JP2017181909A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer which can highly reliably prevent the occurrence of breakage and jam even at the time of re-printing after returning conveyance from a stacking of a continuous recording material.SOLUTION: A printer 1 includes: conveyance means (tractor 17) which conveys a continuous recording material 11 having perforations at a prescribed interval by switching between the normal conveyance and the returning conveyance reverse to the normal conveyance; heating and fixing means (heating and fixing device 23) which thermally fixes toner adhering to the recording material 11 by holding the recording material 11 between a heating member (heat roller 24) and a pressure member (pressure roller 25); pressing means which presses the pressure member to the heating member side; and control means (control unit 35) which decides a position where the pressure member is separated from the heating member at the stop of the normal conveyance in accordance with the length of the recording material 11 and the printing mode, and controls the pressing means on the basis of the decided position.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printing apparatus.

  Conventionally, in a printing apparatus such as an electrophotographic laser printer that prints on a continuous continuous recording material such as continuous paper, the heating and fixing unit controls the recording material so as not to damage it. There is a need for a function that reduces the occurrence of folds and jams.

In relation to such a function, for example, Patent Document 1 discloses that the stacker table is lowered during the return conveyance of the recording material, and control is performed so as to eliminate an excessive load on the recording material. A technique for providing a highly reliable printing apparatus capable of preventing the occurrence of the problem is described.
Japanese Patent Application Laid-Open No. 2004-228688 changes the printing control according to the distance between the transfer position and the fixing position and the length of the page length, and when the perforation of the recording material passes through the fixing portion, A method of moving away from is described.

However, in the technique according to Patent Document 1, when reprinting is performed after the nip (contact) between the heating roller and the pressure roller of the heat fixing unit is released at the perforation of the recording material when printing is stopped, it is again near the perforation. The perforation is less likely to break due to the ironing effect caused by re-niping between the heat roller and the pressure roller. In such a situation, there is a problem that folding failure and jamming are likely to occur due to the folding of the recording material.
In addition, in the technology according to Patent Document 2, a slight speed difference between the tractor and the heating roller in the paper conveyance is accumulated, and the generation of perforated paper in the tractor portion, scratches, and paper jam is suppressed. When the rear end of the printing area of the previous page reaches the fixing position, the pressure roller of the fixing unit is separated from the heating roller. This may cause an unfixed portion depending on the shift of the page length and the paper position, and may cause a missing character, which causes a problem in reliability.

  The present invention has been made in order to solve such problems, and its technical problem is that it is reliable to prevent the occurrence of folding and jamming even during reprinting after returning and transporting from a continuous recording material stacking. It is an object of the present invention to provide a printing apparatus that can prevent the above.

  In order to solve the above-described problem, the printing apparatus according to the present invention conveys a continuous recording material having a perforation at a predetermined interval by switching between normal conveyance and reverse conveyance opposite to the normal conveyance. Heating and fixing means for thermally fixing the toner adhering to the recording material by sandwiching the recording material between the conveying means and the heating member and the pressure member, and pressing for pressing the pressure member to the heating member side Control for determining the position at which the pressure member is separated from the heating member when the normal conveyance is stopped, and controlling the pressing means based on the determined position, according to the length of the recording medium, the length of the recording material, and the printing mode. And means.

  According to the present invention, it is possible to provide a printing apparatus that can reliably prevent the occurrence of folding and jamming even during reprinting after returning and transporting from a continuous recording material stacking.

It is a figure explaining the structural example of the printing apparatus which concerns on one Embodiment. It is the schematic explaining an example of the mechanism which presses a pressure roller to a heating roller in the printer concerning one embodiment. It is the schematic explaining an example of the fixing process at the time of the printing apparatus which concerns on one Embodiment performed 1 page intermittent printing of a recording material. FIG. 4 is a diagram illustrating the state of FIG. 3 in a plan view. It is the schematic explaining an example of the fixing process at the time of performing 2 pages intermittent printing of the recording material which concerns on one Embodiment. It is the figure which represented the state of FIG. 5 in the top view. It is the figure which showed the nip release position at the time of shifting the nip release timing which concerns on one Embodiment, and a re-nip position. It is a block diagram explaining the control function of the printing apparatus which concerns on one Embodiment. 6 is a timing chart for explaining an operation example of the tractor and the fixing device when printing is stopped. 10 is a flowchart illustrating an example of operation processing of a conventional fixing device. 6 is a flowchart illustrating an example of operation processing of the fixing device according to the exemplary embodiment. 6 is a flowchart illustrating another example of operation processing of the fixing device according to the exemplary embodiment.

