing. For this reason, when printing is stopped, the motor 26 is excited to enter the hold state. The hold torque of the motor 26 fixes the tractor 28 via the timing belt 27. Since the tractor 28 is fixed by the hold torque of the motor 26, even if the paper 29 is pulled in the energized state where power is supplied to the continuous printing apparatus, the paper stop position does not deviate unless the paper is torn. However, since the power supply to the motor 26 is cut off during the energy star, the holding force at the paper position by the motor 26 is smaller than the hold state during energization.

  FIG. 1 is a conveyance drive circuit diagram of a continuous paper printing apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a motor, and a stepping motor is used as an example. 2, 3, 4 and 5 are transistors, and 6 is a normally closed relay in which the contact 9 of the relay is closed when no current flows through the exciting winding. In the state where the power is supplied, the contact 9 of the relay 6 is opened, and the transistors 2, 3, 4 and 5 rotate the motor 1 in accordance with each determined excitation procedure. At the time of stop, in order to strengthen the holding force of the motor 1 in order to prevent misalignment, the excitation winding of the motor 1 that was excited last at the time of stop is continuously excited and current is kept flowing.

  The transistors 2, 3, 4, and 5 are all turned off when the power is shut off or when the power is not supplied by the energy star.

  Further, since no current flows through the exciting coil 10 of the relay 6, the contact 9 is closed, and the winding 7 and the winding 8 of the motor 1 are short-circuited. In a state where the contact 9 is closed, when a force for rotating the motor 1 is applied from the outside, an electromotive force is generated because the magnetic flux in the motor 1 is linked to the windings in the motor 1. The electromotive force is generated so that a current flows in the direction in which the motor 1 is rotated in the direction opposite to the direction in which the motor 1 is to be rotated. In FIG. 1, a regenerative current 22 flows through the contact 8 of the winding 8, the winding 7 and the relay, and a force is generated in a direction opposite to the force applied from the outside. Since the regenerative current 22 is due to the interlinkage magnetic flux in the motor 1, no current flows when the motor 1 is in a no-load state when the power is cut off, but a force for shifting the paper stop position is applied from the outside. Sometimes, torque is generated in the motor 1 in the direction opposite to the external force, and the paper stop position is maintained.

  FIG. 2 is a conveyance drive circuit diagram of a continuous paper printing apparatus according to another embodiment of the present invention. Reference numeral 11 denotes a motor, which uses a stepping motor as an example. Reference numerals 12, 13, 14, and 15 denote transistors. Reference numeral 16 denotes a normally-closed two-contact relay that closes a relay contact in a state where no current flows through the exciting winding. In the state where the power is supplied, the relay contacts 19 and 20 are opened, and the transistors 12, 13, 14 and 15 rotate the motor 11 according to a predetermined excitation procedure. At the time of stop, in order to strengthen the holding force of the motor 11 in order to prevent displacement, the excitation winding of the motor 11 that was last excited at the time of stop is continuously excited, and current is kept flowing.

  When the power is shut off or when no power is supplied by the energy star, the transistors 12, 13, 14, and 15 are all turned off.

Further, since no current flows through the exciting coil 21 of the relay 16, the contact 19 and the contact 20 are closed, and the winding 17 and the winding 18 of the motor 11 are connected to the _Vcc line and the GND line which are power supply lines. Since the _Vcc line and the GND line are power supplies, the impedance is low and can be regarded as a short-circuited state. In a state where the contact 19 and the contact 20 are closed, when a force for rotating the motor 11 is applied from the outside, regenerative currents 23, 24, and 25 flow through the winding 17 and the winding 18. The regenerative currents 24 and 25 are affected by the impedance between _Vcc and GND, but the regenerative current 23 is not affected by the impedance between _Vcc and GND. Since the regenerative currents 23, 24, and 25 excite the motor 11 so as to generate torque in the direction opposite to the force applied from the outside, the motor 11 maintains the current stop position with respect to the external force. Since the regenerative current is generated by the interlinkage magnetic flux in the motor, the regenerative current is not generated when the motor 11 is in a no-load state when the power is cut off, and no current flows through the motor 11, but the motor stops when trying to shift the paper stop position. 11 generates torque in the direction opposite to the external force by the regenerative currents 23, 24, and 25 to maintain the paper stop position.

  In the first and second embodiments, a stepping motor is used as an example. However, the present invention uses a linkage magnetic flux. If the motor has a coil, the coil inside the motor is removed when an external force is applied when the power is shut off. By short-circuiting with a relay, a regenerative current flows in the coil, and it is possible to add a function of maintaining a stopped state by generating a force in the opposite direction to the external force in the motor.

  In particular, the continuous paper printing apparatus has a problem that the printed material is wasted due to the paper position being shifted during the energy star. It is useful not only for stepping motors that have a mechanism that operates with a motor but wants to maintain the state before the power is shut off when the power is shut off, and for all motors with windings that want to maintain the state before the power is shut off when the power is shut off. .

FIG. 3 is a conveyance drive circuit diagram of a continuous paper printing apparatus according to an embodiment of the present invention (Example 1). FIG. 9 is a conveyance drive circuit diagram of a continuous paper printing apparatus according to another embodiment of the present invention (Example 2). Schematic of the paper conveyance part of a continuous paper printing apparatus.

Explanation of symbols

1 is a motor, 2, 3, 4 and 5 are transistors, 6 is a relay, 7 and 8 are windings, 9 is a contact, 10 is a coil, 11 is a motor, 12, 13, 14 and 15 are transistors, and 16 is a relay 17 and 18 are windings, 19 and 20 are contacts, 21 is a coil, 22, 23, 24 and 25 are regenerative currents, 26 is a motor, 27 is a timing belt, 28 is a tractor, 29 is paper, and 30 is a photoreceptor. A drum 31, a charging device 32, a developing device 32, a transfer device 33, a fixing device 34, and a stacker 35.

Claims (3)

  A continuous paper printing apparatus comprising a conveying means for conveying paper using a motor, comprising a short-circuit means for short-circuiting the winding of the motor when the power is shut off.   The continuous paper printing apparatus according to claim 1, wherein the power-off time is a power saving mode. 2. The continuous paper printing apparatus according to claim 1, wherein the short-circuit means is a relay.

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