Hereinafter, embodiments will be described with reference to the drawings. For clarity of explanation, the following description and drawings are omitted or simplified as appropriate. In the drawings, components having the same configuration or function and corresponding parts are denoted by the same reference numerals and description thereof is omitted.
FIG. 1 is a diagram illustrating a configuration example of a printing apparatus according to an embodiment of the present invention.
In the printing apparatus 1 of FIG. 1, a laser beam R emitted from the optical unit 12 is applied to the photosensitive drum 13 uniformly charged by the charger 14, thereby electrostatically forming the surface of the photosensitive drum 13. A latent image is formed, and toner is attracted to the photosensitive drum 13 from the developing device 15. At the same time, a continuous recording material 11 (so-called continuous paper) 11 having perforations set at a predetermined interval is conveyed from the hopper 16 by the tractor 17, pressed against the photosensitive drum 13 by the retractor 18, and transferred by the transfer device 19. The toner on the photosensitive drum 13 is transferred onto the recording material 11.

A pair of tractors 17 are provided so as to sandwich the retractor 18, and recording is performed by the driving force of the tractor motor 20 via a belt spanned between each driving roller and a roller attached to the driving shaft of the tractor motor 20. This is a mechanism that facilitates the conveyance drive to the material 11.
In other words, the tractor 17 and the retractor 18 cooperate to function as a conveyance unit that holds and conveys the set recording material 11 (also referred to as a tractor conveyance unit or a recording material conveyance unit). The conveying means is configured to be able to carry the recording material 11 by switching between normal conveyance (forward rotation) for conveying the recording material 11 in the paper feeding direction and reverse conveyance (reverse rotation) opposite to the normal conveyance.

In the printing apparatus 1, the recording material 11 with toner attached is sent from the tractor 17 through the buffer unit 21 to a heat fixing unit (also referred to as a fixing unit) 23.
The buffer unit 21 is configured such that one end side is attached to the drive shaft of the buffer motor 22 and the other end side is supported by the recording material 11 being conveyed. Further, the buffer unit 21 has a sensor 36 attached to the drive shaft portion, and the buffer unit 21 is controlled to be at a fixed position by the tension of the recording material 11.
Specifically, when the buffer unit 21 is pressed downward by the recording material 11, the sensor 36 detects and notifies the control unit 35. The control unit 35 determines that the conveyance speed at the heat fixing unit 23 is faster than the conveyance speed of the tractor 17, and decreases the conveyance speed at the heat fixing unit 23 to adjust the speed difference with the tractor 17. Conversely, when the buffer unit 21 moves upward, the sensor 36 detects and notifies the control unit 35. The control unit 35 determines that the conveyance speed at the heat fixing unit 23 is slower than the conveyance speed of the tractor 17, and increases the conveyance speed at the heat fixing unit 23 to adjust the speed difference with the tractor 17. As described above, the sensor 36 detects whether the conveyance speed of the heat fixing unit 23 is faster or slower than the conveyance speed of the tractor 17 by the upper and lower of the buffer unit 21, and the control unit 35 controls the conveyance speed of the heat fixing unit 23. To do.

The heat fixing unit 23 mainly includes a heating roller 24 and a pressure roller 25, and the pressure roller 25 presses the recording material 11 toward the heating roller 24 by the control unit 35, so that the toner on the recording material 11. To fix.
In other words, the heat fixing unit 23 heats the toner on the recording material 11 by heat-contacting the recording material 11 between the heating roller 24 as a heating member and the pressure roller 25 as a pressure member. Functions as a fixing means. A pressing mechanism (also referred to as pressing means) for pressing the pressure roller 25 toward the heating roller 24 will be described later with reference to FIG.

  As described above, based on the detection result of the sensor 36, the control unit 35 can control the conveyance speed of the recording material, and the buffer unit 21 absorbs the speed difference between the tractor 17 and the heat fixing unit 23 during printing. By performing the speed correction, it is possible to keep the heating roller 24 and the pressure roller 25 in contact with each other even during continuous printing.

  The recording material 11 discharged from the heat fixing unit 23 is sandwiched between the driving roller 26 and the driven roller 27 and sent to the swing fin 28 having one end attached to the drive shaft of the swing fin motor 29. The recording material 11 discharged by receiving a swinging operation from the other end side of the swing fin 28 is easily folded at a perforation, and then a member of the paddle 31 whose one end side is coupled to the drive shaft of the pair of paddle motors 30. The perforations are pressed through the gap and stacked on the stacker table 32. Here, the stacker table 32 is movable in the vertical direction by the driving force of the table motor 33 via a timing belt 34 that bridges the roller attached to the drive shaft of the table motor 33 and the roller provided on the stacker table 32. It has a special mechanism.

  That is, the recording material 11 here swings from the paddle 31 driven by the paddle motor 30 when it is discharged from the swing fin 28 swinged by the swing fin motor 29 and stacked on the stacker table 32. The perforated lines are pressed onto the stacker table 32 in response to the contact force and are deposited on the stacker table 32 in a state where the perforations are easily folded.

  Based on the detection result of the sensor 36 described above, the control unit 35 controls the tractor 17 and the heat fixing unit 24 to adjust the conveyance speed of the recording material 11 and also controls the pressing mechanism. Details will be described later with reference to FIG.

FIG. 2 is a schematic diagram illustrating a mechanism for pressing the pressure roller 25 against the heating roller 24 in the printing apparatus 1 according to the embodiment. The heating roller 24 and the pressure roller 25 are arranged at positions facing each other with the recording material 11 in between.
The heating roller 24 has a structure in which a rotating shaft is rotatably fixed by a holding member (not shown) and is rotated by a motor 49.
The shaft portion of the pressure roller 25 is fitted into the U groove (U-shaped groove) portion of the arm B41, and is fixed by a member (not shown).

The arm A40 is fixed with the same position as the rotation axis 42 of the arm B41 as a rotation axis, and the arm A40 and the arm B41 are arranged so as to be rotatable around the rotation axis 42, respectively.
A cam follower 43 is attached to the arm A 40, and the cam 44 is fixed at a position in contact with the cam follower 43. A plunger 46 is fixed to the arm A 40, and a screw is cut on the opposite side so that it is fixed with a nut 48.
A compression coil spring 47 is attached to a portion sandwiched between the arm A40 and the arm B41, and is adjusted by a nut 48 so as to obtain a predetermined load. The cam 44 has a structure that can rotate around the rotation shaft 45. When the cam 44 is rotated by the motor 50 and the cam follower 43 is pressed against the heating roller 24, the arm B 41 is given a predetermined load via the compression coil spring 47. Thus, the pressure roller 25 is pressed against the heating roller 24 side.

Next, a fixing process when the printing apparatus performs one-page intermittent printing or two-page intermittent printing will be described.
FIG. 3 is a schematic diagram illustrating a fixing process when the printing apparatus 1 performs one-page intermittent printing of the recording material 11. In FIG. 3, it is assumed that the distance from the transfer point X to the nip point Y and the length of two pages of the recording material 11 are substantially the same distance. Here, the transfer point X is a position where the transfer device 19 transfers the toner to the recording material 11. The nip point Y is a position where the heating roller 24 and the pressure roller 25 come into contact with each other and the toner is fixed to the recording material 11 by sandwiching the recording material 11 between the heating roller 24 and the pressure roller 25. In the printing stop state A, data exists between the perforation 0 and the perforation 2.

  After the transfer to the recording material 11 is completed, the printing apparatus 1 feeds one page of the recording material so that an unfixed portion does not occur in order to prevent missing characters. The toner on the recording material 11 is heated by the heating roller 24 and the pressure roller 25. After fixing, the pressure release of the pressure roller 25 away from the heating roller 24 (nip release) is performed at the perforation 1 portion of the recording material 11 so that character peeling does not occur (state B).

Thereafter, the printing apparatus 1 performs the returning operation of the recording material 11 again in preparation for printing so that the leading perforation 2 of the blank portion of the recording material 11 becomes a prescribed speed on the transfer device 19 in the next printing operation. The perforation 2 of the recording material 11 is returned to the upstream side from the transfer point X in consideration of the run-up (state C).
Next, when the reprinting is started, the printing apparatus 1 presses (renips) the pressure roller 25 toward the heating roller 24 (state D), and resumes printing.
The printing apparatus 1 repeats the stop operation, the recording material returning operation, and the reprinting state from the printing stopped state, and changes from state D to state E to state F to state G to state H.

Here, the case where the one-page intermittent printing is repeated from the state A to the state H has been described. However, in the state B, the nip state is released at the perforation 1, and the position where the re-nip is performed in the state H becomes the perforation 1. A phenomenon occurs in which the eye 1 is nipped twice in accordance with the switching operation between the normal conveyance and the return conveyance.
Similarly, when the one-page intermittent printing operation is repeated, the state in which the vicinity of the same perforation is nipped twice as in the case of the perforation 2 and the perforation 3 continues.

FIG. 4 is a plan view showing the state of FIG. FIG. 4 shows a state in which print data is printed in a print area (upwardly slanted line area) on a plurality of pages separated by perforations (broken lines) of the recording material 11.
As described above, the nip release position after printing is performed on the perforation in consideration of character peeling. On the other hand, the re-nip position may be above the perforation due to the returning operation of the recording material 11, and the perforation may be nipped twice.
As described above, when the distance from the transfer point X to the nip point Y is substantially equal to the integral multiple of the length of the recording material 11 (the integral multiple of the folding perforation), printing for each page → stop → restart By repeating printing, nip release and re-nip operation may be repeated at the perforation. In such a case, the rigidity of the perforation of the recording material 11 increases due to the iron effect, and the folding failure due to the middle folding of the recording material 11 is likely to occur.

FIG. 5 is a schematic diagram for explaining a fixing process when two-page intermittent printing of the recording material 11 is performed. As in FIG. 3, it is assumed that the distance from the transfer point X to the nip point Y and the length of two pages of the recording material 11 are substantially the same distance. Data exists between the two. Thereafter, the process proceeds with a stop operation (state K), a return operation (state L), and reprinting (state M). In the stop after reprinting (state N), data exists in the perforation 2 to the perforation 4 of the recording material 11. To do. Further, the operation proceeds again to the stop operation (state O), the return operation (state P), and the reprint (state Q), and the stop operation, the recording material return operation, and the reprint are repeated.
Thus, in the case of two-page intermittent printing, the nip is released at the perforation 1 as shown in the state K, and the nip is released again at the perforation 2 as shown in the state Q. Therefore, the nip release and the re-nip are repeated at the same perforation. It will never be.

  FIG. 6 is a plan view showing the state of FIG. FIG. 6 and FIG. 7 described later represent perforations, print areas, and the like, as in FIG. Similarly to the one-page intermittent printing, the nip release position after printing is performed on the perforation in consideration of character peeling. On the other hand, the re-nip position is different from the perforated line of the recording material 11, and in two-page intermittent printing or intermittent printing of two or more pages (for example, three-page intermittent printing or four-page intermittent printing), The nip release position and the re-nip position do not nip the same perforation twice, and as in continuous printing, there is no possibility that the rigidity of the perforation will increase and folding failure will occur due to the middle folding of the recording material 11.

  Therefore, in the case of one-page intermittent printing, it is preferable to shift the nip release position from the perforation. Therefore, in this embodiment, one-page intermittent printing is performed, and a difference between a value that is an integral multiple of the length of one page of the recording material 11 and the distance from the transfer point X to the nip point Y is within a predetermined range. In this case, the control unit 35 controls the pressing mechanism to shift the nip release position from the perforation. Specifically, the control unit 35 controls the pressing mechanism so that the pressure roller 25 is separated from the heating roller 24 before the perforation at the rear end of one page of the recording material reaches the nip point.

FIG. 7 shows the nip release position and the re-nip position when the nip release timing according to the present embodiment is shifted. 7, it is assumed that the distance from the transfer point X to the nip point Y and the length of two pages of the recording material 11 are substantially the same as in FIG.
In this case, if one-page intermittent printing is performed as described above, pressure is applied twice to the perforation of the recording material 11 by releasing the nip and re-niping, resulting in poor folding of the perforation due to the middle break.
Therefore, the control unit 35 performs nip release on the perforation of the recording material 11 in normal control (normal printing). However, when the position of the nip release is shifted from the perforation, the print prohibited area Ln is used. The pressing mechanism is controlled to release the nip when printing is stopped. The print prohibition area Ln is an area that exists between the perforation and the print area, and is provided on the assumption of a transfer failure or the like.

  In FIG. 7, the pressure roller 25 is pressed against the heating roller 24 until the printing area of the recording material 11, but the pressure roller 25 gradually starts to be separated from the heating roller 24 in the printing prohibited area. The case where the nip is released at a position slightly away from the perforation before the recording material 11 stops is shown. For this reason, the distance Lm between the nip release position and the re-nip position (perforation) becomes longer, the ironing effect on the perforation of the recording material 11 is reduced, and stacking jam due to poor folding due to middle folding can be prevented. . The print prohibited area is an area when the maximum print area is secured within one page of the recording material 11. If the print data is small, the nip release position is shifted away from the perforation and set in the print area. can do. By determining the nip release position within the printing area, the distance Lm between the nip release position and the re-nip position can be increased, and the effect of preventing stacking jam due to poor folding is further improved.

FIG. 8 is a block diagram illustrating the control function of the printing apparatus 1 according to an embodiment. The control unit 35 controls the driving force of the tractor motor 20 and the motors 49 and 50.
The page length information and the printing mode information are input from the outside, for example, by an operator from the input means 60 provided in the printing apparatus 1 (or the host apparatus on which the printing apparatus 1 is mounted), and an information signal is transmitted to the control unit 35. .
The control unit 35 calculates the feed amount during printing using the page length information, and controls the tractor motor 20 (conveying means driving). Further, the control unit 35 determines whether the printing is continuous printing or intermittent printing based on the printing mode information, and controls the tractor motor 20 and the motor 50 that rotates the cam 44 of the mechanism that presses the pressure roller 25 (cam driving). )I do. Further, the control unit 35 receives the position information of the buffer unit 21 detected by the sensor 36 (hereinafter referred to as “buffer position information” as appropriate), and controls the driving force of the motor 49 based on the buffer position information. Then, speed control (heating roller rotation drive) of the heating roller 24 is performed.

In addition, when a print area information or development speed information signal sent from the host controller 70 is transmitted to the control unit 35, the control unit 35 presses the tractor motor 20 and the pressure roller 25 cam 44. It is possible to control the motor 50 that rotates the motor. The host controller 70 is provided in a host apparatus (or the printing apparatus 1) on which the printing apparatus 1 is mounted, and is configured to be able to transmit information to the control unit 35.
Further, the control unit 35 determines the amount of print data by receiving the information amount of the print data, and if the print data is less than the information amount printable in the print area, the nip release position is determined from the perforation. It is possible to determine within a distant print area. The control unit 35 can be configured to receive the amount of print data information from the host controller 70, for example.

  Note that information (for example, page length information, print mode information, print area information, and development speed information) input from the outside to the control unit 35 is not limited to means using the input means 60 and the host controller 70 described above. Instead, it is only necessary that the information can be set in the control unit 35 according to the configuration of the printing device 1 or the higher-level device on which the printing device 1 is mounted.

Next, operations of the tractor and the fixing device when printing is stopped will be described with reference to FIG.
FIG. 9 shows a timing chart of (i) conventional control and (ii) a control timing chart of the embodiment. FIG. 9 shows the timing at which the tractor, the heating roller, and the pressure roller operate according to the print stop signal.
The print stop signal is a signal for instructing to stop printing, and is received by the printing apparatus 1 from the outside.
The tractor 17, the heating roller 24, and the pressure roller 25 operate under the control of the control unit 35 in response to the print stop signal.

Specifically, when receiving the print stop signal, the control unit 35 controls the tractor motor 30 and the motors 49 and 50 using the tractor drive signal, the heating roller drive signal, and the pressure roller drive signal, and the tractor 17 and heating The roller 24 and the pressure roller 25 are operated.
The tractor drive signal is a signal for controlling the tractor motor 20 to operate the tractor 17, and instructing to switch between normal rotation, stop and reverse rotation.
The heating roller driving signal is a signal for controlling the motor 49 to operate the heating roller 24, and instructs to operate by switching between normal rotation and stop.
The pressure roller drive signal controls the motor 50 to drive the cam 44 of the mechanism that presses the pressure roller 25 against the heating roller 24 and instructs the pressure roller 25 to open and close.
The tractor driving signal and the heating roller driving signal can control the driving operation of each motor, and can control the rotational speeds of the tractor 17 and the heating roller 24.

  As shown in FIG. 9I, in the conventional control, when the printing apparatus 1 receives a print stop signal (A), the tractor 17 performs normal rotation after an arbitrary time has elapsed from the print position stop signal (B). After decelerating operation, the vehicle enters a stop state (C). When the feeding operation of the recording material 11 is stopped, the separating operation of the pressure roller 25 starts (D), and after a predetermined time, the pressure roller 25 is separated from the heating roller 24 (E). Thereafter, the tractor 17 enters a reverse operation (F), performs a return operation (GH) of the recording material 11, and stops in a state where the recording material 11 is returned to a predetermined position (I).

  On the other hand, as shown in FIG. 9 (ii), in the control of the present embodiment, when the printing apparatus 1 receives a print stop signal (A), the pressure roller 25 before the tractor 17 enters the stop operation (B). The separation operation (D) starts. Then, the pressure roller 25 is separated from the heating roller 24 (E) faster than when the forward rotation operation of the tractor 17 ends (C). Thereafter, the tractor 17 stops (C), enters a reverse operation (F), performs a return operation (GH) of the recording material 11, and stops with the recording material 11 returned to a predetermined position (I). .

10 to 12 are flowcharts for explaining the operation processing related to the above-described control.
FIG. 10 shows a prior art, and FIGS. 11 and 12 show an operation example of this embodiment.
In the prior art of FIG. 10, assuming that the recording material 11 is first set in the printing apparatus 1, when the recording material length setting (paper length setting) for setting the length of the recording material is performed (step S11), Only normal printing (step S13) or intermittent printing (step S14) has been selected based on the determination of the printing mode (step S12).

In the present embodiment of FIG. 11, when the recording material length is set on the assumption that the recording material 11 is set in the printing apparatus 1 (step S21), the control unit 35 sets the set recording material, as in the prior art. Whether or not the difference between the distance between the transfer point X and the nip point Y and the integral multiple of the recording material length is within a predetermined range is determined based on the length information 11 (step S22). Here, a case will be described in which it is determined whether or not the difference is within a range of ± 0.5 inches.
If the result of this determination is that the difference is within the range of ± 0.5 inches (Y in step S22), the control unit 35 determines whether or not the print mode is one-page intermittent printing (step S24). If the difference is not within the range of ± 0.5 inches (N in step S22), normal mode printing (step S23) is selected. When the printing mode is one-page intermittent printing (Y in step S24), the control unit 35 shifts to a mode for changing the separation timing of the pressure roller (step S25), and the control unit 35 determines the nip release position within the print prohibited area. . On the other hand, if it is not one-page intermittent printing (N in step S24), the control unit 35 selects normal mode printing (step S23).

  FIG. 11 shows a basic operation example from the setting of the recording material 11 to the determination of the nip release position for ease of explanation. The control unit 35 can be configured to start from one of the steps in FIG. 11 according to information received from the outside. For example, when notified that the recording material 11 is set, the control unit 35 starts from step S21, and after the recording material 11 is set once, the printing mode is set until the recording material 11 is set again. Is notified, it starts from step S24.

  FIG. 12 is a flowchart showing another operation example of the present embodiment. The operation from step S31 to S35 in FIG. 12 is the same as the operation from step S21 to S25 in FIG. When the mode is changed to the mode for changing the pressure roller separation timing (step S35), the control unit 35 determines whether the printing range is the maximum width of one page length (maximum width excluding the printing prohibited area). (Step S36) When the printing range is the maximum (Y in Step S36), the nip release position determined in Step S35 is used as it is. On the other hand, when the printing range is not the maximum in the mode of changing the separation timing of the pressure roller 25 (N in step S36), the control unit 35 proceeds to the nip position enlargement mode (step S37), and the nip release position and the re-nip position are changed. The distance Lm from the position is increased.

  FIG. 12 also shows a basic operation example from the setting of the recording material 11 to the determination of the nip release position in order to facilitate the explanation as in FIG. The control unit 35 can be configured to start from one of the steps in FIG. 12 according to information received from the outside. For example, after the recording material 11 is set once and before the recording material 11 is set again, the control unit 35 starts from step S34 when receiving the print mode, and receives the information amount of the print data. You may comprise so that it may start from S36.

11 and 12, it is determined whether or not the difference between the distance between the transfer point X and the nip point Y and the recording material length is within a range of ± 0.5 inch (step S22 in FIG. 11). Step S32 in FIG. 12 is not limited to this difference, and it is only necessary to determine whether or not the nip portion is within a length range in which it can be determined whether or not the perforation overlaps.
11 and 12 show the operation example in which the recording material length is determined in step S22 or step S32 and then the printing mode is determined in step S24 or step S34. However, the printing mode is determined first, and the printing mode is determined. However, only when one page is intermittently printed, an operation for determining the recording material length is also possible.

  Each step of FIG. 11 or FIG. 12 executed by the control unit 35 can be realized by hardware, software, a combination thereof, or the like. When realized by software, the printing apparatus 1 includes a memory that stores a program that causes a computer to execute each step in FIG. 11 or FIG. 12, and the central processing unit reads the program from the memory to realize each step. Causes a computer to execute instructions.

  In the above-described embodiment, the heating member and the pressure member are described as rollers. However, the same effect can be obtained by combining a belt-shaped member and a roller.

  As described above, the printing apparatus 1 according to the embodiment described above includes a tractor 17 that holds and conveys the continuous recording material 11 having a perforation at a set predetermined interval, and between the heating roller 24 and the pressure roller 25. The heat fixing unit 23 presses the recording material 11 to thermally fix the toner on the recording material 11, and the control unit 35 controls the heat fixing unit 23. The control unit 35 changes the separation timing of the pressure roller 25 in the print stop operation based on the length information of the recording material 11 and the print mode information, and the heating roller 24 and the pressure roller 25 when the print is stopped and restarted. Shift the nip position of. As a result, damage to the perforation of the recording material 11 can be reduced, and the recording material 11 can be prevented from being bent or stacked.

  Further, when the printing mode is changed according to information from the host (external) and the page length is a predetermined condition, the printing apparatus 1 changes the position where the pressure roller 25 is separated, The effect of preventing the recording material 11 from being bent or stacking jams can be obtained. Alternatively, the above-described effects can be obtained by changing the position where the pressure roller 25 is separated based on the amount of information of the print data printed on the recording material 11.

  In the technique according to Patent Document 1, the position of the perforation may overlap the re-contact position by the heating roll and the pressure roll of the heat-fixing unit. There is a problem that it is difficult to fold the recording material at the perforation due to the ironing effect that occurs when the nip and the pressure roller are nipped a plurality of times. In the present embodiment, as described above, by reducing the number of times the perforation is niped, it is possible to reliably prevent the occurrence of folding and jamming during reprinting after returning and transporting from a continuous recording material stacking. An advantageous effect can be produced.

Further, in the technique according to Patent Document 2, even when there is data for the next page, the trailing edge of the print area of the previous page is fixed at the fixing position in order to escape a slight speed difference between the tractor and the heating roller in paper conveyance. Is reached, the pressure roller of the fixing unit is separated from the heating roller. Thereafter, the pressure roller is closed when the sheet is conveyed by an arbitrary distance (+ α) from the perforation on the next page. In this case, in the continuous printing state where the data of the next page always exists, the pressure roller is always opened and closed near the perforation, which leads to a decrease in speed in continuous printing and productivity. In the present embodiment, the control unit 35 changes the position at which the pressure member is separated from the heating member in accordance with the length of the recording material and the printing mode, and in addition to the buffer unit 21, the control unit 35, and the sensor 36 described above. The speed difference between the tractor 17 and the heat fixing unit 23 during printing is absorbed by the buffer unit 21 to correct the speed. Accordingly, the heating roller 24 and the pressure roller 25 can always be brought into contact with each other even during continuous printing, and an advantageous effect of not affecting the speed reduction in continuous printing can be achieved.
In addition, in Patent Document 2, depending on the page length, when the leading end of the print area reaches the fixing position, the fixing unit closes and starts fixing. There is a risk of causing this. In the present embodiment, as described above, a configuration that enables continuous printing is realized, so that such a problem can be avoided.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Not too long.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 11 Recording material 12 Optical unit 13 Photosensitive drum 14 Charger 15 Developing machine 16 Hopper 17 Tractor 18 Retractor 19 Transfer device 20 Tractor motor 21 Buffer part 22 Buffer motor 23 Heat fixing part 24 Heating roller 25 Pressure roller 26 Drive Roller 27 Followed roller 29 Swing fin motor 28 Swing fin 30 Paddle motor 31 Paddle 32 Stacker table 33 Table motor 34 Timing belt 35 Control unit 36 Sensor 40 Arm A
41 Arm B
42 Rotating shaft 43 Cam follower 44 Cam 45 Rotating shaft 46 Plunger 47 Compression coil spring 48 Nut 49, 50 Motor 60 Input means 70 Host controller

JP 2009-132487 A JP-A-6-246986

Claims (9)

Conveying means for conveying a continuous recording material having perforations at a predetermined interval by switching between normal conveyance and reverse conveyance opposite to the normal conveyance;
A heating and fixing means for thermally fixing the toner adhering to the recording material by sandwiching the recording material between a heating member and a pressure member;
A pressing means for pressing the pressure member against the heating member;
Control means for determining a position at which the pressure member is separated from the heating member when the normal conveyance is stopped according to the length of the recording material and the printing mode, and for controlling the pressing means based on the determined position; A printing apparatus comprising:   The control means determines the position so as to reduce the number of perforations of the recording material at a nip point where the recording material is sandwiched between the heating member and the pressure member. The printing apparatus according to claim 1.   The control means has a predetermined range in which a difference between a distance from a transfer point at which toner is transferred to the recording material to the nip point, and a value that is an integral multiple of the length of the recording material, and the printing mode However, when the mode is a mode in which the normal conveyance and the return conveyance are switched for each page of the recording material, before the perforation at the rear end of one page reaches the nip point, the addition is performed. The printing apparatus according to claim 2, wherein the position is determined so that the pressure member is separated from the heating member.   The printing apparatus according to claim 1, wherein the control unit receives the print mode from outside and determines the position according to the received print mode.   The control means receives print area information of the recording material from the outside, and determines the position between the print area and a perforation of the recording material based on the print area information. The printing apparatus according to any one of 1 to 4.   The control means receives an information amount of print data, and determines the position based on the information amount of the print data and the print region information so as to reduce a region where the recording material is thermally fixed. The printing apparatus according to claim 5.   The printing apparatus according to claim 6, wherein the control unit determines the position in the printing area.   The control means, when the difference between the distance from the transfer point for transferring toner to the recording material to the nip point and a value that is an integral multiple of the length of the recording material is within a predetermined range, The position is determined using a combination of and a value set as normal printing is used when the difference is larger than a predetermined range. The printing apparatus as described. The control means determines the position using a combination with the length of the recording material when the printing mode is one-page intermittent printing, and when the printing mode is other than one-page intermittent printing, The printing apparatus according to any one of claims 1 to 8, wherein a value set as normal printing is used.

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